异质景观中非点源污染动态变化比较研究

通过在河北省遵化地区于桥水库的上游选取景观特征差异明显的 4个典型流域 ,对地表水体采样分析 ,研究了非点源污染 N(水溶性 N)含量的季节动态变化特征以及与流域形状、景观空间分布格局的相互关系。结果表明 :1平水 (偏干 ,下同 )年份不同季节地表水中非点源污染 N含量高于干旱年份 ,反映出平水年份地表和地下径流对非点源污染的形成起到了较大作用。2干旱年份地表水中非点源污染 N含量季节变化比较平稳 ,且空间变异较小。而平水年份地表水体中非点源污染 N含量季节变化较大 ,表现出两种不同变化形式。 3流域形状和景观类型的相对重要性与非点源污染 N之间没有明显的相关关系 ,而“源”“汇”

PM_(10)、PM_(2.5)消减的异质景观绿地设计研究

城市绿地系统是重要的生态系统之一,因此,考虑到PM_(10)、PM_(2.5)的消减,提出一种异质景观绿地设计方案。采集待设计区域的地形结构与分布信息,构建空间分布模型。获取地区绿地基础特征,从土壤肥力、废弃土地量、淤泥排放量三方面计算土壤生态价值,并设置评价指标权重。在土壤生态价值与美观度约束下,计算不同植被的滞尘量,选取最佳植被,完成景观绿地设计。实验证明,所设计的绿地景观能够有效消减PM_(10)与PM_(2.5),且景观异质性强,说明所设计的异质景观绿地效果较好。

异质城市景观中苔藓植物群落多样性的研究

苔藓植物是一类敏感的环境指示植物．通过对上海市市区及市郊５种景观类型中苔藓植物群落的取样调查，从丰富性、均匀性、相似性等方面进行了多种α和β多样性指数分析．结果表明，５种生境中的苔藓群落多样性指数呈现出明显的梯度变化，对景观异质性有较好指示作用；

景观高度异质区土壤有机质时空变化特征分析

基于GIS和环境相关法,构建了集传统统计学、空间趋势分析、时间稳定性评估、结合辅助信息的地统计混合模型联合的景观高度异质区土壤属性时空变化研究模型,并利用该联合模型揭示了北京市密云县土壤有机质时空变化特征及其影响因素。结果表明,构建的时空联合模型能够较好地体现景观高度异质区土壤有机质时空变化细节特征;土壤有机质以中等稳定为主,且随着时间的推移,随机部分占土壤有机质空间变异的比例越来越大;不同时期土壤有机质含量空间分布格局一致;高土壤有机质含量区域的土壤有机质随时间呈减小趋势,低区与之相反,且高土壤有机质含量区变幅大,而低土壤有机质含量区变幅小;影响密云县土壤有机质时空变异的因素主要为土壤质地和土地利用方式。

沈阳市东陵区景观异质性变化研究

采用沿景观分别切割剖面线、均匀分段的方法,通过对剖面线出现的景观要素异质性信息量的研究,揭示了景观异质性的特点和其变化规律以及与地貌条件、人类干扰的关系.

营造景观异质的大城市环城绿带

本文指出当前大城市环城绿带建设过程中的一些弊病,探讨了营造景观异质的环城绿带的理念,即以自然恢复为主,人工建设为辅,保留现有植被和湿地,适当予以改造。特别分析了农业景观在环城绿带中重要的景观美学、生态学和经济价值。

声景重构下的旅游城市异质化——以秦皇岛为例

针对旅游城市发展的“千城一面”问题,从声景切入,在地方文脉梳理与声景资源挖掘的基础上,对其现有旅游布局作声景构成分析,并从突出地域标志声的角度进行重构。以声景为线索串联各旅游节点,使其特色声景画像形成新的城市品牌,推动旅游城市的异质化发展。以秦皇岛为例,依据其现有城市布局选择阿那亚、北戴河沿海旅游区、海港区工业遗产旅游区与山海关老龙头四个区域作为研究样本,以声漫步与人群访谈法调研各节点的声景构成,并结合地域声景资源进行重构,总结实现秦皇岛旅游形象更新的声景设计策略。

Spatio-temporal Variation of Landscape Heterogeneity under Influence of Human Activities in Xiamen City of China in Recent Decade

Xiamen is an economically competitive and highly urbanized city along the coastal area of Fujian Province, China. The research on spatio-temporal variation of landscape heterogeneity under the influence of human activities is of great importance to the further study on the relationship of landscape pattern and ecological process. It is also crucial to the discovery of spatial variation and intensity distribution of human activities. The research analyzed the intensity of human impacts and the spatial variation features and dynamics of landscape patterns by introducing statistical theories and approaches. We analyzed spatio-temporal variation of landscape heterogeneity using the geostatistical techniques, such as semivariogram and Kriging interpolation.Results show that there is a higher correlation between landscape heterogeneity indexes and human impact index. Both the indexes show a moderate spatial autocorrelation as well as an obvious characteristic of anisotropy. From 1998 to 2008, the spatial differentiation of the changes in the intensity of human activities and the changes in landscape heterogeneity shows that the landscape patterns in Xiamen are closely related with the urban land utilization methods, the condition of traffic and geographical location and the physical geographical condition such as the terrain and the ecological environment. The process of urbanization has a significant impact on the urban landscape pattern.

A Remote Sensing-based Analysis on the Impact of Wenchuan Earthquake on the Core Value of World Nature Heritage Sichuan Giant Panda Sanctuary

In this study,we used remotely sensed data,GIS modeling,and statistical methods to evaluate the damage caused by the Wenchuan Earthquake (May 12,2008) to the giant panda (Ailuropoda melanoleuca) habitat in the World Nature Heritage Sichuan Giant Panda Sanctuary (WHSGPS) in China.A landscape ecological analysis found increases of landscape heterogeneity,complexity,and fragmentation in the giant panda habitat after the earthquake.A terrain analysis found that slope and elevation are directly associated with the distribution of the damaged areas.As slope and elevation increase,the size of the damaged area keeps increase until to a peak,and then starts to drop.The total area of the damaged vegetation in our study area is 114.26 km 2,accounting for 3.78% of the study area;30.46% of that 114.26 km 2 is located in the Core Zone of WHSGPS.There are 18.57km 2 of the damaged vegetation located in the identified suitable giant panda habitat,accounting for 1.75% of the total area of suitable giant panda habitats in the study area.Based on these findings,we conclude that the Wenchuan Earthquake does not have significant impact on the WHSGPS as a whole.

Modeling of forest soil and litter health using disturbance and landscape heterogeneity indicators in northern Iran

This paper focuses on the indicators of soil and litter health, disturbance, and landscape heterogeneity as a tool for prediction of ecosystem sustainability in the northern forests of Iran. The study area was divided into spatial homogenous sites using slope, aspect, and soil humidity classes. Then a range of sites along the disturbance gradient was selected for sampling. Chemical and physical indicators of soil and litter health were measured at random points within these sites. Structural equation modeling(SEM) was applied to link six constructs of landscape heterogeneity, three constructs of disturbance(harvest, livestock, and human accessibility), and soil and litter health. The results showed that with decreasing accessibility, the total N and organic matter content of soil increased and effective bulk density decreased. Harvesting activities increased soil organic matter. Therefore, it is concluded that disturbances through harvesting and accessibility inversely affect the soil health. Unexpectedly, it was found that the litter total C and C:N ratio improved with an increase in the harvest and accessibility disturbances, whereas litter bulk density decreased. Investigation of tree composition revealed that in the climax communities, which are normally affected more by harvesting activities, some species like Fagus orientalis Lipsky with low decomposition rate are dominant. The research results showed that changes in disturbance intensity are reflected in litter and soil indicators, whereas the SEM indicated that landscape heterogeneity has a moderator effect on the disturbance to both litter and soil paths.

Stochastic SIS metapopulation models for the spread of disease among species in a fragmented landscape

Two stochastic models are derived for a susceptible-infectious-susceptible epidemic spreading through a metapopulation： a continuous time Markov chain （CTMC） model and an It6 stochastic differential equation （SDE） model. The stochastic models are numerically compared. Close agreement suggests that computationally intense CTMC simulations can be approximated by simpler SDE simulations. Differential equations for the moments of the SDE probability distribution are also derived, the steady states are solved numerically using a moment closure technique, and these results are compared to simulations. The moment closure technique only coarsely approximates simulation results. The effect of model parameters on stability of the disease-free equilibrium is also numerically investigated.