关键词： wildlife trees   coarse woody debris   wildlife habitat   silvicultural systems   Interior Cedar-Hemlock Zone   inland rainforest  

摘要： Unmanaged cedar (Thuja plicata)-hemlock (Tsuga heterophylla) forests of the northern Interior Wetbelt of British Columbia support standing and dead trees with a variety of structural features that provide habitat for wildlife. We describe the pre-harvest abundance and characteristics of wildlife trees (standing trees with special characteristics that provide habitat for wildlife) and coarse woody debris (CWD) at three silvicultural systems trials in cedar-dominated stands, and the short-term effects of forest harvesting on the abundance and attributes of CWD. The treatments were clearcut, group retention (70% volume removal), group selection (30% volume removal), and unlogged control. We measured standing trees in 75 0.125-ha plots and CWD along 225 24-m transects, using a functional classification system to characterize habitat attributes of trees and logs. CWD assessments were repeated on the same transects after the harvest. The relationship between tree size and occurrence of habitat features was strong for both standing trees and logs. Each of the four major tree species in the study area was associated with specific habitat features that occurred more often in that species than in any other. Large concealed spaces at the bases of trees, providing den sites and escape cover, were associated with hybrid white spruce (Picea engelmannii x glauca). We suggest that these trees had originated on nurse logs that subsequently rotted away;if that supposition is correct, there may be shortages of these structures in future stands that originate from plantations. Forest harvesting had little effect on the volume of CWD, but did affect the decay class distribution, reduce the proportion of pieces having structural habitat attributes, and reduce piece lengths;these effects were generally proportional to the level of harvest removal. Partial-cut silvicultural systems have the potential to mitigate anticipated deficits in large wildlife trees and logs in managed stands, if co

关键词： 12S   cephalopod   COII   gladius   mtDNA genes   phylogeny   sepion   shell   systematics  

摘要： The sepiids are characterized by their cuttlebone or sepion, an internal shell resulting from secondary mineralization of a chitinous 'gladius'. The various species are identified using a combination of shell criteria and 'soft-part' characters. Using mitochondrial genes, we established phylogenetic relationships of sepiids including the three accepted genera (Sepia, Sepiella, Metasepia) and a species complex of uncertain status (Doratosepion). We showed the Sepia genus to be paraphyletic and found no direct correlation between geographical distribution and systematics. We mapped, on the molecular tree, shell characteristics commonly used as reliable diagnostic criteria for taxonomy. Due to the plasticity of the shell, these characters did not appear phylogenetically informative. In an attempt to define systematic categories related to phylogenetic relationships, new clear synapomorphies need to be established for each genus, necessitating a revision of the genus Sepia. (c) 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 89, 139-150.

关键词： Cistus ladaniferus   jejunum   antispasmodic  

摘要： The effects of the aqueous extract of Cistus ladaniferus leaves and stems were studied on the rodent isolated jejunum. The extract produced a reversible concentration dose-dependent (0.1-3 mg/ml) inhibition of the spontaneous motility of the rabbit jejunum. The inhibitory effects of the extract were not affected by pretreatment with the inhibitors of the alpha and beta adrenergic receptors yohimbine, prazosin or propranolol. The extract also inhibited K-induced contractions in rabbit and rat jejunum at a similar concentration range. This result suggests that the antispasmodic action of the extract is mediated through calcium channel blockade. The results confirm the traditional use of C ladaniferus in treating intestinal ache. (c) 2006 Elsevier B.V. All rights reserved.

关键词： 动画   连环画   作品集   中国   现代  

ISBN: (纸本)7802200539

摘要： 本书由四个独立小故事配以大幅彩图组成的经典动物童话合集。

关键词： chital   deer   large seeds   Phyllanthus emblica   Rajaji National Park   regurgitation  

摘要： Ruminant-mediated seed dispersal, an understudied process in tropical forests, was examined via Phyllanthus emblica-Axis axis interaction. A captive Axis deer regurgitated intact P. emblica seeds after retaining them in the rumen for 7-27 h. At Rajaji National Park, a considerable fraction (22%) of deer-regurgitated P. emblica seeds germinated, although lower than unconsumed seeds (72%). The size and strength of seeds like P. emblica might ensure that ruminants regurgitate them intact instead of defecating them.

关键词： ants   Atta   Brazil   Cerrado vegetation   habitat disturbance   habitat selection   nest foundation   road impacts  

摘要： Roads can facilitate the establishment and spread of both native and exotic species. Nevertheless, the precise mechanisms facilitating this expansion are rarely known. We tested the hypothesis that dirt roads are favorable landing and nest initiation sites for founding-queens of the leaf-cutter ant Atta laevigata. For 2 yr, we compared the number of attempts to found new nests (colonization attempts) in dirt roads and the adjacent vegetation in a reserve of cerrado (tree-dominated savanna) in southeastern Brazil. The number of colonization attempts in roads was 5 to 10 times greater than in the adjacent vegetation. Experimental transplants indicate that founding-queens are more likely to establish a nest on bare soil than on soil covered with leaf-litter, but the amount of litter covering the ground did not fully explain the preference of queens for dirt roads. Queens that landed on roads were at higher risk of predation by beetles and ants than those that landed in the adjacent vegetation. Nevertheless, greater predation in roads was not sufficient to offset the greater number of colonization attempts in this habitat. As a consequence, significantly more new colonies were established in roads than in the adjacent vegetation. Our results suggest that disturbance caused by the opening of roads could result in an increased Atta abundance in protected areas of the Brazilian Cerrado.

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。随着养殖结构和养殖方式的调整，原有的基层畜牧兽医管理体制和基层动物防疫队伍已不能适应当前形势，为提高动物防检水平和服务技能，确保畜牧业健康快速发展。会昌县于2004年开展了以“五有一好”（即有一支财政供给、素质较高的基层防检队伍。有一栋固定的办公场所。有一套规范性、可操作性的软硬件建设标准，有一套必备的防检技术工具。有一定的经济收入和工作经费；配备好一位责任心强、素质高的站长）为建设内容，着力推进“双基”建设工作，取得了显著成效。

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