乌鲁木齐土地环境容载力研究

土地环境容载力包括土地环境区划、土地环境人口容量和土地环境城市建设承载力。在分析乌鲁木齐市土地环境现状的基础上，计算了土地环境容载力。     

人口经济与环境整体优化模型初步研究

一个城市在发展中做到人口经济与环境的整体优化，传统的思路是控制人口经济发展。８０年代以来持续发展理论的提出，以产业技术结构的演进，二、三产业的融合来促使人口经济环境由低级向高级发展，取得人口经济与环境的整体优化，这就要求提供实用的研究方法。本文提出人口经济与环境整体优化模型的思路，给出了具体模型的建立方法，讨论各项参数的获取，从而可为城市人口经济与环境整体优化研究奠定基础。     

黄山风景区旅游容量及相关环境问题研究

针对黄山风景区的旅游资源开发现状，重点研究了黄山风景区的主要环境问题，游览景区客流分布状况和旅游容量以及黄山游览景区的环境功能分区；并提出了旅游容量的涵义及其指标体系和扩大黄山旅游容量的措施。     

黄山风景区旅游容量及相关环境问题研究

针对黄山风景区的旅游资源开发现状，重点研究了黄山风景区的主要环境问题，游鉴景区客流分布状交和旅游容量以及黄山游览景区的环境功能分区；并提出了旅游容量的涵义及其指标体系和扩大黄山旅游容量的措施。     

景观生态学在公路景观环境评价中的应用

公路景观环境评价研究是我国公路建设中的新课题，景观生态学的发展为公路景观环境评价研究提供了新理论、方法和技术手段。分析了景观生态学研究内容、方法特点，提出了从景观生态价值、美学质量、视觉容量和景观安全格局4个方面对公路景观环境进行评价，并探讨了具体评价过程，该思想对公路战略环境评价和环境影响后评价也具有启示意义。     

海洋滩涂贝类养殖环境的研究现状

随着海洋滩涂贝类养殖业的发展，滩涂贝类养殖环境日趋恶化，生物病原大量滋生，养殖生产受到了严重的阻碍。文章介绍了我国滩涂的分布、类型和资源开发利用状况；结合滩涂贝类养殖生产和发病状况，从微生物学、底栖生态学和污染生态化学等角度，对我国在海洋滩涂贝类养殖环境方而取得的研究成果进行了综述；提出了滩涂贝类养殖环境方面亟需解决的问题。这些问题包括养殖容量的确定、底栖生物生态的研究、健康养殖模式的确立和污染环境的生物修复等。     

大理苍山洱海自然保护区旅游与环境可持续发展规划的研究

苍山洱海是国家级自然保护区，同时又是国家级风景名胜区，由于旅游业的开展而引发的环境、生态问题日趋突出。针对客观实际，在保护和开发并举的原则下，对该区域的旅游区、旅游模式等进行了规划，提出了旅游区域的环境保护指标、旅游容量，同时制定了相应的管理措施     

环境约束下牧区人口和种群持续增长模型研究

利用多元统计分析方法,对青海湖地区历年人口和种群的统计数据进行分析,并建立在环境约束下人口和种群持续增长模型,对区域人口适度规模、畜群最大环境容纳量和最大持续产量进行了估算和分析。通过估算得出:青海湖地区牦牛环境容纳量为51.9327万头,最大可持续产量为12.9831万头;藏羊环境容纳量为231.203万只,最大可持续产量为57.8007万只。在此分析的基础上,利用建立的相关模型以5a为时间段对青海湖地区未来25a的人口和牲畜数量进行了预测。最后,针对性地提出了大力改善草地生态环境、提高草地利用率和增加草地面积、采取人为措施调节牲畜出栏率、改变草畜生态环境等高原牧区人口、资源与环境可持续发展的对策。     

1995年中国城市环境状况

１９９５年中国城市环境状况到１９９５年底，全国设市城市６４０个，城市人口３７４２７．１万人，其中非农业人口１８３２１．４万人；城市面积１０８２９５６ｋｍ２，其中建成区面积１８４００．９ｋｍ２；城市人口密度３４６人／ｋｍ２，比上年增加２２人。城市环境污...     

中国小城镇有机废物生成、利用和排放状况分析

利用小城镇人口数据及农、牧、副、工等行业生产和环境特点，对中国小城镇有机废物的生成量、利用量和排放量进行了估算，并对它们的潜在资源价值和环境影响作出了评价。     

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。     

Optimal control of Atlantic population Canada geese

Management of Canada geese (Branta canadensis) can be a balance between providing sustained harvest opportunity while not allowing populations to become overabundant and cause damage. In this paper, we focus on the Atlantic population of Canada geese and use stochastic dynamic programming to determine the optimal harvest strategy over a range of plausible models for population dynamics. There is evidence to suggest that the population exhibits significant age structure, and it is possible to reconstruct age structure from surveys. Consequently the harvest strategy is a function of the age composition, as well as the abundance, of the population. The objective is to maximize harvest while maintaining the number of breeding adults in the population between specified upper and lower limits. In addition, the total harvest capacity is limited and there is uncertainty about the strength of density-dependence. We find that under a density-independent model, harvest is maximized by maintaining the breeding population at the highest acceptable abundance. However if harvest capacity is limited, then the optimal long-term breeding population size is lower than the highest acceptable level, to reduce the risk of the population growing to an unacceptably large size. Under the proposed density-dependent model, harvest is maximized by maintaining the breeding population at an intermediate level between the bounds on acceptable population size; limits to harvest capacity have little effect on the optimal long-term population size. It is clear that the strength of density-dependence and constraints on harvest significantly affect the optimal harvest strategy for this population. Model discrimination might be achieved in the long term, while continuing to meet management goals, by adopting an adaptive management strategy.     

Modeling the Effect of Population Dynamics on the Impact of Rabbit Hemorrhagic Disease

Abstract:  The European wild rabbit ( Oryctolagus cuniculus ) is a staple prey species in Mediterranean ecosystems. The arrival and subsequent spread of rabbit hemorrhagic disease throughout southwestern Europe, however, has caused a decline in rabbit numbers, leading to considerable efforts to enhance wild rabbit populations, especially through habitat management. Because rabbit population dynamics depend on habitat suitability and changes in habitat structure and composition subsequent to habitat management, I evaluated the effects of population dynamics on the long-term impact of rabbit hemorrhagic disease on rabbit populations. I used an age-structured model with varying degrees of population productivity and turnover and different habitat carrying capacities, and I assumed the existence of a unique, highly pathogenic virus. My results suggest that disease impact may be highly dependent on habitat carrying capacity and rabbit population dynamics, and the model provided some insight into the current abundance of wild rabbits in different locations in southwestern Europe. The highest disease impact was estimated for populations located in habitats with low to medium carrying capacity. In contrast, disease impact was lower in high-density populations in habitats with high carrying capacity, corresponding to a lower mean age of rabbit infection and a resulting lower mortality from rabbit hemorrhagic disease. The outcomes of the model suggest that management strategies to help rabbit populations recover should be based on improving habitats to their maximum carrying capacity and increasing rabbit population productivity. In contrast, the use of strategies based on temporary increases in rabbit density, including vaccination campaigns, translocations, and temporal habitat improvements at medium carrying capacities, may increase disease impact, resulting in short-term decreases in rabbit population density.     

Can we measure carrying capacity with foraging behavior?

Carrying capacity is one of the most important, yet least understood and rarely estimated, parameters in population management and modeling. A simple behavioral metric of carrying capacity would advance theory, conservation, and management of biological populations. Such a metric should be possible because behavior is finely attuned to variation in environment including population density. We connect optimal foraging theory with population dynamics and life history to develop a simple model that predicts this sort of adaptive density-dependent change in food consumption. We then confirm the model's unexpected and manifold predictions with field experiments. The theory predicts reproductive thresholds that alter the marginal value of energy as well as the value of time. Both effects cause a pronounced discontinuity in quitting-harvest rate that we revealed with foraging experiments. Red-backed voles maintained across a range of high densities foraged at a lower density-dependent rate than the same animals exposed to low-density treatments. The change in harvest rate is diagnostic of populations that exceed their carrying capacity. Ecologists, conservation biologists, and wildlife managers may thus be able to use simple and efficient foraging experiments to estimate carrying capacity and habitat quality.     

Modelling llama population development under environmental and market constraints in the Bolivian highlands

Changes in the size of animal populations over time are mainly determined by demographic and environmental factors. Livestock population dynamics are additionally influenced by harvesting decisions taken by herders. In Bolivia, not much is known about current llama husbandry and the main influencing factors determining population sizes. We collected data on demography, environmental factors and market values affecting the current and future llama population in three different regions in Bolivia. We generated a population model and assessed the future development of the llama population including environmental factors (rangeland carrying capacity, disturbance phenomena), herd structure and dynamics, and economic market demands. We calibrated and validated the llama model on the basis of 20-year data sets of the regions of Oruro, Potosi and La Paz, respectively. Model calibration by means of the Gauss-Marquardt-Levenberg algorithm yielded a model efficiency of 0.94. For model validation, however, the simulation slightly overestimated the observed llama population yielding model efficiencies of 0.91 and 0.87 for Potosi and La Paz, respectively. Model outcomes were most sensitive to death and birth rates of juveniles and death rate of females compared to environmental or other demographic factors. Population trajectories approached an overall carrying capacity for Oruro, Potosi and La Paz of 8.8 × 10⁵, 9.1 × 10⁵, and 9.0 × 10⁵ llama individuals after 100 years of simulation. Hence, detailed monitoring of demographic, environmental, and economic factors can improve predictions of llama population development over time. Further management should focus on improving birth rates and lowering female mortality through providing supplemental food and shelters against the harsh environmental conditions of the Andean highlands.     

Influence of prey reserve capacity on predator–prey dynamics

In this article the dynamics of a predator and prey population has been modelled when a reserve is created to protect a certain number of prey population from predation. This investigation is essential to derive some guiding principles to conserve the prey population and also to understand the behaviour and dependence of predator population on the reserve capacity. The present study concerns analysis of a fairly general model and hence some of the existing results based on specific explicit models, like Lotka–Volterra model and Rosenzweig–MacArthur model, can be derived from this work. In this study, conditions have been derived for coexistence of predator and prey, and extinction of predators. Results are obtained for global stability of required equilibrium of the model. Also, a method is suggested to compute reserve capacity in order to drive the ecosystem state to a required level. The key results developed in this article have been illustrated using numerical simulation. These results can be interpreted in different contexts like resource conservation, pest management, bio-economics of a renewable resource, etc.     

Role of Patch Size, Disease, and Movement in Rapid Extinction of Bighorn Sheep

Abstract: The controversy (  Berger 1990, 1999 ; Wehausen 1999 ) over rapid extinction in bighorn sheep ( Ovis canadensis ) has focused on population size alone as a correlate to persistence time. We report on the persistence and population performance of 24 translocated populations of bighorn sheep. Persistence in these sheep was strongly correlated with larger patch sizes, greater distance to domestic sheep, higher population growth rates, and migratory movements, as well as to larger population sizes. Persistence was also positively correlated with larger average home-range size ( p = 0.058, n = 10 translocated populations) and home-range size of rams ( p = 0.087, n = 8 translocated populations). Greater home-range size and dispersal rates of bighorn sheep were positively correlated to larger patches. We conclude that patch size and thus habitat carrying capacity, not population size per se, is the primary correlate to both population performance and persistence. Because habitat carrying capacity defines the upper limit to population size, clearly the amount of suitable habitat in a patch is ultimately linked to population size. Larger populations (250+ animals) were more likely to recover rapidly to their pre-epizootic survey number following an epizootic ( p = 0.019), although the proportion of the population dying in the epizootic also influenced the probability of recovery ( p = 0.001). Expensive management efforts to restore or increase bighorn sheep populations should focus on large habitat patches located ≥23 km from domestic sheep, and less effort should be expended on populations in isolated, small patches of habitat.     

基于生态足迹法的区域水资源生态承载力计算与评价——以珠海市为例

研究了人类社会对水资源的消耗、对自然生态环境的影响以及该影响的量化方法和量化指标,将生态足迹法引入区域水资源承载力系统,构建珠海市水资源生态承载力计算模型,分析计算水资源供给对区域经济社会发展的生态承载力,并对该地区的水资源生态承载力进行生态盈亏和敏感性评价.结果表明,总体上珠海市水资源系统呈现生态亏损,亏损率为37%,水资源生态承载呈现超载现象,珠海市城市化进程中流动人口增长对区域水资源的生态承载压力较大.研究结果还表明,将生态足迹模型运用到地区水资源承载力中具有较高的可信度,对地方尺度具有适用性.