关键词： abiotic gradients   community structure   East Africa   exclosure experiment   herbivory   livestock-wildlife interactions   plant species richness   plant-herbivore interactions   wildlife decline  

摘要： Herbivores influence the structure and composition of terrestrial plant communities. However, responses of plant communities to herbivory are variable and depend on environmental conditions, herbivore identity and herbivore abundance. As anthropogenic impacts continue to drive large declines in wild herbivores, understanding the context dependence of herbivore impacts on plant communities becomes increasingly important. Exclosure experiments are frequently used to assess how ecosystems reorganize in the face of large wild herbivore defaunation. Yet in many landscapes, declines in large wildlife are often accompanied by other anthropogenic activities, especially land conversion to livestock production. In such cases, exclosure experiments may not reflect typical outcomes of human-driven extirpations of wild herbivores. Here, we examine how plant community responses to changes in the identity and abundance of large herbivores interact with abiotic factors (rainfall and soil properties). We also explore how effects of wild herbivores on plant communities differ between large-scale herbivore exclosures and landscape sites where anthropogenic activity has caused wildlife declines, often accompanied by livestock increases. Abiotic context modulated the responses of plant communities to herbivore declines with stronger effect sizes in lower-productivity environments. Also, shifts in plant community structure, composition and species richness following wildlife declines differed considerably between exclosure experiments and landscape sites in which wild herbivores had declined and were often replaced by livestock. Plant communities in low wildlife landscape sites were distinct in both composition and physical structure from both exclosure and control sites in experiments. The power of environmental (soil and rainfall) gradients in influencing plant response to herbivores was also greatly dampened or absent in the landscape sites. One likely explanation for these observed d

关键词： Agriculture   Biology   Botany   Community ecology   Conservation science   Ecology   Forestry   Global change ecology   Microbial ecology   Microbiology   Mycology   Plant ecology   Research Article   Soil ecology   Systems ecology  

摘要： Biological invasions are often complex phenomena because many factors influence their outcome. One key aspect is how non-natives interact with the local biota. Interaction with local species may be especially important for exotic species that require an obligatory mutualist, such as Pinaceae species that need ectomycorrhizal (EM) fungi. EM fungi and seeds of Pinaceae disperse independently, so they may use different vectors. We studied the role of exotic mammals as dispersal agents of EM fungi on Isla Victoria, Argentina, where many Pinaceae species have been introduced. Only a few of these tree species have become invasive, and they are found in high densities only near plantations, partly because these Pinaceae trees lack proper EM fungi when their seeds land far from plantations. Native mammals (a dwarf deer and rodents) are rare around plantations and do not appear to play a role in these invasions. With greenhouse experiments using animal feces as inoculum, plus observational and molecular studies, we found that wild boar and deer, both non-native, are dispersing EM fungi. Approximately 30% of the Pinaceae seedlings growing with feces of wild boar and 15% of the seedlings growing with deer feces were colonized by non-native EM fungi. Seedlings growing in control pots were not colonized by EM fungi. We found a low diversity of fungi colonizing the seedlings, with the hypogeous Rhizopogon as the most abundant genus. Wild boar, a recent introduction to the island, appear to be the main animal dispersing the fungi and may be playing a key role in facilitating the invasion of pine trees and even triggering their spread. These results show that interactions among non-natives help explain pine invasions in our study area.

关键词： 规模化饲养   动物模型   实验动物   动物资源   云南省   繁殖   成果展示   应用  

摘要： 由中国医学科学院医学生物学研究所代解杰课题组联合昆明理工大学生命科学与技术学院共同完成的“树鼢饲养繁殖种群建立及其在HCV动物模型中的应用”项目历时7年，获得2012年云南省科学技术进步一等奖，开创了云南省特色实验动物资源一一树鼢研究的里程碑，彰显了云南省在树嗣饲养繁殖和运用树鼢建立人类疾病动物模型研究领域的顶尖实力，标志着云南省树胸规模化饲养繁殖与应用研究已达到国际先进水平。

关键词： elephant shrew   tree shrew   Macroscelididae   Tupaiidae   Cryptococcus spp.   Gongylonema spp.   arteriosclerosis  

摘要： Investigations into the cause of mortality and other important findings at necropsy were made into two families of small mammals at the Smithsonian National Zoological Park (SNZP;USA). Necropsy reports from 1976 through 2008 were reviewed for all elephant shrews in family Macroscelididae (n = 118) and all tree shrews in family Tupaiidae (n = 90) that lived for greater than 30 days at the SNZP. Causes of mortality were classified by body system and etiology to identify prevalent diseases and trends across demographics for each family. In elephant shrews, gastrointestinal disease (n = 18) and respiratory disease (n = 22) were important causes of mortality with an increased prevalence of pneumonia in adult males. Trauma was a common cause of mortality in tree shrews (n = 22). Cryptococcosis was an important cause of mortality in both families (n = 8 elephant shrews;n = 13 tree shrews). Bacterial infections, often systemic at time of mortality, were also common (n = 16 elephant shrews;n = 17 tree shrews). Arteriosclerosis was a common comorbid pathology noted at necropsy in certain populations, seen only in Elephantulus rufescens in the family Macroscelididae (n = 22) and in only males in the family Tupaiidae (n = 11). Gongylonemiasis was seen commonly in tree shrews (n = 15), as a comorbid finding, or in 5 cases directly leading to mortality. Awareness of the prevalence of these diseases can help guide prevention and intervention strategies.

关键词： late Miocene   Europe   Palaeoenvironments   Mammalian palaeocommunity   Body mass   Biomass  

摘要： Western European Turolian mammalian faunas and palaeoenvironments are less well known than middle and early late Miocene ones for which more data exist at a time when major climate events occurred (Middle Miocene Climatic Optimum followed by Late Middle Miocene Climatic Cooling). In this respect, rich faunas represent exceptional windows into mammalian diversity and biogeography. They constitute key points to understand local palaeoenvironments and refine larger-scale patterns. Dorn-Durkheim 1 is one of the richest mammalian faunas of Western Europe with at least 79 species of mammals. We investigate this fauna and compare its composition to the faunal and biogeographic context of the European late Miocene. A community-based analysis of body masses of the constituent species together with an original approach on predator-prey biomasses are also attempted to reconstruct its palaeoenvironment. While its composition reflects the known late Miocene context and fits in the biogeographic North-South pattern evidenced by earlier studies, the reconstructed landscape is different from previous hypotheses of densely forested habitats. Our results suggest the presence of a savanna-woodland biome more open than previously thought, in a subtropical-like and seasonal climate. Other palaeoecological studies on elements of the large mammal fauna confirm this interpretation.

关键词： Hyla japonica   Agricultural intensification   Flood irrigation management   Misgurnus anguillicaudatus   Rice paddies   Structural equation modeling  

摘要： In Japan, the density of Japanese tree frogs (Hyla japonica) may not be necessary high in traditional rice fields compared to modern fields because the modernization of drainage systems from shallow earthen ditches to deep concrete-line ones reduces the abundance of predators/competitors for tadpoles, such as dojo loach (Misgurnus anguillicaudatus). This hypothesis was tested using two approaches. First, laboratory experiments revealed that the presence of the loach significantly reduced the survival of tree frog eggs and tadpoles. Second, observational studies in rice fields showed that the direct effect of modernization on tadpoles was not significant but the indirect (and thus total) effects were weakly positive due to the reduction in the density of dojo loach. Our study suggests that recent agricultural intensification in rice fields does not negatively impact all aquatic species but that some species may not be affected or can even flourish by having tolerance for the changes and release from potential predators or competitors.

关键词： Tree hypothesis   Species hypothesis   Seasonality hypothesis   Ecosystem size hypothesis   Brown food web   Litter arthropods   Predator to prey ratios  

摘要： Litter arthropod abundance in tropical forests is patchily distributed in space and time. This patchiness can be described by three general hypotheses relating plant-based effects to litter arthropod distribution. The tree hypothesis (H1) posits that environments maintained underneath tree canopies are different from those between canopies in ways that shape arthropod abundance. The species hypothesis (H2) refines this scenario, positing that different plant species might maintain distinct litter environments to which arthropod abundances respond. Without regard to specific plant effects, seasonal changes in litter profiles (H3) can account for temporal patchiness in arthropod abundance. The ecosystem size hypothesis provides a mechanism for tree, species and seasonal effects. It links increasing food chain length with habitat availability and its heterogeneity. In a Panamanian rainforest we sampled litter arthropods in quadrats located near (1 m) and far away (30 m) from the parent trunk of 93 tree individuals (to test the tree hypothesis) from 10 tree species (to test the species hypothesis) in the early wet season, when litter is deepest. To test for effects of seasonal changes of litter profiles, we then resampled 25 trees (i.e., five individuals from each of five species) in the late wet season, when climatic conditions are similar, but litter is shallowest. We found weak support for all tree, species and seasonality hypotheses. With few exceptions, trees and species did not sustain different arthropod abundances, neither early nor late in the wet season. Collembola abundance increased late in the wet season, when litter is shallowest. Supporting the ecosystem size hypothesis, accumulated litter either due to trees, species and seasonality sustained higher predator abundance and higher predator to prey ratios. Our results suggest that plants may account for detrital, brown, food web structure;but these effects are mostly through plant-based provision of structu

关键词： Cawston Ranch   conservation   hollows   small animals   stags   utilization  

摘要： The objective of this study was to characterize hollows found in selected tree species (in Cawston Ranch in Zimbabwe) as a potential habitat for small mammals because cavities are important as resources for wildlife: for foraging, shelter, roosting and nesting purposes. Four vegetation types were chosen for analysis: Baikiaea plurijuga, Colophospermum mopane, Combretum molle and Commiphora mollis according to abundance and dominance in the plots they occurred. Transect sampling was performed to collect vegetation data. The total number of living trees and stags was recorded in each plot. Trees in a plot were thoroughly inspected for hollows. The following dimensions were measured on cavity trees: hollow size (diameter), hollow location and diameter at breast height. The results indicate that the rate of hollow formation and utilization is significantly dependent on tree species. There was a significant difference in the provision of hollows in stem and crown of a tree in each of the vegetation classes analysed. *** hollows had the highest utilization, whilst *** had the least utilization. Hollows are utilized irrespective of their location as long as the animal finds a niche, and stags at advanced stages of decay are not important in providing habitats for animals.

关键词： LEMURS -- Behavior   SLEEP behavior in animals  

摘要： The article reports that researchers from the Duke Lemur Center in Durham, North Carolina have discovered two species of Lemurs that hibernate underground.

关键词： Canopy crane   feeding guilds   flower-visitors   herbivory   wet tropics  

摘要： Reliable estimates of host specificity in tropical rainforest beetles are central for an understanding of food web dynamics and biodiversity patterns. However, it is widely assumed that herbivores constitute the majority of host specific species, and that most herbivore species feed on leaves. We tested the generality of this assumption by comparing both plant host- and microhabitat-specificity between beetle communities inhabiting the foliage (flush and mature), flowers, fruit, and suspended dead wood from 23 canopy plant species in a tropical rainforest in north Queensland, Australia. Independent of host tree identity, 76/77 of the most abundant beetle species (N12 individuals) were aggregated on a particular microhabitat. Microhabitat specialization (measured by Sm and Lloyd's indices) was very high and did not differ between flower and foliage communities, suggesting that each newly-sampled microhabitat has a large additive effect on total species richness. In accordance with previous studies, host specificity of foliage-inhabiting beetles was most pronounced among herbivorous families (Curculionidae, Chrysomelidae). By contrast, host specificity among flower-visitors was equally high among herbivorous and nonherbivorous families (e.g. Nitidulidae, Staphylinidae, Cleridae). Effective specialization (FT) measures showed that traditional correction factors used to project total species richness in nonherbivorous groups fail to fully capture diversity in the flower-visiting beetle fauna. These results demonstrate that host specialization is not concentrated within folivores as previously assumed.(c) 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 215228.