Arthropods in coarse woody debris in jarrah forest and rehabilitated bauxite mines in Western Australia

Coarse woody debris (CWD) is returned to Alcoa’s rehabilitated mined areas in the jarrah forest as potential vertebrate fauna habitat, however, its value for invertebrate fauna has not been investigated. We sought to determine if CWD in rehabilitated areas supported a similar arthropod fauna to that on fallen logs in the adjacent unmined jarrah forest. Using emergence tents, sampling from logs in 5-year old and 15-year old rehabilitated forest, and in unmined forest, yielded 2266 specimens from 187 taxa. Collembola (43% of total) and Acarina (32%) were the most abundant groups, followed by Diptera (11%), Araneae (4%) and Coleoptera (3%). There were no significant differences in either taxa richness or overall abundance among the three forest types. However, community composition varied significantly. Species richness from the Araneida, Coleoptera and Diptera was highest in the 5-year old rehabilitated forest, while Collembola and Acarina were better represented in the unmined forest; this was related to changes in the environment surrounding the logs as rehabilitated forest develops, and to log condition. The composition of arthropods on logs in the 15-year old rehabilitated forest was intermediate, indicating a trend of increasing similarity to the unmined forest in arthropod fauna as the rehabilitated forest ages. We suggest that over longer time periods, CWD in rehabilitated forest will support arthropod communities similar to those found in unmined forest. Future work should determine if returning logs to mined areas facilitates the return of CWD-dependent taxa

Efeitos da sucessão florestal sobre a anurofauna (Amphibia: Anura) da Reserva Catuaba e seu entorno, Acre, Amazônia sul-ocidental Effect of the forest succession on the anurans (Amphibia: Anura) of the Reserve Catuaba and its periphery, Acre, southwestern Amazonia

O trabalho teve como objetivo verificar a abundância, riqueza e a composição da anurofauna em diferentes estágios sucessionais em uma floresta do Acre (10º04'S, 67º37'W) e seu entorno. Os dados foram obtidos entre agosto de 2005 a abril de 2006 em doze parcelas, localizadas em três áreas diferentes da floresta. Em cada área foram escolhidos quatro tipos de ambientes: floresta primária (mata), floresta secundária (capoeira), entorno (matriz) e floresta secundária (sucessão). Observou-se a presença de 27 espécies distribuídas em sete famílias. Maior abundância foi constatada na matriz dois e capoeira três, e a menor na sucessão um. A maior riqueza foi constatada na matriz dois, com o maior número de espécies exclusivas. A abundância de anuros correlacionou-se significativamente com a circunferência das árvores e lianas. A riqueza de anuros correlacionou-se marginalmente com a circunferência das árvores. A maior riqueza em ambientes de capoeiras e matriz pode ser explicada em grande parte pela existência nesses locais de poças d'água, maior heterogeneidade estrutural e poderem constituir estágios intermediários de perturbação. Esses estágios têm sido apontados como fatores que promovem e mantêm níveis elevados de biodiversidade. Ambientes com níveis intermediários de perturbação são importantes para a conservação da anurofauna.<br>The objective of this work it was verify the abundance, richness, and the anuran composition in plots of vegetation of different succession stages in a forest and the matrix that surrounds it, of Acre (10º04'S, 67º37'W). The sampling was carried out between August 2005 and April 2006 in twelve plots located in three different sites in the forest. In each site four kinds of environments were chosen: primary forest (wood), secondary forest (capoeira), periphery (matrix) and secondary forest (succession). A total of twenty-seven species distributed in seven families was found. Greater abundance was registered in the plots of matrix two and capoeira three and the least in succession one. The richness was greater in matrix two, with the greater number of exclusive species. The abundance of anurans correlated significantly, with the average circumference at the breast height of the trees of the plots. The richness however correlated only marginally, with this structural feature. The larger richness in plots of capoeira and matrix can be explained partially by the existence of temporary ponds and more structural heterogeneity is able constitute intermediary stages in a gradient of perturbation and this can increase the biodiversity. Thus environments with intermediary levels of disturbance are important for the conservation of the diversity of anuran amphibians