PPG Biologia

Intensidade do azul em anéis de crescimento da conífera subtropical Araucaria angustifolia (Bertol.) Kuntze

Thu, 19 Dec 2024 00:00:00 GMT

Intensidade do azul em anéis de crescimento da conífera subtropical Araucaria angustifolia (Bertol.) Kuntze Nunes, Ânderson Juliano This study investigated the feasibility of Araucaria angustifolia as a dendroclimatic proxy in subtropical regions, focusing on tree-ring width (RW) and maximum latewood blue intensity (MXBI). The analyses revealed synchronicity between RW and MXBI chronologies, reflecting eco-physiological responses to climate variability. RW showed a positive correlation with precipitation from April to June of the previous year, suggesting that higher rainfall in the preceding autumn favors wider rings. In contrast, MXBI correlated with the mean temperature for the same period of the current year, indicating that higher temperatures enhance latewood lignification, resulting in greater optical intensity. These patterns highlight distinct climatic responses for each proxy, reflecting different growth cycle phases. MXBI was more strongly related to thermal variables, particularly mean autumn temperature, than to hydrological variables such as precipitation and the Palmer Drought Severity Index (PDSI), whose lack of correlation suggests that high water availability at the study site mitigates drought impacts on tree growth. The moderate correlation between MXBI and RW (r = 0.45, p = 0.002) indicates an interaction between anatomical and optical parameters in recording climate conditions. The EPS for MXBI was 0.745, lower than that of RW (0.894), demonstrating RW's greater robustness as a climate proxy. However, combining both proxies proved effective in reconstructing autumn temperatures. MXBI’s ability to reflect local thermal conditions during autumn is valuable for understanding climate changes in subtropical regions. Future studies should integrate multiple proxies and expand analyses to other ecological contexts to improve climate reconstructions and support conservation strategies.

DNA Barcoding helping the identification of Brazilian cetaceans

Thu, 28 Nov 2019 00:00:00 GMT

DNA Barcoding helping the identification of Brazilian cetaceans Silva, Vanessa Souza Cytochrome C Oxidase Subunit I (COI) is the mitochondrial gene recognized as the DNA Barcoding and used to identify different animal species. In the case of cetaceans (porpoises, whales and dolphins), the COI can assist in more accurate identification and/or confirm the morphological identity of specimens found in advanced state of decomposition on the Brazilian coast, without evident external diagnostic characters. This study aimed to test the efficiency of the COI in the specific identification of most of the 47 species of cetaceans off the Brazilian coast and to generate their respective sequences for depositing them in public sequence databases, in order to subsidize new work by researchers from any country. Part of the world. To this end, the COI was amplified to 152 specimens collected by 13 Brazilian institutions and sent for analysis. The comparison between the sequences obtained and those of cetacean species previously deposited in GenBank was made by the Blast tool, which is based on the similarity between the sequences, which was performed on the Barcode Of Life Data System platform. In addition, most samples had a specimen deposited in a scientific collection as witness material, or specimen images, which allowed their a priori morphological identification in cases where morphological identification diverged from molecular identification. As a result, COI sequences were obtained from 33 species, which represent 70% of the 47 cetacean fauna recorded for the Brazilian coast. Of the 152 sequences analyzed, the COI gene was inefficient in identifying only two species: Stenella coeruleoalba and S. clymene due to the absence of the so-called “gap barcode”, i.g., the absence of well-established inter and intraspecific limits. These results suggest that barcode DNA was efficient in identifying the great majority of cetacean specimens (~93%) studied. However, for species of Delphinidae family the identification should be integrated with other methods, such as Cyt b, nuclear DNA and morphological character analysis whenerver possible.

Interação entre visitantes florais e mirtilo (Vaccinium ashei Reade): o efeito da variação da morfologia floral e comportamento de coleta de recurso floral na polinização

Thu, 26 Aug 2021 00:00:00 GMT

Interação entre visitantes florais e mirtilo (Vaccinium ashei Reade): o efeito da variação da morfologia floral e comportamento de coleta de recurso floral na polinização Santanna, Manoela

Efeitos da urbanização e do clima na produtividade primária de florestas urbanas no Sul e Sudeste do Brasil

Tue, 25 Aug 2020 00:00:00 GMT

Efeitos da urbanização e do clima na produtividade primária de florestas urbanas no Sul e Sudeste do Brasil Conrado, Guilherme Taboada Cities are social and ecological systems characterized by the high human demographic rate, which wields dominance on the structure and functioning of natural and semi natural ecosystems. The urban ecosystems interact substantially with regional and global ecological processes, and it is therefore important to know about the urbanization of the landscape process and its relation with the environment. The urbanization of the landscape is the process by which the urban ecosystems become the landscape matrix, going through phases of expansion and consolidation, and it has brought considerable degradation to the ecosystems of support in the regions and places it is inserted, negatively affecting the efficiency of environmental services. It is imperative to develop and apply urbanization models reconciled with the conservation and functional maintenance of the ecosystems support, and to this end, it is essential to be aware of its dynamic and functioning. In this regard, it is highlighted the studies about urban forests that are the isolated forest areas of the urbanized landscapes, originated from natural ecosystems and that are of great benefit to the local populations, fostering several ecosystem services. The primary productivity is an ecosystem function widely studied in natural and semi natural landscape contexts, and recently in urban landscapes as well where it is, usually, negatively correlated. Besides that, the productivity may further be influenced directly and indirectly by geographical, vegetational and climatic features of a particular region. With this in mind, studies that simultaneously evaluate urbanization effects and climatic changes in the productivity of urban forests are still necessary. Therefore, the present study aims at describing (1) the urban landscape expansion and consolidation patterns and (2) primary productivity of its forests, in nine urban landscapes in this region (two cities and seven metropolitan localities) between 1980 and 2010, as well as (3) testing possible causative variation mechanisms in the productivity of these urban forests, related to urbanization, climatic, vegetational and geographical factors. If the urban forests of the southern and the southeastern regions of Brazil follow the 6 observed patterns in other parts of the world, the primary productivity is temporarily affected by the urbanization process and by the climatic variations. Through the images of the Landsat 5 and Landsat 8 satellites, forests of nine urban regions of this region were monitored as to the changes in the land use and cover (urbanization, vegetation and water), climatic variations and NDVI (Normalized Difference Vegetation Index) since 1980. The average NDVI of the urban forests was calculated for each one of the analyzed decades. Pathways were elaborated to determine which geographical, climatic, vegetal and urban descriptors affect the primary productivity of these forests over time. The NDVI outcomes reported a 35% reduction on the primary productivity of the urban forests in the southern and southeastern cities of Brazil. From the Path Analysis test, it was noticed that the height (β = - 0,71) and the continental area (β = 0,47) indirectly influenced the productivity through the temperature rise (β = - 0,47), the urbanization (β = - 0,39), thus confirming the studies of many regions. If the predictions for urban expansion, vegetation loss and climatic changes for southern and southeastern Brazil hold true, we can expect the forests to be less productive, and possible profound changes in the carbon cycle, in the ecosystem services and in the life quality of the population itself

A influência do fogo sobre anfíbios anuros em campos nativos de Mata Atlântica

Mon, 17 Apr 2023 00:00:00 GMT

A influência do fogo sobre anfíbios anuros em campos nativos de Mata Atlântica Barth, Priscila Cortêz

Sinais dendroclimáticos de Araucaria angustifolia (Bertol.) O. Kuntze em sítios ecologicamente semelhantes

Fri, 26 May 2023 00:00:00 GMT

Sinais dendroclimáticos de Araucaria angustifolia (Bertol.) O. Kuntze em sítios ecologicamente semelhantes Arenhardt, Bruna Borne Dendrochronological studies have increasingly explored tropical and subtropical trees, mainly focusing on their climatic signs. In the Neotropics, growth ring width chronologies of Araucaria angustifolia have been developed at several localities in its range in the southern Atlantic Forest. However, the signals found in the studies do not show a clear pattern of growth response to climate. Understanding the causes of variability in dendroclimatic signals is relevant to direct dendrochronological studies in this species. The present work tests the premise that at independent sites but under similar environmental conditions, chronologies of A. angustifolia exhibit a common growth signal determined by limiting climatic conditions. A new ring width chronology was developed and compared to another preexisting one, in Curitibanos/SC, both under similar climatic, edaphic and vegetational conditions. The chronologies showed good internal level of synchronism and sampling effort. Yours trees had similar growth trajectories. The chronologies showed significant common signal, with moderate size. This common growth pattern, represented by a regional chronology, showed significant dendroclimatic signals with local climate variables and teleconnections with El Niño Southern Oscillation (ENSO), all weak size. Partial correlations showed that this set of climate variables was the determinant of the common signal between the sites. The results confirm the validity of the tested premise. Under the conditions studied, the growth response of A. angustifolia to climate arises from local variations in water and temperature availability, which operate at different stages of the annual growth cycle and are, to some degree, determined by ENSO. This low sensitivity of growth to climate is possibly related to the joint influence of these multiple factors and/or to the moderate variability of growth within sites. It is recommended that future dendroclimatic studies with species be based on comparing more than one site, with robust chronologies and replicating comparable ecological conditions, to avoid experimental biases arising from dating errors and the interaction between local factors with climate on growth.

Silvicultura de Araucaria angustifolia no Rio Grande do Sul: certificação de plantios, perfil das propriedades e crescimento das árvores

Tue, 17 Jan 2023 00:00:00 GMT

Silvicultura de Araucaria angustifolia no Rio Grande do Sul: certificação de plantios, perfil das propriedades e crescimento das árvores Olmedo, Gabriela Morais Conventional agriculture and silviculture strongly impact biodiversity on worldwide scale. Brazil is one of the main representants of these sectors, which must look for more sustainable models. Forest plantations with native species are alternatives to develop socioeconomic production with biodiversity conservation. However, such "bottom-up" approaches to conservation, incorporating the interests of the local population, are little encouraged in the country. Araucaria angustifolia is a native conifer with high timber and non-timber values. Its was intensively harvested until the 1970s, which influenced its classification as endangered to extinction. Although cutting A. angustifolia is prohibited, the timber trade still occurs and is sustained by illegal means, or by licensed private plantations. Thus, because of its high-quality timber and its importance for native biodiversity, silvicultural plantings with this species can be a strategy for conservation use. The aim of this dissertation was to characterize the silvicultural plantations of A. angustifolia in Rio Grande do Sul (RS), in order to support the sustainable development of the sector. The Secretary of Environment of Rio Grande do Sul allows the silvicultural planting of this species, by issuing the Certificate of Identification of Forest Planted with Native Species. Thus, information from all open CIFPEN processes from January 2017 to May 2021 was used as the basis of this research. In total, 640 processes were studied. The properties with A. angustifolia plantations in RS are concentrated in two centers in RS. Landowners showed little interest in new planting of native species. Properties with plantations of A. angustifolia are different in terms of land tenure and environmental aspects compared to properties with silviculture of native species and without silviculture. In summary, these characteristics indicate that the silviculture of A. angustifolia is associated with improved conditions of native ecosystems, besides promoting the conservation of the species itself. The average annual diametric increment is influenced mainly by the age factor, with higher rates occurring up to 40 years of planting, approximately. Above this age range, the best increment results are found in regions with humid autumn, in deep soils with high organic matter content, and also with summers below 142mm of precipitation, characteristics concentrated in a large region in the north of the state of RS and in spots to the west. Still, it is important to consider that other variables not analyzed in this study may have an influence on the growth of the species, such as genetic factors and management. We conclude that to extend the CIFPEN, it is 10 essential that it be better translated and disseminated to the population, especially in relation to legal aspects. Furthermore, this research reflections aimed at expanding the silviculture of A. angustifolia in RS, from the analysis of data from the public environmental agency.

Padrão de ocorrências do lobo-marinho-subantártico Arctocephalus tropicalis (Gray 1872) no sul do Brasil: associação com fatores climáticos e ambientais

Fri, 28 Aug 2020 00:00:00 GMT

Padrão de ocorrências do lobo-marinho-subantártico Arctocephalus tropicalis (Gray 1872) no sul do Brasil: associação com fatores climáticos e ambientais Oliveira, Carlos de The study presents the pattern of occurrences of subantarctic fur seals, Arctocephalus tropicalis, in the southern Brazilian coast and their association with remote and local patterns of climatic variability and anomalies in the concentration of chlorophytes and sea-surface temperature in the region of the breeding colonies of Gough and Tristan da Cunha Islands. The date, sex and age category of 254 records of the species between 1992 and 2013 were analyzed. The representative indexes of the patterns of climatic variability and environmental variables were obtained from four and five months before the records, were assumed as time lapse for displacement for species between their closest breeding colonies and the southern Brazilian coast. As a result, we found a pattern of predominance of adult males, registered mainly in 2002 (n = 92) and 2003 (n = 21) during July, August and September months. The Mixed Generalized Linear Model explained the association between the patterns of climatic variability and the occurrences of A. tropicalis (R² = 0.73) involved the effect of the interaction between the Southern Annular Mode, the South Atlantic Ocean Dipole, the Subtropical Indian Ocean Dipole, the Indian Ocean Dipole and El NiñoSouthern Oscillation with four months lag. A significant association was also observed between the decrease in the concentration of chlorophytes five months earlier in the vicinity of their breeding colonies on the Gough and Tristan da Cunha Islands.

Visitas e uso de recursos por aves em formações naturais de Butia odorata (Barb. Rodr.) Noblick. (Arecaceae) no sul brasileiro

Tue, 06 Aug 2019 00:00:00 GMT

Visitas e uso de recursos por aves em formações naturais de Butia odorata (Barb. Rodr.) Noblick. (Arecaceae) no sul brasileiro Glória, Cyro Menezes da The evolutionary process recorded in several vertebrate taxa was largely determined by the conditions of microclimate, habitat and optimization of the exploitation of food resources (Jordano, 2000; Brown & Lomolino, 2006; Ares 2007; Del Claro 2012; Alves et al., 2012; Thompson, 2012). Food specializations are a reflection of these adaptive processes. Among the different eating habits observed in birds, frugivory deserves to be highlighted due to its high incidence in different groups. Birds are among the animals with the highest number of frugivorous species in the Neotropical region (Moermond & Denslow, 1985; Jordano, 1987; Fadini & De Marco Jr., 2004) where they play an important ecological role by acting as dispersing agents for these plants ( Herrera, 1985; Fleming, 1987; Galetti & Pizo, 2003; Fleming & Kress 2011; Alves et al., 2012). In Brazil, there are about 22 families that feed regularly on fruits (Tinamidae, Rheidae, Cracidae, Odontophoridae, Opisthocomidae, Psophiidae, Columbidae, Psittacidae, Steathornithidae, Trogonidae, Capitonidae, Ramphastidae, Pipridae, Cotingidae, Tytiridae, Corvidae, Turdidae, Mimidae , Vireonidae, Coerebidae, Thraupidae, Fringillidae). Among all animals, birds are considered the most common frugivores among vertebrates (Fleming & Kress, 2011). According to Fleming (1987) it is estimated that 50% to 90% of all trees in tropical forests are dispersed by animals and 20% to 50% of bird and mammal species consume fruits.

Efeito dos fatores ambientais sobre a dieta de anuros em banhados subtemperados do extremo sul neotropical

Mon, 24 Feb 2014 00:00:00 GMT

Efeito dos fatores ambientais sobre a dieta de anuros em banhados subtemperados do extremo sul neotropical Oliveira, Mateus de Temporal variations in wetlands can affect the trophic relationships of anuran species as a function of their prey selectivity level. The aim of this study was to evaluate the influence of time (environmental variables) on the diet of anuran species with predominantly aquatic and terrestrial habits, in wetlands. Coleoptera, Araneae and Hymenoptera were the most important prey for most species, with greater niche overlap between species with the same habit. The species showed reductions in their niche amplitudes in the hot and rainy seasons, suggesting greater predation selectivity in these periods. In general, thermal and rainfall changes affect the diet of anurans differently. Furthermore, these variations may be related both to changes in prey availability, as well as to other aspects, such as the flooding level of wetlands and variations in the pattern of anuran foraging activity.

Desenvolvimento de um índice de integridade biológica baseado em peixes para áreas úmidas

Thu, 06 Oct 2016 00:00:00 GMT

Desenvolvimento de um índice de integridade biológica baseado em peixes para áreas úmidas Vieira, Michela Regina Scherer Wetlands are ecosystems of great ecological, economic and cultural importance. Currently there are less than half of the ones that existed a century ago. This loss is caused by human activities, such as agricultural expansion and increasing urbanization. Moreover, these factors are causing the high level of degradation of the remaining areas of these environments. Due to the presented problem it is necessary to manage the wetlands, to detects of environmental impacts and characterize biologically. The approach called biological monitoring is based on the response of organisms in relation to the environment in which they live. Fish were successfully used as environmental quality indicators and present numerous advantages as indicator organisms for environmental monitoring, as they occur in almost all aquatic environments. They are relatively easy to identify and sensitive to environmental changes. The use of biological indicators to detect the degradation of wetlands, along with the continue use of this approach to assess the quality of the environment, led to the development of a Index of Biological Integrity (IBI) for wetlands that could be used to classify degradation level. This index was first developed Karr, in 1981, showing a multimetric procedure to monitor water resources using the ichthyic fauna. The inclusion of IBI in monitoring programs can be used to detect spatial and temporal trends of water quality, being an effective tool in the conservation and management programs for aquatic ecosystems also in Brazil. In this sense, the specific objectives of the study are to verify the richness, abundance and diversity of fish in wetlands of Rio dos Sinos basin that suffer different human pressures, classify the land use in the vicinity of sampling areas, check the potential of fish community as biomonitoring tool of water quality in wetlands, evaluate the influence of the rural and urban areas on wetlands, identify qualitative and quantitative metrics based on the fish community to aggregate information available about different aspects of wetlands and finally develop na index of biological integrity.

Composição e estrutura da acarofauna (acari: mesostigmata; trombidiformes; endeostigmata) em ambientes edáficos na Mata Atlântica no sul do Brasil

Thu, 25 Feb 2016 00:00:00 GMT

Composição e estrutura da acarofauna (acari: mesostigmata; trombidiformes; endeostigmata) em ambientes edáficos na Mata Atlântica no sul do Brasil Rocha, Matheus dos Santos The aim of this study was to understand the composition and diversity of soil mite fauna related to the Atlantic Forest biome in Rio Grande do Sul, in two different forest types: Atlantic Araucaria forest (AAF) and Atlantic rainforest (ARF). Species richness, abundance and similarity of the soil mite fauna were compared, assessing whether spatial factor (dispersion limit), as well as biotic and abiotic environmental factors influence the community of edaphic mites in Southern Atlantic Forest. For each forest type, were chosen ten sampling sites. To assess the diversity of soil mite fauna in each sampling point, six sub-samples were collected for both the soil microenvironment as to litter microenvironment thereby guarantee adequate sampling effort within each sample point to estimate the diversity and composition mite species. To determine the influence of stochastic processes (dispersion limit) and deterministic (abiotic and biotic factors) in the community of edaphic mites we create two matrices, the first including the geographical distance. The distance between sampling sites was used as a predictor to study the role of dispersion limits in the formation of community. To estimate the potential of deterministic processes which can structure the community of mites, we create another matrix with the abiotic and biotic factors, including the particle size, moisture organic matter of soil , density structure of vegetation, depth and percentage of leaves, branches and fine root of litter and oribatid density were measured. In total have been collected 3081 mites, being 2091 adults and identified in 130 species / morphospecies with 25 singletons and 15 doubletons. The genus Pyrosejus, Polyaspis, Clausiadinychus, Multidendrolaelaps, Athiasella, Veigaia, Holostaspella, Gaeolaelaps, Gymnolaelaps, Labidostoma, Rhagidia, Stereotydeus, Laminochaelia are registered for the first time for the Rio Grande do Sul State and the species Neocunaxoides promatae Rocha, Rodrigues and Ferla, 2015, Bonzia flechtmanni Rocha, Rodrigues and Ferla, 2015 and Dactyloscirus multiscutus Rocha, Rodrigues and Ferla, 2015 were described and illustrated in this study. Total abundance, abundance of adult mites and species richness showed higher values in ARF, which totaled 111 species, while in AAF was observed 90 species. When microenvironments were compared separately, it found that the litter had a higher abundance and species richness. The oribatid density had a significant influence on the abundance and richness of mite fauna. The composition between forest types did not differ, however, it was observed that the mite communities in the closest sampling sites, regardless of forest type were more similar to each other than those far away. The depth of the litter, the particle size, percentage of organic matter in the soil and oribatid density were evaluated factors that have contributed substantially to the variation of the mite fauna community. These results provide strong evidence of the limits of dispersion and biotic and abiotic factors are important drives to the edaphic mite compostion in the Atlantic Forest in southern Brazil. Thus, we can conclude with this study that these environments require urgent attentionbeing priority areas for the conservation of biological diversity, because of its importance to adjacent ecosystems.

Diversidade e composição de aves em áreas remanescentes de floresta ombrófila mista e em plantações de Araucaria angustifolia e de Pinus sp. no sul do Brasil

Fri, 14 Aug 2015 00:00:00 GMT

Diversidade e composição de aves em áreas remanescentes de floresta ombrófila mista e em plantações de Araucaria angustifolia e de Pinus sp. no sul do Brasil Rossi, Liana Chesini Araucaria forests are part of the Atlantic forest’s biome and are distributed over the southern regions of Brazil. Originally occupied an area of 25,379,316 hectares, which today remain least 12.6% of its original formation distributed in small and isolated fragments, where most no more than 50 ha. Initially, the loss of vegetal covering occurred due to extraction and wood logging and later due to agriculture, livestock and forestry. Selective logging and forestry were specially explored in the south of Brazil resulting in the substitution, fragmentation and isolation of natural areas, resulting in a reduction and loss of diversity of birds. Thus, this work aims to characterize the forest interior bird community of Araucaria forest with selective logging and areas of forestry activity with exotic species (Pinus sp.) and native species (Araucaria angustifolia). The aim of the first chapter was to test whether selective logging can cause changes in the richness and species composition in the bird community. Using the methodology of point-counts with fixed radius, they were sampled richness and abundance of species. To this, avifauna surveys were conducted within three protected areas characterized by Mixed Rain Forest: Três Barras National Forest (selective logging more than 40 years) Irati National Forest (primary forest, without selective logging) and Pizzatto Forest Reserve (recent selective logging). Using an exploratory technique called ‘‘Rank Occupancy–Abundance Profiles (ROAPs),’’ it was determined the sensitivity of each species. As species richness, did not differ significantly between protected areas (F1,33 = 1.805, p = 0.180), but the species composition was different (F = 5, 286, p <0.0001). About the degree of sensitivity, FI presented a higher number of species classified as sensitive 65% (n = 61), followed by RFP in 60% (n = 58) and FTB, 53% (n = 45) sensitive species. Through cluster analysis, which considered the sensitivity and the habitat of the species, demonstrated a greater similarity between the FI and the RFP when compared to FTB, which presented different composition compared the two other areas. Thus, different selective logging intensities resulted in compositions of different species between protected areas. This may have occurred because of forest degradation caused by selective logging by modifying natural habitats, continuing in open areas and increasing the size of the edges, allowing the occupation of species able to survive in this environment, thus increasing species richness. The areas studied, even with selective logging are able to maintain a high number of sensitive species, and endangered species, therefore, are important areas for conservation should be preserved. To answer the second objective, the same methodology was applied at the interior of three vegetal formations: Atlantic forest with selective logging, plantation of a native species Araucaria angustifolia and plantation of an exotic species Pinus sp., all of them located at the Três Barras National Forest. No significant differences were recorded in wealth among the three forest types (F2,33 = 3,05, p = 0,6), however, the composition of species was different (F = 4,814, p <0,0001). Insectivores and forest dependent species were more frequent in the native forest with selective logging, and granivores and generalist species showed a closer relationship with the planting of exotic species. The difference of species composition between areas is explained by higher habitat heterogeneity in native forests, which increase resource availability, while plantation areas tend to be more homogeneous and resource-poor. The similarity of species richness between native forest and plantations may occur due to damages caused by selective logging at native forests, which results in a small number of recorded species. Furthermore, management techniques and the advanced age of plantations develop different strata in plantations increasing resource availability and therefore bird richness. Thus, it is concluded that plantations, mainly of native tree species, are able to include an birds associated with native forests, however, natural forest areas are irreplaceable because they contain a bird life with more specialists habits should be preserved.

Dendroecologia de Nectandra megapotamica (Spreng.) Mez. (Lauraceae) em florestas subtropicais de altitude: efeitos climáticos e de distúrbios no crescimento

Tue, 24 Jun 2014 00:00:00 GMT

Dendroecologia de Nectandra megapotamica (Spreng.) Mez. (Lauraceae) em florestas subtropicais de altitude: efeitos climáticos e de distúrbios no crescimento Cavalli, Jonas Dendroecology is the branch of science that studies growth rings. These represent the annual diametric increment of plants and provide valuable information about the dynamics of population development and the relationship and response of their growth with surrounding environmental factors, such as climate and environmental disturbances. A science created and well established in temperate regions, it still needs to identify potential species for studies of this nature in tropical and subtropical zones. In these regions, the Lauraceae family presents itself as one of the most rich species, extremely important in the formation of forest communities, with many good species forming growth rings. This is the case of Nectandra megapotamica, a generally evergreen tree species, with a wide and plastic distribution in the subtropical zones of South America, from the Andes to the Atlantic coast, from dry to waterlogged areas, and which does not have careful dendrochronological studies. In order to expand this knowledge, this dissertation investigated in an altitude Atlantic forest, whether the well-demarcated growth layers of this species are in fact annual, whether they present correlations with climate over time, and whether a sudden release of competition for resources, due to selective cutting of araucarias from the upper stratum of the forest, has an influence on the secondary growth of the plant. N. megapotamica is abundant in subtropical forest formations, and may be promising for dendroecological studies.

Estrutura de comunidades de turbelários em áreas úmidas da planície Costeira do Sul do Brasil, com revisão da diversidade de microturbelários no país

Thu, 26 Feb 2015 00:00:00 GMT

Estrutura de comunidades de turbelários em áreas úmidas da planície Costeira do Sul do Brasil, com revisão da diversidade de microturbelários no país Braccini, João Alberto Leão Microturbellarians are abundant in freshwater and marine ecosystems and may occur in moist terrestrial habitats. However, they are seldom taken into account in studies of biodiversity. Most studies on Brazilian microturbellarians had taxonomical purposes and were done in the years 1940-1950. Thus, information on their occurrence and ecological aspects are dispersed throughout several papers. They are generally benthic, found in diverse environments, such as macrophyte beds, among filamentous algae, directly in substratum, among others. The main goals of this dissertation are (1) to summarize the geographical distribution and ecological aspects of microturbellarians recorded for Brazil, indicating the main gaps in their knowledge and possible actions to enhance studies on this group and (2) to analyze the community structure of turbellarians in different classes of palustrine permanent wetlands in Coastal Plain of Southern Brazil. To reach the first goal we made an extensive literature review of all works with microturbellarian in Brazil. To analyse the community structure, we sampled 25 water bodies, with one sample in each wetland, from October 2013 to February 2014, in the middle coast of Rio Grande do Sul. There are 240 species of microturbellarians registered for Brazil, with records distributed in 12 states. However, just three states located in south Brazil have records of 94% of microturbellarian species. A total of 1257 specimens of turbellarians was collected, representing 62 species and 23 genera, from the orders Catenulida, Lecithoepitheliata, Macrostomida, Rhabdocoela and Tricladida in the middle coastal plain of Rio Grande do Sul. Significant differences were found in abundance and richness in relation to vegetal composition (p<0.05), multi-stratified and floating-leaves wetlands had higher abundance than others and multi-stratified and emergent wetlands had higher richness than others, wetlands without vegetation had lower abundance and richness of this study (p<0.001). The community structure of turbellarians were different among wetlands, being influenced by temperature (p<0.05) and dissolved oxygen (p=0.007) were significantly related to ordenation. From the results of this study, it can be seen that the turbellarian assemblage are strongly related to the habitat heterogeneity. Turbellarians need various environments for their occurrence, thus the conservation of all ecosystems is necessary. Knowledge on the systematics and geographical distribution of Brazilian microturbellarians clearly reflect the scientific activity over many years or decades in two states of southeast and southern Brazil. Considering the scant information on this group in Brazil, which is also the situation of the Neotropical microturbellarians in general, some actions should be proposed. First, it would be necessary to sample in the diverse biomes, as well as in the various river and sea basins, based on standardized sampling protocols. Second, it would be necessary to encourage diverse research groups to include microturbellarians and/or turbellarians in general in biodiversity inventories and studies on community structure of invertebrates. Third, it is necessary to increase the number of research groups on microturbellarians, in order to augment the studies on their morphology, systematic, and ecology.

Anéis de crescimento em espécies da família Lauraceae: características anatômicas e sinais dendroclimáticos

Thu, 26 Mar 2015 00:00:00 GMT

Anéis de crescimento em espécies da família Lauraceae: características anatômicas e sinais dendroclimáticos Ávila, Gabriela de Fátima dos Reis Tree-rings are anatomical structures formed in the secondary xylem of wood plants. These structures delimit the growth cycles and dormancy as response to seasonal climate regimes. Since each ring correspond to one annual growth cycle varying their features as result of physical and biotic conditions, these structures are unique historical records with high resolution and temporal depth reflecting environmental changes. The dendrochronology – science that investigates tree-rings in wood plants – is incipient in tropical ecosystems, taking into account its advancement in temperate zones, and should be developed in tropical zones to provide clearer information about autoecology, forest ecology and climatology, base to tropical biodiversity management. To recognize species forming visible tree-rings in their xylems and that are sensible to climatic fluctuations is the first and prime step to development of dendrochronology. In this Master Dissertation I revise and perform dendrochronological analysis in the neotropical Lauraceae family, mainly in remaining forests of Southern rain forest of Brazil, a hotspot of biodiversity. I focus my efforts in Lauraceae family due to ecological and physiognomic importance of their species to neotropical rain forests. Information about tree-rings are widely available in the scientific literature, especially in the anatomical wood researches. Most species of Lauraceae family form tree-rings in different ecosystems (139 of 156 revised species). In order to facilitate future studies and the recognition of tree-rings I present 156 species described by tree-ring appearance plus 14 other frequent species in Southern rain forest. With temporal series of tree-ring width I verify that Ocotea pulchella, Cinnamomum glaziovii and Ocotea elegans, species from subtropical montane regions of Brazil, have the same growth tendency between individuals (synchronism). Moreover, are sensible to climate variations mainly related to temperature and precipitation. The findings of this dissertation are essential to contribute to development of neotropical dendrochronology, providing a better understanding about tree-rings features of one of the most important families in the tropical regions.

Ecologia populacional e reprodutiva de Pygoscelis antarcticus e Eudyptes chrysolophus em Stinker Point - Ilha Elefante

Tue, 25 Nov 2014 00:00:00 GMT

Ecologia populacional e reprodutiva de Pygoscelis antarcticus e Eudyptes chrysolophus em Stinker Point - Ilha Elefante Werle, Gabriela Bandasz Elephant Island differentiated by being the northernmost island of the South Shetlands archipelago and by having different climatic characteristics (O'Brien, 1974). Present ice-free areas, serve as a breeding site for various bird species. And regarding the avifauna present at the site, there are 14 breeding species: Pygoscelis papua, Pygoscelis adeliae, Pygoscelis antarcticus, Eudyptes chrysolophus, Aptenodytes patagonicus, Macronectes giganteus, Daption capense, Oceanites oceanicus, Fregetactata albacta, Chitta cana, Phalacan 1994). The species Pygoscelis antarcticus (Figure 1) or Antarctic penguin, as it is popularly known, belongs to the order Sphenisciformes and the family Spheniscidae, has a medium height (71-76 cm), with black coloration on the posterior part of the body and white on the anterior part. , near the chin has a black line, characteristic of this species and has a black beak (Willians, 1995). This penguin species has a circumpolar distribution, being found in Antarctica, the South Sandwich Islands, Orkneys Islands, South Shetlands, South Georgia, Bouvet and Balleny (BirdLife International 2012). However, in terms of breeding areas, this species breeds almost exclusively in the islands of Scotland and the Antarctic Peninsula south of the 65C parallel (Stonehouse, 1975; Kooyman, 2002). , Euphasia superba, but also feeds on fish, cephalopods and other crustaceans.

A importância das fontes autotróficas campestres na teia trófica de passeriformes do interior de fragmentos florestais

Sat, 11 Jun 2016 00:00:00 GMT

A importância das fontes autotróficas campestres na teia trófica de passeriformes do interior de fragmentos florestais Bertin, Edna Lais Tropical forests are among the most important terrestrial habitats in terms of the concentration of biological diversity in the world (Ayres et al., 2005). These forests are home to more than 60% of all species already described, even though their extent is restricted to about 7% of the planet's area (Ewers et al. 2008; Gardner et al. 2009). Throughout its distribution, some of the largest formations of tropical forests are found in South America. Among them, the Atlantic Forest, the second largest tropical rainforest in extension in all of the Americas, stands out, second only to the Amazon Forest. Originally it covered more than 1.5 million km², covering northeastern Argentina, eastern Paraguay and Brazil. It is worth noting that Brazil alone is home to 92% of the entire area of this Biome (Fundação SOS Mata Atlântica, 2011; Tabarelli et al., 2005), constituting an important region for its maintenance. Like most tropical forest formations, the Atlantic Forest has been suffering for centuries an intense process of area loss and fragmentation (Myers et al., 2000). Its current area is estimated to represent only 11.4% to 16% of its original extension (Ribeiro et al., 2009).

Betadiversidade de anuros em uma planície de transição entre floresta e campo

Fri, 03 Mar 2017 00:00:00 GMT

Betadiversidade de anuros em uma planície de transição entre floresta e campo Knauth, Débora Schuck β-diversity is an important ecological standard that measures the variation in species composition between sites in a geographic region (LEGENDRE, 2008; BASELGA, 2010). This component consists of the difference in species composition of a community along an environmental gradient (WHITTAKER, 1972) or between habitats (MAGURRAN, 1988; JOST, 2007). The geographic distance and variations in the environmental characteristics of the areas are determining factors for β-diversity (BUCKLEY and JETZ, 2007; BITAR et al., 2014). Environmental heterogeneity exerts a positive force on β-diversity, as it increases the variety of environmental conditions to which different species are adapted, consequently resulting in greater variation in species composition between locations in a region (HEINO et al. , 2015). Greater variation in species composition between localities can lead to greater species richness in the region (i.e. gamma diversity) (SRIVASTAVA, 1999; QIAN and SONG, 2013). Thus, β-diversity influences species diversity at large scales that are important for conservation.

Bioprospecção de agentes de controle biológico de Pomacea canaliculata (LAMARCK, 1804)

Mon, 06 Mar 2017 00:00:00 GMT

Bioprospecção de agentes de controle biológico de Pomacea canaliculata (LAMARCK, 1804) Silva, Daniela da Costa e Rice is among the most consumed cereals in the world, and Brazil is among the 10 largest producers in the world, accounting for the production of 12.432 million tons in 2015. The Rio Grande do Sul crop is essential for the productive growth of rice, being currently the largest producer, responsible for 68% of national production (MAPA, 2016). There are several factors that affect the production of irrigated rice, and it is estimated that the loss due to agricultural pests can reach 80%, depending on the cultivation and management of the crop (PATERNIANI, 2001). The fact that the flooding system creates immense water mirrors in floodplain areas, combined with favorable climate and crop management conditions, provides favorable conditions for the creation of many living associated organisms, including various pests (PICANÇO et al., 1999).

A presença de peixes anuais influencia o banco de propágulos dormentes de invertebrados aquáticos em áreas úmidas intermitentes?

Tue, 21 Feb 2017 00:00:00 GMT

A presença de peixes anuais influencia o banco de propágulos dormentes de invertebrados aquáticos em áreas úmidas intermitentes? Vendramin, Daiane Wetlands play an important role due to its ecosystem services. The dry soils from intermittent wetlands accumulate a variety of dormant structures that adopt survival strategies against adverse environmental conditions. These strategies ensure the survival of the dormant propagule bank at the beginning of the hydrological cycle, allowing this bank to act as food source for late colonizers, which support the establishment of important trophic relationships, such as predation. The effects of predation are diverse and may both diminish or elevate the diversity of the local zooplankton community. Thus, the general objective of this work was to evaluate the influence of the presence of annual predatory fish over the structure and emergence of the dormant propagule bank of aquatic invertebrates in intermittent wetlands. Therefore, it was selected 8 wetlands from the surroundings of the Lagoa do Peixe National Park, four of them with the presence of annual fishes. The dry sediment of each wetland was sieved and homogenized in order to perform two different procedures. In the first one, a sub-sample of each wetland was floated and, in the second step, a sub-sample was incubated and parameters as photoperiod, temperature and oxygen were controlled for 36 days. The results reject the two hypotheses of this work, in other words, the density of dormant stages was similar between the areas (U = 10, df = 1, p = 0.564) and there was no variation in body size of aquatic invertebrates in areas under predation pressure from annual fish (x2 = 0.555, df = 3). The species richness (F1.6 = 0.040, p = 0.849), abundance (F1.6 = 0.692, p = 0.437) and composition (r2 = 0.069, p = 0.827) was similar among wetlands. However, there was difference in the temporal increase of abundance among taxa, as well as certain species are more related to certain areas. These results should be interpreted taking into account that the eclosion of efipial eggs in controlled experiment conditions eliminates others relevant factors that occurs in natural environments, such as abiotic factors related to luminosity, temperature and salinity, as well as several biotic interactions. Then, the study with dormant propagule banks offers information about the aquatic invertebrate community, but there is still a lack of effort in order to increase the understanding of their responses to different environmental conditions.

Padrão espacial e temporal no investimento reprodutivo em aranhas doadoras de presentes nupciais do gênero Paratrechalea Carico, 2005 (Araneae, Trechaleidae)

Thu, 30 Jul 2015 00:00:00 GMT

Padrão espacial e temporal no investimento reprodutivo em aranhas doadoras de presentes nupciais do gênero Paratrechalea Carico, 2005 (Araneae, Trechaleidae) Spindler, Claudia Sabrina The reproductive success of an individual is optimized following trade-off constraints among its life-history components, where the decision to invest into reproduction or maintenance is influenced by selective pressures that defines the direction and intensity of sexual selection. Nuptial feeding represents a reproductive investment by the males, and the fate of an edible item in terms of consumption (physiological maintenance), or reproduction are defined by ecological factor and by the animals’ physiological condition. The main goal of this dissertation was to investigate how such decisions varies along the reproductive season of a population. Based on a field sample procedure, I investigated how males from two spider species from the Paratrechalea Carico, 2005 genus adjust their investments in nuptial feeding along their reproductive season, observing the consequences of such investment in terms of males’ habitat dispersion in relation to other adult categories, and in terms of the occurrence of alternative strategies regarding the nuptial feeding quality. There is a spatial segregation defined by the amount of reproductive investment for both males and females, where males during mate search and females during maternal care shared the same areas. I interpreted this pattern as an adaptive reaction by the non-receptive females in order to gain an extra source of energy, leading to energetic and reproductive costs for the males by wasting their nuptial gifts in a non-sexual interaction. Regarding the nuptial feeding investment along the reproductive season, the probability of occurrence of a high quality nuptial gift (nutritive gifts) showed strong fluctuations along the season, but such changes were not related to an expected pattern of terminal investment. However, the investment rules regarding low quality nuptial gifts (token gifts) were constant over time, corroborating the hypothesis that deceptive gifts constitutes an alternative strategy for those species.

Influência de colônias reprodutivas de aves marinhas sobre populações vegetais nas ilhas Shetlands do Sul, Antártica, sob uma abordagem molecular

Thu, 03 Mar 2016 00:00:00 GMT

Influência de colônias reprodutivas de aves marinhas sobre populações vegetais nas ilhas Shetlands do Sul, Antártica, sob uma abordagem molecular Pereira, Clarissa Kappel Antarctica is the southernmost continent of the globe, and is also the coldest one, whith 96% of its territory permanently ice-covered. Despite the lowest temperatures, high altitudes and the strongest winds, it is home to a large biodiversity. Antarctic seabirds are abundant and takes up much of the coast during the breeding season, which occurs in the austral summer period, from October to March, ice-free period in the maritime Antarctic. Macronectes giganteus, popularly known as South Giant Petrel, is one of the species that occupy these ice-free areas for reproduction, in addition to penguins, skuas, gulls and petrels. The breeding areas of seabirds are often associated with plant communities and populations, among them algae, lichens, mosses and flowering plants. The mosses Sanionia uncinata (Hedw.) Loeske and Andreaea regularis C. Muell., are present as vast green formations, joined by other species as the only two native species of flowering plant in the region - Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl. The D. antarctica is a very common hairgrass in the Antarctic environment, and is associated with breeding colonies of seabirds. These sites are large deposits of guano, because seabirds return systematically each year, forming large breeding colonies with tens, hundreds or even thousands of individuals. Due to this large supply of guano, the soil becomes a deposit of minerals, mainly of nitrogen, increasing tremendously the soil contents of ammonium and nitrate. The problem is that not all vegetation support such high quantities of these substances, so different plant species show trends in the mechanisms of tolerance to stress by ammonium, which have been proven at the molecular level. In recent years, genetic regulators sensitive to NH4+ were identified in Arabidopsis thaliana and genes that were associated with sensitiveness to ammonia all showed responses at the root level, referencing the absorption and ammonia concentration by the root system of the plants. The aim of this study was to investigate and to analyze the influence of breeding colonies of seabirds on plant populations in the South Shetland Islands, Antarctica, from a molecular perspective. From the analysis of the collected samples using the RNA-seq and qRT-PCR approach, it was possible to identify a single differential gene, which was significantly expressed in D. antarctica. The LOC_Os06g16380 gene among the sampled treatments (control, 1m and 10m), showed higher expression coming 1m near breeding areas of M. giganteus. The gene differentially expressed in this work has been described in literature and was related to Heading date I gene (Hd1) found in rice, since they are located in the same region of the transcriptome. Our results suggest that LOC_Os06g16380 gene is associated with the plants ability to tolerate high amounts of ammonium, as soil analysis demonstrated larger contents of ammonium in the nearest sampling sites (1m) of breeding areas of seabirds.

Índice multimétrico de qualidade de água de áreas úmidas baseado em populações de macrófitas aquáticas

Fri, 29 Jul 2016 00:00:00 GMT

Índice multimétrico de qualidade de água de áreas úmidas baseado em populações de macrófitas aquáticas Decarli, Cecilia Biomonitoring is defined as the use of organisms’ answer to evaluate ecosystems modifications. In aquatic ecosystems, this is an important technique to detect pollution and impacts, with low costs. Aquatic ecosystems undergo many kinds of perturbation and it is necessary to quantify them in order to establish conservation programs for these areas. Biotic indexes show the integrity of aquatic ecosystems through the aquatic organisms, in his study the organisms used as models were the aquatic macrophytes. Therefore, the study aims at: 1. To identify the environmental impact level of the wetlands through water physicochemical analysis, land use alteration, habitat degradation and hydrological changes; 2. To compare composition and richness of aquatic macrophytes between reference and impacted wetlands. To identify potential metrics (general aspects of community, functional traits, diversity, dominance, specific species defined by abundance and richness) based on aquatic macrophytes community. 4. To select metrics which give better answers to the water quality gradient of variation in wetlands with different levels of anthropic impact and, 5. To develop a multimetric index of water quality, based on aquatic macrophytes community. A total of 10 wetlands were selected in the low patch of Rio dos Sinos’ River Basin, the selected areas were distributed in different levels of water quality. The aquatic macrophytes were collected in March and November of 2015. Fifty nine species of aquatic macrophytes were identified, totalizing 20 botanical families. Initially, the index was composed by 45 metrics and finished with fivemetrics of: abundance, composition, specific species and richness. The information generated through this study are important to create management and conservation proposals to preserve the southern Brazilian wetlands.

Variação sazonal e preditores ambientais do balanço oxidativo em um peixe anual neotropical

Fri, 22 Feb 2019 00:00:00 GMT

Variação sazonal e preditores ambientais do balanço oxidativo em um peixe anual neotropical Godoy, Robson Souza Oxidative stress occurs when there is an imbalance between pro-oxidants and antioxidants in favor of the pro-oxidants, leading to a rupture of signaling and oxidative balance and/or molecular damage. Oxidative stress has been related to trade-offs between the characteristics of the life history and self-maintenance. Trade-offs are characterized by conflicts between the allocation of energy in one characteristic over another. Organisms that present rapid growth and large investments in reproduction exhibit higher production of oxygen-reative species (ROS) and oxidative stress related to declines in the activity of antioxidant enzymes. Oxidative stress can be influenced by environmental conditions. Annual fish exhibit life history characteristics related to increased ROS production, such as rapid growth, intense reproductive process and accelerated aging, and inhabit temporary pools with large environmental variations. Thus, the objective of this work was to evaluate oxidative balance markers (superoxide dismutase, catalase, glutathione S-transferase, lipoperoxidation and total proteins) throughout the life cycle of the neotropical annual fish species Austrolebias minuano, collected in a natural environment. Our results showed that the species presents an efficient antioxidant system during most of its life cycle, mainly in the reproductive phase in the females and in the senile period of life in males. Increased lipoperoxidation was evidenced only in females in the period corresponding to the growth phase. Males showed reduction in all analyzed markers, except in proteins, throughout life. The expected trade-offs between life and self-maintenance characteristics were exclusive between growth and automanutanation in females. In addition, we showed that the environmental variables influence the variation of the biomarkers analyzed during the life cycle of the species. These results suggest that the annual fishes present a well developed oxidative balance system adapted to face the unpredictability of temporary pools.

Diversidade florística de campos rupestres em inselbergs areníticos nos campos sulinos

Fri, 31 May 2019 00:00:00 GMT

Diversidade florística de campos rupestres em inselbergs areníticos nos campos sulinos Juliano, Ana Maria Grasslands occur extensively in South America in subtropical and temperate latitudes, respectively, in the Patagonic and Pampean biogeographic provinces. In Rio Grande do Sul, grasslands consist of a dominant phyto-physiognomy, covering 63% of the State's surface and in Brazil representing 2.07% of the national territory. The present study gathers data collected in four sandstone inselbergs of the metropolitan region of Porto Alegre, within a dense urban matrix. The floristic survey resulted in 210 native species of vascular flora. Differences in the composition and abundance of species among the inselbers suggest the existence of environmental and historical factors in the spatial distribution of species in the vegetation islands. Given the low floristic similarity among the sites and the expanding urban matrix, attention must be paid to protect these inselbergs in order to conserve the regional biodiversity.

Predição de bandas espectrais e classificação de imagens de satélite para identificação e mapeamento de áreas úmidas: um estudo de caso na Bacia Hidrográfica do Rio dos Sinos

Thu, 19 Aug 2021 00:00:00 GMT

Predição de bandas espectrais e classificação de imagens de satélite para identificação e mapeamento de áreas úmidas: um estudo de caso na Bacia Hidrográfica do Rio dos Sinos Ruppenthal, Ana Caroline Wetlands are ecosystems that have high biodiversity and productivity, in addition to promoting multiple ecosystem services of global importance. In Rio Grande do Sul, wetlands are known by the local term “banhados”. These ecosystems, although widely recognized, are still neglected and degraded. The Rio dos Sinos Hydrographic Basin (BHRS) has been suffering constant anthropogenic pressures that result in the degradation of wetlands, mainly due to the population increase that demands habitable areas. In this context, the need to develop conservation strategies for wetlands in the hydrographic basin is extremely urgent. As they are complex ecosystems due to their hydrology, soil, vegetation and spectral characteristics, Remote Sensing (SR) is an efficient tool in the identification and mapping of wetlands, generating subsidies for the public authorities to create protection and inspection strategies. Thus, this dissertation aimed to i) delimit the remaining wetlands of the BHRS using centimetric images GeoEye-1 and free GIS; ii) measure wetlands using an Unmanned Aerial Vehicle (UAV); iii) to propose a method to predict spectral bands from a centimeter-resolution RGB image by means of Artificial Neural Network (ANN), in order to generate an image with high spatial resolution and higher spectral resolution for subsequent classification of wetlands; and iv) prepare a guide for identifying BHRS wetlands, presenting a method for measuring wetland indicators in the field. The results showed that the use of centimetric images increases the accuracy of wetland mapping, with a total area of 93.11km² being mapped. The prediction of spectral bands using ANN was able to generate an image with spatial (2m) and spectral resolution (RGB+NIR+RE 1,2,3,4 + SWIR 1 and 2). The predicted image generated a better delimitation of wetlands when compared to the raw image (RGB+NIR). Finally, the Wetlands Identification Guide provided a scientific and technical basis for identifying wetlands in the field. It was concluded that the results of this work will serve as a subsidy to complement the environmental planning of the BHRS and the conservation of the remaining wetlands.

Uso de habitat e migração norte do Calidris canutus rufa (maçarico-de-papo-vermelho) do extremo sul do Brasil ao Canadá

Tue, 30 Mar 2021 00:00:00 GMT

Uso de habitat e migração norte do Calidris canutus rufa (maçarico-de-papo-vermelho) do extremo sul do Brasil ao Canadá Brum, Antônio Coimbra de During migration to breeding or wintering areas, Calidris canutus rufa stops for days or weeks in stopovers that it selects along its routes. Among them is the middle coast, in the extreme south of Brazil, where the Lagoa do Peixe National Park is also located. This place is characterized by having coastal ponds, wetland areas, extensive areas of dunes, stream channels and wide sandy beaches, an ideal environment for shorebirds. Here the results of two studies with this subspecies are presented. The monitoring of five individuals, started in April 2019, using PinPoint GPS Argos 75, from Lagoa do Peixe, with the aim of investigating migration routes and differences in migration strategies. The second, through censuses of flocks of Red Knots, between the years 2019 and 2020, with the objective of analyzing the habitat use during the migratory processes and if variables related to the environment would justify the pattern of the presence of birds in the habitat. In the first work, differences were found in routes, distances traveled, travel time, migration speed, stop times and connectivity. The birds migrated along the route of Central Brazil and the Atlantic Route. One of them performed a direct flight of 8,300 km, from Lagoa do Peixe to Delaware Bay - USA. Another stopped in Maranhão and a third accessed an unknown environment for the species, Baía Santa Rosa – Mouth of Amazonas River, Brazil. The fourth had a record on the Atlantic coast of Suriname. The migration speed ranged from 53 km / day to 1,230 km / day. Birds with better body condition covered greater distance in less time, above 900 km / day. This work highlights the existence of variation in migration strategies within the same population and demonstrates the importance of the connectivity of fundamental environments for the viability of the subspecies. In the second study, differences were found between the size and distance of the flocks. In the northward migration, the flocks are larger and maintain a greater distance between themselves. During the northward migration, the formation of two clusters with different environmental preferences was detected. A group at the southern end seems to be influenced by the size of the area of the ponds and wetlands and the flocks grouped at the northern end at the distance of ponds, wetlands and drainages channels were important to explain their presence. During the southward migration four clusters were identified, however the flocks were distributed more evenly throughout the area, and the most important variables for the flock groups were distance from the ponds and urban areas. The distance between the bands also played a complementary role. The variables distance from ponds, pond area, distance from drainages and urban areas were the variables that seem to better respond to the pattern of ordering the presence of flocks in the habitat. The distribution of the flocks is structured in areas that have a high similarity of the studied variables, denoting the influence of the environment in the places where the birds are present differently when migrating to their breeding or wintering areas. Habitat use studies are essential to identify preferred environments for the purple-breasted curlew that must be protected.

Padrão temporal e a influência das condições climáticas e ambientais nas fatalidades de quirópteros em um complexo eólico no sul do Brasil

Thu, 28 Feb 2019 00:00:00 GMT

Padrão temporal e a influência das condições climáticas e ambientais nas fatalidades de quirópteros em um complexo eólico no sul do Brasil Amaral, Izidoro Sarmento do In Brazil, the energy demand created by economic development has rapidly and intensely transformed the natural landscape, not only with wind energy but also with other types of projects. These changes in an environment that has a mega diversity must be accompanied by studies that describe and can predict the effects of these changes on ecosystems, supporting efforts to reduce impacts and conserve the species. The relationship between bats and wind farms in Brazil is little known, and existing publications have been published in the last five years. In this context, in order to analyze the relationship between bat fatalities at the Santa Vitória do Palmar Wind Complex and their spatial and temporal patterns, between July 2014 and June 2018, monthly circular transects were carried out in search of carcasses in the around 129 wind towers. During the searches, the fatalities found were recorded along with the tower number, date and distance of each carcass found to the base of the tower. All carcasses found were identified at the lowest possible taxonomic level and were later removed to avoid recounts. Information on deaths was first analyzed in annual sets, using the Friedman test and then separated by seasons to understand the influence of different land use classes on the spatial pattern observed in fatalities. To investigate the relationship of activity indices with climate, acoustic monitoring of the bat community was used to generate generalized linear models (GLM) with Poisson distribution, using climate variables as predictor variables. The second order Akaike Information Criterion (AICc) and the coefficient of determination (R2) were used to rank and select the models, comparing models with all possible combinations of predictor variables. At the end of 48 months, 266 bat carcasses belonging to six species of insectivorous bats were recorded. The results showed the predominance of the species Tadarida brasiliensis among the observed fatalities, in addition to the first record of death of specimens of the genus Eptesicus in wind towers. The data also revealed that deaths occur exclusively between the months of October and May and that the wind towers closer to the urban center concentrated a greater number of deaths. The time series of bat deaths revealed a higher frequency of deaths in the first year (69% in 2014), followed by a reduction in the next two years and a small increase in the fourth year of monitoring. The models curiously revealed a positive relationship between activity and wind speed. According to the data obtained, the best possible scenarios for the installation of new parks would be places with a distance greater than 4 km from urbanized centers and with a predominance of fields. Thus, the most important mitigation proposal for bat deaths in the study region is the programming of the towers to stop on nights with certain weather conditions, which should be based on minimum criteria such as the ideal temperature range for the activity ( 15°C – 22°C) where 83% of the activity occurs and the seasonal distribution of deaths, applying the measures mainly in the most critical months, between December and March.

Ecologia espacial do Atobá-Mascarado Sula dactylatra (Lesson, 1831) na Ilha da Trindade, Oceano Atlântico Sul

Fri, 28 Feb 2020 00:00:00 GMT

Ecologia espacial do Atobá-Mascarado Sula dactylatra (Lesson, 1831) na Ilha da Trindade, Oceano Atlântico Sul Benemann, Victoria Renata Fontoura Modeling suitable hábitats for biodiversity maintenance under changing environments may serve as an important tool for biological conservation purposes. Trindade and Martim Vaz is an oceanic archipelago located ~1.200km from the coast of Brazil, and has been under ecological succession since feral goat eradication, which have devastated its original vegetation. We modeled nesting hábitat suitability of a surfacenesting seabird - the Masked Booby Sula dactylatra - at Trindade Is., predicted its current nesting distribution, and proposed the future potential distribution under four possible vegetation scenarios on the island. We mapped 87 active nests of S. dactylatra during the breeding seasons of 2017 and 2019, from October to November at Trindade Is. We fitted nest occurrence points in response to five topographical (Elevation, Slope, Insulation, Aspect and Flow Length) and two vegetation (Succession and Remnant) variables, using an Ensemble Species Distribution Model (ESDM) of seven different algorithms: Boosted Regression Trees – GBM, Random Forests – RF, Generalized Linear Models – GLM, Generalized Additive Model – GAM, Artificial Neural Network – ANN, Multiple Adaptive Regression Spline – MARS, and Maximum Entropy - Maxent. We evaluated model accuracy based on two metrics: ROC and AUC, and tested for multicollinearity between variables using VIF test. Analyses were performed using the “biomod2” package in software R 3.6.1. Our models showed accuracy above 0.8 in both used metrics (ROC and TSS). Our results indicate areas of very high nesting hábitat suitability along the Southwest and Northwest faces of Trindade Is., mostly in elevations varying from 150-450 m. Elevation and Aspect were the variables that better explained S. dactylatra selection for nesting hábitats. Based on our predictions of distribution in response to possible vegetation scenarios, we found that the ecological succession will not affect the nesting distribution of S. dactylatra on the island substantially. Since S. dactylatra select areas of high elevations near cliff edges to nest, it is deductible that the predicted increase in the vegetation coverage does not reach these high areas because of geomorphological characteristics, such as elevation, soil composition and depth. We encourage further studies to address topographical variables of the finest spatial resolution spatial resolution as possible, as well biotic variables in order to model present and future species’ distribution.

Ecologia espacial e trófica de uma população antártica de petrel-gigante-do-sul Macronectes giganteus (Gmelin, 1789)

Wed, 27 Mar 2019 00:00:00 GMT

Ecologia espacial e trófica de uma população antártica de petrel-gigante-do-sul Macronectes giganteus (Gmelin, 1789) Finger, Júlia Victória Grohmann The breeding season is a critical moment in the life history of a seabird. Due to the need of alternate between self-feeding foraging trips and trips to attend the nest, individuals suffer restrictions upon their foraging ranges and resource use. This restriction causes the increase in intraspecific competition. The Southern Giant Petrel (SGP) Macronectes giganteus is a top predator species of the Southern Ocean. It has generalists feeding habits and a marked sexual dimorphism in size. As a strategy to reduce competition, females and males usually show spatial and resource use segregation, which varies temporarily and in intensity according to degree of restriction in each breeding stage. Studies indicate that individuals from generalist species, such as the SGP, can minimize competition even more through the reduction of their niche breadth, becoming specialists at the individual level. In comparison to other regions where SGPs breed, the spatial and isotopic ecology of SGP breeding in the Antarctic region is poorly investigated, mainly due to logistical difficulties. Thus, the overall goal of this dissertation is to describe the trophic and spatial ecology of an Antarctic southern petrel population (Macronectes giganteus) throughout the breeding season. Remote tracking data of females and males breeding at Elephant Island, Maritime Antarctica were used to estimate foraging areas (FA, kernel UD) across the different stages of the breeding season (incubation, guard and chick-rearing); and also to quantify the degree of spatial overlap among sexes; Individual FAs were used to estimate consistency in space use. The ratios of stable isotopes δ13C and δ15N from different tissues (red blood cells and feathers) were analyzed to investigate temporal variations in habitat and resource use and on the degree of intersexual overlap in the isotopic niche and also to test the occurrence of individual consistency in these traits. Results showed that males and females were highly overlapped in space across the breeding season; both foraged in pelagic waters of the Antarctic and Subantarctic Zone. As expected, the greatest restriction in FAs was in guard, when the chick is still thermally dependent and requires constant feeding. The isotopic niche of males and females was also overlapped in most stages, but during chick-rearing. In this stage, breeding constraints loosen up, but food availability decreases. Niche positions varied among periods, especially in terms of used water masses. These reflect changes in foraging areas according to the feeding needs of adult and chick. Males usually fed on higher trophic levels than females, except during incubation. A high individual consistency among stages in large-scale space use was found. However, unlike expected, there was no individual specialization in resource and habitat use, due to a high within individual variation in both axes of the isotopic niche. This is the first study to analyze spatial distribution and trophic data of SGP in a matching temporal scale and to report the breeding distribution of SGP from Antarctica. The level of sexual segregation found in this study are consistent to patterns of Subantartic and Patagonian populations. The absence of individual consistency in the isotopic niche suggests the population of SGP from Elephant Island is a type A generalist, where all individuals are generalists. However, we suggest that within individual variation should be further investigated taking into account different stages of the annual cycle, breeding seasons of different years and variation in environmental conditions.

Uso de sedimentos de áreas úmidas naturais na emergência de invertebrados aquáticos em arrozais do sul do Brasil

Thu, 21 Feb 2019 00:00:00 GMT

Uso de sedimentos de áreas úmidas naturais na emergência de invertebrados aquáticos em arrozais do sul do Brasil Silva, Bruna Mallmann da Increased awareness of wetlands services and the extent of the loss and degradation of these habitats have resulted in greater efforts to protect and restore them. The ability to return to original states after disturbances makes the zooplankton community a useful tool for assessing restoration of degraded wetlands. The main objective of this study was to evaluate rice paddy recovery patterns by reestablishing the zooplankton community using natural wetland sediments in laboratory trials. Our hypotheses of study were: (1) the richness and abundance of invertebrates is lower in the rice fields than in the natural wetland; (2) the richness of invertebrates is greater as we increase natural wetland supplements; (3) the composition of invertebrates varies between different sediment supplements. To do this, the sediment sampling was carried out in eight wetlands in the Coastal Plain of southern Brazil. The experiment was divided into four treatments: rice paddy sediment, sediment from natural wetlands, 95% rice sediment and 5% sediment from natural areas and 70% rice sediment and 30% sediment from natural areas, corresponding percentages the weighing of dry sediment. A total of 4,493 individuals belonging to 24 taxa were found throughout the experiment. The hypotheses that the richness and abundance of invertebrates is lower in the rice paddies than in the natural wetlands and lower in sediments with fewer natural lagoon sediment supplements were rejected in our study, where treatments did not influence this variation. The hypothesis that the composition of invertebrates varies between different sediment supplements of natural wetlands in rice paddy sediments was corroborated in our study, since the composition differed mainly between rice paddy sediments and natural wetlands, and between sediments with more natural wetlands sediment in rice paddy sediment. These results indicate that natural wetland sediment supplements may be an important recovery strategy for man-abandoned crops. The results found in this study showed that there is recovery of species from the zooplankton community of dormant propagules when inserting sediments of natural moist areas in rice fields.

Análise dos remanescentes de Pinípedes (Carnivora - Otariidae) em sítios arqueológicos da planície costeira do Rio Grande do Sul, Brasil

Fri, 26 Oct 2018 00:00:00 GMT

Análise dos remanescentes de Pinípedes (Carnivora - Otariidae) em sítios arqueológicos da planície costeira do Rio Grande do Sul, Brasil Ferrasso, Suliano Pinnipeds are marine carnivores that emerged in the mid-Oligocene, around 65 million years ago. They occur in virtually every ocean in the world and have been interacting with human populations since prehistory in various regions of the globe. For the Brazilian coast eight species of pinnipeds have already been recorded, of which seven have been found on the coast of Rio Grande do Sul. Based on the analysis of bone remnants recovered at archaeological sites, it is suggested that the past records of pinnipeds on the coast of Brazil would be associated with Quaternary deposits. For the Rio Grande do Sul state coast there are few studies on osteology of pinnipeds, mostly diagnostic or sexual dimorphism studies base on skull samples of current species but there is very little information related to archaeological remnants of pinnipeds. In this context, it is still necessary the analyses of the species composition, abundance of individuals, occurrence and type of interaction of these species with prehistoric humans in the region. The present study was carried out in five archaeological sites on the north coast of Rio Grande do Sul (NCRS), between Xangri-la (29 ° 47'23.72 "S, 50 ° 02'1824" W) and Arroio do Sal 29 ° 27'0.27 "S, 49 ° 49'1.74" W), which were linked to the Sambaqui Tradition. The method of prospecting (excavation) was used in order to obatin several artificial horizontal levels, deepening vertically, forming successive artificial levels to assure the depth and origin of the faunistic remnants. The volume of material prospected at these five sites ranged from 0.30 m3 to ± 15.18 m3. In this study, six squares with faunal remnants of the five sites were selected for analysis, each differing in size and archaeological stratigraphic thickness. All the bone remains found in each square were collected in the excavated trenches and taken to the Archaeological Technical Reserve of the Instituto Anchietano de Pesquisas / Vale do Rio dos Sinos (IAP-UNISINOS). During the laboratory screening, only the remnants of pinnipeds were selected for this study, based on the comparison with skeletons of specimens of current species and the literature. As a result of taxonomic richness from the perspective of zooarchaeology, 159 remnants of pinnipeds were found as number of idenfied specimens (NISP) in the NCRS sites, totaling a minimum number of individuals (MNI) of 17. The RS-LN-19 site of Xangri-la presented the largest NISP, with 130 remnants only for the Otariidae Family, and with at least two identified species (Arctocephalus australis and Otaria flavescens). The analysis of the bone remnants of the genus Arctocephalus revealed the predominance of young individuals, and mainly adults of O. flavescens. This result in the past composition of the pinniped species found in the sambaquis in the RS coast suggests that they are the same that occur today, besides indicating that the ancient human populations already interacted with these animals. However, it is not ruled out that Antarctic and subantarctic antarctic have also occurred in the region in the past, since in some cases it was only possible to identify until the genus in the remnants analyzed. Finally, it is important to note that in 19.53% (n = 25) of the remaining bone remnants, anthropic manipulation marks were identified as cut (small oblique, transverse and subparallel incisions) and 5.46% (n = 7) blackened spots, possibly dut to burning. In this way, it is suggested that the ancient human populations of NCRS could use pinnipeds as an occasional food resource.

Influência da monocultura de eucalipto sobre a vegetação campestre em área de Pampa no sul do Brasil

Fri, 29 May 2009 00:00:00 GMT

Influência da monocultura de eucalipto sobre a vegetação campestre em área de Pampa no sul do Brasil Hübel, Ingo The establishment of monocultures of eucalyptus is criticized and regarded as responsible for soil degradation and significant biological changes. In Rio Grande do Sul, south Brazil, the conservation of grasslands is confined to areas of permanent preservation - APP's, defined by current legislation as the riparian vegetation extending 30 m from both sides of watercourses. This study investigates the possible changes induced by eucalyptus plantations on adjacent grassland APPs. The study was conducted in Formosa ranch, located in the municipality of São Gabriel, RS. Three areas with the interface between eucalyptus plantations and grassland APPs, and three other areas without eucalyptus plantations (control areas) were chosen for the study. A total of 120 1 m2 plots were randomized along linear transects established at 5 and 30 m from the edge of the APP both to the APP itself and towards the plantation interior (in areas with plantations) or towards grasslands outside APPs (in control areas). A grid of 10 by 10 cm was used to assess the cover-abundance of all vascular species present at each plot revealing a total of 145 plant species. The richness and diversity of species showed the same trend for areas with eucalyptus: inside plantations species richness was greater in the edge, while in the adjacent APP species richness did not present a clear distance gradient. Such a distinction between APPs and areas distant from APPs was not detected in control areas. In conjunction these results suggest a possible effect of the plantation upon the species richness of adjacent APPs. The composition and coverage-abundance varied significantly among the areas studied . Environmental factors such as soil humidity and compaction, and relief slope were important in determining the composition and abundance of species in APPs. This study shows that the maintenance of APPs do not suffice to preserve the integrity of grassland vegetation.

Riqueza e composição das comunidades de formigas em quatro formas de cultivo de erva-mate (Ilex Paraguariensis St. Hil., 1822) na Encosta Superior do Nordeste do Rio Grande do Sul

Wed, 31 May 2006 00:00:00 GMT

Riqueza e composição das comunidades de formigas em quatro formas de cultivo de erva-mate (Ilex Paraguariensis St. Hil., 1822) na Encosta Superior do Nordeste do Rio Grande do Sul Steffens, Luiz Eduardo In the Rio Grande do Sul State, the maté, Ilex paraguariensis St. Hil. (Aquifoliaceae), is one of the main native components of the mixed ombrophilous forest understory with social-economical and environmental value. The present study aimed at surveying and comparing the ant species richness and composition among four differently cultivated maté fields: native, intercropping system, monoculture and herbicide treated, determining the occurrence and the dominance patterns and the species status. In each fields, ten maté trees were randomly sampled during 12 months using beating tray with a sample effort of 20 beatings per tree. At the same time, 100 sweeps using the entomologic net sampled the vegetation between the maté trees per field. Of the 35 taxa collected, 27 occurred in the native fields, 26 in the herbicide treated fields, 19 in the monoculture and 18 taxa in the mixed culture fields. Fourteen (40.0 %) were common to all cultivation techniques, six (17.1 %) were exclusive to the native fields and four (11.4 %) in the herbicide treated fields. A single exclusive taxon (2.8 %) occurred in the areas of herbicide treatment, mixed culture and monoculture. The native field differed significantly (p=0.031) from the mixed one. The subfamily Myrmicinae was the most representative with 17 genera. The herbicide treated and the monoculture fields had the highest similarity (Sj=71.8 %). Most of the species status was categorized as accidental, dominant and as intermediate. The functional groups distribution presented great similarity among the four ant communities, suggesting that the cultivation form interferes more on the wealth of species than on the functional structure of the ants.

Filogeografia e diversidade genética dos cachalotes Physeter macrocephalus Linnaeus, 1758 no Atlântico Sul Ocidental

Mon, 21 Aug 2017 00:00:00 GMT

Filogeografia e diversidade genética dos cachalotes Physeter macrocephalus Linnaeus, 1758 no Atlântico Sul Ocidental Quevedo, Tainã Coelho Sperm whales, Physeter macrocephalus Linnaeus, 1758, are widely distributed throughout the world's oceans. However, males and females have marked differences in their distribution pattern. Worldwide studies on genetics, ecology and vocal behavior comparing populations suggested the existence of a strong matrilineal social structure with female high philopatry in tropical regions, and gene flow mediated by males. The populations of the southwestern Atlantic Ocean (SWA) are still considered the least known and studied. In order to identify possible management units of the species in the SWA, the present study presented the first analysis of the genetic diversity and the evaluation of the potential structuring of the sperm whale populations along the SWA, using sequences from the mitochondrial DNA control region (mtDNA) of 565 bp obtained from samples collected in the region. In addition, it was also aimed to establish the phylogeographic relationships among these SWA populations and those of the rest of the world. Fifty-eight sperm whales from three geographic areas on the Brazilian coast (northeast = 15, southeast = 3, south = 36) and one from the coast of Argentina (n = 4) were analyzed and compared with 1577 sequences from other oceans and available in GenBank (Atlantic = 362, Indian = 159 and Pacific = 1056). In addition, the sex of 39 specimens was molecularly determined in order find females outside of the northeastern coast of Brazil, which would confirm the existence of more than one sperm whale population in the SWA. The analysis of mtDNA sequences revealed the existence of four genetic groups and seven haplotypes in SWA. The haplotype (Hd) and nucleotide (π) diversities observed for the species as a whole in SWA were Hd = 0.6824 e π = 0.002296, respectively. The selective neutrality tests did not suggest significant changes in the effective population size or recent population expansion for the species in SWA. The results of the molecular analysis of variance (AMOVA) revealed that between 9.14% (ΦST) and 12.31% (FST) of the genetic diversity variation observed are due to differences between populations. However, this geographical differentiation was only significant between the populations of northeast and southeast-south Brazil, which had the highest fixation index between them (northeast and southeast-south Brazil: FST = 0.1089, ΦST = 0.1378; northeast Brazil and Argentina: FST = - 0.1076; ΦST = - 0.0512; southeast-south of Brazil and Argentina: FST=0.0742; ΦST=0.1206; P<0.00001). The population of northeastern Brazil had the lowest genetic diversity of the study (Hd = 0.5128 and π = 0.001796), when compared to the southeast-south populations (Hd = 0.6659 and π = 0.002482), and Argentina (Hd = 0.8333 and π = 0.002043). The southeast-south coast of Brazil presented three exclusive haplotypes in a total of seven, while the coast of Argentina presented a particular haplotype. Only the samples from the southeast-south region of Brazil presented an exclusive genetic group, suggesting that the distribution of the genetic variation is better understand with the existence of three groups of sperm whales along the SWA (northeast of Brazil, southeast-south of Brazil and Argentina), which could be considered as different management units. Regarding the worldwide genetic structure of sperm whales, 39 haplotypes and four genetic groups were recovered, and only the Pacific Ocean presented an exclusive genetic group. AMOVA revealed that between 8.89% (FST) and 16.39% (ΦST) of the observed genetic variation was due to differences among the populations of the world. AMOVA indicated that there is a geographical differentiation between the SWA and the other oceans, which had high indexes of fixation between them (SWA and North Atlantic: FST = 0.1837, ΦST = 0.3142, SWA and Indian Ocean: FST = 0.0898; ΦST = 0.1661; SWA and Pacific: FST = 0.11140; ΦST = 0.0757; P<0.00001). The unified sample of the SWA did not present exclusive haplotypes. However, individuals from the southeast-south of Brazil only shared six of seven haplotypes with the population of the Pacific Ocean. From 39 sperm whales with sex molecularly determined, nine were males and 30 females, 18 females were found in the southern region, outside the tropical region, suggesting that there are at least more than one reproductive population in WSA. These results, together with the differences in genetic variability and the lack of sharing of haplotypes among the studied populations, suggest that sperm whales from southeast-south of Brazil would be a management unit, potentially isolated, in reproductive terms, from the others. However, mtDNA is a matrilineal marker and exclusively presents the evolutionary history of females. In this context, the continuity of these studies, including new samples and nuclear markers, will be fundamental for the identification of real units of management of the species in the SWA and particularly in Brazilian waters.

Efeitos da elevação do dióxido de carbono atmosférico e da mudança climática na fixação de carbono em Araucaria angustifolia

Mon, 24 Jul 2017 00:00:00 GMT

Efeitos da elevação do dióxido de carbono atmosférico e da mudança climática na fixação de carbono em Araucaria angustifolia Cenci, Bruna Treviso The increase in the concentrations of atmospheric CO2 in the last century must impact ecosystems primary productivity. This effect may be direct and positive, due to a fertilization mechanism, or indirect (positive or negative) through climate changes. Evidences on the variation of carbon balance in forests in the last decades indicate neutral responses in boreal regions, positive in temperate regions and negative in the tropics. There is little evidence about how primary productivity responds to these global changing factors in subtropical forests. In this study, we investigate how the primary productivity of a dominant conifer in subtropical moist forests of the Southeast region of South America (Araucaria angustifolia) has been affected throughout the last century by elevated CO2 concentrations and consequent climate alterations. For a population of this species, we have tested the validity of the following hypothesis: (i) the increase of atmospheric CO2 indirectly affects the rate of carbon fixation, through the impact of global warming in the local temperature and rainfall regimes; and (ii) besides this indirect effect, the increment in CO2 directly affects the rate of carbon fixation through a fertilization mechanism. In an initial sample of 25 A. angustifolia trees from 0,33 ha of mature subtropical forest in the south of Brazil, we estimated annual series of wood carbon content for 14 trees using series of dendrochronologically dated growth-ring widths (from a preexisting study) and growth-ring densities (by X ray densitometry), and hypsometric (adjusted to local population) and volumetric (general for the species) equations. The individual series were combined in an average index series of carbon increment (I vector), previously removing ontogenetic tendencies (through Regional Curve Standardization) and time autocorrelation (by autoregressive models). By comparing I to regional series of mean temperature and total rainfall (estimations of CRU TS4) through a Correlation Function, we selected several climatic variables related to carbon fixation (P and T matrices). Instrumental data of atmospheric C concentration (NOAA EARL) and estimations of global temperature (CRU TEM4) composed matrices C and A, respectively. Finally, the validity of causal models describing the relations among matrices I, T, P, A e C according to the different hypothesis of the study, was tested through Path Analysis. The resulting chronology of residual indexes of carbon increment comprehended the period of 1890 to 2014, with averages of rbar = 0,27 and EPS = 0,77. In the subsequent analysis, we considered the period of 1901 to 2008 (common period with the climate series). Both models were not rejected in the Path Analysis (P > 0,1), and the model which represents the i hypothesis was considered the most plausible by the greater p-value for the Fisher’s C-statistic (Fisher-C = 9.25, gl =10, P = 0.508). In this model, global warmth comes from the elevation of CO2 which negatively affects the increase in carbon content in A. angustifolia through regional temperature elevation (in previous) may. Besides this climatic factor, rainfalls in previous march and june affected carbon fixation in a positive way, although both are not influenced by CO2 through global warming. In summary, climatic variables explained 19% of temporal variation of carbon increase in the trees. These results demonstrate that, despite the known positive impact of CO2 in water use efficiency in this species (and site), this does not translate into a greater primary productivity, possibly by the ombrophilous character of the regional climate. On the other hand, the change into autumns with higher temperatures has resulted in lower primary productivity of A. angustifolia throughout the last century. As this is the dominant species and plays a key role in the trophic structure, this negative effect of the climatic change in its productivity may, possibly, indirectly impact the structure and the operation of the ecosystems in which it is inserted.

Análise do conflito entre pescadores artesanais e funcionários do Parque Nacional da Lagoa do Peixe, uma unidade de conservação de proteção integral

Fri, 10 Mar 2017 00:00:00 GMT

Análise do conflito entre pescadores artesanais e funcionários do Parque Nacional da Lagoa do Peixe, uma unidade de conservação de proteção integral Doebber, Camila The Lagoa do Peixe National Park, created in 1986 on the middle coast of Rio Grande do Sul, is a conservation unit (CU) of integral protection, where the use of natural resources is not allowed in its territory, generating conflicts between PARNA’s administration and the traditional communities that lived in that area even before the CU creation. The objective of this work was to describe the perception and knowledge of fishermen and PARNAs ICMBio employees about the conflict, searching for suitable solutions. To do so, semi-structured interviews were conducted with 96 fishermen (of the 127 registered) and 11 ICMBio employees, using questionnaires containing 63 questions in the case of fishermen and 33 in the case of employees (questions being open and closed, arranged in Likert scale). Among the fishermen, 60 believed that fishing at PARNA may be prohibited in the near future and most of them (68,8%) showed some degree of concern about their fishing activity in the PARNA verifying the desire to remain in the fishing activity. In case the fishing was forbidden, 91% of fishermen would like to receive a monetary compensation. PARNA employees also cited financial aid as a form of compensation, besides training courses for other activities (e. g. tourism) to mitigate the conflict. As alternative activities for the fishermen the employees cited agriculture, fish farming, livestock, forestry and handcraft activities. Besides that, fishermen and employees see some touristic potential for PARNA as an alternative activity in relation to fishing, where there is the possibility for the fishermen to work in the tourism sector inside PARNA, in activities as guides, maintenance and direct assistance to visitors. However, the perception of the fishermen is that even though their representatives exist on the Advisory Council of PARNA, there is still difficulty in their internal dialogue, as well as the small knowledge about the decisions coming from meeting of the Advisory Council. On the other hand, there is the fishermen perception that the dialogue between the management team and fishermen has been improving over the years, and that fisherman have some knowledge of local fisheries legislation. The obtained answers showed that most of fishermen and employees see an economical solution for the case of the future fishing prohibition at PARNA, which is feasible in the terms of law. The precondition is the implementation of a social and economic program for the absorption of their labor in a socially and economically dignified conditions, as tourism for example. However, the desire for fishing continuity by the fishermen in PARNA suggests alternative solutions that allow their stay in the place, as the elaboration of a Commitment Term, according to Normative Instruction nº 26/2012, or the re-categorization of the conservation unit, making part of Lagoa do Peixe a conservation unit for sustainable use, such as an Extractive Reserve.

Riqueza, estrutura e composição de espécies arbóreas em floresta secundária invadida por hovenia dulcis thunb, caracterização do seu nicho de regeneração e efeitos alelopáticos

Fri, 25 Feb 2011 00:00:00 GMT

Riqueza, estrutura e composição de espécies arbóreas em floresta secundária invadida por hovenia dulcis thunb, caracterização do seu nicho de regeneração e efeitos alelopáticos Boeni, Bruna de Oliveira The impact of invasive species on native species has been widely recognized as an important cause of the changes in the global diversity. Invading species are able to affect the structure and function of invaded ecosystems. Among the exotic plant species that invade forests in Brazil, Hovenia dulcis is frequent in areas of secondary vegetation. Thus, the first part of this work compares the phytosociological parameters among areas of secondary vegetation invaded by H. dulcis and areas without this exotic species. H. dulcis presented one of the biggest values of absolute density and basal area, demonstrating its importance for the structure of the areas where it occurs. However, the structural variables and the species richness had not been modified in function of the presence of the exotic species. The species composition was altered by the presence of the invading species when the effects caused by unmeasured variables that influence the dynamics of forest succession were controlled, indicating that variations in the composition among areas are in good part determined by differences in abiotic conditions and history of each area, and secondarily by the presence of H. dulcis. The abundance and distribution of the plant species are determined in part during the initial periods of regeneration, when they are more vulnerable to its immediate environment. Changes in require of biotic factors in the different periods of phases of ontogenetic development of the plant can reveal change of the niche of regeneration of this. The availability of light, the fall and accumulation of litter are factors that affect the structure and dynamics of the plant community in different ways. Thus, the second part of this study intends to evaluate the ambient variables around individuals of H. dulcis during the phases of ontogenetic development from young to old saplings and adults, evaluating changes in the regeneration niche in relation to the ambient variables, the ontogenetic period and the seasonal deciduousness of H. dulcis. The analyses indicated differences among the ontogenetic phases only in canopy opening and herbaceous covering. The species composition around H. dulcis individuals also varied among the ontogenetic phases. The percentage of canopy opening differed between adult individuals in relation to young saplings only in the non deciduous period, probably due to the dominance of the exotic species in the canopy. Thus, a change in the regeneration niche in function of the canopy opening is observed. The low density of the tree crowns of H. dulcis exacerbates the effect of the canopy opening in points where adults are established in relation to young saplings. The litter depth during the deciduous period was higher around adults and young saplings. The deciduousness and consequent increase in the leaf litter can favor the survival and growth of the most light demanding species, such as those typical of the initial stages of forest succession, as a result of the increase in the amount of light that arrives at the understory, which, however, can negatively affects seedling that are intolerant to elevated luminosity. The allelopathic compounds produced by plants come from the secondary metabolism and may be present in different plant tissues, being released to the environment in different ways. The allelopaty has been recognized as an important ecological mechanism that influences the dominance in plant communities, being able to determine the structure, composition and the dynamics of such communities. H. dulcis presents among others phenolic compounds, in its leaves that can cause changes during the process of seed germination of native species. Therefore, the third part of this work tests the potential allelopathic effects of leaf extracts of H. dulcis on the germination and growth of the root and aerial parts of seedlings of Casearia sylvestris. The watery leaf extracts of H. dulcis present allelopathic effect in seeds and seedlings of C. sylvestris. The leaf extracts in all concentrations reduced the germination percentage, and lead to a great inibitory effect in root development that can hinder the future establishment of the plants, affecting the uptake of vital resources. Seeds in contact with the leaf extracts presented a reduction in the germination speed. Thus, seedlings of C. sylvestris exposed to alleloquimic compounds of H. dulcis leaves had its initial development delayed. Thus, one concludes that the great density of individuals of H. dulcis corroborates the invasion for this species that modifies the composition of species in the forest in regeneration. H.dulcis modifies its niche of regeneration and thus it influences the niche of the regenerant native species and still it presents inibitiry allelophatic effect on the germination and development of seedlings of the native species.

Influência das mudanças climáticas globais na estrutura e dinâmica da comunidade fitoplanctônica de um lago raso subtropical: uma abordagem experimental

Tue, 31 Jul 2012 00:00:00 GMT

Influência das mudanças climáticas globais na estrutura e dinâmica da comunidade fitoplanctônica de um lago raso subtropical: uma abordagem experimental Wieliczko, Andressa da Rosa Climate change is considered one of the greatest threats to aquatic ecosystems around the globe. Among the planned changes including the dynamics of phytoplankton, the growth of cyanobacteria are among the most cited. The objective of this study was to evaluate the isolated and combined effects of increased temperature and nutrients on phytoplankton community structure in a large subtropical shallow lake. The study was conducted in microcosms to simulate possible scenarios of climate change alone and in combination with nutrient enrichment (N and P), from samples of winter and summer. The isolated and or combined influence increase of temperature and nutrients promoted non significant changes in total biomass, species richness and diversity of Lake Mangueira. Biomass of Bacillariophyceae was significantly influenced by the combined effect of factors, while the significant increase in biomass of Cyanobacteria occurred only under the isolated effects of heating and enrichment. Descriptors species composition in both periods was not altered. This indicated that the temperature increases and the increase in nutrient concentrations were not sufficient to promote changes in the phytoplankton community structure in Lake Mangueira, and the turnover of bloom-forming species was not observed, as expected. The resilience of aquatic ecosystems depending on the extent of climate change disturbance might contribute to understand the responses of these environments on the numerous predictions and expectations.