关键词： 树鼩   动物模型   综述  

摘要： 树鼩属于低等灵长类动物,其形态、生理机能和生化代谢等与人类相似,实验研究的结果容易推广到人,广泛应用于医学生物学研究。研究人员利用树鼩已经建立许多模拟人类疾病的树鼩动物模型,如肝炎病毒性疾病、糖尿病、肿瘤和老年痴呆模型等。对树鼩在动物模型中的应用研究进行概述。

关键词： climate extremes   ecosystem processes   extreme climate events   flowering   frugivores   fruiting   nectarivores   tree reproductive phenology   vertebrate species  

摘要： Forest vertebrate fauna provide critical services, such as pollination and seed dispersal, which underpin functional and resilient ecosystems. In turn, many of these fauna are dependent on the flowering phenology of the plant species of such ecosystems. The impact of changes in climate, including climate extremes, on the interaction between these fauna and flora has not been identified or elucidated, yet influences on flowering phenology are already evident. These changes are well documented in the mid to high latitudes. However, there is emerging evidence that the flowering phenology, nectar/pollen production, and fruit production of long-lived trees in tropical and subtropical forests are also being impacted by changes in the frequency and severity of climate extremes. Here, we examine the implications of these changes for vertebrate fauna dependent on these resources. We review the literature to establish evidence for links between climate extremes and flowering phenology, elucidating the nature of relationships between different vertebrate taxa and flowering regimes. We combine this information with climate change projections to postulate about the likely impacts on nectar, pollen and fruit resource availability and the consequences for dependent vertebrate fauna. The most recent climate projections show that the frequency and intensity of climate extremes will increase during the 21st century. These changes are likely to significantly alter mass flowering and fruiting events in the tropics and subtropics, which are frequently cued by climate extremes, such as intensive rainfall events or rapid temperature shifts. We find that in these systems the abundance and duration of resource availability for vertebrate fauna is likely to fluctuate, and the time intervals between episodes of high resource availability to increase. The combined impact of these changes has the potential to result in cascading effects on ecosystems through changes in pollinator and seed dispe

关键词： genotypic diversity   herbivores   predators   species diversity   species richness  

摘要： Despite potential interactive effects of plant species and genotypic diversity (SD and GD, respectively) on consumers, studies have usually examined these effects separately. We evaluated the individual and combined effects of tree SD and mahogany (Swietenia macrophylla) GD on the arthropod community associated with mahogany. We conducted this study within the context of a tree diversity experiment consisting of 74 plots with 64 saplings/plot. We sampled 24 of these plots, classified as monocultures of mahogany or polycultures of four species (including mahogany). Within each plot type, mahogany was represented by either one or four maternal families. We surveyed arthropods on mahogany and estimated total arthropod abundance and species richness, as well as abundance and richness separately for herbivorous and predatory arthropods. Overall tree SD and mahogany GD had positive effects on total arthropod species richness and abundance on mahogany, and also exerted interactive effects on total species richness (but not abundance). Analyses conducted by trophic level group showed contrasting patterns;SD positively influenced herbivore species richness but not abundance, and did not affect either predator richness or abundance. GD influenced predator species richness but not abundance, and did not influence herbivore abundance or richness. There were interactive effects of GD and SD only for predator species richness. These results provide evidence that intra- and inter-specific plant diversity exert interactive controls on associated consumer communities, and that the relative importance of SD and GD may vary among higher trophic levels, presumably due to differences in the underlying mechanisms or consumer traits. Resumen A pesar del potencial de efectos de interaccion entre la diversidad de especies y la diversidad genotipica (DS y DG respectivamente) sobre los consumidores, en general dichos efectos han sido evaluados de manera aislada. Evaluamos los efectos individu

关键词： Wildlife crime   Enforcement   Mobile app   Conservation technology   Customs  

摘要： Accurate field identification of illegally traded wildlife and wildlife products is critically important in the detection and suppression of wildlife crimes. Yet many law enforcement officers and concerned citizens lack access to resources for identifying species and products;this is particularly true for those with no formal expertise in biology, zoology or wildlife training. Emerging digital technologies such as mobile applications may provide important easy-to-use decision-tree style tools for in situ identification. With local government and civil society partners, we are piloting such tools in China and Vietnam to identify whole animals and ivory products;and in the United States developing tools that will be used at U.S. military bases in Afghanistan to identify species from wildlife products. We are coordinating these efforts to minimize redundancy and overhead;we benefit from shared backend support for a photo database and species ID keys that can be translated easily to ensure enough flexibility for targeting needs of the specific country and audience. Planned inclusion of 'ask the expert' and geolocation functions will increase accuracy in identification and aid monitoring and research of supply chains. For these emerging technologies to be successful, deployment must be accompanied with on-the-ground trainings to recruit and retain enforcement personnel. The establishment of a supporting network of experts and a user community will be critical for long-term implementation and evaluation of success. Preliminary response from users of a pilot app in China demonstrates high potential for employing these technologies as routine tools to help fight wildlife crimes. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Birds   Deadwood   Exotic Species   Forest Management   LIFE Project   Saproxylic Organisms  

摘要： The cavities that develop in veteran trees represent a key microhabitat for forest biodiversity and especially for secondary cavity nesters that rely on this resource for shelter. Since the availability of deadwood, veteran and hollow trees is threatened by forest management, we explored the possibility of increasing the presence of these scarce resources. To increase the abundance of dead wood-microhabitats, 113 trees of the hybrid planes (Platanus x acerifolia) were converted into new living structures, the Habitat Trees (HT). To investigate the potential of this resource on the native avian fauna, six types of cavities were designed according to the size requirements of the target bird species. The temporal evolution of the cavities and their use by birds were then studied for eight years. The artificial cavities generally did not compromise growth and stability of the trees, and the majority remained alive. These hollows offered better thermal insulation compared to traditional nest-boxes and natural cavities. Their use increased during the first three years, reaching the 80%. In the following years, the use declined (probably because of the increase of rot and displacement of the lids). This highlights the need of management to maintain their suitability through time. Our results suggest a possible cost-effective alternative use of alien tree species, which should be included in management actions to compensate the shortage of hollow trees in managed forests.

关键词： Akaike's information criterion   Biodiversity conservation   Ecosystem engineer   Evenness   Richness   Southeastern coastal plain  

摘要： Keystone species are important drivers of diversity patterns in many ecosystems. Their effects on ecological processes are fundamental to understanding community dynamics, making them attractive conservation targets for ecosystem management. However, many studies assume keystone effects are constant. By developing functional relationships of species' effects and assessing how they vary with context, we can design more efficient conservation strategies to maintain keystone impacts. The threatened gopher tortoise (Gopherus polyphemus) is presumed to be a keystone species promoting biodiversity in endangered longleaf pine ecosystems of the Southeastern Coastal Plain, USA. Although many commensals use tortoise burrows, their putative keystone influence on emergent diversity patterns lacks critical evaluation. We quantified the functional relationship between tortoise burrow density and non-volant vertebrate diversity in a longleaf pine savanna, located in central Florida. Tortoise burrow density had a positive effect on vertebrate diversity and evenness but did not affect species richness. This relationship was robust across fire disturbance regimes and was the primary factor explaining diversity at the local scale. Our results demonstrate keystone effects of the gopher tortoise through an ecosystem engineering mechanism. Continued gopher tortoise population declines will have large, negative impacts on vertebrate diversity in this biodiversity hotspot. Therefore, maintaining gopher tortoise populations is critical to effectively conserve dependent species and the function of endangered longleaf pine ecosystems. We show that developing a functional understanding of keystone relationships (not a binomial categorization) can lead to important insights into community processes.

关键词： 生活   动物   高层建筑物   卡耐基   市中心   电梯   左手  

摘要： 钢铁大王卡耐基去纽约市中心一幢高层建筑物，乘电梯时，他遇到一位开电梯的人，这人的左手被齐腕砍断。卡耐基就问这位没有左手的人，会不会因为没有手感到难过。 ”

关键词： 哺乳动物化石   内蒙古宁城   河北省   地穴   树栖   中国地质科学院   地球   中国北方地区  

摘要： 据2015年2月13日《参考消息》援引报道，美国芝加哥大学和中国地质科学院地质研究所研究人员在中国北方地区发现两件柱齿兽类的原始哺乳动物化石。其中一种被命名为攀援灵巧柱齿兽的化石于2011年发现于内蒙古宁城，生活在距今1．65亿年前，是已知最早的树栖型哺乳动物，有特化的牙齿可食树汁树液。另一种被命名为短指挖掘柱齿兽的化石于2012年发现于河北省青龙县，生活在距今1．6亿年前，是已知最早的地穴型哺乳动物，牙齿可食昆虫。

关键词： common garden   community assembly theory   community evolution   community networks   community phenotype   community-genetic correlations   ecological genetics and ecogenomics   interacting foundation species hypothesis   physical proximity hypothesis   Populus  

摘要： Community genetics studies frequently focus on individual communities associated with individual plant genotypes, but little is known about the genetically based relationships among taxonomically and spatially disparate communities. We integrate studies of a wide range of communities living on the same plant genotypes to understand how the ecological and evolutionary dynamics of one community may be constrained or modulated by its underlying genetic connections to another community. We use pre-existing data sets collected from Populus angustifolia (narrowleaf cottonwood) growing in a common garden to test the hypothesis that the composition of pairs of distinct communities (e.g. endophytes, pathogens, lichens, arthropods, soil microbes) covary across tree genotypes, such that individual plant genotypes that support a unique composition of one community are more likely to support a unique composition of another community. We then evaluate the hypotheses that physical proximity, taxonomic similarity, time between sampling (time attenuation), and interacting foundation species within communities explain the strength of correlations. Three main results emerged. First, Mantel tests between communities revealed moderate to strong (=0.25-0.85) community-genetic correlations in almost half of the comparisons;correlations among phyllosphere endophyte, pathogen and arthropod communities were the most robust. Secondly, physical proximity determined the strength of community-genetic correlations, supporting a physical proximity hypothesis. Thirdly, consistent with the interacting foundation species hypothesis, the most abundant species drove many of the stronger correlations. Other hypotheses were not ***. The field of community genetics demonstrates that the structure of communities varies among plant genotypes;our results add to this field by showing that disparate communities covary among plant genotypes. Eco-evolutionary dynamics between plants and their ass

关键词： Livestock   Facilitation   Herbivory   Nurse plants   Spatial association  

摘要： Successful persistence of dry forests depends on tree regeneration, which depends on a balance of complex biotic interactions. In particular, the relative importance and interactive effects of shrubs and herbivores on tree regeneration are unclear. In a manipulative study, we investigated if thornless shrubs have a direct net effect, an indirect positive effect mediated by livestock, and/or an indirect negative effect mediated by small vertebrates on tree regeneration of two key species of Chaco forest (Argentina). In a spatial association study, we also explored the existence of net positive interactions from thorny and thornless shrubs. The number of Schinopsis lorentzii seedlings was highest under artificial shade with native herbivores and livestock excluded. Even excluding livestock, no seedlings were found with natural conditions (native herbivores present with natural shade or direct sunlight) at the end of the experiment. Surprisingly, seedling recruitment was not enhanced under thornless shrubs, because there was a complementary positive effect of shade and interference. Moreover, thornless shrubs had neither positive nor negative effects on regeneration of S. lorentzii. Regeneration of Aspidosperma quebracho-blanco was minimal in all treatments. In agreement with the experiment, spatial distributions of saplings of both tree species were independent of thornless shrubs, but positively associated with thorny shrubs. Our results suggest that in general thornless shrubs may have a negligible effect and thorny shrubs a net positive effect on tree regeneration in dry forests. These findings provide a conceptual framework for testing the impact of biotic interactions on seedling recruitment in other dry forests.