PPG Biologia

Relação da dieta e Helmintofauna de sete espécies de corujas da região sul do Brasil

Mon, 20 Oct 2025 00:00:00 GMT

Relação da dieta e Helmintofauna de sete espécies de corujas da região sul do Brasil Dums, Marcos Owls are nocturnal birds of prey that play a fundamental ecological role as top predators in various ecosystems. By consuming a wide range of prey and occupying both urban and natural environments, these birds directly reflect environmental changes, revealing complex ecological interactions that, until recently, were largely unexplored in terrestrial habitats under strong anthropogenic influence. Studies on their diet and parasitofauna allow us to understand not only trophic interactions but also the impacts of anthropogenic factors such as pollution and habitat fragmentation. In this context, the integrated analysis of stomach contents and helminths in owls offers an effective approach to assess ecosystem health and monitor the effects of human activities on wildlife. This thesis aimed to characterize, in an integrated manner, the diet and helminth fauna of seven owl species found in conflict situations along the coastal region of Santa Catarina, Brazil. For this purpose, data were collected from necropsies of 64 individuals found along the BR101 highway between 2006 and 2021. Stomach content analysis revealed a generalist and opportunistic diet, composed mainly of insects and small mammals, with interspecific variation. Plastic fragments were also detected in the digestive tract of all analyzed owls, indicating accidental or indirect contact with urban waste—an unprecedented finding that positions these birds as new sentinels of terrestrial pollution. The helminth fauna included representatives from the groups Nematoda, Cestoda, Digenea, and Acanthocephala, with significant differences in prevalence and parasitic load among species. Parasite richness showed a correlation with dietary diversity, indicating that diet directly influences the composition of acquired parasites. The presence of mesoplastics in wild owls reinforces the impact of human activities on ecosystems and highlights the importance of these birds as bioindicators of environmental health. The combination of classical necropsy methods with ecological and parasitological analyses demonstrates the potential of rescued carcasses as valuable data sources for monitoring wildlife and understanding the relationships among environmental contamination, feeding behavior, and parasitism. These results confer a strategic role to owls in the study of trophic networks, parasitic cycles, and environmental impacts in fragmented areas.

Concentração de microplásticos em cérebro, fígado, rim e músculo, de um peixe iliófago no Rio dos Sinos

Thu, 28 Aug 2025 00:00:00 GMT

Concentração de microplásticos em cérebro, fígado, rim e músculo, de um peixe iliófago no Rio dos Sinos Silveira, Daniela da Cunha This thesis investigated contamination by microplastics (MPs), a xenobiotic present in the environment, in a fish species found in the Sinos River, RS. The main objective was to analyze MP contamination in the brain, liver, kidney, and muscle tissues of the species Cyphocharax voga. The study tested the hypothesis that there are significant differences in the concentration of plastic particles among the organs of 54 individuals, consisting of 25 males and 29 females. For the identification of MPs, the chemical staining technique with Nile Red dye was used, followed by fluorescence microscopy analysis.The results indicated a higher mean concentration of MPs/g in the brain (192 ± 124 MP/g), followed by the liver (65 ± 37 MP/g), kidney (47 ± 25 MP/g), and muscle tissue (39 ± 24 MP/g). The analysis also revealed significant differences in MP contamination between sexes in the brain and liver. A significant mean correlation was observed between the liver and kidney (p = 0.004; r = -0.481), as well as between the brain and kidney (p = 0.012; r = -0.424). Furthermore, the results evidenced the presence of MPs in all sampled tissues and reinforced the brain as a sensitive organ for biomonitoring. MP fragments were the most abundant form, occurring in significantly higher amounts compared to foams/films, spheres, and fibers.Although no correlation was found between MP concentration and the condition factor (Kn), one of the secondary objectives of this study, the research results confirmed the initial hypothesis, highlighting the existence of differences in MP contamination in the brain, liver, kidney, and muscle tissues of aquatic organisms, and underscoring the need for continuous monitoring of MP pollution in humanimpacted environments.This work provides important knowledge on the occurrence of MPs in freshwater fish, which may be useful for future studies on the hazards of these pollutants to the health of aquatic environments, as they can be considered a model for other vertebrates, including humans.

Ecologia do forrageiro e quantificação de mercúrio no atobá-pardo (Sula leucogaster) (BODDAERT, 1783) em dois arquipélagos brasileiros

Fri, 13 Dec 2024 00:00:00 GMT

Ecologia do forrageiro e quantificação de mercúrio no atobá-pardo (Sula leucogaster) (BODDAERT, 1783) em dois arquipélagos brasileiros Benemann, Victória Renata Fontoura The Optimal Foraging Theory predicts that a predator adjusts its foraging strategies to maximize energy gain, spending the least amount of energy possible to meet its energy demands. Foraging efficiency is a metric used to measure the final energy balance resulting from an individual's foraging activities, where the energy gain obtained by prey consumption should be greater than the energy cost of searching, capturing and ingesting it. The brown booby (Sula leucogaster) is a seabird of the Sulidae family, widely distributed in tropical and subtropical oceans both in coastal and pelagic zones and is characterized by exhibiting a high trophic plasticity. The main goal of this thesis is to investigate the foraging behavior and efficiency of brown boobies in two populations of the species, comparing the environmental conditions and the anthropic influence in each one. The specific goals are to (1) determine the foraging areas in the Moleques do Sul archipelago (MS) and investigate how oceanographic variables and the distribution of trawling fleets influence the foraging habitat use, (2) test intersexual differences in foraging behavior, (3) compare the prey species composition and nutritional quality of brown boobies diet between MS and São Pedro and São Paulo (SPSP) archipelagos, (4) compare foraging efficiency between the two archipelagos, and (5) determine and compare mercury concentration in feathers of juveniles and adults from the two archipelagos. Breeding adults (n = 39) were tracked for three days with biologgers programmed to collect geographic coordinates, acceleration, and depth data during foraging trips in both archipelagos. Of these 39 individuals tracked, 26 had their diet samples collected through spontaneous regurgitation to analyze diet and nutritional composition. To analyze mercury concentration, ventral feathers were collected from 58 individuals: 21 in MS and 37 in SPSP. No significant influence of trawling fleets spatial distribution was found on the choice for foraging areas in MS during the studied period. A significant difference was observed in protein and lipid contents, but not in energy density between the prey of the two archipelagos. Brown boobies from MS performed trips farther from the breeding colony and dived deeper, which resulted in higher energy expenditure than in SPSP. The foraging efficiency of brown boobies was higher in SPSP than in MS, probably due to the greater availability of prey in this archipelago. Regarding mercury contamination, no significant differences were observed concerning sex and age, but there were differences between the archipelagos, where individuals from MS showed higher concentrations. This thesis presents new information on the foraging behavior and mercury contamination of the brown booby in the studied archipelagos, especially for the MS population, which represents the southern limit of the species distribution in the Atlantic Ocean and is still poorly studied.

Eficácia da gestão em unidades de conservação da natureza do estado do Rio Grande do Sul, Brasil

Wed, 28 May 2025 00:00:00 GMT

Eficácia da gestão em unidades de conservação da natureza do estado do Rio Grande do Sul, Brasil Witt, Patrícia Bernardes Rodrigues The implementation of protected areas, especially Conservation Units (CUs), is a globally recognized conservation strategy. However, these territories require efficient management to achieve their conservation objectives. When the management of CUs is deficient, it harms their own objectives, affecting biodiversity and ecological processes, in addition to causing social and economic impacts. This study aimed to evaluate, in a qualitative and quantitative way, the effectiveness of management and the threats that affect 11 Conservation Units of the Full Protection group, in the state of Rio Grande do Sul, in southern Brazil. This evaluation was carried out through interviews with managers with application of the parameters, concomitantly with the review of the official documents of each CU. For this analysis, the adapted method of Effectiveness of Management of Protected Areas (EMAP) was used through the Likert scale with five levels, eight scopes, 73 indicators and 65 evaluation scenarios. Of the CUs assessed in southern Brazil, 91% presented results that indicated that their effectiveness ranged from average to very unsatisfactory, with low management effectiveness. In 18% of the CUs, the quality of management was very unsatisfactory, 37% unsatisfactory; 36% average and only 9% satisfactory. Thus, it was found that the main objectives for which the protected areas were created are not being met effectively. To assess the incidence of 23 threat variables in the CUs, attributes such as magnitude, scope, permanence, dynamics, probability of materialization and mitigation actions were adopted. The valuation of the attributes was measured using Likert scales with five levels. The higher the percentage obtained, the lower the risk or severity of threats, and the lower the percentage obtained, the greater the threats assessed, that is, severity alert. The threat factors were selected considering field information surveys, management plans, the reality of protected areas and their characteristics, based on other methods that analyzed threats to the effectiveness of management in protected areas. The results obtained demonstrated that there are threat factors in all 11 analyzed protected areas, with different levels of severity. The Delta do Jacuí State Park (PEDJ) presented the highest value (gradient) of threats (42.21%), followed by the Tainhas State Park (PETA) (59.96%) and Espigão Alto State Park (PEA) (68.48%), considered to have a medium threat value. Seven other protected areas obtained low threat values: Itapeva State Park (PEVA) 72.46%; Ibitiriá State Park (PEIB) 72.64%; Espinilho State Park (PEESP) 74.28%; Itapuã State Park (PEIT) 80.98%; Turvo State Park (PETU) 81.88%; Aratinga Ecological Station (EEA) 84.24% and Serra Geral Biological Reserve (REBIOSG) 84.96%. Only the Banhado dos Pachecos Wildlife Refuge (RVSBP) presented very low threat values (89.13%). In general, actions to be implemented by management to achieve the objectives of the CUs are recommended: adoption of a qualitative and quantitative assessment model; increase in staff; training of teams and managers; improvement of infrastructure, materials and equipment; budget forecasting and headings directed on a regular basis; land regularization, implementation of advisory boards; updating of management plans and implementation of threat monitoring systems for state CUs.

Efeitos das mudanças climáticas globais sobre a distribuição e a dispersão do lobo-marinho-subantártico Arctocephalus tropicalis (Gray, 1872)

Mon, 28 Jul 2025 00:00:00 GMT

Efeitos das mudanças climáticas globais sobre a distribuição e a dispersão do lobo-marinho-subantártico Arctocephalus tropicalis (Gray, 1872) Oliveira, Carlos de Understanding species’ geographic distribution is essential for comprehending how environmental factors influence biodiversity patterns. By identifying the set of environmental conditions that affect this distribution, it is possible to predict changes in species abundance and spatial occupancy. However, climate change has caused abrupt shifts in distributions in both terrestrial and marine environments, representing a growing threat to biodiversity. Top predators, such as the sub-Antarctic fur seal (Arctocephalus tropicalis), are particularly vulnerable, as they rely on the abundance and location of their prey and on the stability of their breeding, foraging, and resting habitats. This study aimed to analyze, from a climate change perspective, the environmental factors that influence the distribution of A. tropicalis, with emphasis on its main breeding colonies on the Tristan da Cunha/Gough Islands (TDC/Gough) and on the species’ extra-limital occurrences along the Brazilian coast. To this end, time series (1982–2021) of oceanographic variables were evaluated in the TDC/Gough region, including sea surface temperature (SST), shifts in the Sub-Antarctic Front (SAF) and northern boundary of the Subtropical Front (STFN), and chlorophyll-a (Chl-a) concentration as a proxy for productivity. SST, SAF, and Chl-a showed significant positive annual trends, whereas STFN exhibited a negative trend, indicating a southward shift of the SAF and a northward expansion of the STFN toward the colonies. These changes may negatively impact lactating females by increasing foraging distances and reducing reproductive success. In addition, 656 records of A. tropicalis along the Brazilian coast between 1992 and 2021 were compiled and analyzed, with a predominance in the southern region (69%) and higher frequency during the austral winter months (July to September). Association models revealed that variables such as seasonality (sine and cosine), mixed layer depth (MLD), and SAF were strongly correlated with occurrence patterns. Regional variables such as Chl-a and the South Atlantic Ocean Dipole Index (SAODI) influenced records in the southern region, while the Southern Annular Mode (SAM) and the South Atlantic Subtropical Dipole Index (SASDI) affected records in the southeastern and northeastern regions. These results support the hypothesis that multiple environmental factors may differently influence the species’ dispersal routes along the Brazilian coast. Habitat suitability models indicated that the current potential distribution of A. tropicalis (suitability > 0.7) is concentrated around subantarctic and subtropical colonies but also includes areas not currently colonized, such as the Falkland/Malvinas Islands, Tierra del Fuego, southern Chile, Kerguelen Islands, southern Australia, Tasmania, and New Zealand. Projections of A. tropicalis distribution for the years 2050 and 2100, based on AR6 climate scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5), indicated a shift toward sub-Antarctic and polar regions and an increase in moderately suitable areas (0.5–0.9). However, a significant contraction in highly suitable areas (>0.9) was also projected, particularly in current breeding colonies such as TDC/Gough and Amsterdam Island. The results suggest that current breeding colonies of A. tropicalis may become less suitable as the century progresses, while new areas south of its current range may become favorable, indicating a possible geographic expansion of the species. This includes the potential overlap with other otariid species and, consequently, the occurrence of natural hybridization events, as already recorded between A. tropicalis, A. gazella, and A. forsteri on Macquarie Island. On the other hand, the colonization of South American coastal areas as new breeding sites is unlikely due to the lack of suitable ecological conditions. Factors such as the need for remote islands with rocky substrates, a prolonged lactation period, urbanized coastal zones subject to human disturbance, and the risk of pup predation by domestic dogs severely limit the species’ reproductive success in these regions. Together, the results indicate that climate change may reshape the distribution of A. tropicalis, both by altering its breeding areas and by expanding its extra-limital dispersal.

Revisão sistemática de Ancistrus (Kner 1854), ocorrente na bacia hidrográfica da Laguna dos Patos

Sat, 25 May 2024 00:00:00 GMT

Revisão sistemática de Ancistrus (Kner 1854), ocorrente na bacia hidrográfica da Laguna dos Patos Widholzer, Ronaldo Libardi Sebastian Wolff and H. von Ihering collected close to Camacuã river and Regan described the species Ancistrus brevipinnis in a single paragraph, with the type localityin Rio Grande do Sul, providing few diagnostic characters and based on a single individual. Subsequently, the distribution of this species was restricted to the Laguna dos Patos basin. Due to the existence of polymorphisms, these populations were studied to better define these characters and to describe new species. A study was conducted based on a review of data and morphometric analyses of 303 samples from across the basin. This allowed for the redescription and restriction of this species to the Camaquã River microbasin, as well as the description of a new species, A. megacanthus. Subsequently, with 44 samples of genomic material, a phylogenetic analysis (Maximum Likelihood and Bayesian) were conducted using the markers Co1, 16S, and Rag2, along with the construction of a haplotype network. As a result, two more species were described: one occurring in the microbasins of the Sinos and Gravataí Rivers; and another in the Mirim Lagoon. Even so, the molecular data obtained suggest the existence of one or more species inhabiting the Meridional Plateau region, with a distribution that extends beyond the basins boundaries.

Comportamento alimentar do Petrel-Gigante-do-Sul na Antártica: seleção de habitat, variação individual e efeitos da personalidade

Thu, 13 Jul 2023 00:00:00 GMT

Comportamento alimentar do Petrel-Gigante-do-Sul na Antártica: seleção de habitat, variação individual e efeitos da personalidade Finger, Júlia Victória Grohmann The intraspecific variability in the foraging behavior of seabirds is a known fact. In addition to variations associated with sex, morphological classes or age, it is common for individuals to specialize their feeding behavior to varying degrees, some being highly faithful to specific areas and consistent in their foraging strategies. Individual variation in foraging can have important implications for the species. Recent studies indicate that animal personality – consistent individual variation in behavioral traits, e.g. boldness or aggression – can lead individuals to differ in their foraging behavior. The overall goal of this thesis was to investigate sexual and individual differences in habitat selection and foraging behavior of southern giant petrels(Macronectes giganteus) and the effects of personality on these patterns. The giant petrel population studied here breeds on Nelson Island, in the maritime Antarctic. GPS tracking devices were used to investigate the breeding distribution and fine-scale foraging behavior of 67 individuals throughout the 2019/2020 and 2021/2022 breeding seasons. The behavioral test “response to a novel object” was also applied to define the personality of tracked individuals, based on their level of boldness. Step-selection functions were used to investigate which environmental variables determine foraging habitat selection, analysis of repeatability and Bhattacharyya affinity indexes were used to investigate consistency in metrics and foraging areas throughout breeding, respectively. The population was also constantly monitored to identify potential opportunistic feeding behaviors. Giant petrels showed a wide spatial distribution during reproduction. Females foraged along the entire western Antarctic Peninsula while males were concentrated along the northwest coast. Proximity to penguin colonies strongly influenced foraging habitat selection for males, while for females, water column depth was more important. Both sexes overlapped their distribution with fishing areas in Antarctica and females, in particular, used areas with fishing effort on the continental shelf of Patagonia Argentina. The population showed average consistency in foraging areas between trips, as well as in the maximum distance and duration of foraging trips. Despite the existence of interindividual personality variation, it did not influence the consistency of foraging areas, nor the metrics of trips. The main source of variation was in terms of breeding stage and sex. Intergenerational cannibalism and coprophagy of Weddell seal feces were recorded for the first time for the species. The first behavior, expressed only by males, was possibly the result of individual specialization in this resource. The second, expressed by both females and males, occurred mainly after long incubation shifts, probably to quickly recover from fasting before a long feeding trip. Due to its wide distribution in the Antarctic Peninsula, a selection of habitat associated with varied marine zones, penguin colonies, seal resting areas and fishing activities, the species is configured as an important platform to monitor isolated populations and activities. illegal fishing in and out of Antarctica.

Eclosão de estágios dormentes de invertebrados aquáticos em áreas úmidas subtropicais e do semiárido brasileiro e suas implicações práticas na restauração ecológica

Mon, 30 May 2022 00:00:00 GMT

Eclosão de estágios dormentes de invertebrados aquáticos em áreas úmidas subtropicais e do semiárido brasileiro e suas implicações práticas na restauração ecológica Vendramin, Daiane Intermittent wetlands are among the most diverse and threatened environments in the world, being characterized by cycles of flooding and drought that directly influence the dynamics of their aquatic communities. Many wetland invertebrates adopt the production of dormant stages as strategy to resist the period of hydric stress. By performing the function of biotic reservoir, dormant stages contribute to the reestablishment of the community after flooding, and can be used in restoration initiatives over degraded wetlands. In this context, the main objective of this thesis was to assess the hatching dynamics adopted by dormant stages of aquatic invertebrates in subtropical and semiarid Brazilian wetlands, as well as to analyze the practical implications of using this community in wetland restoration efforts. In this sense, this work used the ex situ methodology of dry sediment hydration, with constant photoperiod, temperature and oxygenation. Also, sediment samples were collected in intermittent wetlands of the southern Brazilian Coastal Plain (12 study sites), in intermittent wetlands of the Brazilian tropical semiarid (six study sites), and in the floodplain wetlands of Rio dos Sinos (eight study sites). In the Coastal Plain, our results demonstrate that hatching dynamics of dormant stages are influenced by the sequential combination of hydration events. In the Brazilian semiarid, the short-term variation in hatchling community structure over a hydration period showed that the hatching dynamics of the invertebrate egg-bank is mostly composed by delayed-hatching strategies. Finally, an experimental study with the sediment of the Sinos River floodplain wetlands indicated the potential of transposing sediments with banks of invertebrate dormant stages to ecological restoration of mining-impacted wetlands. Our findings improve the knowledge about the hatching dynamics of aquatic invertebrates in subtropical and semiarid wetlands, contributing to restoration and conservation projects for Brazilian wetlands.

Influência de fatores ambientais sobre a composição, diversidade funcional e doenças infecciosas em comunidades de girinos no Sul do Brasil

Mon, 07 Mar 2022 00:00:00 GMT

Influência de fatores ambientais sobre a composição, diversidade funcional e doenças infecciosas em comunidades de girinos no Sul do Brasil Santos, Roseli Coelho dos Landscape changes impact biodiversity, altering the species composition of a community and threatening the more vulnerable species with extinction. Amphibians are highly susceptible to environmental changes and are negatively affected by habitat fragmentation and loss, climatic changes, exotic species, and diseases. Due to this, amphibians are considered the most threatened group on the planet, with several species already extinct or threatened with extinction. The largest number of threatened species in Brazil occur in the Atlantic Forest. Therefore, knowing the composition, functional diversity attributes, and dynamics of the infection caused by pathogens such as chytridiomycosis and ranavirosis is extremely important for amphibian conservation in this biome. In Brazil’s South Region, remnants of the Atlantic Forest form a mosaic with areas of pastures, agriculture and urbanization. Studies on the ecology of tadpole communities are scarce in this portion of the Atlantic Forest. Here, we present unprecedented studies on anuran community composition, functional diversity attributes, and infection by pathogens of emergent diseases (chytridiomycosis and ranavirosis) using tadpoles as study models. We conducted field collections between October 2018 and March 2019 in waterbodies (streams and ponds) located in forest remnants in Brazil’s South Region. The study area included seven forest remnants in the states of Paraná, Santa Catarina, and Rio Grande do Sul. We collected about 3000 tadpoles from 22 species in 30 waterbodies. In the laboratory, we identified the tadpoles and determined the presence of deformities in the oral apparatus and zoosporangia of the fungus Batrachochytrium dendrobatidis (Bd) and performed morphological measurements. We also used qPCR to identify ranavirus in the studied communities. We used satellite images to assess land use of the sampled areas, analyzed morphological data of the microenvironments and physical and chemical parameters of the water in the waterbodies. We showed that the dissimilarity in the composition of tadpole communities was influenced by larger areas of forest and pasture, with the habitat-specialist species being associated with forests. Attributes of tadpole functional diversity were selected by physicochemical characteristics of the water and morphological characteristics of the habitat, which act differently on lentic and lotic waterbodies. We did not record the presence of ranavirus in the studied communities but found a high prevalence of Bd. Tadpole communities in landscapes with larger forest areas were indicators of the Bd fungus. Similarly, two habitat-specialist species (Boana curupi and Crossodactylus schmidti) and one habitat-generalist (Boana faber) were Bd- 7 indicator species, the latter using forest areas as shelter. Thus, we conclude that the southern Atlantic Forest has a high prevalence of Bd, and forest environments have a greater influence on the dynamics of this fungus in the aquatic environments. Our study provides important data on the composition, functional diversity, and vulnerability to emergent pathogens in anuran communities in a little-known region of the Atlantic Forest.

Como a água do entorno de lagoas artificiais afetam a composição, diversidade e a saúde de anuros neotropicais

Fri, 11 Mar 2022 00:00:00 GMT

Como a água do entorno de lagoas artificiais afetam a composição, diversidade e a saúde de anuros neotropicais Preuss, Jackson Fabio Agricultural practices can reshape the environment and affect the survival of aquatic organisms. In modified landscapes, artificial ponds used for fish farming often provide excellent habitat opportunities for amphibian populations, contributing to the maintenance of local diversity. Data point to a predominant role of the habitat around these lakes and of the water quality for amphibians, suggesting that the characteristics of the terrestrial and aquatic environment act as an environmental filter on these animals. Thus, these systems can be good study models to assess the relationships between amphibians and anthropic changes in their habitat. Contamination of these ponds can also increase disease pressure, where the mechanisms underlying this pattern are not always known. For example, artificial ponds that receive nutrient enrichment should strongly influence the selection of environmental bacteria, which have the potential to alter the microbiome composition of aquatic animals and their vulnerability to disease. However, these changes in the host microbiome associated with diseases of aquatic organisms have received little attention when related to the enrichment of nutrients of animal origin. We analyzed how anthropogenic environmental changes in landscape and water quality affect the composition, diversity and health of anuran amphibians in artificial ponds in southern Brazil. We sampled a set of artificial ponds with different landscapes and levels of contamination from the point of view of frog diversity as well as the effects of water quality on the composition of the host's skin microbiome and its relationship with chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd). Our results indicate that this integrated farming system of fish and swine was responsible for outbreaks of fecal coliforms, disturbing the bacterial communities of the amphibian skin, so that the hosts recruited higher proportions of Bd-facilitating bacteria and had higher intensity and prevalence of infection. Our findings also highlight that despite the risk of chytridiomycosis, these artificial lakes can act as important breeding sites for anurans, especially in anthropic habitats with low availability of breeding sites. But the ability to offer reproductive opportunities, and consequently, help maintain anuran populations, depends on the configuration of the habitat in which these ponds are located. The physical-chemical parameters of the water and the configuration of the habitat around the ponds are the elements that most explained the variation in frog diversity. However, the characterization of the surrounding environment played a predominant role in the differences between communities. The level of soil exposure in the surrounding area was the component that most acted on the 4 turnover component of beta diversity. We expose here that the species turnover process is a consequence of the landscape simplification caused by the removal of the original vegetation cover (forests), culminating in biotic homogenization. Among the water parameters, only the phosphate concentration proved to be relevant for the configuration of the communities. Phosphate spikes can be derived from sewage or fertilizer contamination. Both types of contamination are likely to occur in the study area, even though it is characterized by low human population density and whose economic activity is based on small-scale (family) agriculture. Despite the enormous potential of artificial lakes in the maintenance of regional frog communities, these may be acting as ecological traps and their effectiveness will depend on the presence of forest remnants as well as on the quality of the water.

Dinâmica da paisagem as áreas protegidas

Wed, 10 Mar 2021 00:00:00 GMT

Dinâmica da paisagem as áreas protegidas Ribeiro, Soraya The loss of biodiversity is common to all ecosystems in the world, in Brazil the situation is no different, where the conversion of natural to agricultural areas is leading to a loss of natural environments in all biomes. One of the alternatives for conserving environments is the creation of protected areas, where a portion of the biome is protected in the midst of a changing environment. Being considered a protected area is not always a guarantee of achieving conservation objectives, as management deficiencies, financial and personnel resources, legal and management aspects do not always manage to make these areas immune from external pressures. This work aims to evaluate two categories of protected areas in Brazil, the Integral Protection Conservation Units and the Ramsar Sites. For this evaluation, a study was carried out using land use as landscape metric, focusing on the interior and buffer zone. This analysis was performed using remote sensing tools using the bases of the Probio (2007), Mapeamento de uso e cobertura vegetal do Rio Grande do Sul: LABGEO-UFRGS (2018) and MapBiomas Collection 3 (2017) projects. The results showed that these protected areas are not immune to external pressures, with many areas presenting anthropic use in their interior incompatible with their category. In the case of Sitios Ramsar, the results showed a good state of conservation and a relationship with the surroundings that served as a shield from anthropic pressures. In the Pampa Biome Conservation Units, the analysis of the integral protection category showed the need to discuss management alternatives for the conservation of natural fields.

Distribuição espacial e diversidade da comunidade zooplanctônica em áreas úmidas no sul do Brasil

Tue, 27 Aug 2019 00:00:00 GMT

Distribuição espacial e diversidade da comunidade zooplanctônica em áreas úmidas no sul do Brasil Freiry, Raquel Fontoura The distribution of species among sites can be influenced by processes related to biotic and abiotic factors (species sorting) and by processes independent of the environment (spatial processes). Zooplankton is strongly influenced by species sorting processes, although the importance of each process depends on geographic distance, landscape configuration, dispersal hability and life cycle phases of species. In temporary ponds zooplankton responds rapidly to changes in the environment and can be found in both the water column (active phase) and the sediment (dormant phase). The spatial distribution and effects of environmental gradients on the structure of active and dormant phase zooplankton remain unknown. In this sense, the general objective of this thesis was to evaluate the distribution of zooplankton at different spatial scales and to verify the influence of geographic distance and environmental predictors (local and regional) associated to variation of beta diversity, and additionally, to test concordance on the structure of active and dormant phases of zooplankton along a transition region between the Forest and Grassland biomes in southern Brazil. The study was carried out in twelve intermittent ponds along a forest-grassland transition in southern Brazil, within a 520-km. A total of 124 zooplankton taxa were found. The main results were that the zooplankton dormant phase was structured by local environmental factors (physical and chemical variables and habitat structure) and the active phase was structured by local (habitat structure) and regional factors (climate). Concordance patterns in species richness and composition were not found between phases and the evaluation of the active phase resulted in greater species richness. The beta diversity of the dormant phase showed greater variation in the scale of ponds, mainly in the Atlantic Forest biome. In relation to the groups, Rotifera was structured by local environmental factors and Cladocera and Copepoda were structured by both (local and regional). Concordance patterns significative were found between the richness of Cladocera and Rotifera (dormant phase), and between Cladocera and Copepoda (active phase). Significative concordance was also found in the composition of Cladocera and Copepoda and Rotifera and Copepoda. The combined results of both phases indicate that species sorting process explained the structure of zooplankton metacommunities, although the phases were distinctly affected by local and regional environmental predictors. The lack of concordance on richness and composition between phases indicates that the dormant phase are not adequate surrogates of active phase in temporary ponds, under similar incubation conditions. However, there is initial evidence that cladocerans and copepods can be employed as surrogates of other groups in temporary ponds, if the conclusions are strictly limited to similar life phase. In addition, as both respond to climate, expected that Cladocera and Copepoda may be more affected by climate change predicted for decades to come. These results may be useful for the planning of restoration and conservation strategies for temporary ponds of transition areas between grassland and forested biomes, since different environmental variables and spatial scales influenced zooplankton composition in the region.

Qualidade da água e estrutura taxonômica e funcional de macroinvertebrados em áreas úmidas com colônias de nidificação de aves aquáticas no sul do Brasil

Fri, 23 Aug 2019 00:00:00 GMT

Qualidade da água e estrutura taxonômica e funcional de macroinvertebrados em áreas úmidas com colônias de nidificação de aves aquáticas no sul do Brasil Zardo, Daniela Cristina Waterfowl can impact nutrient concentration in wetlands by producing large amounts of nitrogen and phosphorus-rich feces and can control the structure of the macroinvertebrate community via bottom-up mechanism. The objective of this study was to evaluate the water quality and the taxonomic and functional structure of macroinvertebrates in wetlands with nesting colonies of aquatic birds in southern Brazil. Macroinvertebrate communities were seasonally sampled in eight intermittent wetlands differing according to the occurrence of nesting colonies of waterbirds (four with the presence of rookeries; four without). Sampling was done in each wetland in the spring of 2016 (October) and one in the fall of 2017 (May). Water samples were collected for quantification of nutrients (ammonia, total phosphorus, nitrate, total organic nitrogen, total nitrogen, orthophosphate and organic phosphorus), physical and chemical variables of water (water temperature, pH, electrical conductivity, dissolved oxygen, saturation of dissolved oxygen, total dissolved solids and turbidity) were measured in situ and a sediment sample was collected for quantification of the organic matter. The main results showed that the concentrations of ammonia, total phosphorus, organic orthophosphate, organic nitrogen, total nitrogen and total dissolved solids were higher in the wetlands with waterbird nesting than in the wetlands without nests. We sampled 11,471 individuals distributed in 70 taxa. The rates of functional diversity, abundance, richness and taxonomic composition and functional composition were not influenced by the presence of birds, but abundance and taxonomic composition varied between sampling periods. Functional traits such as the debris food type, cylindrical body shape and active aquatic habit were shown to be associated with wetlands with waterbird nesting, whereas traits referring to grabbing and swimmer habits, macrophyte food type and type of passive air dispersion were associated with wetlands without nesting. Among the nutrients, the total phosphorus influenced the functional composition of aquatic insects and the orthophosphate the taxonomic composition. These results contribute to the ecology of wetlands and to a better understanding of the interactions between wetlands, waterbirds and aquatic macroinvertebrates.

Podem as lavouras de arroz auxiliarem na conservação de macroinvertebrados aquáticos do sul do Brasil? : unindo o sistema produtivo com conservação da biodiversidade

Tue, 25 Feb 2014 00:00:00 GMT

Podem as lavouras de arroz auxiliarem na conservação de macroinvertebrados aquáticos do sul do Brasil? : unindo o sistema produtivo com conservação da biodiversidade Dalzochio, Marina Schmidt Wetlands are prioritary ecosystems for conservation due to their vast biological diversity and productivity, besides their many functions and value. In southern Brazil conservative data show that about 90% of the original wetlands are already destroyed due to agricultural expansion, mainly the irrigated rice fields. On the other hand, rice is the most important cereal grown in developing countries, being the main food source for more than half of the world population. Also, a high diversity of plants and animals has been found in these agricultural areas. The main goal of this study was to assess the structure and diversity of macroinvertebrates in rice fields with different rice cultivation systems (organic and conventional) and ages (3, 10 and 20 years) over the different hydrological phases of the cultivation cycle in an important rice cultivation area in Rio Grande do Sul to preserve the biota in these agroecosystems. Sampling was conducted over two cultivation cycles (August 2010 to June 2012) in 17 rice fields and eight natural wetlands in the coastal plain of Rio Grande do Sul. Qualitative samples were obtained using a dip net. The samples were collected by kicking up the substrate and then sweeping above the disturbed area to capture dislodged or escaping macroinvertebrates. Five random sweeps of 1 m each were performed in each area. The main results were: sampling resulted in a total of 37,035 individuals in 82 taxa of macroinvertebrates collected in rice fields and natural wetlands; organic agriculture negatively affects aquatic macroinvertebrate community as much as conventional, even in functional terms and the first years of cultivation of rice crops are the most impactful for the community of aquatic macroinvertebrates. These results can be used in management plans which aim at reconciling agricultural production and biodiversity conservation in Rio Grande do Sul.

Metabólitos secundários de plantas nativas e exóticas, com potencial inseticida, ao polífago, Spodoptera frugiperda (Lepidoptera, Noctuidae)

Fri, 12 Jul 2013 00:00:00 GMT

Metabólitos secundários de plantas nativas e exóticas, com potencial inseticida, ao polífago, Spodoptera frugiperda (Lepidoptera, Noctuidae) D'Incao, Marianna Pilla Spodoptera frugiperda, a polyphagous Lepidoptera that causes large reductions in the productivity of rice and maize monocultures. Faced with fewer losses, agricultural producers look for different control methods, such as biological, genetic and cultural control, in addition to conventional tactics, such as periodic applications of chemical insecticides. The growing increase in losses due to pest attacks is accompanied by a decrease in the efficiency of chemical products. The search for control measures that cause less environmental impact and are of primary importance, which has been stimulating the resurgence of the use of insecticide plants as a promising tool in insect control. In this context, the present research had as general objective to carry out a selection regarding the insecticidal potential, evaluating 27 native and exotic plants regarding their insecticidal potential. From the results obtained, 3 plants were selected for better evaluation of the lethal, sublethal and histopathological effects of their secondary metabolites, when extracted by 4 different processes. With the aqueous, infusion and polypeptide extracts of Euphorbia pulcherrima, Rhododendron simsii and Maytenus ilicifolia it was not possible to have a LC50, as they did not cause 100% mortality of exposed caterpillars for 7 days. Therefore, bioassays were carried out to evaluate the sublethal effects of these extracts. The E. pulcherrima polypeptide extract caused a decrease in the larval development time of this lepidopteran. The supercritical extract of E. pulcherrima and R. simsii caused corrected mortality of 51% and 73%, respectively. The corrected mortality of S. frugiperda, when exposed to the superior extract via supercritical extraction of M. ilicifolia was 100%, enabling them to perform bioassays to define the LC50, which was specified as 0.104 mg extract / ml acetone. The supercritical extracts of E. pulcherrima and R. simsii caused damage to the gastrointestinal epithelium of exposed caterpillars.

Reconstrução do histórico de distúrbios no dossel e seus efeitos na estrutura e funcionamento da Floresta Ombrófila Mista

Tue, 29 Nov 2016 00:00:00 GMT

Reconstrução do histórico de distúrbios no dossel e seus efeitos na estrutura e funcionamento da Floresta Ombrófila Mista Urruth, Leonardo Marques Trees are sessile organisms that consume resources and interact primarily with neighboring trees. Whereas many factors affect tree-growth, understand the causes of variations in growth over their tree life trajectories is very valuable information on ecology, and may have many applications. Dendrochronology provides the proper approach to the reconstruction of the long-term tree-growth variation. In this thesis, I realized a canopy disturbance reconstruction, through the analysis of tree growth surges patterns in Ombrophyllous Mixed Forests (FOM) in northeastern Rio Grande do Sul. Using morphological data from two permanent plots projects inventories we observed that the disturbance histories described were strongly related to the current forest structure. Whereas the FOM has been widely and intensively subjected to logging, and disturbance chronologies revealed synchronistic events of abrupt changes in tree growth, likely due to selective logging. I also investigate the complementarity effect on tree growth, based on functional dissimilarity between focal trees and surrounding tree communities, analyzing also the influences of disturbance histories. Positive effects of complementarity were observed in tress of A. angustifolia. Furthermore, such positive effects were dependent on the history of longtime post-disturbance stability. We also observed that Lauraceae trees occurring in intensively logged plots the complementarity effect was significant, and the growth performance of the trees depends on the responses to environmental filter.

Metacomunidades de macroinvertebrados aquáticos em áreas úmidas intermitentes de altitude do sul do Brasil

Mon, 27 Jul 2015 00:00:00 GMT

Metacomunidades de macroinvertebrados aquáticos em áreas úmidas intermitentes de altitude do sul do Brasil Bieger, Leandro Wetlands are priority ecosystems for conservation, because of its high biological diversity, provided by its complexity and heterogeneity of habitats and its numerous functions and values, such as intermittency. The search for the processes that shape its communities and for the determinants of its biodiversity is focused on the role of local environmental factors and regional spatial factors. A metacommunity may be defined as a set of local communities connected by the dispersion of species that potentially interact with each other. Another way to understand the factors that determine diversity of species at different spatial scales is investigating, simultaneously, the beta diversity and the relationship between local and regional diversity. The goal of this study was to analyze the influence of local factors and regional factors in the composition of aquatic macroinvertebrate communities, as well as verifying how the beta diversity varies between different spatial scales and between different types of habitat. Three collections of aquatic macroinvertebrates were performed in 20 high altitude wetlands in southern Brazil. The main results were: the samples showed a total of 27,884 individuals in 64 taxa; local and regional factors of wetlands did not explain the structure of aquatic macroinvertebrates metacommunities, considering all taxa or taxa classified according to the dispersal strategies (active and passive); a weak contribution of the habitats in the number of species or diversity variation in the community. The beta diversity is higher among wetlands (regional scale) than among habitats of the same wetland, regardless of their hydroperiod, thus indicating strong influence of regional factors in species composition. The development of ecological studies that address the metacommunity theory, conciliated with how the diversity of species varies between different spatial scales, is fundamental, considering the biodiversity conservation priority of wetlands in southern Brazil.

Arroz puitá inta CL cultivado na planície costeira do Rio Grande do Sul: comunidades bacterianas, características físico-químicas dos solos e valor nutricional

Tue, 07 Mar 2017 00:00:00 GMT

Arroz puitá inta CL cultivado na planície costeira do Rio Grande do Sul: comunidades bacterianas, características físico-químicas dos solos e valor nutricional Panizzon, Jeremias Pakulski Bacteria has a key role in maintaining the life and balance of ecosystems. Rice crops suffer microbial actions, including interactions between plants and micro-organisms. The agro-ecosystems are composed of several micro-habitats and allow the adaptation of a great microbial diversity. Rice crop management promotes changes in the physical and chemical characteristics of the water and due to changes in pH, turbidity, temperature, radiation and organic matter, may be related to the dynamics of the microbial communities present in the soil. The objective of this project was to evaluate the bacteriological communities present in the soil of the Puitá Inta CL rice, sowed in two rice regions, in the 2013/14 and 2014/15, with different soil types (Internal Coastal Plain / PCI and External Coastal Plain / PCE). In this study, we identified heterotrophic bacteria that can assist plants in their development and in the production of more nutritious grains and in the analysis of the physical and chemical elements of the soils, as well as the determination of the nutritional composition of the Puitá Inta CL rice grains, brown and Polished, produced in each region of study. The data of this research were presented in four chapters that correspond to the publications in the form of scientific articles. The results revealed a total of 29 bacterial species, of which 27 were recorded in PCE and 22 were PCI, in the different phenological phases of Oryza sativa. The abundance of Colony Forming Units (CFUs), the PCE region obtained 18.5% of the species in before sowing, 22.3% in the vegetative phase, 22.3% in the reproductive phase and 36, 9% during seed maturation (F1.9 = 7.84, p <0.05). The diversity estimated by the Shannon index was higher at maturity (M = 3.901) compared to the values obtained in the soil of other phenological phase (M = 2.97). The abundance of CFU in the PCI was 23.9% in before sowing, 21.7% in the vegetative phase, 20.7% in the reproductive phase and 33.7% during seed maturation (F1.9 = 7.03, P <0.05). The estimated diversity was higher in maturation (M = 3.801) compared to the values obtained in the soil of the other phenological phases (M = 2.46). Evenness index indicates that species distribution was similar in both regions (PCE and PCI) during maturation (E = 0.988 and 0.967). The high values obtained in the CCA analysis explain the variation observed in the three axes: for the first agricultural year they explain 67% of the variation of the species and for the second agricultural year they explain 86.5%. These data indicate that the maturation stage of plants to the diversity of bacterial species is predominant. The results of the PCA show that the first three axes explain 74.19%: axis 1 (47,12%) includes the variables Clay, pH and Hydrogen + Aluminum; The second axis (15.79%) includes Phosphorus, Electron exchange capacity pH 7 and Magnesium; And the third axis (11,28%) Aluminum, Organic Matter and Index of analysis and correction of acidity. The spatial result pattern shows a significant difference between the soils of each region, which can be verified by MANOVA (Wilk’s Lambda: 0.008, p <0.0001 and F = 61.6). Rice nutritional value, phenolic content and antioxidant content were tested by the Mann Whitney method, which reveals the difference between, brown and polished rice from each rice region (p<0,001), it is not temporal difference (p>0,05) between them (2013/14 and 2014/15).

Funções e serviços ecossistêmicos no parque nacional da Lagoa do Peixe: repensando conceitos e indicadores para conservação da biodiversidade em sítio Ramsar do Sul do Brasil

Tue, 14 Mar 2017 00:00:00 GMT

Funções e serviços ecossistêmicos no parque nacional da Lagoa do Peixe: repensando conceitos e indicadores para conservação da biodiversidade em sítio Ramsar do Sul do Brasil Müller, Jackson The planet's ecosystems are being severely destroyed or altered due to human activities, with an unprecedented intensity of changes in aspects of land use, alteration of biogeochemical cycles due to the release of pollutants, destruction and fragmentation of several habitats, introduction of exotic species and changes weather conditions (SALA et al., 2000; ELLIS et. al. 2013). For Duarte et al. (2009) and Palomo et al. (2012) the entire set of changes influenced by human activities has effects generated on a global scale. In addition, and even if it is not so recognized, there is strong evidence that changes in ecosystems cause direct or indirect influences on human well-being, compromising their functioning and their ability to generate substantial benefits for society (ELLIS et al. , 2013). In this context, to study the relationship between nature and society, it is necessary to analyze at least two fundamental aspects: how human beings affect the integrity of ecosystems and how they, in turn, affect human well-being (MARTIN-LOPES et al., 2007).

Desafios da pecuária de corte frente à conservação dos ecossistemas campestres: desenvolvimento sustentável no Bioma Pampa

Thu, 18 Jan 2018 00:00:00 GMT

Desafios da pecuária de corte frente à conservação dos ecossistemas campestres: desenvolvimento sustentável no Bioma Pampa Freitas, David Santos de Pampa Biome, a region where cattle farming is indicated for conserving natural grasslands, is a biome that allows the integration of food production with biodiversity conservation. The landscape is maintained by the grazing of ruminants that traditionally occupy the area. The conversion of natural grasslands and consequent alterations of the landscapes highlights the need for better management strategies for cattle farming and natural grasslands. Therefore, it is important to identify which municipalities encounter difficulties while working on concepts of sustainability that are applicable to cattle farming and which criteria need more attention for a better scenario. The use of indicators for this scenario is a valid strategy and can support public policies for the conservation of the Pampa. Thus, this research aims to identify areas of tension in relation to the concept of sustainable development and the precepts of beef cattle production, analyzing the implications of this activity for the conservation of the natural grasslands of the Brazilian Pampa Biome and evaluate the impact of grazing on productivity of subtropical grasslands. In the first article, municipalities were characterized according to factors that require specific actions for sustainable development based on a Sustainable Stress Index (STI). The STI is an index composed of descriptors variables for the economic, social and environmental realities in governmental databases. Despite the analysis revealed most of Pampa’s municipalities with intermediaries STI it was also possible to analyze the locations that stand out positively and negatively according to the STI. Only three municipalities had low tension results in the three dimensions, indicating that, although the values are in a moderate range, few municipalities are fully featured in the dimensions analyzed. In the second paper, indicators of the aboveground net primary (calculate with Normalized Difference Vegetation Index – NDVI) production were used to evaluate the impact of livestock in subtropical grasslands. An inverse quadratic relation between the cattle herd and the NDVI values was observed, indicating that more cattle affect negatively the primary productivity. In the same way, rainfall presents an inverse quadratic relation with a primary productivity. The cattle price showed a positive quadratic relation with the cattle herd, indicating that the economic variations indirectly affect the primary productivity through the size of cattle herds. The results indicate that the variations in productivity are based on climatic and economic factors, being fundamental the analysis of the number of animals in the fields, as well as of cattle price fluctuations, indicating that they are indispensable for the multidisciplinary strategies for conservation strategies in the subtropical grasslands. Hence, the economic and social interests are fundamental for the elaboration of management strategies towards the conservation of grasslands ecosystems.

Dendrocronologia na Floresta Atlântica de Tabuleiros: uma abordagem sobre a floresta e o clima

Tue, 28 Nov 2017 00:00:00 GMT

Dendrocronologia na Floresta Atlântica de Tabuleiros: uma abordagem sobre a floresta e o clima Fontana, Cláudia This thesis aimed to contribute to the understanding of the influence of climate on the growth of tropical tree species. For that, a review of the dendrochronological researches with a climatic approach developed in the Atlantic Forest Biome was carried out, seeking to verify the evidenced climatic signs and the methods applied to the chronologies. The wood anatomy of Copaifera lucens was investigated with a focus on the anatomical characteristics of the growth-rings. It has also tested the influence of climate on its radial growth. The results of the literature review showed that few species are explored through dendrochronology (10 spp.), and there are no studies for the northern part of this biome. Climatic signals related to precipitation were observed in 87% of the chronologies and to temperature in 50% of them, although there is no synchronism between the periods of the influence of these variables in the species. The results of the wood anatomy added anatomical characteristics previously not described for C. lucens, such as gelatinous fibers, bifurcated fibers (intrusive growth) and cluster vessels. Although the wood anatomy contributes to the understanding of the wood structure, studies of cambial activity are showed to clarify the formation of the annual and intra-annual rings, and especially the formation of secretory canals. The results of the dendrochronological studies demonstrate that C. lucens, despite the high growth variation within and between individuals, is promising for climate reconstruction. Their series presented a strong positive correlation with the evapotranspiration index for the current summer. The climatic scenarios for the region of occurrence of the species show a reduction in precipitation, and it can be inferred that its growth in the future will be compromised. As a general conclusion, it was observed that the effects of climate in the Atlantic Forest are still little explored through dendrochronology. It is necessary to intensify dendroclimatic studies to clarify the climatic influences in the different phytophysiognomies of this biome. The anatomy of the Copaifera genus is complex and the factors that control the formation of the annual ring deserve more research efforts. Given the marked sensitivity of the ring width series to the water availability of summer and the considerable longevity of its trees, C. lucens has a high potential for dendroclimatic reconstructions in the northern region of the Brazilian Atlantic Forest.

Estrutura de comunidades de aranhas em áreas úmidas subtropicais: padrões espaço-temporais

Fri, 10 Mar 2017 00:00:00 GMT

Estrutura de comunidades de aranhas em áreas úmidas subtropicais: padrões espaço-temporais Ávila, Arthur Cardoso de Wetlands are ecosystems of high biological diversity and are among the most productive ecosystems on Earth, with enormous ecological and social importance for humanity. Even so, wetlands are one of the planet's most endangered ecosystems by human activities. Changes in natural hydroperiod and flood frequency are factors that alter the integrity of these ecosystems, especially in smaller and intermittent wetlands. Spider communities are present in a wide variety of environments, including wetlands, constituting different food guilds, which are related to the complexity of the ecosystem. The general objective of this study was to analyze spatial and temporal patterns of diversity in spider communities in wetlands with different hydroperiods and different regions in southern Brazil. Sampling was done four times in a total of 12 wetlands in the region of the highlands and two times in a total of 24 wetlands in the Atlantic Forest and Pampa Biomes. The main results were: A total of 2549 individuals were collected from 14 families of spiders in the wetlands from the highlands and from the different Biomes; The hydroperiod and habitat heterogeneity affect the community of spiders, considering the diversity of morphospecies and guilds. There was a pattern of latitudinal distribution of spider communities with a higher diversity of spiders in wetlands of the Atlantic Forest. Thus, these results demonstrate that spiders can act as indicator organisms for these endangered ecosystems. Therefore, this data may provide important information in the future for the conservation of wetlands.

Variação da diversidade e composição de macroinvertebrados em riachos da bacia hidrográfica do Rio dos Sinos, RS, Brasil

Thu, 27 Feb 2014 00:00:00 GMT

Variação da diversidade e composição de macroinvertebrados em riachos da bacia hidrográfica do Rio dos Sinos, RS, Brasil Moraes, Aline Bianca The aquatic macroinvertebrate community can be structured by processes in multiple spatial scales. Reduction or substitution of riparian forest by different land uses and the impacts on the physical and chemical conditions of streams can negatively affect the macroinvertebrate community causing homogenization of composition. Therefore, we assessed the following hypotheses. Article I) Macroinvertebrate richness and EPT (Ephemeroptera, Plecoptera and Trichoptera) richness decrease with reduced riparian zone width; macroinvertebrate and functional feeding group (FFG) composition vary with a reduced riparian zone width; and reduced riparian zone width similarly influence the macroinvertebrate community in different stream substrates. Article II) Land use (forest, agriculture, pasture and urbanization) alters physical and chemical variables in streams; and β diversity decreases, or the macroinvertebrate composition is more homogeneous, in stream reaches impacted by land use. Article III) γ diversity is not homogenously distributed among scales, with differences between the pattern observed in winter and summer; and β diversity depends on different substrate types, but most composition dissimilarity occurs in larger spatial scales, regardless of the season analyzed. In order to obtain these responses we selected reaches of three headwater streams in the Sinos River watershed, northeastern southern Brazil. The macroinvertebrate composition on litter substrate differed from that on riffle (stone and gravel) substrata, showing proportionally lower diversity within the lowest scale (α1) and higher diversity at the highest scale (β4). We found differences in the composition (β diversity) between the reach scale and the stream scale in both winter and summer. There were significant differences in macroinvertebrate composition among riparian zone widths. The macroinvertebrate composition and FFG differed among substrates, independent of riparian zone width. The physical and chemical stream variables varied according to the land use intensity. A homogenization of the community, or reduced β diversity, occurred with increased stream velocity, ammoniacal nitrogen and total phosphorous, and higher heterogeneity occurred with more shade and higher pH. Our results revealed that streams in southern Brazil support a very heterogeneous macroinvertebrate community and the role of spatial configuration in these streams strongly influences macroinvertebrate diversity. A riparian width greater than 15 m is necessary to maintain composition and trophic conditions of macroinvertebrate families found in more pristine states of conservation. Furthermore, the results emphasize the importance of β diversity studies for evaluating the homogenization of macroinvertebrate community in streams impacted by different land uses in southern Brazil.

Diversidade de helmintos ictioparasitos da bacia do Rio Tramandaí, sul do Brasil

Wed, 28 Feb 2018 00:00:00 GMT

Diversidade de helmintos ictioparasitos da bacia do Rio Tramandaí, sul do Brasil Rodrigues, Alice Pozza Fish have the highest indices of parasite infections because the water environment facilitates the spread, reproduction and life cycle of most pathogenic agents. Parasites are an essential part of aquatic communities and parasitic diseases occur as a consequence of the imbalance between environment, host and parasite. The activity of different parasite species, mainly those that cause injuries or even great mortality to their hosts, have been the object of study especially in fish of economic interest. The reduction of the assimilation and growth rates of the hosts, caused by helminths, may limit their survival, either directly or indirectly. Additionally, parasitic helminths comprise a group of diseases that is connected to socio-environmental conditions and may lead to problems in public health, including zoonoses. Among the main food-borne parasitic zoonosis, those caused by the consumption of fish have been highlighted due to the increase in their incidence in several regions of the world in recent years. Studies directed to the knowledge of the parasite biodiversity associated to the freshwater fish fauna in Rio Grande do Sul are still scarce and, so far, no research study directed to the description of ichthyo-parasitic helminth species of the Tramandaí river has been conducted. Therefore, this work aims to know the diversity and occurrence of the helminth fauna associated with fish species collected in the Tramandaí river basin. For this purpose, we collected 300 fish between August 2015 and February 2017 and in the Laboratory of Ichthyology of Unisinos they were identified and underwent a necropsy. The helminths that were found were preserved, stained and identified. We calculated the parasitic indices such as prevalence, mean infection intensity and mean abundance. To evaluate the influence of parasitism on the development of fish, we performed a t-test, a Mann Whitney U test and calculated the Condition Factor. From the necropsy, we surveyed 3048 helminths distributed in the phyla Nematoda and Acanthocephala and in the class Trematoda. Among the identified trematodes, Clinostomum sp. and Ascocotyle sp. have zoonotic potential. For the fish evaluated regarding the effect of parasitism, Statistical analysis results indicated that the infection caused by the helminths does not interfere with the development of the analyzed fish.

Ecologia de comunidades de turbelários límnicos em áreas úmidas do sul do Brasil

Thu, 21 Feb 2019 00:00:00 GMT

Ecologia de comunidades de turbelários límnicos em áreas úmidas do sul do Brasil Braccini, João Alberto Leão One of the big challenges in ecology is trying to understand the patterns of community structure and their variations along environmental gradients. Among these gradients, habitat complexity is related to several environmental characteristics, such as: topographic complexity or substrate roughness, substrate diversity, refuge variety, substrate height, percentage of vegetation cover and vegetation composition, which have a strong influence on communities. Intermittent wetlands have an annual hydroperiod, being characterized by unique fauna and flora that contribute significantly to the local diversity. In turn, permanent wetlands have water throughout the whole year and water staying for long periods allows the occurrence of non-ephemeral species. Altitude is a condition that strongly influences the climate of a region and consequently its biota, an increase in altitude causes diminution in mean temperature, changes in terrain, topography and hydrography, which lead to changes in the general structure of communities. A spatial approach, on the other hand, implies that geographical distance can influence community structure, i.e., the greater the distance between two communities, the less similar they should be. The main objective of this thesis is to analyze the influence of local and regional factors on the richness, abundance and species composition of turbellarian species in freshwater environments in southern Brazil along a series of environmental gradients. The samples occurred in 40 natural wetlands in highland environments (Araucaria Plateau) and along the whole coast of the state of Rio Grande do Sul, between the years 2016 and 2017. A total of 3008 turbellarian specimens of 76 species was collected. In highland environments, the factors hydroperiod, habitat complexity, total dissolved solids (TDS) and, for richness, also pH, considering seasonal variations, were the factors that best-explained variations in turbellarian richness and abundance. There was also influence of these variables on species composition (p < 0.05). Turbellarian species richness was higher in coastal wetlands than in highland wetlands (p < 0.05). The turbellarian communities were distinct between highland and coastal wetlands (p <0.05) with exclusive taxa for both wetland groups, where TDS was an important variable for species composition. Across a latitudinal gradient in Coastal Plain, species richness presented correlation to space, with the highest stimated values in middle coast, and species richness showed a positive relation to phytoplankton density and negative to salinity (p < 0.05). We observed the highest estimated specimen abundance in the south coast; there was a positive relationship between specimen abundance and an increase of turbidity and a decrease of dissolved oxygen (p < 0.05). Species composition was weakly explained, with a significant relation to salinity and turbidity (p < 0.05). The results of this study highlight how dynamic and complex turbellarian communities are, with the direct influence of local and regional factors on richness, abundance and species composition. There was an expressive increase in the knowledge of factors that influence these invertebrate communities in natural neotropical wetlands.

Endozoocoria entre organismos aquáticos: a importância das aves para a dispersão de plantas, invertebrados e peixes

Fri, 19 Feb 2021 00:00:00 GMT

Endozoocoria entre organismos aquáticos: a importância das aves para a dispersão de plantas, invertebrados e peixes Silva, Giliandro Gonçalves The wide distribution of freshwater species sessile or with low locomotion capacity inhabitants isolated continental aquatic systems has always been an ecological puzzle. Passive dispersal through a transport vector is the main explanation for understanding the dispersal among these wetlands, and waterbirds play an important role in this process. In the Neotropical region, studies on the dispersal promoted by waterbird are scarce. In this thesis, studies are presented addressing the importance of waterbird for the dispersal of plants, invertebrates and fish in the neotropical region. Field data collections and ex situ experiments were carried out. Regarding plant diaspores, it was possible to identify the dispersal depends on the interaction between the bird species and the season. Still on plants, it was proved that an entire angiosperm (Wolffia columbiana) survives the passage through the digestive tract of two species of Anatidae, representing a dispersal mode previously unknown. On invertebrates, the dispersal promoted by birds is associated with the bird species, with no effect of the season or sample weight. Finally, it has been proven that killifish (Rivulidae) eggs continue their development and hatch even after being ingested and expelled by a bird, representing an unknown dispersal means to a vertebrate. In this thesis, it is demonstrated that the endozoochory promoted by waterbirds is fundamental to understand the dispersal dynamics of aquatic organisms in neotropical wetlands.

Composição e diversidade de borboletas frugívoras (lepidoptera: nymphalidae) em unidades de conservação e fragmentos florestais adjacentes de mata atlântica no sul do Brasil

Fri, 28 Aug 2020 00:00:00 GMT

Composição e diversidade de borboletas frugívoras (lepidoptera: nymphalidae) em unidades de conservação e fragmentos florestais adjacentes de mata atlântica no sul do Brasil Bordin, Sandra Mara Sabedot Many are the threats to the Atlantic Forest biome, e.g., fragmentation represents a threat to the diversity of Lepidoptera. Fruit-feeding butterflies make up a species-rich taxonomic group, being loyal to their habitats, well known and rapidly sampled. The diversity of fruit-feeding butterflies is influenced by abiotic and biotic variables. This thesis presents information on 1) the list of fruit-feeding butterflies species and composition analysis (similarity), 2) analysis of composition and diversity (abundance and species richness), 3) and influence of abiotic and biotic variables on composition, abundance and richness of fruit-feeding butterflies sampled in Conservation Units (CU) and respective adjacent forest fragments (FFs), in Mixed Ombrophilous Forest, Western Santa Catarina, Brazil. The study was conducted in the Chapecó National Forest (FLONA), Mata Preta Ecological Station (ESEC) and Araucárias State Park (PAEAR) and their respective adjacent forest fragments. Fruit-feeding butterflies were collected using Van Someren-Rydon traps. Collections occurred between December 2017 and March 2018, totaling 24 sampling days. We recorded 4,231 fruit-feeding butterflies belonging to four subfamilies, 12 tribes and 49 species. In FLONA, we recorded 37 species, with 29 in its FFs; ESEC included 29 species with 33 in its FFs; and PAEAR included 33 species with 28 in its FFs. Of the recorded species, 15 are new records for state of Santa Catarina and 10 are new records for the Western region of the state. The most abundant species in our study were: Manataria hercyna (Hübner, [1821]), Hermeuptychia sp., Yphthimoides ordinaria Freitas, Kaminski & Mielke, 2012, Forsterinaria quantius (Godart, [1824]), Eryphanes reevesii (Doubleday, 1849), Moneuptychia soter (Butler, 1877) and Morpho epistrophus (Fabricius, 1796). Satyrinae had the highest richness (S=34) and abundance (90.58%) in all sampled areas. The estimated sampling coverage for the CU and forest fragments was above 97%. Species richness and abundance of fruit-feeding butterflies differed between the Conservation Units and their adjacent forest fragments and composition was shown to be altered, with species loss from one environment to another. There was a grouped pattern separating the samples of CU and FF. Both the similarity regarding abundance and species composition varied from 50 to 55%. The sampled fruit-feeding 4 butterflies species showed a variation of occurrence in the samples of 85.23% in the Chapecó National Forest, 75.92% in the Mata Preta Ecological Station and 66.28% in the Araucárias State Park. We observed a nested pattern of the assemblages in the Chapecó National Forest and Araucárias State Park and their respective adjacent forest fragments. Abundance and species richness of fruit-feeding butterflies of FLONA and PAEAR were positively related to relative air humidity, temperature and luminosity. The abiotic variables explained between 23.3% and 39.1% of the fruit-feeding butterflies assemblages, with luminosity and relative air humidity being the most significant variables. There was a positive relation of the richness of fruit-feeding butterflies to canopy height and openness, and, regarding abundance, to canopy openness in the areas of FLONA. For ESEC, there was a positive relation of abundance and richness to canopy openness. The composition of fruit-feeding butterflies in FLONA varied with canopy height and openness, and in ESEC it varied with canopy openness. The abundance of fruit-feeding butterflies was positively related to the isolation level of FLONA, and negatively to the area. This study contributed to the knowledge and characterization of the guild of fruit-feeding butterflies in the state of Santa Catarina. The fauna of fruit-feeding butterflies of Western Santa Catarina, investigated for the first time in CU, was shown to be expressive and with good representativeness for the Atlantic Forest biome. Moreover, we emphasize the important role of CU in maintaining the diversity of fruit-feeding butterflies in FFs and the relevance of environmental variables. We perceive the need to conserve adjacent forest fragments in highly fragmented areas, a common situation in the Atlantic Forest, thus avoiding the loss of fruit-feeding butterflies diversity. We highluminosity the need for other surveys and studies directed to understand the relationships between fruit-feeding butterflies and the influence of other environmental variables, especially in a scenario of environmental degradation and global climate change. However, we expect that the generated knowledge will be useful for the elaboration of plans for the management and conservation of subtropical butterflies in Mixed Ombrophilous Forest of Southern Brazil.

Influência de gradientes espaciais sobre comunidades de macroinvertebrados aquáticos em áreas úmidas costeiras de dois biomas no sul do Brasil

Fri, 27 Mar 2020 00:00:00 GMT

Influência de gradientes espaciais sobre comunidades de macroinvertebrados aquáticos em áreas úmidas costeiras de dois biomas no sul do Brasil Bacca, Roberta Cozer Species do not have similar and uniform distributions along environmental gradients, due to biotic and abiotic restrictions. However, the effects of many environmental gradients on the structure of animal communities are still unknown. Aquatic macroinvertebrates are important representatives of wetland ecosystems, and their communities are influenced by the duration of the water and local, regional and spatial processes. In this sense, the general objective of the thesis was to analyze the beta diversity and evaluate the influence of spatial gradients on the taxonomic and functional structures of aquatic macroinvertebrate communities in coastal wetlands in southern Brazil in the Atlantic Forest and Pampa biomes. In relation to beta diversity, macroinvertebrate communities were studied in 24 lagoons on the coastal plain of the states in the states of SC and RS, distributed along a latitudinal gradient. We assessed the influence of local factors (water quality and habitat structure) and regional factors (climate) on the beta diversity of macroinvertebrate communities. Our study demonstrated that differences in species composition between wetlands are more strongly influenced by environmental differences than by geographic distance between wetlands. In terms of taxonomic and functional analysis of aquatic macroinvertebrates, communities were studied in 12 distributed ponds along a latitudinal gradient in the Coastal Plain of the states of SC and RS, between the Pampa and southern Atlantic Forest biomes, in two years (2015 and 2016). Regarding taxonomic analyzes, our study demonstrated that differences in species composition between wetlands are influenced by both local, regional and spatial environmental variables. For functional categorization, the genders were classified according to the characteristics of voltinism, dispersion, habits, trophic groups and maximum body size. The relative effects of the environment, climate and biome on the functional structure of the community were also evaluated. Our study demonstrated that the differences in the functional structuring of species between wetlands are influenced by both local, regional and spatial environmental variables. These results contribute to the ecology of wetlands and to a better understanding of the interactions between wetlands and aquatic macroinvertebrates.

Efeitos dos processos locais e regionais na estrutura das comunidades fitoplanctônicas de áreas úmidas subtropicais

Wed, 25 Mar 2020 00:00:00 GMT

Efeitos dos processos locais e regionais na estrutura das comunidades fitoplanctônicas de áreas úmidas subtropicais Brizolla, Mariane Cenira Padilha One of the main questions that challenges community ecology is to know how the different local and regional factors, and the dispersion capacity of species determine the structure and dynamics of biological communities. Traditionally, local processes are used to describe community structures, however, in recent years the ecology of metacommunities seeks to integrate local factors with regional factors, emphasizing the importance of the spatial dimension in ecology studies. Through the exploration of local and regional factors influence on aquatic ecosystems, it is possible to indicate the consequences of human impacts and work on the conservation of aquatic ecosystems, with efficient conservation policies. Based on these assumptions, the main objective of this thesis was to analyze the phytoplankton structure in a spatial gradient of wetlands at the coastal plain of southern Brazil taking into account the distribution patterns of the communities, its functional structure based on functional morphological groups (MBFG), and the influence of local and regional variables. The sampling was carried out between the months of May and June 2017 in 15 wetlands of the coastal plain of Rio Grande do Sul, covering an extension of 560 km. In relation to the main results obtained, 114 phytoplankton species were identified, distributed in nine phytoplankton classes. There was a community distribution pattern opposed to the nested pattern (antinested), which was correlated mainly with the variable TDS (total dissolved solids), which tends to promote light limitation by interfering with photosynthetic ability of microalgae. The Zygnematophyceae class presented the highest total species richness and the highest total biomass value. The functional morpho group IV (small nonflagellated organisms) was the most representative in number of species, and the functional morpho group VII (large mucilaginous colonies) had the highest biomass values. Regarding the metacommunity approach, it was observed that there was an influence of local and regional factors. The decay of similarity with distance and antinested pattern, are influenced by the the effect of space, evidencing a limitation of species dispersion. The local and regional factors tend to contribute to the observed patterns and show a spatial structure of phytoplankton communities in the studied wetlands, influenced mainly by species that dominate shallow environments with dominance of macrophytes. Considering the total species composition, turbidity was the only variable that was associated with the community structure. Regarding the taxonomic classes, different groups were formed according to the analyzed class, where the better adjustments contained urbanization, nitrite, area, dissolved oxygen and total dissolved solids. The results of the present study highlight how dynamic and complex the phytoplankton communities are, with a significant increase in knowledge about the factors that influence microalgae communities in natural subtropical wetlands.

Respostas fisiológicas de moringa oleifera lam. e suas interpretações para o cultivo e utilização da espécie no clima tropical continental do estado do Mato Grosso, Brasil

Fri, 28 Feb 2020 00:00:00 GMT

Respostas fisiológicas de moringa oleifera lam. e suas interpretações para o cultivo e utilização da espécie no clima tropical continental do estado do Mato Grosso, Brasil Bernardi, Claudio João The Moringa (Moringa oleifera Lam.) is a perennial species, of Moringaceae family, originating of Indian northeast region, widely distributed in India. It can adapt to a wide range of soils. It is a multipurpose plant with almost all parts having food or medicinal value and its seeds have industrial importance to vegetable oil production. In Brazil, the M. oleifera is known at Maranhão state since 1950 and it is used mainly in the water treatment. Cultivation of sexual propagation species is essential knowledge of the germinal process. In the current work, the seeds were divided in three groups L (light), M (medium) e P (heavy) according their fresh weight. The L subsample represented 14.04%, the M subsample 68.06% and the P subsample 17.90%. The seeds of L subsample presented in average 23.54% of water and 94.73% of organic material. The seeds of M subsample presented in average 42.28% of water and 93.21% of organic material. The seeds of subsample P presented in average 33.66% of water and 93.91% of organic material. For germination were evaluated the influence of depth, sowing position, the influence of light, temperature and seed weight. The germination presented the three-phase system. The begin of phase one was observed after one hour. After 24 h the seeds passed to phase II, which were registered a reduction in water absorption keeping the weight of the seeds almost constant. After five repetition, in average, the Germination Speed Index (GSI) of L seeds presented 55.39, M seeds 79.19 and P seeds 79.17. The germination percentage considering the average among treatments, depth and position of the hilum of L seeds were 68.5%, M seeds were 86.7% and P seeds were 88.3%. For growth, the experiment was divided into two stages: Primary growth comprising the first six months and secondary growth when transferring 112 seedlings to planting area. Both experiments presented increase of volume, weight and size. Reproductive phenology and pollination biology were studied in an experimental planting area, in which 112 individuals were tagged and monitored fortnightly for observations of phenological studies. For the study of floral morphology and biology, flowers and inflorescences were tagged and monitored until fruit formation. Floral visitors were observed throughout the experiment, noting the frequency, time and behavior of their visits. Moringa oleifera demonstrated sub-branch flowering pattern of intermediate duration. Floral attributes are related to melithophilia syndrome. The anthesis occurs predominantly between 06h00 and 12h00, observing the presence of nectar from the pre-anthesis phase. The flowers were visited by four genera of Hemiptera, six of Lepidoptera and 2 species of birds.

Avifauna nos parques eólicos do extremo sul do Brasil

Fri, 22 Feb 2019 00:00:00 GMT

Avifauna nos parques eólicos do extremo sul do Brasil Falavigna, Tamara Justo Wind energy has definitely been integrated into the world energy matrix and there are public policies for the continuity of its development. Brazil also adhered to the use of this source and Rio Grande do Sul (RS) occupies the fourth place in installed capacity, exploring approximately 1.7% of its wind potential in 18 wind farms in commercial operation. A main issue observed in the discourse in support of wind energy is the search for sustainable development, since the source offers environmental benefits, such as: reducing the need for non-renewable sources, like coal and oil, with a consequent reduction of water use and reduction of habitat destruction. However, the installation of this type of energy also represents a generation of negative impacts, especially on the community of birds by the collision with the wind turbines. The assessment of this impact is commonly done through fatality records and many models have been deployed to predict this risk in an attempt to balance the risks and benefits in order to minimize adverse environmental effects. Thus, the objectives of this work were: (i) to evaluate the species composition, richness and bird mortality in the wind farms in RS, comparing the regions of implantation; (ii) to verify how the technical characteristics of the wind farms, environmental factors and landscape affect the mortality rate; (iii) to evaluate three phases of a wind farm: pre-construction, construction and operation regarding the composition of bird species, environment guilds and mortality, and (iv) propose a collision risk index. In this way, secondary avifauna data were obtained from fauna monitoring reports submitted to the RS environmental agency of 11 operating wind farms located in three regions: Coxilha de Santana, North Coast and South Coast. A total of 315 bird species were registered in all wind farms, the majority being resident, insectivorous and from open area. The species composition is different in the three regions, however, for mortality this pattern is not repeated. The technical characteristics of the wind farms and the evaluated environmental factors do not have relation with the species that died, although when the landscape structure is added this pattern changes. The average mortality rate observed was 0.494 individual/turbine/year and the mortality rate estimated was 1.154, being similar with results found in other wind farms in the United States and Spain. The evaluation of the composition of species in the three phases of a wind farm showed that the pre-construction phase is different from the four years of operation, indicating a possible impact of the operation of the wind farm on the bird community. The results show that care must be taken when analyzing the effects of wind farms on birds, especially in the absence of long-term studies to confirm impact trends. The proposed risk index considered only morphological and ethological characteristics of the species. However, the collisions that were recorded and evaluated in this study are mostly occurring with species that present medium to low collision risk and what would explain the collisions would not be the species themselves, but the structure of the landscape and some characteristics of wind farms. Thus, it is fundamental to develop studies to improve or to unravel a new index, testing the inclusion of different factors, in order to lead to results closer to reality, seeking the best conservation of avifauna in wind farms.

Investigando a ecologia trófica de planárias terrestres neotropicais : ecomorfologia, desenvolvimento e comportamento

Thu, 21 Feb 2019 00:00:00 GMT

Investigando a ecologia trófica de planárias terrestres neotropicais : ecomorfologia, desenvolvimento e comportamento Boll, Piter Kehoma The role of predators in structuring communities is well studied in groups such as vertebrates and spiders, while the role of other admittedly important predators, such as land planarians, is little known. Land planarians for a diverse group of terrestrial flatworms, especially in tropical regions, and are carnivorous, mostly predators, but their sensitivity to environmental changes makes them difficult to keep in the laboratory, which reduces the number of studies on their behavior. For example, the feeding habits of most species, including the composition of their diet and their predatory behavior, is unknown. Due to the relevance of studies on the trophic ecology of land planarians for the adequate management of their populations, this work aimed to enrich the knowledge on the morphological, physiological and behavioral diversity of land planarians regarding their diet and their predatory behavior. To facilitate the identification of food items without the need to conduct exhaustive offers of possible prey, we compared morphological variables of several planarian species to their known feeding habits. The results indicate that the thickness of the cutaneous musculature is a more important variable to define the diet of land planarians than pharynx anatomy, suggesting a higher diversity in the morphological adaptation for capturing prey and lower for prey consumption. In a species of more generalist habits, which includes both gastropods and other planarians in its diet, we examined the influence of different diets on survival, growth and fecundity. Specimens receiving a mixed diet (planarians + slugs) survived, on average, less than specimens feeding only on planarians or only on slugs. In the mixed group, there was a preference for planarians. There was no significant difference in growth between the groups. The larger number of egg capsules was laid by specimens feeding only on slugs but the group receiving the mixed diet laid heavier capsules. The constant alternation between different food items seems to have negative effects on the planarians, suggesting the need for great physiological changes to digest different prey items. The heavier capsules laid by the group that had the lowest survival suggest terminal investment, with an increase in reproductive investment at the end of life. Finally, we examined the behavior of prey detection and the behavior of predator recognition in a land planarian that feeds on woodlice and is the prey of other land planarians. The planarian was unable to detect remote chemical and mechanical signals of the prey and did not follow chemical trails of the prey, suggesting an ambush behavior for prey capture. When touched directly by a predator, the planarian showed an immediate escape response, which did not occur when touched by non-predators. Species phylogenetically close to predators, but which are not themselves predators of the planarians, also triggered an escape response, suggesting similar chemical signatures that cannot be distinguished by the planarian. Chemical secretions and trails alone rarely triggered an escape response, indicating the need for tactile stimuli or a subtler avoidance response that was not detected. The ambush behavior for the capture of woodlice and the quick escape response in the presence of a predator planarian seem adequate strategies for the capture of fast-moving prey and the escape from slow-moving predators. In overall, the results highlight the great morphological, ecological and behavioral diversity of land planarians.

Sistemática do gênero Trichomycterus Valenciennes, 1832 (Siluriformes : Trichomycteridae) do norte da América Andina

Fri, 29 Mar 2019 00:00:00 GMT

Sistemática do gênero Trichomycterus Valenciennes, 1832 (Siluriformes : Trichomycteridae) do norte da América Andina Peixoto, Paula Fishes of Siluriforms order has the most diversity and Ostariophsi’s distribution, presenting about 5500 species described in the Neotropical Region. The Trichomycteridae family is among the largest catfish families in the Neotropical Region with about 360 valid species in 41 genera and 8 subfamilies. The family forms a monophyletic group with the exception of the Trichomycterinae, which presents taxonomic problems mainly because most of the representatives are located in the Trichomycterus genus, a non-monophyletic group with a considerable richness of approximately 75% of the total family species and possibly a great diversity still unknown. The problematic of the Trichomycterus genus is questioned in several studies, mainly due to the absence of exclusive synapomorphs that make it difficult to study phylogenetic relationships, leading to taxonomic revisions in which some species of Trichomycterus have been redescribed in other genera of the subfamily such as Silvinichthys, Ituglanis, Potamoglanis and Cambeva. In addition, this genus has a very large diversity and distribution (South America) that can lead to the geographic and genetic isolation of certain populations, evidencing non-monophyletic. In this context, our main objective was to study the phylogeny of Trichomycterus of Andean America, with emphasis on the species of Colombia, in order to identify phylogenetic relationships between the cis-andine and trans-andine species from 348 morphological characters. This study also provides the redescription of two Trichomycterus from the Pacific coast of Colombia e Ecuador, Trichomycterus gorgona e Trichomycterus taenia. The study range 49 taxa of which, 38 internal group and 11 external group. The genera used in the external group were Astroblepus, Bullockia, Cambeva, Eremophilus, Hatcheria, Ituglanis, Scleronema and Silvinichthys. Morphometry and meristic of the specimens were carried out, surveying 348 morphological characters that were compiled from the works of DoNascimiento (2013), Baskin (1973), de Pinna (1992, 1988, 1989, 1998), Arratia (1990), Costa & Bockmann (1994) and Katz et al,. (2018) and used for the first time in this work with inner group species followed by a phylogenetic analysis for the interpretation of cladograms and relationships between Cisandine and Transandine species. Trichomycterus polyphylism remained in our results. We also identified that Trichomycterus stricto sensu is restricted to the southeastern region of Brazil and, therefore, the Transandine species belong to a genus not yet described. The relationship of Trichomycterus stricto sensu as Cambeva's sister group was corroborated in this work as well as the monophily of the Cambeva genus and the relations between Scleronema and Ituglanis.

Avaliação da interação tritrófica de Soja Bt, Spodoptera eridania (Lepidoptera: Noctuidae) e Dolichozele sp. (Hymenoptera: Braconidae)

Mon, 31 Jul 2017 00:00:00 GMT

Avaliação da interação tritrófica de Soja Bt, Spodoptera eridania (Lepidoptera: Noctuidae) e Dolichozele sp. (Hymenoptera: Braconidae) Salles, Silvia Martins de The development of insect resistance poses a threat to pest control using Bt plants. The conservation of natural enemies may contribute to reduce the evolution of Bt soybean resistance. Among the insects of interest for use in the control of species of the genus Spodoptera, parasitoids have been considered the most important due to their efficiency and specificity in relation to the host. In this way, this study aimed to evaluate the interactions of Spodoptera eridania (Lepidoptera: Noctuidae) and the endoparasitoid Dolichozele sp. (Hymenoptera: Braconidae) when treated with Bt soybean that synthesizes Cry1Ac protein. For this purpose, S. eridania larvae were exposed to the following treatments: (T1) non-parasitized and fed with conventional soybean; (T2) non-parasitized and fed with Bt soybean; (T3) parasitized and fed with conventional soybean; (T4) parasitized and fed with Bt soybean; and (T5) parasitized and fed with transgenic BRR soybean. The biology of the parasitoids descendant from larvae fed with Bt soybean was evaluated by observing the date of formation of the parasitoid pupa, date of emergence, sex, adult parasitoid longevity and survival. In the evaluation of the parasitoid preference for larvae fed with Bt soybean and non-Bt soybean, larvae received different exposure times to the parasitoid female, of 2h, 4h and 6h. In the treatments using Dolichozele sp. isolated or in conjunction with Bt soybean, mortality was significantly higher than the control treatment (F = 63.5; gl = 4.14; P = 0.001), with a mean larval mortality of 17.0 (T3), 20.2 (T4) and 17.5 (T5). Through the enzyme-linked immunosorbent assay (ELISA), it was possible to detect the transfer of the Cry1Ac protein in S. eridania and Dolichozele sp.). The parasitoids emerged from larvae fed Bt soybean showed significant difference in the pupal phase (F = 15.058, gl = 2, P = 0.001) in the treatments T4 (16.6 days) and T5 (17.08 days) when compared as control T3 (18.2 days). The survival of the parasitoids that emerged from larvae fed with Bt soybean (T4) was lower (Kaplan-Meier, Log Rank, X2 = 8.22, gl = 2, p = 0.016, Breslow, X2 = 9.58, gl = 2, p = 0.008; Tarone-Ware, X2 = 9.94, gl = 2, p = 0.007). There was a positive correlation between the exposure time and the parasitism rate of Dolichozele sp. in S. eridania (Spearman's Rho = 0.758, p = 0.001). The results of this study indicate that the parasitoid has a positive effect on the control of S. eridania, however its development and survival may be influenced by the presence of the Bt toxin. Dolichozele sp. presented the potential to act positively in strategies to manage the evolution of resistance to Cry proteins in Bt soybeans, as they may help suppress pest populations.

Contribuições à sistemática e distribuição preditiva dos roedores Juliomys (Cricetidea, Sigmodontinae)

Fri, 26 Feb 2016 00:00:00 GMT

Contribuições à sistemática e distribuição preditiva dos roedores Juliomys (Cricetidea, Sigmodontinae) Sarti, Paulo Tomasi The Juliomys are small-sized arboreal rodents. Since its establishment in 2000, the genus has been studied, and new information has been presented progressively. However, due to the short time period, many questions are still awaiting for answers related about general biology, ecological relationships, geographic distribution, species richness, and phylogenetic position within the Sigmodontinae. Morphometric and genetic studies are important tools to explore these lines. The aim of this study was to analyze the morphology and the genetic markers in order to subsidize the systematic and biogeography of Juliomys species. We use methods of morphologic, morphometric, and molecular analyses to define the new taxon. We produce maps of potential occurrence of the species according to the environmental preferences. Finally, we tested the monophyly of the genus within Sigmodontinae through the study of a molecular marker. Corroborating previous studies, we describe and propose a new species for the genus. The species distribution modeling revealed interesting patterns with unequal distributions along the Atlantic Forest biome. We endorse that Juliomys it is a monophyletic clade, despite the morphological differences. Studies grounded phylogenetically as well as monophyletic clades should be based delivery approaches. It is notorious that natural history museum collections are essential sources of wildlife information, which was crucial to this study. The conservation of fauna takes the systematic and biogeography assumptions, as those presented in this study, to underpin their actions.

Variação morfométrica entre os sexos, variabilidade genética e inferência de expansão histórica de Pygoscelis antarcticus, nas ilhas Shetland do Sul, Antártica

Thu, 21 Nov 2013 00:00:00 GMT

Variação morfométrica entre os sexos, variabilidade genética e inferência de expansão histórica de Pygoscelis antarcticus, nas ilhas Shetland do Sul, Antártica Brummelhaus, Jaqueline Chinstrap penguin (Pygoscelis antarcticus) has their populations distributed mainly in South Sandwich, South Georgia and South Shetlands Islands, and the Antarctic Peninsula. This specie presents low sexual dimorphism, monogamy and philopatric behavior. This thesis aims to: 1) to evaluate sexual dimorphism among males and females and among two breeding areas (King George and Elephant Islands) using morphological characters and to obtain a discriminant function based on the characters that best identify the sex of Chinstrap penguins; 2) to determine the spatial structuring of population genetic variation among breeding colonies at King George and Elephant Islands, using mitochondrial control region. In the assessment of sexual dimorphism using morphological characters, were found that males were 6 to 9.4% larger than females and discriminant equation formulated correctly classifies 80.6% of the birds. There was no difference in sexual dimorphism between the breeding colonies of King George and Elephant Islands. However, the discriminant function should be used with caution in different locations than are produced because penguins may be misclassified. When discriminant equations from Deception and King George Islands were tested for Elephant Island data, we obtained only 67.7% and 71% accuracy. Where there is doubt in the field, it would be interesting to apply molecular sexing technique. For genetic variability using mitochondrial control region, were found 38 haplotypes for 61 individuals analyzed, only two were shared in the colonies and all others are exclusive. FST and AMOVA values revealed that the divergence between populations is low and that most of genetic variation (98.3%) occurred within populations. This could be explained by a high gene flow among populations, but does not corroborate with the philopatric behavior of this specie. The neutrality tests and Mismatch distribution point to a neutral evolution and possibility of expansion, which occurred more 2 Mya and the last 1 Mya, the effective population size remained constant. The results show the occurrence of a population expansion from a genetically homogeneous population and maintenance of effective size in long time scale can have widely contributed to the lack of genetic structuring among the current colonies of Chinstrap penguin.

Influência da heterogeneidade espacial e da escala de tempo na estrutura e dinâmica da comunidade fitoplanctônica em um lago raso subtropical (Lagoa Mangueira, RS)

Mon, 30 Mar 2015 00:00:00 GMT

Influência da heterogeneidade espacial e da escala de tempo na estrutura e dinâmica da comunidade fitoplanctônica em um lago raso subtropical (Lagoa Mangueira, RS) Teixeira, Lacina Maria Freitas The phytoplankton is formed by very different organisms of polyphyletic origin, composed mainly by autotrophic unicellular beings who are not able to overcome the current (FALKOVISK; RAVEN, 1997). The dynamics, distribution and structure of phytoplankton communities can be explained by a variety of biotic and abiotic factors related to environmental heterogeneity. The principal objective of the present study was evaluate the influence of spatial heterogeneity and the temporal, on the structure and dynamics of phytoplankton in a subtropical shallow lake (Mangueira Lagoon, RS). The study took place in the Mangueira Lagoon (southern Brazil), which is a shallow aquatic ecosystem (Zmax = 7 m) long (90 km long, 3-10 km wide), continuous hot polymictic, considered oligo-mesotrophic, under the direct influence of an adjacent wetland on the north and has its margins inhabited largely by aquatic macrophytes, especially in the south. Samples were taken in the subsurface of the water, quarterly, for two years, in 19 sites, including the pelagic and coastal zones and the southern, central and northern regions of the lagoon, for abiotic and biological analysis. Samples were also collected in short time intervals during 60 days in the pelagic and coastal zones in the south region. The structure of the phytoplankton community was analyzed by measures of chlorophyll a, biomass, richness, diversity of species, descriptors species and functional diversity. Cyanobacteria (e.g., Chroococcus limneticus, Aphanocapsa conferta, Aphanothece smithii, Planktolyngbya contorta) was the most representative group independently of region (southern, central or north) or zones (coastal or pelagic). It was observed a clear spatial pattern to the north of the lagoon, which showed higher values of total biomass and chlorophyll. However, richness and descriptors species showed no clear spatial pattern. The Redundancy Analysis (RDA) showed strong temporal organization of the species as a function of the abiotic scenario, indicating that the high degree of temporal variability due to the local hydrodynamics was the main determining factor of the structure of phytoplankton community in the Mangueira Lagoon during the period of study. The results of the analysis of functional diversity showed that there was no spatial organization considering the forms of life and the size structure of the phytoplankton community during the period of study, although the phytoplankton functional groups had responded to changes in resources, especially increasing its variety and contribution in the months of spring and summer, segregating the north of the lagoon, independently of the studied zones (pelagic and coastal). In short timescale the phytoplankton community from the pelagic area was more equitable than that from the coastal region over time. The contribution of the species Chroococcus limneticus, Aphanocapsa conferta and Aphanothece smithii from the 9th day in the pelagic region and practically the entire period studied in the coastal region indicate that despite the variation in precipitation and wind observed over time, steady-state of the phytoplankton community in environments strongly conditioned by hydrodynamics may occur.

Dinâmica de comunidade de espécies arbóreas em manchas de Mata Atlântica com matrizes de pecuária e silvicultura de eucalipto no extremo sul do Brasil

Tue, 27 Aug 2013 00:00:00 GMT

Dinâmica de comunidade de espécies arbóreas em manchas de Mata Atlântica com matrizes de pecuária e silvicultura de eucalipto no extremo sul do Brasil Vier, Iliane Freitas de Souza The vegetation of southern Brazil is composed of Pampa and Atlantic Rain Forest biomes. Our study areas are located near the boundaries of these two biomes, forming a 24 grassland-forest mosaic. The livestock and eucalyptus plantations are widely diffused throughout these formations. The change of matrix management, of livestock for eucalyptus plantations, can lead to changes in the autoecological attributes of forest tree species. The study of the autoecological attributes in environments with different historical of land use can help to understand how tree species respond to changes in habitat or environmental conditions. This study aims to analyze how autoecological attributes between forest tree species varies as a consequence of change in management matrix at the southern Atlantic Rain Forest, of grasslands with extensive livestock for eucalyptus plantations on these pastures. Specifically, we intend to (i) determine the effect of changing management on autoecological attributes among species, and having this effect, (ii) what patterns of autoecological change can be identified between species. According to our results, the change in management of landscape matrix caused changes in autoecological patterns of tree species. The extent of these variations was different for each species and depended on their phenotypic plasticity and local environmental conditions. Long-term, patterns of autoecological change found may reflect a change in species composition due to the change in management of landscape matrix.

O conhecimento ecológico local e a percepção ambiental de uma população de pescadores do Rio Grande do Sul

Fri, 06 Jan 2012 00:00:00 GMT

O conhecimento ecológico local e a percepção ambiental de uma população de pescadores do Rio Grande do Sul Baptista, Cristina Paes Barreto The Knowledge of Traditional population can be an important tool in conservationist actions. Artisanal fishermen have a distinct knowledge about their surrounding environment. This thesis has as object 1) To identify the environmental perception of the fishermen as well as how age, fishing experience and time spent in school influence that perception 2) Identify the use of the wetlands and its fishing and water resources by a population of fishermen from the cities of Imbé and Tramandaí and 3) Investigate how the LEK(local ecological knowledge) can help elaborate management plans and if this knowledge is present on management plans and/or Conservation Unit's consultative councils in the Rio Grande do Sul state and co-management actions. The fishermen have a positive perception about their environment and there is no relation between negative perceptions regarding conservationist actions and social-economical factors. In this interaction between the fishermen from Tramandaí and Imbé with their surrounding ecosystem it was found a rich knowledge about that environment. Besides, much of that knowledge is in accordance to what is registered by the scientific community. The experience and lifestyle of the fishermen contribute positively to their preservationist view regarding the environment, making them strong allies in management plans, although their contribution is not well recongnized.

Distribuição geográfica da avifauna no Rio Grande do Sul - Brasil

Fri, 25 Feb 2011 00:00:00 GMT

Distribuição geográfica da avifauna no Rio Grande do Sul - Brasil Fonseca, Vanda Simone da Silva