24 research outputs found
Riparian wetlands of low-order streams in Brazil: extent, hydrology, vegetation cover, interactions with streams and uplands, and threats
Effects of flooding on the spatial distribution of soil seed and spore banks of native grasslands of the Pantanal wetland
Estudo floristico e fitofisionomico das principais formações arboreas do Pantanal de Pocone-Mato Grosso
Orientador : Hermogenes Freitas Leitão FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Foram realizados estudos florlsticos e fisionômicos das principais formações arbóreas no Pantanal do Município de Poconé-Mato Grosso. O conhecimento das denominações regionais possibilitaram a identificação de várias unidades vegetacionais arbóreas Constatada as diferenças fisionômica e ou florística e baseando-se nos critérios de: uniformidade vegetacional, áreas não muito alteradas e facilidade de acesso, escolheu-se as áreas de estudo. O método de amostragem foi o de parcelas. Foram caracterizadas floristicamente e descritas: Três formações arbóreas de agrupamento de vegetais (capões) e duas formações arbóreas em paleodiques (cordilheiras). Para cada área estudada é apresentada a listagem das espécies encontradas.Os resultados mostram que o Pantanal da região de Poconé apresenta em termos de unidades vegetacionais arbóreas, dois padrões básicos: cerrados e florestas. Os cerrados ocorrem principalmente nas áreas periféricas situadas na região norte do Pantanal de Poconé, tendo o rio Pinxaim como limite sul de sua distribuição. Três tipos de Cerrados foram identificados: lixeiro (Cerrado_em ilhas); cerrado Mesosotrófico (Cerrado em Cordilheiras ou Capões); carvoeiro (Formação homogênea de Callistene fasciculata). As florestas ocorrem em três unidades fisionômicas: Capões, Cordilheiras ou em Linhas de drenagem. Foram identificadas dois tipos de Florestas: floresta semidecídua e floresta inundável. Não foi observado nenhum endemismo e a análise da vegetação e da composição floristica permite concluir que a atual cobertura arbórea do Pantanal de poconé representa espécies típicas de outras regiões, sendo a maior contribuição proveniente da Província do Cerrado, e espécies de Florestas Semidecidua de solo calcáreo. As Florestas do Planalto Central e do Sudoeste do Brasil tem também contribuição muito expressi- va, enquanto que as da Província Amazônica tem menos expressãoAbstract: Not informed.MestradoBiologia VegetalMestre em Ciências Biológica
Distribution of woody plant communities along the flood gradient in the Pantanal of Poconé, Mato Grosso, Brazil.
The woody vegetation of the northern Pantanal of Mato Grosso near Poconé
can be divided into Cerrado, Cerradão, and semi-deciduous and deciduous
forests occurring on non-flooded habitats, and different types of
floodplain forests occurring in periodically inundated habitats. An
analysis of a transect of 440 m length and an area of 8,800 m2 crossing
a levee at Cassange River, a right-hand affluent of Cuiabá River, showed
50 tree species. 12 species occurred only in areas of prolonged
flooding, 24 species showed a wide distribution on the topographic
gradient, and 14 species occurred only on dry habitats that become
flooded for short periods only during extreme flood events. Species
distribution on the flood gradient is shown, and the impact of the flood
pulse on phenology and community structure is discussed. The low number
of highly flood-adapted species is interpreted as the result of
pronounced, long-lasting paleoclimatic dry periods. A broad ecological
amplitude with respect to flooding seems to be the most efficient
strategy of tree occupation in the Pantanal under the actual
hydrological and climatic conditions. Data from other inventories are
used to present a general model of tree distribution in the northern
part of the Pantanal of Mato Gross
Environmental Dynamics of Dissolved Black Carbon in Wetlands
Wetlands are ecosystems commonly characterized by elevated levels of dissolved organic carbon (DOC), and although they cover a surface area less than 2 % worldwide, they are an important carbon source representing an estimated 15 % of global annual DOC flux to the oceans. Because of their unique hydrological characteristics, fire can be an important ecological driver in pulsed wetland systems. Consequently, wetlands may be important sources not only of DOC but also of products derived from biomass burning, such as dissolved black carbon (DBC). However, the biogeochemistry of DBC in wetlands has not been studied in detail. The objective of this study is to determine the environmental dynamics of DBC in different fire-impacted wetlands. An intensive, 2-year spatial and temporal dynamics study of DBC in a coastal wetland, the Everglades (Florida) system, as well as one-time sampling surveys for the other two inland wetlands, Okavango Delta (Botswana) and the Pantanal (Brazil), were reported. Our data reveal that DBC dynamics are strongly coupled with the DOC dynamics regardless of location, season or recent fire history. The statistically significant linear regression between DOC and DBC was applied to estimate DBC fluxes to the coastal zone through two main riverine DOC export routes in the Everglades ecosystem. The presence of significant amounts of DBC in these three fire-impacted ecosystems suggests that sub-tropical wetlands could represent an important continental-ocean carrier of combustion products from biomass burning. The discrimination of DBC molecular structure (i.e. aromaticity) between coastal and terrestrial samples, and between samples collected in wet and dry season, suggests that spatially-significant variation in DBC source strength and/or degree of degradation may also influence DBC dynamics
The Pantanal Ecology Project: Challenges and Progress of a Brazilian-German Scientific Collaboration
Since 1991, Brazilian and German researchers of the Pantanal Ecology
Project (PEP [a cooperative effort between the Federal University of Mato
Grosso, UFMT, and the Max-Planck-Institute of Limnology, MPIL]) have been
studying the structures and functions of the various ecosystem types of the
Pantanal. This work focused on delivering a solid scientific database for
proposing management concepts and conservation plans, including analysis of
environmental impacts and their socio-economic effects. The interdisciplinary
approach is based on the flood pulse concept (Junk et al. 1989), which uses the
annual hydrological changes as the driving force for patterns and processes in
floodplain ecosystems. Limnologists, plant ecologists, zoologists, and geographers cooperate in selected landscape units such as floodplain lakes, an
inundation gradient, a bird breeding site and the catchments of tributaries to the
Pantanal. In the past 10 years, PEP has contributed more than 100 scientific
publications on this issue (see homepage http://www.mpilploen.
mpg.de/mpilts2d.htm). Scientific education is one important pillar for the
sustainable transfer of acquired knowledge into society. In a training course at
the UFMT set up by PEP in 1994, 150 students performed studies in wetland
ecology to obtain their Ph.D., M.Sc., or B.Sc. degrees. During this time,
laboratories and field stations were established to enhance scientific
infrastructures. The Brazilian-German cooperation on the Pantanal has now
become the intellectual nucleus for the establishment of the United Nations
University – Pantanal Regional Environmental Program at the UFMT. Analyzing
the effects of changes in the flooding regime in the Pantanal will form the focus
of future cooperative research
FITOSSOCIOLOGIA DA COMUNIDADE ARBÓREA DE CERRADO Sensu Stricto DO PARQUE NACIONAL DA CHAPADA DOS GUIMARÃES
Entre as savanas tropicais, o Cerrado apresenta maior diversidade de plantas com cerca de 12.000 espécies descritas. Considerado um dos hotspots mundiais de biodiversidade, o Cerrado vem sofrendo forte ameaça e o conhecimento dos padrões de distribuição vegetal em áreas com grande diversidade se torna imprescindível para a criação estratégias de conservação. O Parque Nacional da Chapada dos Guimarães (PNCG), localizado na área central do Cerrado, possui uma grande diversidade de ambientes devido às variações de altitude, sendo a tipologia mais representativa, a de Cerrado sensu stricto. Este trabalho teve como objetivo analisar a riqueza, diversidade e estrutura horizontal da comunidade arbórea desta tipologia. Para isto, foram alocadas 6 parcelas de 20 x 250 m (5000 m2), em isolinhas, e amostrados todos os indivíduos com diâmetro a altura da base (DAB) ≥ 5 cm. Para verificação da suficiência amostral, utilizou-se o estimador não paramétrico de Jackknife, a diversidade foi estimada pelo índice de Shannon e de Simpson. Foram amostradas 100 espécies arbóreas distribuídas em 64 gêneros e 36 famílias botânicas. As famílias que mais contribuíram para a riqueza foram Fabaceae com 18 espécies, Myrtaceae com 7 espécies, Vochysiaceae e Apocynaceae com 6 espécies e Bignoniaceae com 5 espécies. A comunidade arbórea de Cerrado sensu stricto do PNCG possui densidade de 1.861,33 (± 719.93) indivíduos por hectare, e a área basal de 15,14 (±7,01) m2 ha-1. Um grupo de 20 espécies representa 82,75 % do total dos indivíduos e 80,79 % da área basal por hectare. A diversidade da vegetação arbórea é de 3,24 nats/indivíduo pelo índice de Shannon, e 0,70 pelo índice de Simpson o que indica alta diversidade florística para a comunidade arbórea estudada.Palavras-chave: savana, estrutura horizontal, índices de diversidade.PHYTOSOCIOLOGY OF THE CERRADO Stricto Sensu COMMUNITY IN THE “PARQUE NACIONAL DA CHAPADA DOS GUIMARÃES”ABSTRACTAmong the tropical savannas, Cerrado presentes greater diversity of plants with about 12.000 described species. The Cerrado biomeis considered one of the world’s biodiversity hots pots and has come under strong threat, so the knowledge of plant distribution patterns in areas with high diversity is indispensable to create conservation strategies. The Chapada dos Guimarães National Park (CGNP), located in the central area of the Cerrado, has a large variety of environments due to variations in altitude, being the most representative type, the Cerrado sensu stricto. The objective of this study was to analyze the richness, diversity and horizontal structure of the arboreal community of this typology. To this, were allocated 6 plots of 20 x 250 m (5000 m2), in isolines, and sampled all individual with diameter of the base height (DAB) ≥ 5 cm. In order to verify the sample sufficiency, we used the nonparametric estimator of Jackknife, diversity was estimated by Shannon and Simpson index. One hundred tree species distributed in 64 genera and 36 botanical families were sampled. The families who most contributed to the richness were Fabaceae with 18 species, Myrtaceae with 7 species, Vochysiaceae and Apocynaceae with 6 species and Bignoniaceae with 5 species. The arboreal community of Cerrado sensu stricto of the CGNP has density of 1.861,33 (± 719.93) individuals per hectare, and basal area of 15,14 (±7,01) m2 ha-1. A group of 20 species represents 82.75% of all individuals and 80.79% of the basal area per hectare. The diversity of arboreal vegetation is 3,24 nats/individual by Shannon index, and 0,70 by Simpson index which indicates high floristic diversity for the arboreal community studied.Keywords: savanna, horizontal structure, diversity index.DOI: http://dx.doi.org/10.14583/2318-7670.v04n02a0