@article {1674, title = {The cost-effectiveness of biodiversity surveys in tropical forests}, journal = {Ecology Letters}, volume = {11}, year = {2008}, pages = {139-150}, abstract = {The identification of high-performance indicator taxa that combine practical feasibility and ecological value requires an understanding of the costs and benefits of surveying different taxa. We present a generic and novel framework for identifying such taxa, and illustrate our approach using a large-scale assessment of 14 different higher taxa across three forest types in the Brazilian Amazon, estimating both the standardized survey cost and the ecological and biodiversity indicator value for each taxon. Survey costs varied by three orders of magnitude, and dung beetles and birds were identified as especially suitable for evaluating and monitoring the ecological consequences of habitat change in our study region. However, an exclusive focus on such taxa occurs at the expense of understanding patterns of diversity in other groups. To improve the cost-effectiveness of biodiversity research we encourage a combination of clearer research goals and the use of an objective evidence-based approach to selecting study taxa. }, keywords = {biodiversity, cost-effectiveness, indicator species, sampling efficiency, Tropical forests}, author = {Gardner, T. A. and Barlow, J. and Araujo, I. S. and Avila-Pires, T. C. and Bonaldo, A. B. and Costa, J. E. and Esposito, M. C. and Ferreira, L. V. and Hawes, J. and Hernandez, M. I. M. and Hoogmoed, M. S. and Leite, R. N. and Lo-Man-Hung, N. F. and Malcolm, J. R. and Martins, M. B. and Mestre, L. A.} } @article {1675, title = {Understanding the biodiversity consequences of habitat change: the value of secondary and plantation forests for neotropical dung beetles}, journal = {Journal of Applied Ecology}, volume = {45}, number = {3}, year = {2008}, pages = {883-893}, abstract = {1. Secondary and plantation forests are becoming increasingly widespread in the tropics. A recent meta-analysis on the impacts of land-use change on tropical forest dung beetles concluded that regenerating forests can be effective in helping to offset species loss following deforestation. How- ever, our understanding of the extent to which these results can be generalized to new locations remains very poor. 2. We attempted to overcome many of the design limitations that characterize previous studies by collecting spatially independent dung beetle samples from primary, secondary and Eucalyptus plantation forests in north-east Brazilian Amazonia across a large quasi-experimental landscape that minimized confounding edge and fragmentation effects. 3. We recorded 9203 dung beetles, comprising 85 species. Species richness was significantly higher in primary forest and the majority of species were more abundant there than elsewhere, whereas secondary and plantation sites harboured an impoverished subset of primary forest species. 4. Our data illustrate the low value of tropical secondary and plantation forests for dung beetles in our study area, and our conclusions are more pessimistic than those of earlier studies. 5. Because of differences in the order of species rank-abundance and rank-biomass patterns, re-coding community data from abundance to biomass significantly altered the analytical weight of individual species in determining community patterns. Larger bodied beetles were more prone to local extinctions and abundance declines and this effect was consistent both within and between genera. 6. Synthesis and applications . Our study demonstrates that secondary and plantation forests in a large neotropical landscape host exceptionally impoverished dung beetle communities. Furthermore, the depletion of beetle abundance combined with a reduction in average body mass in converted forests is likely to have detrimental consequences for the maintenance of dung beetle-mediated ecosystem services in these habitats. Differences in biogeographical and landscape context, and the influence of common limitations in sampling design, may explain why many other studies have painted a more optimistic picture of the conservation value of anthropogenic habitats. In the absence of further evidence we caution strongly against the claim that forest regeneration schemes on degraded land can effectively offset the loss of species following deforestation, and urge that conservation strategies prioritize the protection of remaining areas of primary forest.}, keywords = {biomass, brazil, deforestation, habitat change, habitat value, sampling bias, Scarabaeinae, Tropical forests}, author = {Gardner, T. A. and Hernandez, M. I. M. and Barlow, J. and Peres, C. A.} }