Area-weighted Mean Patch Fractal Dimension Research Articles

Spatial-temporal changes of landscape and habitat quality in typical ecologically fragile areas of western China over the past 40 years: A case study of the Ningxia Hui Autonomous Region.

In this paper, we use the InVEST model and five periods of land use data from 1980 to 2020 to assess the habitat quality of the Ningxia Hui Autonomous Region in Western China, which has characteristics of a typical fragile ecosystem. We further analyse the spatial and temporal characteristics of habitat quality evolution and its relationship with land use and landscape pattern indices to explore the close relationship between regional habitat quality changes and human natural resource conservation and utilization. The research results show that the overall habitat quality of Ningxia Hui Autonomous Region was stable and at a moderate level (0.57-0.60) during the 40 years from 1980 to 2020; Habitat patches (2020) with low (24.89%), high (22.45%) and very high (29.81%) quality occupy a larger proportion of the area, followed by very low (13.31%) and moderate levels (9.54%). Over the past 40 years, there have been 275 sample sites in Ningxia where habitat quality has deteriorated, 1593 sample sites where the habitat quality has remained stable, and 184 sample sites where the habitat quality has increased. From 1980 to 2020, the Mean Patch Area of landscape types in Ningxia decreased by 25.9 hm2. The Patch Density increased by 0.06 /hm2. The Largest Patch Index decreased by 15.69%. The Edge Density increased by 2.5 m/hm2. The Contagion Index decreased by 2.99%. The Area-Weighted Mean Patch Fractal Dimension remained basically unchanged (0.01). The Landscape Shape Index showed a trend of first increasing and then decreasing, increasing by 13.94. The Area-Weighted Mean Shape Index has been reduced by 9.45. The Shannon Diversity Index and Shannon Evenness Index both show an increasing trend, but the amplitude is relatively small, with 0.09 and 0.04, respectively. There was a significant spatial aggregation of high and low habitat quality in Ningxia, with high values usually distributed in the northern and southern areas with good natural conditions and low values distributed in areas with frequent human activities and poor natural conditions. The decrease in habitat quality in Ningxia was mainly due to the expansion of cultivated land and construction land, the increase in landscape fragmentation and the resulting decrease in connectivity. On the other hand, due to the implementation of ecological protection measures, such as the project of returning farmland to pasture and grass to forest, the quality of habitats in Ningxia increased. The conclusions of this study support the idea that the conservation of habitat quality in ecologically fragile areas should fully preserve the original natural habitats and reduce the interference of human activities to increase the habitat suitability of the landscape and the habitat connectivity between patches. At the same time, targeted ecological protection policies should be developed to restore the areas where the habitat quality has been damaged and ultimately maintain the stability of biodiversity and ecosystems in ecologically fragile areas. Meanwhile, for ecologically fragile areas with similar ecological characteristics to those of Ningxia, our research supports the idea of increasing the protection of the stability of the original habitats, increasing the proportion of ecological restoration projects, financial investment and seeking cooperation with local community managers and residents will help to improve the quality of the regional habitats and the enrichment of the biodiversity, and ultimately promote the harmonious coexistence of human beings and nature in the modernized sense of the word.

Impact of urbanization on the spatial and temporal evolution of the water system pattern: A study of the Wuhan metropolitan area in China

With the rapid economic development and continuous urbanization, the status of river ecosystems is undergoing profound changes. Therefore, quantitative assessment of the impact of urbanization on the water system is highly desirable. Considering Wuhan metropolitan area as the study area, this study constructed an indicator system and used the entropy technique for order preference similarity to ideal solution (TOPSIS) method to quantify the urbanization level of each city. The urbanization process was divided into four periods based on the results of the urbanization level measurement. Then, the theory of landscape ecology was used to establish the evaluation index system of the water system pattern. Finally, the study used the grey relational analysis model to analyze the relationship between urbanization and evolution of water patterns under different periods. The results indicate that (1) from 2000 to 2019, the urbanization level of Wuhan metropolitan area exhibited an increasing trend, while the four indicators of the quantitative attribute and the two indicators of complexity showed a decline. (2) A negative correlation was observed between urbanization level and water system pattern indicators, with the correlation ranging from 0.55 to 0.62 (maximum value is 1). The urbanization process shows the most significant impact on the quantitative characteristics of water systems. (3) After classifying the urbanization stages, the correlation further increased between 0.55 and 0.95. (4) The four indicators of water patterns with the highest correlation with urbanization in the given periods are class area, area-weighted mean patch fractal dimension, edge density, and number of patches. Management can judge the corresponding human activities in relation to the current stage of the urbanization process and targeted protection of the water systems.

Linking landscape characteristics to shorebird habitat quality changes in a key stopover site along the East Asian–Australasian Flyway migratory route

The area and quality of shorebird stopover habitat along the key East Asian–Australasian Flyway migratory route has decreased. The cause is not fully understood. We apply an InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) model to examine shorebird habitat quality between 1975 and 2020 in the Yellow River Delta (YRD), and link landscape characteristics to habitat quality. Mean habitat quality declined from 0.42 to 0.20, areas of high habitat quality declined by 31.75%, and those of low and medium quality increased by 18.67% and 12.98%, respectively. Increased percentages of landscape (PLAND) and largest patch index (LPI) for city, industrial mining, reservoir/pond, and mariculture land-usage categories, and decreased PLAND and LPI for coastal wetlands significantly contribute to decreased mean habitat quality. Increased mean patch area (AREA_MN) and area-weighted mean patch fractal dimension (FRAC_AM) for city and reservoir/pond also greatly contribute to habitat quality decrease. For Spartina alterniflora, increased PLAND, LPI, number of patches (NP), AREA_MN, FRAC_AM and aggregation index (AI) contribute to reduced mean habitat quality. In the Shandong YRD National Nature Reserve, the impact of increased S. alterniflora invasion on shorebird habitat quality is greater than that of other forms of land use. In contrast, in Non-Reserve, the increased area of degraded land poses a greater threat to habitat quality than other factors. Managing S. alterniflora in Reserve, and reducing human activity in Non-Reserve, is required to curtail further decreases in habitat quality.

Restoration recommendations for mitigating habitat fragmentation of a river corridor

Flow discharge and anthropogenic activities influence the composition and configuration of habitat patches in river ecosystems. Understanding the response of habitat landscapes and the corresponding fish habitat quality is crucial for river management. We investigated the reaction of fish habitat suitability and variant flow discharge performance in examining aquatic habitat patch fragmentation. The hydraulic simulation and fish habitat calculation were used to determine the flow characteristics, habitat conditions, and river landscapes. FRAGSTATS was applied to explore the composition and configuration of habitat patches. Cluster analysis and logistic regression were employed to compute the spatiotemporal variabilities of riverscape indices and establish the relationship between riverscape attributes and fish habitat quality. The results indicate that the changes in specific habitat features are associated with the riverscape indices of total edge (TE), mean nearest-neighbor distance (MNN), interspersion and juxtaposition index (IJI), mean patch size (MPS), and area-weighted mean patch fractal dimension (AWMPFD). The flow discharge is the key to determining habitat fragmentation in rivers, with natural barriers occurring at low flow. In contrast, weirs are anthropogenic obstacles that have significant adverse effects on the downstream corridor. A priority restoration activity to conserve river habitat is to create refuge pools during dry seasons by modifying channel morphology. The positive correlation between habitat suitability and MPS and the negative relationship between habitat suitability and AWMPFD highlight the patch size and shape complexity that are critical indices for pool creation. The prediction of the landscape attributes of the outcomes under different scenarios could support the decision-making in river management. The innovative integrated method presented in this study provides a solid foundation and supports the implementation of nature-based solutions for sustainable river management.

Land use alteration strategy to improve forest landscape structural quality in Radhanagar forest range under Bankura district

Such kind of human necessities restructured the existing landscape pattern which brings imbalance in regional biodiversity. Radhanagar Forest Range (RFR) in Bankura district has been faced same kind of activates since 1960. As a result, forest patch becomes isolated and structurally complex in nature which is an important cause for extinction of wild animal. To control this damage forest department increased forest area through several plantation schemes in vacant or barren land. But plantation areas were not appropriate in the question of structural forest quality in this region. The present study seems that forest structural quality is a vital consideration for balancing biodiversity, in concern of several ecological processes like species movement, connectivity, colonization and edge contrast. Suitable forest patch structure may possible when appropriate areas i.e. forest encroached areas will be select for plantation. To prove this statement, study considers two types of landuse alteration into forest land i) all barren land altered into forest and ii) selected encroached areas altered into forest land in RFR. ArcGIS 10.3 version software is used for technical map editing and preparing these spatial alteration maps. After that several landscape ecological indexes like Total Core Area Index (TCAI), Mean Core Area (MCA) at 300 m specified edge depth, Total Edge (TE), Edge Density (ED), Area Weighted Mean Shape Index (AWMSI), Area Weighted Mean Patch Fractal Dimension (AWMPFD) and Mean Patch Size (MPS) are calculated using FragStat 4.2 version software to compare both spatial alteration forest qualities. Comparison analysis explains that encroached areas alteration into forest land is qualitative to improve forest structural quality. It is interesting to know that less area will be planted in encroached area to get utmost forest structural qualities.

气候、植被和地形对大兴安岭林火烈度空间格局的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 气候、植被和地形对大兴安岭林火烈度空间格局的影响 DOI: 10.5846/stxb201902140264 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31570462）；江西省教育厅科学技术研究项目（GJJ160275） Effects of climate, vegetation, and topography on spatial patterns of burn severity in the Great Xing'an Mountains Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在北方森林中火干扰是森林景观变化的主导因素。林火烈度作为衡量林火动态的重要指标，较为直观地反映了火干扰对森林生态系统的破坏程度，其空间格局深刻地影响着森林景观中的多种生态过程（如树种组成、种子扩散以及植被的恢复）。解释林火烈度空间格局有助于揭示林火干扰后森林景观格局的形成机制，对预测未来林火烈度空间格局以及制定科学合理林火管理策略均有重要意义。基于LandsatTM/ETM遥感影像，将2000-2016年大兴安岭呼中林区的36场火的林火烈度划分为未过火、轻度、中度、重度4个等级。采用FRAGSTAT景观格局分析软件从类型水平上计算了斑块所占景观面积比、面积加权平均斑块面积、面积加权平均斑块分维数、面积加权边缘面积比、斑块密度5个景观指数，以对林火烈度空间格局进行了定量化描述。并且采用随机森林模型，分析了气候、地形、植被对林火烈度空间格局的影响及其边际效应。通过研究得出以下结果：（1）相对于未过火、轻度、以及中度火烧斑块，重度火烧斑块的面积更大、形状更简单；（2）海拔对重度火烧斑块的空间格局起着至关重要的作用，其次是坡向、坡度、植被覆盖度、相对湿度、温度等；（3）随着海拔的升高，面积加权平均斑块面积和面积加权平均斑块分维数的边际效应曲线呈上升趋势，而面积加权边缘面积比和斑块密度呈下降趋势；除了面积加权平均斑块面积外，都受到火前植被覆盖度的影响，且植被覆盖度为0.2-0.3范围内，重度火烧斑块在景观中所占比例最大。总的来看，2000-2016年大兴安岭呼中森林景观中重度火烧斑块与未过火、轻度以及中度火烧斑块存在显著差异性。相对于气候，地形和植被对于塑造重度火烧斑块空间格局具有重要作用。因此，应针对重度火烧区域进行可燃物处理，从景观层面上合理配置森林斑块，从而降低高烈度森林大火发生的风险。 Abstract:Fire is a major driver of forest landscape change in boreal forests. Burn severity is one of the main indexes for measuring the damage degree of fire on forest ecosystems. Spatial patterns of burn severity affect numerous ecological processes (e.g., species composition, seed dispersal, and vegetation restoration). Explaining spatial patterns of burn severity is conducive to reveal the formation mechanism of forest landscape patterns after fire, which is of great significance for predicting spatial patterns of burn severity in the future and formulating scientific fire management strategies. Based on Landsat TM/ETM remote sensing images, we mapped the burn severity of 36 fires that occurred between 2000 and 2016 in Huzhong forest region of the Great Xing'an Mountains by calculating the post-fire Normalized Burn Ratio index (NBR) and classified the fires into unburned, low, moderate and high severity classes. For each fire, we calculated five landscape metrics to quantitatively describe spatial patterns of burn severity at the class level using the FRAGSTATS program. The landscape pattern metrics were percentage of landscape (PLAND), area-weighted mean patch size (AREA_AM), area-weighted mean fractal dimension index (FRAC_AM), perimeter-area ratio (PARA_AM), and patch density (PD). Using Random Forest models, we analyzed the relative importance and marginal effects of weather, topography, and vegetation variables on determining spatial patterns of burn severity. The results showed that:1) compared with unburned, low-, and moderate-severity patches, the high-severity patches were more larger and simpler in shape. 2) Elevation played an important role in shaping spatial patterns of burn severity, followed by aspect, slope, vegetation coverage, relative humidity, and temperature. 3) With the increase in elevation, the marginal effect curve of area-weighted mean patch area and area-weighted mean patch fractal dimension showed an obvious increasing trend, whereas area-weighted perimeter-area ratio and patch density exhibited a decreasing trend. In addition to area-weighted mean patch area, all of them were affected by pre-fire vegetation coverage. When pre-fire vegetation coverage ranged fom 0.2 to 0.3, the proportion of high-severity patches in the landscape were the largest. In general, the high-severity patches differed significantly from unburned, low- and moderate-severity patches for five spatial pattern metrics. Topography and vegetation were more important in shaping the spatial pattern of high-severity patches than climate. Therefore, it would be urgent to implement forest fuel treatment in high-severity areas. It is necessary to allocate different forest patches reasonably from the landscape level, then to reduce the risk of high-severity forest large fires. 参考文献 相似文献 引证文献

普者黑岩溶湖泊湿地湖滨带景观格局演变对水质的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 普者黑岩溶湖泊湿地湖滨带景观格局演变对水质的影响 DOI: 10.5846/stxb201703130419 作者: 作者单位: 西南林业大学国家高原湿地研究中心;西南林业大学环境科学与工程学院,西南林业大学环境科学与工程学院;西南林业大学农村污水处理研究所,西南林业大学环境科学与工程学院,西南林业大学环境科学与工程学院;西南林业大学农村污水处理研究所,西南林业大学林学院,西南林业大学环境科学与工程学院;西南林业大学农村污水处理研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31760245，31560237，31460195） The effects of landscape pattern evolution in Puzhehei karst lake wetland littoral zone on water quality Author: Affiliation: National Plateau Wetlands Reasearch Center, Southwest Forestry University;College of Environmental Science and Engineering, Southwest Forestry University,College of Environmental Science and Engineering, Southwest Forestry University;Research Institute of Rural Sewage Treatment, Southwest Forestry University,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:湖滨带作为湖泊与陆地之间的过渡带，是健康湖泊生态系统的重要组成部分。湖滨带景观格局的演变会对湿地水质产生重要影响，因此探究影响岩溶湿地水质变化的湖滨带关键景观因子，对深入了解景观格局对岩溶湿地水质的影响过程与机制具有重要意义。选择普者黑岩溶湖泊湿地为研究对象，以2005、2007、2009、2011年共4年的Landsat遥感影像及水质监测数据为基础，通过划定湖泊湿地湖滨带缓冲区域，运用秩相关分析和冗余分析研究湖滨带景观格局对普者黑岩溶湖泊湿地水质的影响。结果表明，湖滨带不同缓冲区内景观结构类型比例差异较大；枯水期水质与土地利用类型和景观格局指数的影响大于丰水期；景观格局在不同缓冲区尺度对岩溶湿地的水质具有不同的效应；随着监测点缓冲距离的增加，个别景观指数可较好的揭示湖滨带景观格局演变对岩溶湿地水质的影响，其中，蔓延度指数（CONTAG）、斑块结合度指数（COHSION）、均匀度指数（SHEI）对水质参数的影响较大，边界密度（ED）、聚集度（AI）对水质参数的影响随缓冲距离的增加逐渐减弱，其他景观指数对水质影响差异并不明显，最大斑块指数（LPI）在缓冲距离≤ 300m的区域内与水质的关系较密切，面积加权平均斑块分维数（AWMPFD）与水质参数有显著负相关性，多样性指数（SHDI）对水质的影响具有不确定性；另外，大部分水质参数与土地利用面积比例有较好的相关性，且湿地面积比例是表征岩溶湖泊湿地水环境质量的主要指标。 Abstract:The lake littoral zone, an important transitional area between land and lake, is an integral part of a healthy lake ecosystem. The evolution of landscape patterns in the lake littoral zone will have an important effect on wetland water quality. Therefore, studying the key littoral zone landscape factors that affect karst wetland water quality changes is of great importance in understanding the process and the underlying mechanism regarding how landscape patterns effect karst wetland water quality. Using Puzhehei karst lake wetland as the study area, and obtaining Landsat remote sensing images and the collected water quality monitoring data from 2005, 2007, 2009, and 2011, we studied the influence of landscape pattern indices on Puzhehei karst lake wetland littoral zone water quality through delineating the buffer zones and using correlation and redundancy analysis. The results showed that the littoral zone landscape patterns were quite different in various buffer zones. The effects of water quality on land use type and landscape pattern indices in the low flow period was greater than that in the high flow period; the landscape patterns had different effects on the water quality of karst lake wetlands at different buffer zones. Individual landscape indices better revealed the influence of landscape pattern evolution on water quality in the Puzhehei karst lake wetland, accompanied by increased buffer zone distances. Among them, Contagion Index, Patch Cohesion Index, and Shannon's Evenness Index values had a substantial influence on water quality, and Area-weighted Mean Patch Fractal Dimension exhibited a significantly negative correlation with water quality parameters. The effects of other landscape indices on water quality were not significant. Among them, the effects of Edge Density and Aggregation Index values on water quality gradually weakened accompanied by the increased buffer region distances. Largest Patch Index values were closely correlated with water quality when the buffer distance was less than 300m. Beyond this, the effect of Shannon's Diversity Index on water quality was uncertain. Additionally, most water quality parameters showed a good correlation with land use type area, and the proportion of wetland area was the main index to characterize the water environment quality of the karst lake wetland. 参考文献 相似文献 引证文献

近40年艾比湖湿地自然保护区生态干扰度时空动态及景观格局变化

PDF HTML阅读 XML下载 导出引用 引用提醒 近40年艾比湖湿地自然保护区生态干扰度时空动态及景观格局变化 DOI: 10.5846/stxb201609081825 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 新疆维吾尔自治区自然科学基金项目（2016D01C029）；自治区青年科技创新人才培养工程项目（2013731002）；国家自然科学基金项目（41361045，41130531）；国家自然科学基金（新疆联合基金本地优秀青年人才培养专项）（U1503302） Analysis of the temporal and spatial dynamics of landscape patterns and hemeroby index of the Ebinur Lake Wetland Nature Reserve, Xinjiang, over the last 40 years Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以新疆艾比湖湿地为研究区，利用1972、1998、2007年及2013年4个时期的 Landsat遥感影像作为数据源，并结合湿地的土地覆被状况，参考《全国土地利用分类》建立艾比湖湿地生态干扰类型分类系统。借助生态干扰度指数、景观格局指数以及GIS空间分析方法，探讨艾比湖湿地的生态干扰度的时空动态及景观响应机制。结果表明：（1）1972-2013年，研究区的生态干扰度总体呈现较为稳定的趋势，但其空间分布发生变化。生态干扰度类型之间的转化速率有加快的趋势。（2）1972-2013年，边缘密度指数（ED），平均形状指数（MSI），面积加权的平均斑块分形指数（AWMPFD）及景观分离度（DIVISION）4项景观格局指数大体呈上升的趋势，2013年区域的景观指数较为稳定。（3）景观格局指数与生态干扰程度有密切的一致性。生态干扰度与景观格局指数空间分布相关性大小依次为：边缘密度指数（ED） < 景观丰度密度（PRD） < 香农多样性指数（SHDI） < 平均形状指数（MSI） < 面积加权的平均斑块分形指数（AWMPFD） < 景观分离度（DIVISION）。客观系统的认识和评价艾比湖湿地的生态系统及环境，可为干旱区实现自然环境的保护，协调土地利用及环境保护之间的关系提供较为实用的参考。 Abstract:Wetlands are an important part of ecological systems. Wetlands not only provide the survival habitats and resources for plants, animals, and human but also are highly beneficial for the environment. In arid zones in particular, wetlands have received considerable scientific attention. The hemeroby index provides a measure of the magnitude to which the vegetation of an ecological environment deviates from the natural state as a consequence of human activities. It is beneficial to manage rationally for economic development in order to protect the ecological environment. The present study fills a gap in our understanding of the sustainable development of the wetland ecosystem in the Ebinur Lake Wetland Nature Reserve, Xinjiang Uyghur Autonomous Region, China. A hemeroby-type classification system for the Ebinur Lake Wetland Reserve was established based on multiple datasets, including Landsat MSS/TM/ETM+/OLI image data obtained in 1972, 1998, 2007, and 2013. The study explored the spatiotemporal dynamics of hemeroby and the landscape pattern response through hemeroby, landscape pattern, spatial patch, and GIS spatial analyses in the study area. The following results were obtained: (1) From 1972 to 2013, the ecological hemeroby degree for the Ebinur Lake wetland showed a relatively stable trend; however, there were marked changes in its spatial distribution. The distribution of the partially disturbed type of wetland has obviously changed. This indicates that the degree of naturalness of wetland vegetation is unstable and susceptible to human interference in this area. There was a high conversion rate of different hemeroby index (HI) types from 1972 to 2013. Dynamic changes in hemeroby degree are more likely to be attributed to natural, human, and policy-driven forces that result in a comprehensive effect. During the period 1972-2013, changes in natural factors (mean annual evaporation, temperature, and precipitation) and human factors (livestock, population, and GDP) led to change in the distribution of vegetation and Ebinur Lake area, which influenced the degree of naturalness of the ecological system. (2) During the period 1972-2013, there were significant increases in four landscape pattern indices, edge density (ED), mean shape index (MSI), area-weighted mean patch fractal dimension index (AWMPFD), and landscape division (DIVISION). However, in 2013, the regional landscape index was relatively stable. (3) High values of ED and AWMPFD were recorded for areas with a high HI. This shows that landscape patch fragmentation and complexity is higher in areas with a high HI, and that the degree of naturalness is unstable. Low values of patch fragmentation and complexity are mainly concentrated in areas with a low HI. This indicates that landscape pattern indices and the HI have good consistency and correlation with regard to spatial distribution. The HI was positively correlated with DIVISION, AWMPFD, MSI, Shannon's diversity index, patch richness density, and ED, in a decreasing order of influence. Evaluation of the ecological environment of the Ebinur Lake region provides a practical reference for the protection of the natural environment and resources, and will prove beneficial for the coordinated management of the environmental for sustainable development. 参考文献 相似文献 引证文献

Evaluating the effectiveness of landscape configuration metrics from landscape composition metrics

Although landscape configuration and landscape composition metrics are correlated theoretically and empirically, the effectiveness of configuration metrics from composition metrics has not been explicitly investigated. This study explored to what extent substantial information of configuration metrics increases from certain easily calculated and extensively used composition metrics and how strongly the effectiveness is influenced by different factors. The effectiveness of 12 landscape configuration metrics from the percentage of landscape (PLAND) of each land-use class and patch density (PD) was evaluated through the coefficient of determination (R 2) of multivariate stepwise linear regression analysis of 150 town-based landscape samples from three regions. The different landscape configuration metrics from PLAND and PD presented significantly different performances in terms of effectiveness [the contagion index and aggregation index possess minimal information, and the effective mesh size (MESH) and area-weighted mean patch fractal dimension possess abundant information]. Furthermore, the effectiveness of configuration metrics showed different responses to changing cell sizes and different land-use categorization in different regions (interspersion and juxtaposition index, patch cohesion index, and MESH exhibited large variations in R 2 among the different regions). No single, uniform, consistent characteristic of effectiveness was determined across different factors. This new approach to understanding the effectiveness of configuration metrics helps clarify landscape metrics and is fundamental to landscape metric assessment.

Urban Sprawl Patterns and Processes in Delhi from 1977 to 2014 Based on Remote Sensing and Spatial Metrics Approaches

Abstract Recent decades have witnessed rapid urbanization and urban population growth resulting in urban sprawl of cities. This paper analyzes the spatiotemporal dynamics of the urbanization process (using remote sensing and spatial metrics) that has occurred in Delhi, the capital city of India, which is divided into nine districts. The urban patterns and processes within the nine administrative districts of the city based on raw satellite data have been taken into consideration. Area, population, patch, edge, and shape metrics along with Pearson’s chi statistics and Shannon’s entropy have been calculated. Three types of urban patterns exist in the city: 1) highly sprawled districts, namely, West, North, North East, and East; 2) medium sprawled districts, namely, North West, South, and South West; and 3) least sprawled districts—Central and New Delhi. Relative entropy, which scales Shannon’s entropy values from 0 to 1, is calculated for the districts and time spans. Its values are 0.80, 0.92, and 0.50 from 1977 to 1993, 1993 to 2006, and 2006 to 2014, respectively, indicating a high degree of urban sprawl. Parametric and nonparametric correlation tests suggest the existence of associations between built-up density and population density, area-weighted mean patch fractal dimension (AWMPFD) and area-weighted mean shape index (AWMSI), compactness index and edge density, normalized compactness index and number of patches, and AWMPFD and built-up density.

湖北宜昌松林景观格局与松材线虫流行的关系及驱动力

PDF HTML阅读 XML下载 导出引用 引用提醒 湖北宜昌松林景观格局对松材线虫流行及扩散的影响 DOI: 10.5846/stxb201406161248 作者: 作者单位: 北京林业大学林学院,北京林业大学林学院,中国林业科学院森林生态环境与保护研究所,北京林业大学林学院,湖北省林业科学研究院,湖北省宜昌市夷陵区森防站,湖北省宜昌市夷陵区森防站 作者简介: 通讯作者: 中图分类号: 基金项目: 国家林业公益性行业科研专项(201204501) The relationship between pine forest landscape patterns and pine wilt disease in Yichang, Hubei Province Author: Affiliation: College of Forest,Beijing Forest University,College of Forest,Beijing Forest University,Research Institute of Forest Ecological Environment and Protection,College of Forest,Beijing Forest University,Hubei Academy of Forestry,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:景观格局对能量流、物质流和物种流等生态学过程影响显著。为了探究区域生境差异对病虫害发生及扩散的影响,以湖北省宜昌市夷陵区松材线虫病为对象,结合区域森林资源二类清查矢量数据和松材线虫病普查资料,运用景观生态学的原理和方法,探究景观格局对松材线虫病发生的影响。研究结果表明:1)松林景观类型百分比、平均斑块面积、自然连接度和聚合度与松材线虫病的发病率成正相关;2)松林斑块的粒级结构分析表明,中、小斑块能抑制松材线虫病的发生,巨斑块、超大斑块对松材线虫的发生有利;3)从景观干扰上分析显示人类活动强度与松材线虫病发病率成正相关;4)在景观尺度水平上,景观的破碎度大、多样性指数高、蔓延度指数小、斑块形状简单、受人类活动影响大的乡镇松材线虫病发病率高。通过斑块类型尺度和景观尺度两个水平上的分析可知,在夷陵区乡镇尺度上,由小斑块松林组成且斑块聚集度低、景观破碎化程度低的景观格局对松材线虫病有一定的抑制作用。研究结论对当地松材线虫病的防治就有较好的参考价值。 Abstract:Landscape patterns have significant and complex effects on a variety of ecological processes, including the flow of matter and nutrients and the distribution and movement of species. To explore the impacts of regional habitat differences on the occurrence and spread of forest diseases and insect pests, we focused on the pine wood nematode in Yichang in the Yiling district of Hubei Province. Using forest inventory vector data collected by the Forestry Survey and Planning Institute of Hubei and census data of pine wilt disease in the Yiling district from 2007 to 2012, collected by the Station of Pest and Disease Control and Quarantine, we examined the effects of forest landscape patterns on pine wilt disease, as predicted by landscape ecology theory. Seven towns continuously infected with pine wilt disease from 2007 to 2012 were selected as the research area. The landscape of the Yiling district were classified into 10 types by ArcGis10 according to the intensity of human activities, the land use classification, and the dominant tree species group. To characterize the research area at the level of patches within a class, we calculated the landscape patch area, mean patch area, percentage of landscape patch area, patch cohesion index, aggregation index, geometric mean nearest neighbor distance, and the interspersion-juxtaposition index. And the pine forest landscape were classified into 5 grades by patches' area size(Apatch): the small patch(Apatch<10 hm2), the middle patch(10 ≤ Apatch < 50 hm2), the large patch(50 ≤ Apatch < 100 hm2), the super patch(100 ≤ Apatch < 200 hm2), the huge patch(Apatch ≥ 200 hm2). At the landscape level, we calculated the edge density, Shannon's diversity index, the contagion index, and the area-weighted mean patch fractal dimension. Landscape pattern indices were calculated using FRAGSTATS3.4. Morbidity was determined as the ratio of the annual average area infected with pine wilt disease compared with the total pine forest area of any one town. Correlation analysis between landscape pattern indices and morbidity was performed using SPSS18 software. The main results were as follows: 1) The percentage of pine forest landscape patch area, the average patch size, and the degree of natural connection and polymerization of patches were all positively correlated with pine wilt disease morbidity; 2) Analysis of the granularity of the pine forest landscape showed that the proportion of area composed of small- and middle-patch sizes was negatively correlated with pine wilt disease morbidity, while the proportion of huge-patch and super-patch sizes was positively correlated; 3) The intensity of human activity, which can interfere with the landscape, was also positively correlated with pine wilt disease morbidity; and 4) At the landscape level, as edge density and Shannon's diversity index increased, pine wilt disease morbidity increased. The contagion index, in contrast, was negatively correlated with pine wilt disease morbidity, as was the area-weighted mean patch fractal dimension. These results suggest that fragmentation of the entire landscape will facilitate the spread of pine wilt disease. Thus, using the analysis of landscape patterns at the patch and landscape level, we can infer that, in the Yiling district, a forest landscape composed of small pine forest patches with a low aggregation index and low degree of fragmentation of the entire landscape can somewhat prevent the spread of pine wilt disease. The findings of this study can be used as a guide to aid the prevention and control of pine wilt disease in the Yiling district. 参考文献 相似文献 引证文献

Predicting the Effects of Urban Development on Land Transition and Spatial Patterns of Land Use in Western Peninsular Malaysia

Analyzing the effects of urban development on dynamic and spatial patterns of land use is vital to establish more efficient land management policies. However, in Malaysia, such effects are usually explained without quantitative metrics. This research quantified the future impact of urban expansion on the dynamic of land use by developing the area-independent dynamic metric. The metric was calculated based on summarizing the cross tabulation matrices of change in an urbanizing area at west coast of Peninsular Malaysia. Another two land use measures involving vulnerability to gain and vulnerability to loss were used to evaluate tendency of land classes to transition. The effects of urban development on spatial patterns of land use were quantified using two landscape metrics involving the Edge Density (ED) and Area-Weighted Mean Patch Fractal Dimension (AWMPFD). Analyses were carried out on a set of spatial land use data including observed 1997, 2002, and 2008, as well as a simulated near future land change for the year 2020 under a spatio-temporal land use model. Results showed that urban development practices would influence the dynamic of land transition in the near future. Urban growth would experience a fast-growing dynamic and high vulnerability to gain than loss while the dynamic and vulnerability of forest/wetland covers would decrease in terms of loss. Moreover, agriculture practices tend to be hindered by further urban development in the coming years. Another important finding was that urban development process would influence the spatial patterns of land use in the near future.

Green corridors and fragmentation in South Eastern Black Sea coastal landscape

Green corridors are inevitable part of land cover and land use planning activities as they affect climate, hydrology and ecology of the urbanized regions. Detection and monitoring of green corridors and their relative functions are very important in terms of landscape management. They also carry information on changing speed from “green to grey” and fragmentation level of the urbanized regions. Analyzing the fragmentation level of the landscape formation reflects the management strategy and overall success of decision makers. This paper aims to assessment landscape fragmentation in relation to green corridor planning for the first time on coastal section of Trabzon and Rize city centers from South Eastern part of the Black Sea. The study area is densely populated coastal region with linear-littoral formation. Remote Sensing (RS), Geographical Information System (GIS) and in-situ techniques were used to detect pattern and role of green corridors in the study area. Green coverage was extracted by using Support Vector Machine (SVM) classification algorithm. SVM classifier performed better on digital aerial images when compared to multispectral satellite data. After the classification, five land use/cover (LULC) classes were obtained: urban green areas, asphalt ways, water, other urban objects and shades with 94.64 and 96.53 overall accuracies for Trabzon and Rize cities, respectively. Shape related landscape metrics were computed to show the level of fragmented green covers in study area. Larger patches were observed in Rize with higher Largest Patch Index (LPI) values. Computed Area Weighted Mean Shape Index (AWMSI) and Area Weighted Mean Patch Fractal Dimension (AWMPFD) values indicated higher urbanization rates in Trabzon city. Green corridor networks were proposed for each city by considering the fragmentation level and landscape design rules. Finally, some implications were done towards creating ecologic cities in the context of sustainable landscape and ecological conservation.

Multitemporal analysis of forest fragmentation in the upstream region of the Nenjiang River Basin, Northeast China

The present study investigated the forest transition and fragmentation process using historical topographic maps and multi-temporal satellite images in the upstream region of Nenjiang River Basin, Northeast China from 1954 to 2010. Area-weighted centroid method, associated with the area-weighted mean patch fractal dimension (AWMPFD) and core area percentage of landscape (CPL), were used to estimate the spatial movement of forest as well as its spatial fragmentation process. The forest was further classified into high dense forest, low dense forest, and shrub forest to analyze the forest transition process, among these forest types or between forests and other landscape types. An obvious deforestation was observed during 1954–2000, with two different fragmentation processes in two periods: the first fragmentation process from 1954 to 1976 was mainly observed along the ecotone between forest and other landscape classes while the second fragmentation process from 1976 to 2000 was observed both in the ectone and interior area of forest patches. The afforestation process was observed during 2000–2010 due to the issue of a series of policies by the national and local government. GIS-based landscape index, coupled with socio-economic and political driving forces analysis, proved its unique value and effective in assessing landscape pattern and dynamics.

The investigation of relationship between rural settlement density, size, spatial distribution and its geophysical parameters of China using Landsat TM images

This study investigates the rural settlement density, size, and spatial distribution in China using land use vector maps extracted from Landsat TM images. The patch density (PD), mean patch size (MPS), standard deviation of patch size (SD), Euclidian mean nearest neighbor distance (MNN), and area weighted mean patch fractal dimension (AWMPFD) were calculated by GIS software to measure the characteristics of about 7.56×105 rural settlements. The results indicate that rural residential settlements in China were small with MPS of only 16.27ha, and more than half of them were below 10ha. China is divided into seven regions and the regional disparity is investigated across the seven regions, as well as within each region. The relationship between PD and digital elevation model (DEM), annual mean temperature and annual mean precipitation was investigated at the two levels. While DEM had a negative impact on PD, the annual mean temperature and precipitation had a mixed impact on the PD. In Northeastern China, North China Plain, Middle and Lower Yangtze River Plain, Inner Mongolia Plateau, Loess Plateau, and Southwestern China, the annual mean temperature had a strong positive impact on PD, but in the Southeastern China, no apparent correlation was found. While a significantly positive correlation between PD and annual mean precipitation was found in Inner Mongolia Plateau and Loess Plateau, a negative relation was found in Southeastern China and Southwestern China, and no obvious relationship found between them in Northeastern China, North China Plain, Middle and Lower Yangtze River Plain. In Northwestern China and Tibet Plateau, there was no apparent relationship between PD and annual mean temperature and annual mean precipitation. The results also demonstrate that annual mean temperature and annual mean precipitation did not have as much impact on MPS of rural settlements as topography and DEM. Rural settlements are impacted more by the topography and climatic parameters than are urban areas, as rural populations are more dependent on agriculture. The relationship between rural settlements and climatic parameters reflects the climatic impact on human living environment and food availability and productivity.

河口湿地人为干扰度时空动态及景观响应——以大洋河口为例

The aims of this research were to:(1) provide a theoretical basis for in-depth analysis of the influence of human activities on estuarine wetlands over a regional scale;(2) quantify the impact of anthropogenic interference on the landscape pattern index;and(3) establish a theoretical basis for the monitoring and evaluation of anthropogenic interference in estuarine wetlands.Based on aerial photographs from 1958,1970,and 1984(2 m resolution),and the spot5 image of 2008(5 m resolution),this study explored the spatiotemporal dynamics of hemeroby and the landscape pattern response scheme through hemeroby analysis,landscape pattern analysis,spatial patch analysis,and GIS spatial analysis in the Dayang estuary.The research evaluates: 1) the primary forcing landscape factors for spatial and temporal variation of hemeroby in an estuarine wetland;2) the response mechanism of landscape pattern index on the type of hemeroby;and 3) landscape indices associated with hemeroby in space.Results indicate that: 1) completely hemeroby regions increased from 4.16 km2 in 1958 to 9.16 km2 in 2008,while partially hemeroby regions increased from 115.82 km2 to 180.57 km2,and hemeroby regions declined from 291.23 km2 to 221.13 km2.Historically,hemeroby showed heterogeneous changes.The center of hemeroby moved gradually from land to ocean,and ocean aquaculture is the main driving factor in the change of hemeroby.Over time,hemeroby shows an upward trend,but the intensity of hemeroby changes are different at different historical periods,and hemeroby shows non-homogeneous characteristics at different historical periods.Comparing the change in different landscape types,we found paddy yield was the primary landscape type in 1958,aquaculture water in ocean and farmland showed upward increases in 1970,and after the 1980s aquaculture water in the ocean was the primary landscape type of human activities.Temporally,anthropogenic disturbance has led to an overall decrease in the number of patches(NP),edge density(ED),mean shape index(MSI),and area-weighted mean patch fractal dimension(AWMPFD) between 1958 and 2008.Through analysis of the landscape pattern index of different hemeroby types,we found that human disturbance has a certain effect on the landscape pattern index.Spatially,hemeroby is positively correlated with number of patches(NP),edge density(ED),and area-weighted mean patch fractal dimension(AWMPFD) in order of decreasing influence,while it is not significantly correlated with the mean shape index(MSI).The relationship between human disturbance activities and landscape pattern(four indices: number of patches(NP),edge density(ED),area-weighted mean patch fractal dimension(AWMPFD),mean shape index(MSI)) constituted differences in time and space within estuarine areas.Thus,heterogeneity and complexity of the landscape were greater in human disturbance areas over some time intervals,and heterogeneity and complexity of landscape showed declines in the continuing role of human disturbance with time.Therefore,the dimension of time and space should be distinguished in remote sensing monitoring responses of landscape patterns on human activities in estuarine wetlands.

Sprawl in Taipei’s peri-urban zone: Responses to spatial planning and implications for adapting global environmental change

Peri-urban areas are often characterized by valuable natural environment and resource bases to provide essential ecosystem functions for urban residents. Observing land cover change over time can reveal the effects and impacts of urbanization in peri-urban areas. This paper investigates the spatial pattern of land conversion in the Taipei–Taoyuan area by interpreting the 1990 and 2006 SPOT images for comparison with the land cover map of 1971. Calculation of the normalized difference vegetation index (NDVI) compares the vegetation greenness on the two satellite images. Eight landscape metrics were used to analyze the spatial and temporal changes of landscape patterns of peri-urbanization in Taipei–Taoyuan area: total urban area, number of urban patches, mean urban patch area, largest patch index, area-weighted mean shape index, area-weighted mean patch fractal dimension index, edge density of urban area, and contagion index. Results indicate that the built-up area in the study region has increased by 130% from 466.32 km 2 in 1971 to 1071.43 km 2 in 2006. A comparison of landscape metrics between urban planned districts and non-urban planned districts indicates that urban sprawl in non-urban planned districts is more severe than in urban planned districts and the landscape in non-urban planned districts is highly fragmented. Existing built-up areas have a greater influence on urban expansion outside urban planned districts than in urban planned districts. It is suggested that a guiding plan is required to integrate planning in both urban and non-urban planned districts to overcome urban sprawl in peri-urban areas.

Landscape structure analysis of Kansas at three scales

Recent research in landscape ecology has sought to define the underlying structure of landscape pattern as quantified by landscape pattern metrics. One method used by researchers to address this question involves statistical data reduction techniques. In this study, principal components analysis (PCA) was performed on 27 landscape pattern metrics derived from a Kansas land cover data base at three spatial resolutions: 30 m, 100 m, and 1 km. A hexagonal sampling grid was used to subset the landscape and FRAGSTATS software was used to calculate landscape pattern metrics. The PCA reduced the number of variables from 27 to 5. A five-component PCA solution explained between 81 and 89% of the variation in the data set. The components were interpreted as overall landscape texture, patch shape and size, cropland and grassland class-specific metrics, patch interspersion, and a nearest neighbor attribute. These five dimensions were identified at each resolution level. The first component was stable throughout the resolution levels, whereas the order of importance changed for the latter four components. That most components consistently appeared at each resolution level supports the use of the same subset of pattern metrics for landscape monitoring in the region at different resolutions. The individual metrics emerging as most important were similar to those noted in other research and include the modified Simpson’s diversity index, the area-weighted mean patch fractal dimension, the interspersion and juxtaposition index, and the largest patch index for grasslands.