Dinâmica espacial da assembleia de mamíferos de médio e grande portes em ambiente de várzea e terra firme na Amazônia Central
Studies that try to understand how mammals use the space are extremely important to improve conservation decisions. Despite the high knowledge of mammals in the Amazon forest, little is known about this group in the varzea forests. These forests are located in the lowland inundated regions of the...
| Autor principal: | Alvarenga , Guilherme Costa |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Assuntos: | |
| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/11919 http://lattes.cnpq.br/3944016436400914 |
| Resumo: |
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Studies that try to understand how mammals use the space are extremely important to
improve conservation decisions. Despite the high knowledge of mammals in the
Amazon forest, little is known about this group in the varzea forests. These forests are
located in the lowland inundated regions of the Amazon basin, and are seasonally
inundated by white-water rivers. Varzea forests were, and still are, intensively used by
humans, because of the easy access and the high fertility of it soils. Beyond that,
climatic changes and the actual Brazilian politics, which encourages constructions of
hydroelectric plants, are direct threats to the varzea and the animals that live there. The
goal of this study is understand how variations on the vegetation influence the
distribution of medium and large-sized mammals in the varzea forest. For this, we
executed two consecutive years of camera traps surveys during dry season in
Sustainable Development Reserves Amanã and Mamirauá, Central Amazonia.
Specifically, we compared the community composition of mammals between an upland
forest (Amanã) and a varzea forest (Mamirauá), and we tested the response of
mammal’s species to the vegetation variation in the varzea forest. The sampling grid in
each reserve consisted of up to 50 baited camera trap stations and an overall sampling
effort of 4075 camera trap*days. We used a pre-exist landscape mapping of Mamirauá
Reserve and from it we calculated the area (km2) of the habitats inside two different
scales (500 m and 1000 m) around each camera trap station. The comparison between
the mammal species of upland and varzea was made with an ordination by NMDS of
two dimensions and after that a Similarity Analysis (ANOSIM), both using Bray-Curtis
indice. To test the influence of the varzea vegetation’s in the mammal distribution we
used Generalized Linear Models (GLM) and, for the species with too many zeros, Zero-
Inflated Models (ZIP/ZINB) or Hurdle Models (ZAP/ZANB). During the study, we
recorded 21 medium and large-sized mammal species of 3443 records. Among this
species, seven are classified as ‘vulnerable’ globally or in Brazil. As expected the
community composition of mammals were different between upland and varzea forest.
At the varzea we recorded only six species, while upland recorded 20 species. The
mammal’s community of várzea forest presented a hierarchical subgroup pattern of the
upland community, and all the species registered in the várzea have semi-arboreal
habits. Tree species recorded in varzea forest were more represented there than in
upland forest, which could be related with biggest populations at this region. The varzea
vegetation’s were related with almost all species distributions, the exception was
Leopardus wiedii. The total number of records and the composition of species were
influenced by the habitat chavascal, such there were fewer records with chavascal area
increase. At the same way, Didelphis marsupialis e Nasua nasua avoided areas of
chavascal. N. nasua avoided too the open fields of herbaceous vegetation. The specie
Coendou prehensilis was positively influenced by constant water habitats and high
varzea forest, while Panthera onca avoided high varzea forest. |