人工封育区植物群落恢复演替系列种群生态位动态特征——以宁夏盐池为例

为了解干旱半干旱区草原植物生态位格局,运用Levins生态宽度指数及Pianka生态位重叠指数,对宁夏盐池人工封育草原3种不同措施下的植物生态位宽度及生态位重叠进行计量。结果表明:茵陈蒿(Artemisia capillaries Thunb)和新疆猪毛菜(Salsola sinkiangensis A.J.Li)的生物、生态学特性决定了它在该区的优势地位,其生态位宽度远远高于其他物种,并且出现下降的趋势;生态位重叠结果均表明,生态位宽度大的物种不一定和其他物种有大的重叠值,较高的生态位宽度和较高的生态位重叠之间并不存在直接的线性关系;较高的Pianka生态位重叠值都出现在生态位宽度较小的物种之间。这一现象从另外一个角度说明植被恢复过程中环境资源存在着高度的空间异质性。     

不同水平的仙湖苏铁种群在土壤资源上的生态位宽度

在基株和无性系两个水平上，分析了珍稀濒危植物仙湖苏铁种群在土壤资源上的生态位宽度，以及该种群对土壤资源的潜在利用能力，探讨该种群对资源的利用状况，从而为种群的保护提供科学依据。结果表明，在有机质、全氮、速效磷、速效钾等土壤养分资源轴上，无性系种群的生态位宽度大于基株种群；而且无性系种群比基株种群具有更大的潜在利用土壤资源的能力，说明无性繁殖可能是种群在日益恶化的生境中赖以生态的主要方式。当土壤有机质在3．348％～3．832％、全氮在0．164％～0．186％、速效磷在2．092～2．868mg／kg、速效钾含最在108．34～137．28mg／kg范围之间时，种群分布的个体数最多。因此，抑制周边生境恶化，改善土壤养分结构将有助于促进仙湖苏铁种群的恢复和发展。     

A Comparative Analysis of Specialization and Extinction Risk in Temperate-Zone Bats

Abstract:  Identifying the factors that influence the extinction risk of animals is essential in conservation biology because they help identify endangered species and provide the basis for their preservation. We present a comparative study that uses data from the literature on the diet and morphological specialization of European and North American bat species to investigate the effect of specialization on extinction risk. We focused on bats because many species are endangered and their high ecological diversity makes them a good model system for our purpose. After correcting for phylogenetic inertia, we compared the influence of dietary niche breadth as a measure of food specialization and of wing morphology as a measure of foraging strategy, habitat adaptation, and migratory ability on the vulnerability of 35 insectivorous bat species. Our results do not support the hypothesis that a narrow dietary niche breadth is related to high extinction risk. Instead they suggest that habitat specialization, which is reflected in wing morphology, influences the extinction risk of bats. Our study shows that an initial risk assessment in temperate-zone bats could be based on data of wing morphology but not on dietary data obtained from fecal analyses.     

万木林中亚热带常绿阔叶林林隙主要树种的高度生态位

对万木林自然保护区中亚热带常绿阔叶林林隙内外主要树种的生态位宽度和生态位重叠进行了研究。结果表明：桂北木姜子和浙江桂在林隙内外部都占有较高的生态位宽度；生物学特性和生态学特性接近的树种高度生态位重叠较大，反之则较小；在林隙内，出矾和薄叶山矾的高度生态位重叠最大，而桂北木姜子和黄瑞木、尖叶水丝梨，浙江桂和尖叶水丝梨的高度生态位重叠较小；在非林隙内，山矾和黄瑞木的高度生态位重叠最大，桂北木姜子和尖叶水丝梨、黄瑞木的高度生态位重叠较小，表3参13     

Predicting the Range of Chinese Mitten Crabs in Europe

Abstract:  Ecological niche modeling provides a means for predicting the potential future distribution of a nonindigenous species based on environmental characteristics of the species' native range. We applied this method to the Chinese mitten crab (Eriocheir sinensis) , a catadromous crustacean with a long history of invasion in Europe. We used genetic algorithm for rule-set prediction to predict the potential European distribution of mitten crab based on its distribution in 42 locations in its native Asia. The climatic variables, air temperature, number of days, amount of precipitation, and wetness index, contributed significantly to predictions of native distribution limits. Although the genetic algorithm for rule-set prediction model was developed for the native range, the species' extensive distribution in Europe ( n = 434) allowed independent validation of the predictions. Application of the model to Europe was successful, with 84% of occurrences in regions predicted to be suitable by >80% of the models and <4% of occurrences in areas predicted suitable by <50% of the models (mainly along the northern range). At the watershed scale, areas with established mitten crab populations had significantly higher habitat matching than sites that were not invaded. The independent validation of the Asian-based model by the European distribution revealed that predictions were highly accurate. The model also identified large areas of Europe, particularly along the Mediterranean coast, as vulnerable to future invasion. These predictions can be used to develop strategies to control the spread of mitten crab by preventing introductions into vulnerable areas.     

洞庭湖区退田还湖过程中小型兽类的生态位特征

为了解退田还湖工程实施后的小兽群落状况,2003~2010年对洞庭湖区退田还湖后9种不同类型生境中小型兽类的生态位特征进行了调查.共布放64 432夹日,捕获小型兽3 066只,总的捕获率为4.76%,包括啮齿目10种和食虫目2种.小型兽类各种群的生态位宽度以褐家鼠和黑线姬鼠最高,分别为0.819 8和0.765 6,为广生态位的种类;随后依次是臭鼩、东方田鼠、刺猬、巢鼠、黄胸鼠、小家鼠、黄毛鼠、针毛鼠,分别为0.689 0、0.573 7、0.527 3、0.482 8、0.394 8、0.289 7、0.265 1、0.098 5;社鼠和大足鼠最低,仅在1种生境中有捕获.从生态位宽度指数的季节变化看,黑线姬鼠、褐家鼠、东方田鼠和臭鼩在四季的生态位宽度指数均较高.从空间生态位宽度和生态位重叠指数看,除黑线姬鼠和褐家鼠利用生境较广外,洞庭湖小兽群落可分为3个类群:栖息于环湖丘岗林地生境的社鼠、针毛鼠和黄毛鼠类群,以湖滩生境为主的东方田鼠、巢鼠和臭鼩类群,以及以村庄周围的农田生态系统为主的家鼠类群.从生态位指标和捕获数量看,黑线姬鼠、东方田鼠和褐家鼠是当地需要重点关注的种类.东方田鼠种群数量高峰年份与低谷年份比,其生态位宽度以及与其它种类的生态位重叠指数均较高,高峰年份东方田鼠冬季在双退垸出现,说明退田还湖已扩大了东方田鼠的繁殖基地,对东方田鼠种群发展有利,在种群暴发年份,易形成更加严重的危害.     

半干旱区人工封育草场植被群落生态位研究——以宁夏盐池县长期定位监测点为例

人工封育是草场恢复和重建的一种主要措施。为研究半干旱区人工封育草地植物种群生态位,以宁夏盐池县人工封育区3种不同处理方式（长期完全封育、短期完全封育、短期不完全封育）为研究对象,将封育区分为封育核心区（E区）、封育边缘区（E1区）和封育外围区（E2区）,通过分析在该地区出现的27种植物种群的Levins生态位宽度指数和Pianka生态位重叠指数,揭示植物种群生态位在干旱荒漠环境下的变化规律,为进一步分析该地区群落稳定性提供依据。研究结果表明：1）核心区和外围区生态位宽度最大的都是刺沙蓬Salsola ruthenica lljin,分别为0.832和0.810,而边缘区生态位宽度最大的是丝叶山苦荬Lxeris chinensis var.graminifolia,为0.742,这2种植物的生物学特性决定了它们能够很好的适应封育区的环境,并很好的利用封育区的资源,结果是它们的生态位宽度明显高于其他物种。2）对三区内不同植物种群的生态位宽度分析结果显示,三区的群落稳定性表现为E1区〉E2区〉E区;长期的完全封育并不利于封育区内植物群落的稳定;而短期的完全封育措施比不完全封育措施更有利于植被群落的稳定。3）通过分析三区内不同植物种之间的生态位重叠得出,E区生态位重叠最大值出现在草地风毛菊Saussurea amara、苦豆子Sophora alopecuroides L、沙芦草Agropyron mongolicum Keng与臭蒿Artemisia hedinii之间,都是0.98。E1区生态位重叠最大值是达乌里胡枝子Lespedeza davurica和草木樨状黄芪Astragalus melilotoides之间（0.82）。E2区生态位重叠最大的一对是草木樨状黄芪和冰草Agropyron cristatum（0.99）。相关分析表明：生态位宽度与生态位重叠之间并没有明确的线性关系。生态位宽度窄的物种之间可能有较高的生态位重叠,反之,则较低,但并不是完全如此。     

Does the choice of climate baseline matter in ecological niche modelling?

Ecological niche models (ENMs) have multiple applications in ecology, evolution and conservation planning. They relate the known locations of a species to characteristics of its environment (usually climate) over its geographical range. Most ENMs are trained using standard 30-year (1961-1990) or 50-year (1951-2000) baselines to represent current climate conditions. Species occurrence records used as input to the models, however, are frequently collected from time periods that differ from those from which the climate is derived. Since climate variability can be significant within and outside baselines, and the distributions of some plants and animals (e.g., annual plants, insects) can adjust to environmental conditions on much shorter time scales, this mismatch between collection records and climatic baselines may affect the utility and accuracy of model outputs. We investigated how the choice of baseline periods influenced modelling efforts, anticipating that climate baselines derived from the same temporal period as the species records would yield improved ENMs. Ten simulated species’ distributions were modelled using an ENM (Maxent) for (a) occurrences and climates within the same temporal period, based on eighteen 10-year baselines within the 20th century and (b) all available samples and climate baselines from 1951-2000 and 1961-1990. Each model was projected onto all the available 10-year climate scenarios and compared to the models trained on the corresponding scenario. We show that temporal mismatches of species occurrences and climate baselines can result in significantly poorer distribution models. Such temporal mismatch may be unavoidable for many studies, but we emphasize here the need to match the time range of samples and climate data whenever possible.     

城市生长管理与城市生态规划

本文从城市生长机制着手 ,论述了生态位的竞争与演化以及导致城市结构和空间的变化 ;城市管理模式随着城市功能的转变而从后果导向转向原因导向的生长管理。并提出在生长机制研究的基础上进行城市生态规划 ,重点应突出生态评价、生态功能分区及定量模拟     

Modeling Habitat Suitability for Complex Species Distributions by Environmental-Distance Geometric Mean

This paper presents a new habitat suitability modeling method whose main properties are as follows: (1) It is based on the density of observation points in the environmental space, which enables it to fit complex distributions (e.g. nongaussian, bimodal, asymmetrical, etc.). (2) This density is modeled by computing the geometric mean to all observation points, which we show to be a good trade-off between goodness of fit and prediction power. (3) It does not need any absence information, which is generally difficult to collect and of dubious reliability. (4) The environmental space is represented either by an expert-selection of standardized variables or the axes of a factor analysis [in this paper we used the Ecological Niche Factor Analysis (ENFA)].We first explain the details of the geometric mean algorithm and then we apply it to the bearded vulture (Gypaetus barbatus) habitat in the Swiss Alps. The results are compared to those obtained by the median algorithm and tested by jack-knife cross-validation. We also discuss other related algorithms (BIOCLIM, HABITAT, and DOMAIN). All these analyses were implemented into and performed with the ecology-oriented GIS software BIOMAPPER 2.0.The results show the geometric mean to perform better than the median algorithm, as it produces a tighter fit to the bimodal distribution of the bearded vulture in the environmental space. However, the median algorithm being quicker, it could be preferred when modeling more usual distribution.