关键词： Forest-grassland segregation   Herbivore-vegetation interaction   Rewilding   Norway spruce Picea abies   European beech Fagus sylvatica   Swiss Jura Mountains  

摘要： The pasture-woodlands of Central Europe are low-intensity grazing systems in which the structural richness of dynamic forest-grassland mosaics is causal for their high biodiversity. Distinct mosaic patterns in Picea abies- and Fagus sylvatica-dominated pasture-woodlands in the Swiss Jura Mountains suggest a strong influence of tree species regeneration ecology on landscape structural properties. At the landscape scale, however, cause-effect relationships are complicated by habitat selectivity of livestock. We asked which tree species regeneration traits and what kind of feedbacks among local-scale vegetation dynamics and landscape-scale herbivore behavior are causal for the contrasted landscape structural characteristics of Picea- and Fagus-dominated pasture-woodlands. We performed simulation experiments of mosaic pattern formation in both pasture-woodland types. The regeneration traits, namely dispersal distance, resistance to browsing and tolerance to shade, and the rules for habitat selection of cattle were modified and the corresponding shifts in landscape structure were analyzed. Dispersal distance showed a significant, but only local, effect promoting forest fringe formation. Saplings' resistance to browsing mainly determined overall tree cover, but did not influence landscape structure. At the landscape scale, both shade tolerance of saplings and selective habitat use by cattle were responsible for forest-grassland segregation: high shade tolerance triggered segregation, whereas non-selective habitat use hindered it. Existing local-scale theory on pasture-woodland dynamics is complemented by an herbivore-vegetation feedback among spatial scales. In low-intensity pastures, where large herbivores are preferentially "grazers" and trees form dense canopies, an intrinsic trend towards forest-grassland segregation at the expense of forest-grassland ecotones is predicted.

关键词： Evolution   phylogeny   animal kingdom   DNA  

摘要： New phylogenomic methods have made it possible to obtain a robust phylogenetic tree of the animal kingdom. The resulting tree confirms much of what was already known but also contains some nice surprises.

关键词： Termites   Herbivores   Predation (Biology)   Macrotermes   Grazing  

摘要： Herbivores do not forage uniformly across landscapes, but select for patches of higher nutrition and lower predation risk. Macrotermes mounds contain higher concentrations of soil nutrients and support grasses of higher nutritional value than the surrounding savanna matrix, attracting mammalian grazers that preferentially forage on termite mound vegetation. However, little is known about the spatial extent of such termite influence on grazing patterns and how it might differ in time and space. We measured grazing intensity in three African savanna types differing in rainfall and foliar nutrients and predicted that the functional importance of mounds for grazing herbivores would increase as the difference in foliar nutrient levels between mound and savanna matrix grasses increases and the mounds become more attractive. We expected this to occur in nutrient-poor areas and during the dry season when savanna matrix grass nutrient levels are lower. Tuft use and grass N and P content were measured along transects away from termite mounds, enabling calculation of the spatial extent of termite influence on mammalian grazing. Using termite mound densities estimated from airborne light detection and ranging (LiDAR), we further upscaled field-based results to determine the percentage of the landscape influenced by termite activity. Grasses in close proximity to termite mounds were preferentially grazed at all sites and in both seasons, but the strength of mound influence varied between savanna types and seasons. In the wet season, mounds had a relatively larger effect on grazers at the landscape scale in the nutrient-poor, wetter savanna, whereas in the dry season the pattern was reversed with more of the landscape influenced at the nutrient-rich, driest site. Our results reveal that termite mounds enhance the value of savanna landscapes for herbivores, but that their functional importance varies across savanna types and seasons.

关键词： outreach   power   trust   Kenya   Tanzania  

摘要： We developed a "continual engagement" model to better integrate knowledge from policy makers, communities, and researchers with the goal of promoting more effective action to balance poverty alleviation and wildlife conservation in 4 pastoral ecosystems of East Africa. The model involved the creation of a core boundary-spanning team, including community facilitators, a policy facilitator, and transdisciplinary researchers, responsible for linking with a wide range of actors from local to global scales. Collaborative researcher-facilitator community teams integrated local and scientific knowledge to help communities and policy makers improve herd quality and health, expand biodiversity payment schemes, develop land-use plans, and fully engage together in pastoral and wildlife policy development. This model focused on the creation of hybrid scientific-local knowledge highly relevant to community and policy maker needs. The facilitation team learned to be more effective by focusing on noncontroversial livelihood issues before addressing more difficult wildlife issues, using strategic and periodic engagement with most partners instead of continual engagement, and reducing costs by providing new scientific information only when deemed essential. We conclude by examining the role of facilitation in redressing asymmetries in power in researcher-community-policy maker teams, the role of individual values and character in establishing trust, and how to sustain knowledge-action links when project funding ends.

关键词： IBM   Functional types   Trait-based approach   Shrub encroachment   Birds  

摘要： Climate change and land use management practices are major drivers of biodiversity in terrestrial ecosystems. To understand and predict resulting changes in community structures, individual-based and spatially explicit population models are a useful tool but require detailed data sets for each species. More generic approaches are thus needed. Here we present a trait-based functional type approach to model savanna birds. The aim of our model is to explore the response of different bird functional types to modifications in habitat structure. The functional types are characterized by different traits, in particular body mass, which is related to life-history traits (reproduction and mortality) and spatial scales (home range area and dispersal ability), as well as the use of vegetation structures for foraging and nesting, which is related to habitat quality and suitability. We tested the performance of the functional types in artificial landscapes varying in shrub:grass ratio and clumping intensity of shrub patches. We found that an increase in shrub encroachment and a decrease in habitat quality caused by land use mismanagement and climate change endangered all simulated bird functional types. The strength of this effect was related to the preferred habitat. Furthermore, larger-bodied insectivores and omnivores were more prone to extinction due to shrub encroachment compared to small-bodied species. Insectivorous and omnivorous birds were more sensitive to clumping intensity of shrubs whereas herbivorous and carnivorous birds were most affected by a decreasing amount of grass cover. From an applied point of view, our findings emphasize that policies such as woody plant removal and a reduction in livestock stocking rates to prevent shrub encroachment should prioritize the enlargement of existing grassland patches. Overall, our results show that the combination of an individual-based modelling approach with carefully defined functional types can provide a powerful tool f

关键词： 物种多样性   G-F多样性   大型底栖动物   红树林   互花米草   光滩   瓯江口  

摘要： 为了解瓯江口树排沙湿地不同生境大型底栖动物群落多样性,于2014年10月至2015年6月对红树林、互花米草及光滩3种生境开展大型底栖动物调查。共鉴定出大型底栖动物48种,隶属于5纲15目31科40属。大型底栖动物年平均栖息密度和生物量,红树林生境最高,互花米草生境次之,光滩生境最低。采用物种多样性指数和G-F多样性指数分析不同生境大型底栖动物群落多样性,发现红树林生境大型底栖动物的多样性高于互花米草生境和光滩生境。单因素方差分析表明:物种数、栖息密度、生物量及物种多样性季节间差异不显著,而物种数、Shannon-Wiener多样性指数与Margalef物种丰富度指数生境间差异显著。人工恢复红树林有助于提高大型底栖动物群落的多样性。

关键词： Araraquara virus   hantavirus pulmonary syndrome   Necromys lasiurus   Rodentia  

摘要： This paper describes the diversity of rodent fauna in an area endemic for hantavirus cardiopulmonary syndrome (HCPS) in Brazil, the population dynamics and the relationship of rodents with hantavirus in the Cerrado (savanna-like) biome. Additionally, an analysis is made of the partial S segment sequences of the hantaviruses obtained from serologically confirmed human HCPS cases and from rodent specimens. Rodents were collected during four campaigns. Human serum samples were collected from suspected cases of HCPS at hospitals in the state of Minas Gerais. The samples antibody-reactive by ELISA were processed by RT-PCR. The PCR product was amplified and sequenced. Hantavirus was detected only in Necromys lasiurus, the wild rodent species most prevalent in the Cerrado biome (min-max: 50-837%). All the six human serum samples were hantavirus seropositive and five showed amplified PCR products. The analysis of the nucleotide sequences showed the circulation of a single genotype, the Araraquara hantavirus. The environmental changes that have occurred in the Cerrado biome in recent decades have favoured N. lasiurus in interspecific competition of habitats, thus increasing the risk of contact between humans and rodent species infected with hantavirus. Our data corroborate the definition of N. lasiurus as the main hantavirus reservoir in the Cerrado biome.

关键词： Brushtail possum   herbivore management   herbivory models   plant-herbivore interactions   Trichosurus vulpecula  

摘要： Invasive herbivores are often managed to limit their negative impact on plant populations, but herbivore density - plant damage relationships are notoriously spatially and temporally variable. Site and species characteristics (both plant and herbivore) must be considered when assessing the potential for herbivore damage, making it difficult to set thresholds for efficient management. Using the invasive brushtail possum Trichosurus vulpecula in New Zealand as a case study, we parameterized a generic model to predict annual probability of browse-induced mortality of five tree species at 12 sites. We compared predicted and observed tree mortality for each species+site combination to establish herbivore abundance - tree mortality thresholds for each site on a single and combined tree species basis. Model results indicated it is likely that possum browse was the primary cause of all tree mortality at nine of the 12 species-site combinations, allowing us to estimate site-specific thresholds below which possum population numbers should be reduced and maintained to keep tree mortality under a predetermined level, for example 0.5% per year. The browse model can be used to set site- and species-specific management action thresholds, and can be adapted easily for other plant or herbivore species. Results for multiple plant or herbivore species at a single site can be combined to create conservative, site-wide management strategies, and used to: determine which sites will be affected most by changes in herbivore abundance;quantify thresholds for herbivore management;and justify expenditure on herbivore control.

关键词： African savanna   biological control   browsing   exotic plant species   impala   local biodiversity   Macrotermes   national parks   plant invasion   seedling predation  

摘要： Invasion of exotic species is a global challenge and the potential for adverse effects on local biodiversity is particularly high in protected areas. Protected African savanna areas support globally important biodiversity. At the same time, forest plantations are widespread throughout Africa and exotic tree species frequently invade natural areas. To evaluate the potential invasiveness of plant species, it is pertinent to know to what extent, if at all, consumption by native herbivore assemblages differentially affects exotic and indigenous plants. We studied how two globally widespread exotic trees Eucalyptus grandis and Grevillea robusta and two common indigenous trees Milicia excelsa and Maesopsis eminii responded to natural herbivory by large herbivores and termites. We experimentally exposed 720 tree seedlings to: (i) no large herbivores or termites;(ii) termites only;(iii) large herbivores only;and (iv) both large herbivores and termites. When exposed to large herbivores and termites, the total survival was much higher for the exotics with 45% (***) and 63% (***) compared to the indigenous species (both 20%). Exposure to large herbivores affected early seedling survival of natives more than the exotics. Apart from the indigenous ***, survival did not decrease when seedlings were exposed to termites. Large herbivores retarded seedling growth for all species. The exotic *** was the only species capable of growth when exposed to large herbivores. Exposure to termites had only a small, but significant effect resulting in a 7% size difference in all *** and applications. Our results highlight how browsing might, for some tree species, adversely affect native seedling survival and growth more than exotic species in protected African savanna. If exotic species are to be used in plantations, managers should consider planting tree species and varieties that are sensitive to ungulate browsing. This will not compromise economic gain

关键词： Analgesic   animal models   Ficus   pain  

摘要： Introduction: According to the WHO, 70-80% population in developing countries still relies on nonconventional medicine mainly of herbal origin. Even in developed countries, use of herbal medicine is growing each year. Pain is an unpleasant feeling often caused by intense or damaging stimuli. Traditionally, different plant parts of Ficus benghalensis are claimed to have several analgesic properties. Few scientific evidences support these uses. Interestingly, still others contradict these uses. It was shocking to find very scarce scientific studies trying to solve the mystery. Materials and Methods: It was a quantitative experimental study in Swiss albino mice of either sex. Sample size was calculated using free sample size calculating software G*Power version 3.***.9.2. Hot-plate test and tail-flick test were central antinociceptive paradigms. Writhing test was peripheral model for pain. Test drugs were aqueous root extracts of F. benghalensis at 100 mg/kg and 200 mg/kg mouse weight prepared by Soxhlet method. Suitable negative and positive controls were used. The experimental results were represented as mean +/- standard deviation statistical level of significance was set at P < 0.05. For calculation, parametric test - one-way analysis of variance (ANOVA) or nonparametric test - Mann-Whitney U-test was appropriately used. Results: Hot-plate reaction time at 100 mg/kg (13.64 +/- 1.30 s) and 200 mg/kg (10.32 +/- 2.23 s) were nonsignificant (P = 0.425 and P = 0.498, respectively) compared to negative control (11.87 +/- 1.92 s). One-way ANOVA revealed nonsignificant (P = 0.178) between-group comparison in mean tail-flick reaction time. Test drug at 200 mg/kg produced statistically significant more writhing (36.00 +/- 14.85 in 10 min) than negative control, normal saline (11.83 +/- 12.43 in 10 min) or the positive control, Indomethacin (3.50 +/- 5.21 in 10 min), P value being 0.031 and 0.003, respectively. Conclusion: Aqueous root extracts of F. benghalensis at 200 mg/kg p