关键词： determinants of plant community diversity and structure   extinction   functional diversity   Kruger National Park   phylogenetics  

摘要： There has been much debate on the impact of large herbivores on biodiversity, especially given that large mammals are becoming locally extinct in many places. The use of evolutionary information on community structure has typically been limited to evaluating assembly processes, for example, competition or habitat filtering, whereas a lack of long-term experiments has precluded the test of predictions considering more complex biotic interactions. Reconstructing the complete phylogeny of the trees and shrubs of the Kruger National Park from DNA data, we tested for phylogenetic signal in antiherbivory traits and compared the phylogenetic structure of communities under various degrees of herbivore pressure using experimental plots spanning several decades. We show that all antiherbivory traits examined demonstrated weak but significant phylogenetic signal, and that exclusion of large herbivores results in impoverished species diversity in restructured communities. Surprisingly, we also show that reduction in species diversity coupled with community reorganization does not necessarily result in a decrease in phylogenetic diversity, and that community responses to herbivore exclusion depend on initial structure. Synthesis. Extinction of large mammal herbivores will have cascading effects on plant diversity;however, impacts on plant community structure are contingent on initial conditions. This research has implications for best practice when managing large herbivores and natural habitats.

关键词： Nesting habits   Grasslands   Trees   Birds   Snakes   Predation   Squirrels   Raccoons  

摘要： Globally, grasslands and the wildlife that inhabit them are widely imperiled. Encroachment by shrubs and trees has widely impacted grasslands in the past 150 years. In North America, most grassland birds avoid nesting near woody vegetation. Because woody vegetation fragments grasslands and potential nest predator diversity and abundance is often greater along wooded edge and grassland transitions, we measured the impacts of removing rows of trees and shrubs that intersected grasslands on potential nest predators and the three most abundant grassland bird species (Henslow's sparrow [Ammodramus henslowii], Eastern meadowlark [Sturnella magna], and bobolink [Dolichonyx oryzivorus]) at sites in Wisconsin, U. S. A. We monitored 3 control and 3 treatment sites, for 1 yr prior to and 3 yr after tree row removal at the treatment sites. Grassland bird densities increased (2-4 times for bobolink and Henslow's sparrow) and nesting densities increased (all 3 species) in the removal areas compared to control areas. After removals, Henslow's sparrows nested within <= 50 m of the treatment area, where they did not occur when tree rows were present. Most dramatically, activity by woodland-associated predators nearly ceased (nine-fold decrease for raccoon [Procyon lotor]) at the removals and grassland predators increased (up to 27 times activity for thirteen-lined ground squirrel [Ictidomys tridecemlineatus]). Nest success did not increase, likely reflecting the increase in grassland predators. However, more nests were attempted by all 3 species (175 versus 116) and the number of successful nests for bobolinks and Henslow's sparrows increased. Because of gains in habitat, increased use by birds, greater production of young, and the effective removal of woodland-associated predators, tree row removal, where appropriate based on the predator community, can be a beneficial management action for conserving grassland birds and improving fragmented and degraded grassland ecosystems.

关键词： 树鼩   人类疾病动物模型  

摘要： 由于树鼩的生理、生化和解剖学等生物学特性与人类相似,人们利用树鼩建立了多种人类病毒性疾病动物模型,并在细菌感染疾病、呼吸系统、内分泌、神经系统疾病和肿瘤等方面有广泛的研究和应用,本文就树鼩在人类疾病动物模型研究中应用的新进展进行概述。

关键词： 树鼩   动物福利   措施  

摘要： 树鼩在生物学特性、生理生化、新陈代谢和基因组等方面近似于人类,被广泛应用于生理学、病理学、病毒学、免疫学、药理学及遗传学等多个领域。迄今为止用于生物医学研究的树鼩大部分来自野生,实验树鼩尚无国家质量控制标准。为了保证树鼩引种、驯化、饲养、繁殖、质量控制及福利的规范化和科学化,提高树鼩繁殖率和成活率,本文从兽医公共卫生及实验动物科学的角度,对野生树鼩的捕捉、运输、检疫、饲养及繁育等方面的基本原则及技术操作和福利要求作一简述,为从事树鼩工作的有关人员及树鼩实验动物化研究提供参考。

关键词： Frankliniella   Faramea cyanea   Hancornia speciosa   Solanum lycocarpum   plantanimal interactions   Brazil  

摘要： This study shows that three Frankliniella (Thysanoptera) species have species-specific associations with their hosts: F. varipesFaramea cyanea (Rubiaceae);F. musaeperdaHancornia speciosa (Apocynaceae) and F. fulvipesSolanum lycocarpum (Solanaceae). All thrips species had a marked preference for flowers in anthesis, as in this stage flowers provide food and protection from environment. Frankliniella musaeperda and F. varipes populations were female-biased while F. fulvipes was male-biased. Since many species of Frankliniella have economic importance, studies on the ecology of these species are essential, given the possibility of invasion of agricultural systems in the future.

关键词： 树鼩   实验动物   基础生物学   人类疾病动物模型  

摘要： 动物模型在生物医学领域(如回答人体各种重大生物学问题、解析人类疾病机理和新药研发等方面)已经做出了不可替代的巨大贡献。转化医学存在的问题使得树鼩(Tupaia belangeri chinensis)实验动物重新得到重视;人类疾病的树鼩模型也再次受到越来越多的关注。该文综述了国内外特别是近年来我国树鼩研究进展,包括树鼩基础生物学及动物模型方面取得的成绩,并分析了该领域目前存在的困难和问题,探讨了未来的一些研究方向。

关键词： 动物模型   人类疾病机理   实验室   树鼩基因组  

摘要： 由中科院昆明动物所动物模型与人类疾病机理重点实验室、深圳华大基因研究院等单位合作完成的破译树鼩基因组研究工作于2013年2月在《自然·通讯》（Nature Communications）杂志上在线发表。研究人员通过完成高质量的树鼩（Tupaia belangen chinensis）全基因组测序及比较基因组分析，阐明了其系统分类地位和相关生物学特征的遗传基础，尤其是树购用于若干重要疾病如HBV、HCV感染以及抑郁症模型创建的遗传学基础。该研究将能推动树鼩应用于生物医药的系统研究。

关键词： browse   diet   herbivore   insectivore   muroid rodents   omnivore   savanna   stable isotopes  

摘要： It is well established that massive consumption of plants by the abundant and diverse assemblage of savanna ungulates in East Africa competitively suppresses the native guild of herbivorous to omnivorous small mammals. An important role of woody plant suppression in the Acacia-dominated savannas for this guild of rodents, when released from ungulate competition, has been demonstrated only recently, but without direct evidence of which species are involved. In an effort to establish which of the common species in this guild are most likely to impact growth of trees and forbs, as opposed to grasses or insects, or both, I present data on atomic and isotopic ratios of fecal carbon and nitrogen from 8 commonly occurring muroid rodents from savanna and bush habitats on the Laikipia Plateau of central Kenya: Acomys percivali, Acomys wilsoni, Aethomys hindei, Arvicanthis niloticus, Mastomys natalensis, Mus spp. (thought to be mostly M. minutoides), Saccostomus mearnsi, and Gerbilliscus robustus. In this region where all grasses are C-4 and all trees and other nongrasses are C-3, different ratios of C-13:C-12(delta C-13) in plant tissues give pure grazers, pure browsers, and mixed-feeding herbivores distinctive carbon isotope signatures. Degree of omnivory is revealed by C:N and, arguably, by delta C-15, but the latter is influenced by dietary protein quality and varies widely by plant species and soil type. Joint consideration of stable-isotope data, total C:N, and microhistological analysis of feces allowed better resolution of dietary niche of each species than any of these data sets could, alone. Grass was either coequal to browse (dicots) or dominated the plant portion of each species' diet, which was somewhat unexpected given rodents' hypothesized role in limiting Acacia recruitment. All species consumed some arthropods. A. niloticus, the only diurnal species, was the most herbivorous, being largely a grazer. S. mearnsi, A. hindei, and M. natalensis were mixed-feeding

关键词： Horse   Impacts   Mechanization   Productivity   Cost   Compaction  

摘要： The authors tested animal and machine harvesting as alternative systems for salvaging windthrown trees in regenerated patch cuts. Removal intensity was very low, averaging between 10 and 20 m(3) ha(-1), or between 30 and 60% of the initial stocking. Both systems performed well. Damage to regeneration never exceeded 5% of the total number. Soil disturbance was very shallow, and interested less than 3% of the total area. No significant difference was found between the animal and the machine treatments. From an economic viewpoint, the animal system broke even, whereas the machine system accrued an average profit of over 200 ha-1. However, profit was not as large as to become a major driver. Park users may represent the main factor when selecting a specific salvage system, and should be the subject of future research. (C) 2012 Elsevier B.V. All rights reserved.

关键词： Animal types   Behavioral ecology   Bioethics   Biology   Community ecology   Conservation science   Ecological economics   Ecology   Large animals   Population biology   Population dynamics   Population ecology   Research Article   Risk-benefit analysis   Science policy   Species interactions   Veterinary science   Wildlife  

摘要： Large African predators, especially lions (Panthera leo) and leopards (Panthera pardus), are financially valuable for ecotourism and trophy hunting operations on land also utilized for the production of other wildlife species for the same purpose. Predation of ungulates used for trophy hunting can create conflict with landholders and trade off thus exists between the value of lions and leopards and their impact on ungulate populations. Therefore productionist and conservation trade-offs are complexly graded and difficult to resolve. We investigated this with a risk-benefit analysis on a large private wildlife production area in Zimbabwe. Our model showed that lions result in substantial financial costs through predation on wild ungulates that may not be offset by profits from hunting them, whereas the returns from trophy hunting of leopards are projected to exceed the costs due to leopard predation. In the absence of additional income derived from photo-tourism the number of lions may need to be managed to minimize their impact. Lions drive important ecological processes, but there is a need to balance ecological and financial imperatives on wildlife ranches, community wildlife lands and other categories of multiple use land used for wildlife production. This will ensure the competitiveness of wildlife based land uses relative to alternatives. Our findings may thus be limited to conservancies, community land-use areas and commercial game ranches, which are expansive in Africa, and should not necessarily applied to areas where biodiversity conservation is the primary objective, even if hunting is allowed there.