关键词： 动物防疫体系建设   会昌县   基层   成功经验   农业人口   兽医管理体制   福建  

摘要： 会昌县地处江西东南边陲,紧邻广东梅州、福建龙岩,辖19个乡镇246个行政村,总人口44.06万人,其中农业人口37.5万人,是一个典型的农业县,养殖业是农业生产的重头戏.

关键词： fertilization   defoliation   herbivory   condensed tannins   compensation   trade-offs   plant defenses   resistance  

摘要： Resource availability, degree of herbivore damage, genetic variability, and their interactions influence the allocation of investment by plants to resistance and tolerance traits. We evaluated the independent and interactive effects of soil nutrients and moisture, and simulated the effects of herbivore damage on condensed tannins (resistance) and growth/regrowth (tolerance) traits of Terminalia sericea, a deciduous tree in the Kalahari desert that constitutes a major component of livestock diet. We used a completely crossed randomized-block design experiment to examine the effects of nutrients, water availability, and herbivore damage on regrowth and resistance traits of T. sericea seedlings. Plant height, number of branches, internode length, leaf area, leaf mass for each seedling, combined weight of stems and twigs, and root mass were recorded. Condensed tannin concentrations were 22.5 and 21.5% higher under low nutrients and low soil moisture than under high nutrient and high water treatment levels. Tannin concentrations did not differ significantly between control and experimental seedlings 2 mo after simulated herbivore damage. Tannin concentrations correlated more strongly with growth traits under low- than under high-nutrient conditions. No trade-offs were detected among individual growth traits, nor between growth traits and condensed tannins. T. sericea appeared to invest more in both resistance and regrowth traits when grown under low-nutrient conditions. Investment in the resistance trait (condensed tannin) under high-nutrient conditions was minimal and, to a lesser degree, correlated with plant growth. These results suggest that T. sericea displays both resistance and tolerance strategies, and that the degree to which each is expressed is resource-dependent.

关键词： Pseudotsuga menziesii   Picea abies   community structure   canopy   diversity   ecological guilds   Coleoptera   Heteroptera   Neuropterida   Araneae  

摘要： The ecological effects of planting exotic Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in Central Europe are still poorly understood. The aim of this study was to answer the question of whether Douglas-fir affects tree specific arthropod communities in different mature forest types (Douglas-fir, spruce and beech dominated) in Southern Germany. Therefore, arthropod communities of stem and tree crown strata of Douglas-fir and spruce (Picea abies L.) were sampled in the years 1999-2001 using arboreal photo-eclectors and flight interception traps. Statistical analysis was conducted for all species and focused on conifer specialists at three levels: (1) species diversity, (2) guild structure and (3) community structure. Within the stem stratum, species diversity was significantly higher on spruce than on Douglas-fir independent of year and stand composition. This could not be explained by a single feeding guild, rather by species changing strata during the vegetation period. In contrast, species diversity in tree crowns was approximately the same for both conifer species. However, communities in Douglas-fir crowns were conspicuously different from those in spruce crowns, especially in the Douglas-fir dominated stand type. While zoophagous insects exhibited higher activity on Douglas-fir in 2000, xylophagous beetles were more abundant on spruce in 2001. In European beech stands with widely spaced Douglas-fir trees, the site specific and broad-leaved tree related fauna might be maintained. In addition, Douglas-fir with its resource of Adelges cooleyi and crowns that overtop the broad-leaved tree canopy, offer additional resources for several aphidophagous and thermophile species.

关键词： forage nutrients   selective utilization   forage quality   herbivore conservation   monitoring   herbivore nutrition   scale   Kruger National Park  

摘要： Extensive studies in the Serengeti showed a strong link between patchy herbivory and forage quality, and the factors that determine forage patch selection at different scales have been evaluated in various models. The purpose of this study was to examine to what extent favoured forage patches in the Lowveld of South Africa are determined by forage quality and how important these are as forage resources. Understanding the factors that determine herbivore distribution will provide insights into how the utilization of forage by herbivores affects and is influenced by the ecosystem and thereby improve our abilities to conserve and manage these systems. The Kruger National Park is a large wildlife conservation area, with stratified rainfall and soil nutrient patterns. Tuft utilization and number of faecal deposits were used to determine favoured forage patches within these stratifications. On the low-nutrient granites, the use of grass tufts on the crests of hillslopes was about a quarter that on sodic sites, and a third of that of termite mounds. On the high-nutrient basalts, utilization of crests was about a third of that of termite mounds and about a quarter of the utilization of sodic sites in the wet and growth season, but towards the end of the dry season all patches were utilized to a similar extent. On sodic sites, shorter grass grazers accounted for almost ten times more faecal deposits than other species, although there was evidence of all the other large herbivore groups also utilizing these sites. The foliar nitrogen and phosphorus concentrations from termite mounds and sodic patches were up to twice that found on the crests in the wet season, especially on the granites, indicating that forage quality may indeed play an important role in determining favoured forage patches. Furthermore, only the patches on the sodic sites and termite mounds produced foliage of sufficient quality to support reproduction and maintenance of body condition. These patches thus for

关键词： Cullenia exarillata   non-flying mammals   pollination   Western Ghats  

摘要： Many non-flying mammals help in the pollination of plant species in tropical forests. However, this remains poorly documented from India. Here we demonstrate with Cullenia exarillata, a canopy tree in the Western Ghats, how a wide range of visitors frequent flowers of the tree and how among them a few select mammals are important in pollination. Since Cullenia also uses bats as a pollinating vector, we further discuss how the dual strategy of using non-flying mammals and bats could have evolved in the wet forests of the Western Ghats.

关键词： browsing damage   Eucalyptus globulus   forestry   marsupial   plantation   repellent   thistles   vegetation management  

摘要： Browsing of commercial tree seedlings by mammalian herbivores can reduce long-term plantation productivity, and is an economic problem worldwide. Characteristics of both tree seedlings and their neighbours can influence browsing on the former, particularly by generalist herbivores. The nature of the combined effects of seedlings and their neighbours is, however, unknown. If effects are additive, it should be possible to exploit the capacity of herbivores to make foraging decisions at multiple scales in order to manage browsing of tree seedlings in forestry plantations. We conducted a field trial that focussed on browsing of Eucalyptus globulus seedlings by native marsupial herbivores. Our aim was to determine the absolute and relative importance of characteristics of both seedlings and neighbouring vegetation on browsing of seedlings. Seedlings with and without a chemical repellent were planted in vegetation patches that varied in the abundance and height of thistles. Browsing of seedlings was assessed over 16 weeks. Characteristics of both seedlings and neighbouring vegetation were shown to influence the degree to which seedlings were browsed, and the effects were additive. Repellent-treated seedlings received less browsing than those without repellent;and browsing decreased with increasing thistle cover. The presence of thistles also increased the time it took for browsers to find seedlings. Results are consistent with the associational plant refuge hypothesis, and vegetation effects may be manifested via an alteration in plant apparency. These results have applications in the forestry industry. They demonstrate the principle that the use of less palatable seedlings combined with tall, unpalatable vegetation can reduce browsing on plantation seedlings in the short-term, and that the effects are additive. (c) 2006 Elsevier B.V. All rights reserved.

关键词： distance sampling   efficiency   African mammals   cluster sampling  

摘要： Effective management and conservation of wildlife populations require reliable estimates of population size, which can be difficult and costly to obtain. We evaluated how precision in estimates of herd size and abundance varies with sample size and strip width using two field surveys and bootstrap resampling of the field data. We also examined precision under distance sampling and evaluated the cost-effectiveness of both survey techniques. Precision in estimates of abundance increased with increasing sample size and varied with strip width independently of sample size. The hazard rate key function was best for five species in two surveys with contrasting visibility conditions. Precision in density was more sensitive to the number of herds sighted than to variation in herd size and effective strip width for distance sampling. Strip counts produced lower abundance estimates but higher precision than distance sampling. We estimated that distance sampling would cost about US$3.1 km(-1) of transect. Strip counts deserve serious consideration for surveys of species that occur at high densities and form large, loose agglomerations but distance methods are suitable for species occurring at moderate to low densities in areas where visibility varies substantially. Distance sampling may thus need to be supplemented by strip counts to efficiently estimate densities of rare, abundant and highly clustered multi-species assemblages of African savanna mammals. In small areas, it may often prove necessary to conduct several surveys to obtain adequate sample sizes for distance models.

关键词： ants   birch   enemy-free space   Epirrita autumnata   plant structure   spiders   tritrophic interactions  

摘要： 1. Vegetation structural complexity is an important factor influencing ecological interactions between different trophic levels. In order to investigate relationships between the architecture of trees, the presence of arthropod predators, and survival and parasitism of the autumnal moth Epirrita autumnata Borkhausen, two sets of experiments were conducted. 2. In one experiment, the architectural complexity of mountain birch was manipulated to separate the effects of plant structure and age. In the other experiment the trees were left intact, but chosen to represent varying degrees of natural complexity. Young autumnal moth larvae were placed on the trees and their survival was monitored during the larval period. 3. The larvae survived longer in more complex trees if predation by ants was prevented with a glue ring, whereas in control trees smaller canopy size improved survival times in one experiment. The density of ants observed in the trees was not affected by canopy size but spider density was higher on smaller trees. The effect of canopy structure on larval parasitism was weak-, larger canopy size decreased parasitism only in one year. Until the fourth instar the larvae travelled shorter distances in trees with reduced branchiness than in trees with reduced foliage or control treatments. Canopy structure manipulation by pruning did not alter the quality of leaves as food for larvae. 4. The effect of canopy structure on herbivore survival may depend on natural enemy abundance and foraging strategy. In complex canopies herbivores are probably better able to escape predation by ambushing spiders but not by actively searching ants.

关键词： canopy arthropods   Eucalyptus obliqua   forest entomology   geographic distance   tree age   Tasmania   invertebrate trapping  

摘要： Despite the anthropogenically-induced changes to forest tree demographics, few studies have examined the differences in arthropod species composition between the crowns of trees of different ages. We tested for differences in the taxonomic composition of the canopy arthropod faunas of 100 y.o. and old-growth trees, using eight pairs of trees in an Eucalyptus obliqua tall open-forest with a rainforest understorey in the Warra Long Term Ecological Research Site in southern Tasmania and compared these differences to those related to geographic distances. Sticky traps, hanging flight-intercept traps and bark funnel traps were used to sample the canopy arthropods in different placement situations. There were no significant differences between 100 y.o. and old-growth trees at the tree level, but several at the trap and placement levels. Ordination analyses and correlation analyses indicated that high inter-pair variability related to the geographic distance between trees was partially masking tree age effects. The age of E. obliqua does influence canopy arthropod species composition, but this effect was weaker than the geographic effect that was evident in a relatively uniform forest with a maximum distance between trees of only 324 m. This implied high beta diversity in the forest type has implications for the planning of conservation reserves. Further work is needed to see if age effects are stronger in forests of the ages created by silvicultural treatment. (c) 2006 Elsevier B.V. All rights reserved.

关键词： 疾病动物模型   树鼩   亚热带地区   亚洲东南部   啮齿类动物   哺乳动物   大体解剖   新陈代谢   发病机理   灵长类  

摘要： 树鼩(tupaia,tree shrew)是最低等的灵长类哺乳动物,主要分布于亚洲东南部的热带和亚热带地区.由于具有体小、比较容易饲养、价廉及新陈代谢和大体解剖远比啮齿类动物更接近人类等优点,树鼩已广泛用于病毒、细菌、寄生虫和神经、内分泌、泌尿、肿瘤等方面的研究.疾病动物模型为研究疾病的发病机理、治疗及防治提供了平台.本文对树鼩作为疾病动物模型的研究作一概述。