Insights on the functional composition of specialist and generalist birds throughout continuous and fragmented forests.

A decline in species number often occurs after forest fragmentation and habitat loss, which usually results in the loss of ecological functions and a reduction in functional diversity in the forest fragments. However, it is uncertain whether these lost ecological functions are consistently maintained throughout continuous forests, and so the importance of these functions in continuous forests remains unknown. Point counts were used to assess both the taxonomic and functional diversity of specialist and generalist birds from sampling in a continuous primary forest compared with forest fragments in order to investigate the responses of these groups to forest fragmentation. We also measured alpha and beta diversity. The responses of specialists and generalists were similar when we assessed all bird species but were different when only passerines were considered. When examining passerines we found lower total taxonomic beta diversity for specialists than for generalists in the continuous forest, while taxonomic beta diversity was higher in the fragmented forest and similar between bird groups. However, total functional beta-diversity values indicated clearly higher trait regularity in continuous forest for specialists and higher trait regularity in fragments for generalists. Specialists showed significantly higher functional alpha diversity in comparison with generalists in the continuous forest, while both groups showed similar values in fragments. In passerines, species richness and alpha functional diversity of both specialist and generalist were explained by forest connectivity; but, only fragment size explained those parameters for specialist passerines. We suggest that considering subsets of the community with high similarity among species, as passerines, provides a better tool for understanding responses to forest fragmentation. Due to the regularity of specialists in continuous forest, their lost could highly affect functionality in forest fragments.

Decadal persistence of frugivorous birds in tropical forest fragments of northern Paraná / Persistência de aves frugívoras após uma década em fragmentos florestais do norte do Paraná

Forest fragmentation is a major cause of loss of species. We evaluated the local extinction of medium-large frugivorous bird species in six forest fragments of northern Paraná: the Parque Estadual Mata dos Godoy (PEMG), the largest and most preserved forest fragment in the region, and five other fragments. Fixed-width point counts and line transects were conducted along trails in the PEMG for 10 days: from September 2010 to March 2011, and from August 2011 to November 2011. Avian surveys in each of the other forest fragments were made over four days from October to December 2011. We compared data with a previous census carried out 10 years earlier. No extinction events were recorded from the PEMG. However, the relative abundance of species significantly changed during the ten years between surveys. In all the other forest fragments at least two frugivorous bird species disappeared, and in some as many as seven. Protecting the PEMG is crucial for the maintenance of frugivorous bird populations in our studied landscape.

A fragmentação florestal é uma das principais causas da perda de espécies. Avaliamos a extinção local de aves frugívoras de médio e grande porte em seis fragmentos do norte do Paraná: o Parque Estadual Mata dos Godoy (PEMG), maior e mais preservado remanescente florestal da região, e outros cinco fragmentos. Foram realizadas amostragens por pontos de escuta de distância limitada e por transecções no PEMG ao longo de 10 dias: entre setembro de 2010 e março de 2011, e entre agosto e novembro de 2011. Os outros cinco fragmentos foram amostrados ao longo de quatro dias entre outubro e dezembro de 2011. Os dados foram comparados com um levantamento prévio realizado há 10 anos. Não foram observadas extinções no PEMG. No entanto, foram observadas alterações significativas na abundância relativa das espécies em dez anos (Wilcoxon Signed-Rank). Nos outros fragmentos florestais verificou-se o desaparecimento de pelo menos duas espécies, sendo que a variação foi de duas a sete espécies. A proteção do PEMG parece ser crucial para a manutenção das populações de aves frugívoras na paisagem estudada.

Evaluating the ecological integrity of Atlantic forest remnants by using rapid ecological assessment.

The need for quick identification of priority areas for biodiversity protection makes rapid assessment methods important management tools for defining conservation strategies. An increasingly used rapid assessment method is rapid ecological assessment (REA), a fast and flexible survey directed toward selected indicator species and vegetation forms. The purpose of this study was to propose and test REA based on plant community features of the semideciduous Atlantic forest (SAF). Correlation tests were performed between data collected by REA and plant species diversity, richness, and abundance collected by conventional woody plant inventory methods. The study was conducted in 21 SAF patches in Northern Paraná State, Brazil. The phytosociological inventory was conducted along a single transect and required 2 days to complete (excluding time spent for herbarium identification), whereas REA was conducted along three to four transects per working day. REA results correlated positively with woody plant diversity, proving REA to be an efficient method for defining the conservation status of SAF fragments, but accuracy of evaluations of threats to biological integrity are relatively low. Both the selection of appropriate variables and the skill level of field staff are critical and can strongly influence REA results.