城市生态系统承载力研究进展

承载力一词来自生态学,最初应用于对自然生态系统中生物数量的研究。从城市生态学与城市生态系统理论的发展角度介绍了城市生态学中承载力一词含义及其发展过程,并重点介绍了国内外学者对资源承载力、环境承载力及生态承载力的研究与应用。针对城市所具有的明显自然-社会-经济复合生态系统特征,笔者认为应该在城市生态系统承载力研究中强调社会经济系统能力的贡献。     

区域地下水资源承载力综合评价的集对分析方法

集对分析是一种新的不确定性分析方法,针对关于确定-不确定系统给出了分析背景下的联系度表达式,由于其联系度概念具有鲜明的辨证性、完整性,成为处理不确定性问题的独具特色的思想方法。应用集对分析法对关中地区的地下水资源承载力进行了综合评价,评价结果得出:西安地下水资源承载力已达Ⅲ级,该地区地下水资源开发已接近饱和值;咸阳、宝鸡、关中平原、渭南等地区地下水资源承载力属于Ⅱ级,地下水资源开发利用已有相当的规模,但仍有一定的开发利用潜力。评价结果与模糊综合评价、投影寻踪法和物元分析法的结果基本相同。本方法具有概念明确、计算简单,结果合理。该方法为水文水资源的分析、评价提供了一种更为简便的方法。     

广东耕地资源的人口承载力研究

在总结广东省耕地资源特征的基础上,分析预测了2010年广东人口的发展趋势和消费水平,广东耕地资源的现实生产力、潜在生产力,以及2010年耕地的发展规模和粮食生产力。分析得出结论:2010年广东人口突破8300万人的可能性较大;届时人均消费水平将有较大的提高;广东粮食自给率为70%时,将会出现耕地承载力严重超载。本文最后提出了提高耕地资源的人口承载力的对策。     

庐山风景名胜区旅游环境容量分析

运用有关旅游环境容量的理论与方法,通过资源空间容量、生态环境容量、经济发展容量和当地居民心理容量4个子系统进行分析,得出庐山风景名胜区旅游环境容量综合值为12804人次/d,其中生态环境容量中的水环境容量是最主要的限制因子。最后指出庐山风景名胜区以牯岭镇为单一中心的空间格局和旅游路线是造成庐山旅游压力的根本原因,并提出相应的解决措施。     

Predicting Extinction Times from Environmental Stochasticity and Carrying Capacity

Managers of small populations often need to estimate the expected time to extinction T_e of their charges. Useful models for extinction times must be ecologically realistic and depend on measurable parameters. Many populations become extinct due to environmental stochasticity, even when the carrying capacity K is stable and the expected growth rate is positive. A model is proposed that gives T_e by diffusion analysis of the log population size n_t (= log_e N_t). The model population grows according to the equation N_t+1 = R_tN_t, with K as a ceiling. Application of the model requires estimation of the parameters k = logK, r_d = the expected change in n, v_r = Variance(log R), and ϱ the autocorrelation of the r_t. These are readily calculable from annual census data (r_d is trickiest to estimate). General formulas for T_e are derived. As a special case, when environmental fluctuations overwhelm expected growth (that is r_d 0), T_e = 2n_o(k - n_o/2)/v_r. If the r_t are autocorrelated, then the effective variance is v_re v_r (1 + ϱ)/(1 - ϱ). The theory is applied to populations of checkerspot butterfly, grizzly bear, wolf, and mountain lion.     

基于人均生态承载力的安徽省资源环境公平性研究

通过对人均生态承载力内涵的扩展,提出了生态承载系数的概念。从多个时间断面出发,计算2001—2010年安徽省17个地市的人均生态承载力,并选取能源消耗、水资源消耗、SO2排放和COD排放4个评价因子,构建基于人均生态承载力的安徽省资源环境基尼系数和生态承载系数的计算与评价方法。结果表明:(1)安徽省SO2排放的资源环境基尼系数高于0.4的警戒线,能源消耗的资源环境基尼系数接近0.4的警戒线,水资源消耗和COD排放的资源环境基尼系数均处于相对平均等级。(2)总体来看,省内资源型城市马鞍山、淮南,经济较发达城市合肥和沿江工业城市安庆、芜湖是安徽省资源消耗和污染物排放不公平性的主要因子,需要优化资源环境分配;皖南山区城市黄山、池州和宣城是安徽省资源消耗和污染物排放公平性的主要因子。该研究可为安徽省资源环境安全性评估和分配提供理论依据。     

环境承载力理论在北京市和房山区的应用

基于环境承载力的相关理论,建立环境承载力评价指标体系,并对北京市和房山区进行了实证研究。分析结果表明,北京市和房山区经济系统和社会系统的承载状况良好,资源环境系统存在较多问题,房山区的问题尤为突出。基于上述结论,进一步提出了区域经济环境协调发展的对策建议。     

基于重金属污染的耕地生态承载力改进模型研究

将耕地重金属污染引入耕地生态足迹研究中,对传统耕地生态承载力模型进行了改进,并以江苏省为例进行实证研究.结果表明,运用改进的生态承载力模型计算所得2005年江苏省人均耕地生态承载力为0.127 hm2,比传统模型计算结果0.134 hm2小;人均耕地生态赤字为0.067 hm2,比传统模型计算结果0.060 hm2大;耕地生态可持续指数为0.39,比传统模型计算结果0.41小,但2种模型计算方式下耕地利用均属于弱不可持续状态.与传统模型计算结果相比,改进模型所得结果能够反映江苏省耕地利用的实际情况,以及重金属污染对江苏耕地可持续利用所产生的负面影响.     

基于目标规划模型的大连市水资源承载力分析

结合“大大连”建设的规划和“十五”及2010年远景规划,选取了人口、国内生产总值、公共绿地面积三个决策变量建立目标规划模型,采取3种方案对大连市水资源承载力进行预测,通过对预测结果的分析并结合水资源承载力的特点提出增强水资源承载力的方案:以可持续发展的观点来设计城市发展规划;调整和改造产业结构;改变城市绿化结构;兴修水利,发展节水技术达到水资源可持续利用。     

规划环境影响评价中的水资源承载力分析

应用系统动力学原理构建了规划环评中水资源承载力的理论模型;并在吸收PSR（Pressure-State-Response）和DSR（Driving-State-Response）模型分析方法基础上,采用＂目标-准则（系统）-指标＂的框架模式,构建了规划环评中水资源承载力的指标体系,并提出了计算模型,最后将一整套技术程序及方法应用于广州市南沙区发展规划环境影响评价中水资源承载力分析,验证其实用性及可行性,最终为决策者调整及优化规划方案提供强有力的科学依据。     

长江三角洲地区复合生态系统生态承载力研究

利用生态压力与生态弹性力之间的相互作用关系构建了生态承载力评价的指标体系,并以长江三角洲地区为例,对复合生态系统生态承载力进行评价。结果显示,上海市、江苏省、浙江省的生态压力指数在过去的10 a中虽略有起伏,但整体都在缓慢增大,生态弹性力指数也基本保持持续增长的态势,生态承载力水平基本向好的趋势发展,但依然处于高压平衡甚至失衡状态。     

基于资源环境承载力的渤海滨海城市产业结构综合评价

以经济效益、资源产出力、资源环境承载力相协调为目标,在多层次评价指标体系下,引入产业结构综合评价坐标系统(CECS,comprehensive evaluating coordinate system),对基于资源环境承载力的产业结构进行定性和定量相结合的描述分析,在分析产业结构构成时综合运用统计学方法和威孚-托马斯逼...     

区域农田畜禽承载量预测模型构建与应用:以赤峰市为例

为对区域现有生猪养殖数量的合理性进行评价及对生猪养殖承载量进行预测,从畜禽养殖-耕地-作物系统出发,基于农田养分平衡理论及有机和无机肥合理配施方法,构建区域农田畜禽承载量预测模型。以赤峰市为例,设定有机和无机肥配施比例为5∶5,并保持现有农田N或P2O5养分盈余量不变,分别基于N和P2O5养分盈余量不变实地应用该模型。结果表明,基于N时可新增生猪养殖数量43.6万头,承载量为630.8万头;基于P2O5时可新增生猪养殖数量369.3万头,承载量为1 041.3万头。位于西拉木伦河南岸的松山区、翁牛特旗、喀喇沁旗、宁城县和敖汉旗是可新增生猪养殖的主要区域。从环境压力角度考虑,推荐基于N的预测值作为计算赤峰市可新增生猪养殖量和承载量的依据。     

基于DIAHP的旅游环境容量分析及相关对策研究

基于普通层次分析法的基本原理,融入"权变"思想,针对旅游环境容量的动态性,提出了1种动态改进层次分析法(DIAHP),分析旅游环境容量随时间变化的动态波动特征.最后,通过对南戴河国际娱乐中心的实证研究,验证了其可行性和有效性.     

Effects of Artificial Roosts for Frugivorous Bats on Seed Dispersal in a Neotropical Forest Pasture Mosaic

Abstract:  In the Neotropics ongoing deforestation is producing open and heavily fragmented landscapes dominated by agriculture, mostly plantations and cattle pastures. After some time agriculture often becomes uneconomical and land is abandoned. Subsequent habitat regeneration may be slow because seed inputs are restricted by a lack of incentives—such as suitable roost sites—for seed dispersers to enter deforested areas. Increasing environmental awareness has fostered growing efforts to promote reforestation. Practical and cost-efficient methods for kick-starting forest regeneration are, however, lacking. We investigated whether artificial bat roosts for frugivorous bat species can attract these key seed dispersers to deforested areas, thereby increasing seed rain. We installed artificial bat roosts in a forest-pasture mosaic in the Costa Rican Atlantic lowlands and monitored bat colonization and seed dispersal. Colonization occurred within a few weeks of installation, and 10 species of bats occupied the artificial roosts. Five species of frugivorous or nectarivorous bats colonized artificial roosts permanently in both primary habitat and in deforested areas, in numbers similar to those found in natural roosts. Seed input around artificial roosts increased significantly. Sixty-nine different seed types, mostly of early-successional plant species, were transported by bats to artificial roosts in disturbed habitats. The installation of artificial bat roosts thus successfully attracted frugivorous bats and increased seed inputs into degraded sites. This method is likely to speed up early-vegetation succession, which in turn will attract additional seed dispersers, such as birds, and provide a microhabitat for seeds of mid- and late-successional plants. As well as supporting natural forest regeneration and bat conservation, this cost-efficient method can also increase environmental awareness among landowners.     

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.     

The intrasponge fauna of Spheciospongia vesparia (Porifera,Demospongiae) at Curaçao and bonaire

The infauna of 35 individuals of Spheciospongia vesparia (Lamarck, 1814) of different volumes and from different sites and depths have been inventoried and compared. The number of sponge-inhabiting taxa is logarithmically related to sponge volume. Biomass and total number of the animals contained in the sponge are directly proportional to sponge volume. Numerical and taxonomic composition of infaunas from different sampling sites is fairly constant. Biomass and total number of sponge-inhabiting animals is not significantly different for any of the 4 sampling sites. Several taxa, however, are more abundant in sponges from one or more localities. The ratio of total biomass to total number of intrasponge fauna is found to be significantly smaller for sponges collected in deep water than in shallow water. Differences from and similarities with Pearse's results (1932, 1950) on the infauna of the same sponge species at Dry Tortugas and Bimini are discussed. The relation of the number of contained taxa and the volume of a sponge is compared with the relation of island size and number of taxa present according to MacArthur and Wilson's island-theory (MacArthur, 1972). Finally the erratic occurrence of some taxa as opposed to the highly regular occurrence of some other taxa is discussed. It is concluded that the composition of the sponge-infauna in specimens larger than 11 is highly constant and that the sponge-inhabiting fauna constitutes an ecological community.