Effects of forest fragmentation on nocturnal Asian birds:A case study from Xishuangbanna,China

Owls have the potential to be keystone species for conservation in fragmented landscapes, as the absence of these predators could profoundly change community structure. Yet few studies have examined how whole communities of owls respond to fragmentation, especially in the tropics. When evaluating the effect of factors related to fragmentation, such as fragment area and distance to the edge, on these birds, it is also important in heterogeneous landscapes to ask how ＇location factors＇ such as the topography, vegetation and soil of the fragment predict their persistence. In Xishuangbanna, southwest China, we established 43 transects （200 mx60 m） within 20 forest fragments to sample nocturnal birds, both visually and aurally. We used a multimodel inference approach to identify the factors that influence owl species richness, and generalized linear mixed models to predict the occurrence probabilities of each species. We found that fragmentation factors dominated location factors, with larger fragments having more species, and four of eight species were significantly more likely to occur in large fragments. Given the potential importance of these birds on regulating small mammal and other animal populations, and thus indirectly affecting seed dispersal, we suggest further protection of large f ragments and programs to increase their connectivity to the remaining smaller fragments.

Variation in forest soil fungal diversity along a latitudinal gradient

In forest ecosystems,plant communities shape soil fungal communities through the provisioning of carbon.Although the variation in forest composition with latitude is well established,little is known about how soil fungal communities vary with latitude.We collected soil samples from 17 forests,along a latitudinal transect in western China.Forest types covered included boreal,temperate,subtropical and tropical forests.We used 454 pyrosequencing techniques to analyze the soil communities.These data were correlated with abiotic and biotic variables to determine which factors most strongly influenced fungal community composition.Our results indicated that temperature,latitude,and plant diversity most strongly influence soil fungal community composition.Fungal diversity patterns were unimodal,with temperate forests(mid latitude)exhibiting the greatest diversity.Furthermore,these diversity patterns indicate that fungal diversity was highest in the forest systems with the lowest tree diversity(temperate forests).Different forest systems were dominated by different fungal subgroups,ectomycorrhizal fungi dominated in boreal and temperate forests;endomycorrhizal fungi dominated in the tropical rainforests,and non-mycorrhizal fungi were best represented in subtropical forests.Our results suggest that soil fungal communities are strongly dependent on vegetation type,with fungal diversity displaying an inverse relationship to plant diversity.