Data/hora: 04/06/2024 18:13:12

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 03/10/2008
Data da última atualização: | 03/10/2008
Autoria: | QUEIROZ, G.; NORONHA, F.; PELLENS, R.; GARAY, I.
Título: | Disturbances caused by tracks upon soil fauna and soil properties in Atlantic forest fragments of southeastern Brazil.
Ano de publicação: | 2008
Fonte/Imprenta: | In: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.
Idioma: | Inglês

Conteúdo:

Loss and fragmentation of habitats resultant from human activities are considered the main
causes of modification of forest ecosystems. Studies about fragmentation consider, in general,
the edge effect as the only factor of perturbation of the remnants. However, when human activities
takes place in fragments, tracks are opened and may originate alterations in ecological
processes. The present work aim at the evaluation of the degree of perturbation brought about
by tracks by studying organic layers and soil mesofauna, as indicators of the functioning of
decomposition subsystem.
The study was fulfilled in the REBIO Sooretama and in two fragments ? Pasto Novo,
classified as a high diversity site, in relation to tree species, and Bionativa, classified as a poor
diversity site ? of Table-land Atlantic Forest (Sooretama, ES, Brazil). Within the fragments a
gradient of three situations were analyzed: preserved forest areas (FA), intermediate forest
areas (IA) and tracks (TR). At REBIO, the control site with over 22 thousand hectares, only the
FA was sampled. Samples of both fauna and humus layers were obtained at sites and situations
according to Pellens & Garay, 1999 and Garay et al. 1995, respectively.
Forest areas stock of litter was highest for REBIO (4,7 t/ha), followed by Pasto Novo (4,3
t/ha) and Bionativa (1,9 t/ha). Within the fragments, the confrontation of the FA and TR situations
revealed a decrease of six folds in the amount of litter, as well as decreases of two to four folds
in nutrients (N, P and Ca2+) and organic matter stocks in the top soil. These differences go
along with drastic modifications in the structure of soil animal communities. The major differences
in abundances were observed when considering separately the social insects and the other
groups: Formicidae and Isoptera show a decrease in both fragments in relation to REBIO. These
differences were even stronger comparing IA and TR within fragments. Alterations were also
verified in the presence/absence of certain groups and in the abundance and richness ? e. g.
the medium richness of groups in TR is inferior to FA (9 vs 15 in Pasto Novo; 9 vs 12 in Bionativa
and 14 in REBIO).
Many of the euedaphic artropods, e.g. Pseudoscorpionida, Araneae, Diplopoda and
Diplura, except for Isopoda, Symphila, Coleoptera larvae and Chilopoda, had at least a significant
decrease in abundance in the fragments when compared to REBIO. Nevertheless, all these
groups had a statistically significant difference in their abundance or even disappeared ? e.g.
Chilopoda, Diplopoda, Symphila and Diplura ?, when the gradient inside the fragments were
analyzed, i.e. they follow the tendency of disappearance of litter and the loss of structure of
organic layers.
Our results indicate a greater disturbance in the interior of forest fragments ? comparison
of FA, IA and TR ? than the comparison of REBIO and forest areas of fragments. The changes
are quantitative and qualitative for both the humic layers and edaphic mesofauna. This reveals
the importance of an adequate management of tracks, aiming at the functional sustainability
and conservation of biodiversity among the remnants of Atlantic Forest.

Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (43786-1) - UPE - PL - -- - CD0305 -  -  - DIS