Evaluation of five landscape-level metrics for measuring the effects of urbanization on landscape structure: the case of Tucson, Arizona, USA

Landscape-level metrics can be used to measure changes in landscape structure over time. Four landscape-level metrics and rank-size distributions were used to describe changes in landscape structure caused by urbanization in a portion of the Tucson, Arizona metropolitan area between 1984 and 1998. This analysis describes what each metric conveys regarding how urbanization affects landscape structure. It also compares the efficacy of rank-size distributions with the other metrics. Results indicate all five metrics provided information about a specific aspect of landscape structure including patch size, shape, or dispersion. Results indicate that rank-size distributions and their scaling exponents are useful because they provide information not available from the other metrics. Rank-size distributions describe the patch-size scaling properties of specific land-cover types, the relative effect of large and small patches on the distribution of patch sizes, the magnitude of change in patch size, where patch sizes differ from what is expected by the regression model, and the range of patch sizes displaying fractal patterns.     

Spatiotemporal changes of landscape pattern in response to urbanization

The combined method of urban gradient analysis and landscape metrics in analyzing the changes of landscape pattern has been widely applied since its introduction by Luck and Wu (2002). In order to address the temporal dynamics of landscape change, this study integrated transect analysis with temporal trend analysis and specifically discussed how changes of residential pattern are related to forms of urban growth. Using Dane County, Wisconsin, USA as an example, a 60 km transect passing through the City of Madison was set up to represent a continuum of rural-urban-rural landscapes. Changes of landscape pattern from 1968 to 2000 were analyzed by FRAGSTATS with four metrics—percentage of landscape (PLAND), Shannon's evenness index (SHEI), patch density (PD), and mean patch size (MPS). Findings from metric analyses revealed that the degree of land-use diversity and landscape fragmentation is positively related to the degree of urbanization.Specifically, at the class-level, residential land-use type shows the strongest positive relationship to the degree of urbanization in all of the class-level metrics adopted. Changes in residential land-use pattern were further analyzed with the number of housing units. The analyses revealed that there are different patterns of residential development along the transect in the study area—with the core urban area expanding outward in a contiguous manner while the rural areas have scattered development. This study demonstrated the additional insights into landscape change by integrating the spatial and the temporal perspectives and by targeting the forms of residential developments.     

Relating surface fire spread to landscape structure: An application of FARSITE in a managed forest landscape

Recent studies suggest that manipulation of landscape patterns is the most preferred method to reduce susceptibility of landscape to fire spread. We evaluated the effects of landscape spatial pattern and spatial heterogeneity of fuel loading on surface fire spread using the FARSITE model in Chequamegon National Forest landscape, Wisconsin. Five forest management scenarios were developed to generate different landscape spatial patterns with unique fuel loading distribution. For each management scenario, 16 fires were simulated. We found that altered landscape spatial pattern and spatial heterogeneity of fuel loading interactively influenced fire spread. Moreover, we revealed that numerous, irregular-shaped, and different types of patches reduced fire spread. Among tested indices of landscape spatial pattern, patchy density, mean patch shape, patch shape standard deviation, area weighted mean shape index (AWMSI) and Shannon's diversity index were meaningful for predicting fire spread. However, the effect of landscape spatial pattern on fire spread decreased as fuel loading became more spatially heterogeneous. We also found that the effect of landscape spatial pattern on fire spread became insignificant when AWMSI was less than 4.33. Our results suggested that a forest management plan would need to consider the number, shape, size and type of forest patches for regulating fire spread.     

Trends in urbanization and patterns of land use in the Asian mega cities Jakarta,Bangkok, and Metro Manila

Asian mega cities have experienced rapid population growth and continue to grow. Urbanization in those areas is proceeding differently from the patterns of city growth experienced in Western countries. Understanding the characteristics of Asian urbanization will be indispensable for the establishment of a local landscape planning system. In this study, we used the Clark linear exponential model and the Newling quadratic exponential model to compare the spatial distribution of population densities in three Southeast Asian mega cities: Jakarta, Bangkok, and Metro Manila. We analyzed land-use patterns in each of the three cities by examining the mixture of urban and agricultural land use. The Clark and Newling models showed that the three cities were at different stages of urbanization. Jakarta had entered the suburbanization stage, Metro Manila was still at an early stage of urbanization, and Bangkok was at an intermediate stage between Jakarta and Metro Manila. Analysis of spatial patterns revealed areas of mixed land use within and around the city region in the three cities and that these areas of mixed land use would shift outward as urbanization proceeds. These findings indicate that planning concepts need to respect the vernacular landscape of each Asian mega cities as well as its stage of urbanization.     

Spatio-temporal dynamics and evolution of land use change and landscape pattern in response to rapid urbanization

Analyzing spatio-temporal characteristics of land use change is essential for understanding and assessing ecological consequence of urbanization. More importantly, such analysis can provide basic information for appropriate decision-making. By integrating historical high spatial-resolution SPOT images and spatial metrics, this study explored the spatio-temporal dynamics and evolution of land use change and landscape pattern in response to the rapid urbanization process of a booming-developing city in China from 1996 to 2006. Accurate and consistent land use change information was first extracted by the change detection method proposed in this study. The changes of landscape pattern were then analyzed using a series of spatial metrics which were derived from FRAGSTATS software. The results indicated that the rapid urbanization process has brought about enormous land use changes and urban growth at an unprecedented scale and rate and, consequently, given rise to substantial impacts on the landscape pattern. Findings further revealed that cropland and water were the major land use types developed for urban sprawl. Meanwhile, the landscape pattern underwent fundamental transition from agricultural-land-use dominant landscape to urban-land-use dominant landscape spanning the 10 years. The results not only confirmed the applicability and effectiveness of the combined method of remote sensing and metrics, but also revealed notable spatio-temporal features of land use change and landscape pattern dynamics throughout the different time periods (1996–2000, 2000–2003 and 2003–2006).     

城市化背景下的小城市景观格局变化分析——以浙江省乐清市为例

中小城市是今后吸纳城市化人口的重要组分,理解其格局与过程对城市可持续发展至关重要。景观格局的时空变化是探索城市化驱动力、城市化对环境—经济—社会影响的基础。研究基于景观生态学原理,利用长三角小城市——乐清市2005年—2009年连续五年的土地利用类型矢量数据,分析各年份土地利用变化,并运用Arc GIS内嵌Patch Analysis软件进行景观格局指数计算,从斑块类型水平和景观水平对景观格局变化进行了分析。结果显示,在斑块类型水平上,五年间建设用地面积大幅增加,其他用地类型破碎化程度加剧,?本连通度较高的林地越来越分散。在景观水平上,景观结构趋于破碎化,斑块形状更加复杂,将此结果与全球多个中小城市进行比较,这为研究城市化驱动下生态系统功能变化提供基础信息与依据。     

An evaluation of VEGETATION-1 imagery for broad-scale landscape mapping of Russia: effects of resolution on landscape pattern

The problem of efficient use of multi-scale data for land-cover and landscape mapping has already attracted considerable attention in landscape ecology and some other disciplines. Over the last few decades, however, with the development of satellite remote sensing techniques, the questions of efficient planetary and macro-regional ecological mapping and modeling and integration of multi-scale data have become especially pertinent. The purpose of this study is to test the suitability of the coarse-resolution VEGETATION/SPOT imagery for landscape mapping. Effects of changing spatial resolution on land-cover proportion estimates were examined in 16 different landscapes using spatially degraded high-resolution imagery from the Russian satellite, RESURS-F. Comparison of simulated coarse-resolution data and original images and ancillary data for sites with different landscape patterns, showed strong scale dependence of the landscape characteristics (land-cover proportion, fragmentation, patchiness) in different case study areas, such as sub-boreal forest, sub-urban areas, and an agricultural region in the steppe zone.     

Micropolitan areas: Exploring the linkages between demography and land-cover change in the United States cities

Micropolitan statistical areas in the United States are important transitionary regions that may provide insights into the economic, demographic, and social forces driving urbanization. Land cover change may provide significant insights into the dynamics of these important transitionary units. Our work investigates three questions: (1) How is the national landscape changing within micropolitan statistical areas with regards to land cover? (2) Are land-cover conditions in micropolitan areas closer to rural or metropolitan areas or are they unique? (3) How closely are demographic patterns linked to land conversion for development within micropolitan areas?When compared to metropolitan and rural areas within the US, our results demonstrate that micropolitan areas are unique with regards to the total amount of developed land, as well as land conversion to development. Within the micropolitan areas, we show that demographic categories such as population, population density, or population growth are not adequate predictors of land-cover change and that the geographic patterns of land conversion for development may provide valuable insights into the impact of micropolitan areas on the US national landscape.     

Fragmentation of a Landscape: incorporating landscape metrics into satellite analyses of land-cover change

The relationship between trajectories of forest-cover change and the biophysical and social characteristics of the landscape in the mountains of Western Honduras is addressed. Metrics of land-cover change were used to infer patterns of land-use change, using Landsat TM imagery from 1987, 1991 and 1996. With 15-20% of the land cover changing across each two-date period, the study landscape was very dynamic. Areas of reforestation were significantly larger than areas of deforestation, across all dates. Patch size was a good indicator of economic activity. Stable patches of forest and agriculture were fewer and larger, compared to forest regrowth and clearing. Small patches of swidden agriculture were found close to roads, at lower elevations and on more gradual slopes between 1987 and 1991. Between 1991 and 1996, expansion of export coffee production resulted in forest clearings on steeper slopes and at higher elevations. Results highlight the importance of landscape metrics in monitoring land-cover change over time.     

Impacts of land-use change on mammal diversity in the upper reaches of Minjiang River, China: Implications for biodiversity conservation planning

The objective of this study was to assess land use change and the related biodiversity variations in the forest landscape of the upper reaches of Minjiang River, China. We examined temporal changes of land use at different periods. Remotely sensed images taken in 1974, 1986 and 2000 were rectified and classified based on the physiognomic characteristics of the vegetation. We applied landscape pattern metrics based on landscape composition, the shape and size of patches and patch isolation. We also calculated the suitable area for mammals in the upper reaches of Minjiang River and biodiversity of medium and large-sized mammals with Genera-Family index (G-F index). As a result of timber harvesting and increase of population, the forest area decreased and other land-use types increased. The suitable area for mammals decreased by 81,339 ha from 1974 to 2000, about 21.55% of the habitat in 1974. The number of medium and large-sized mammal species had decreased from 31 to 26, with G-F index decreased by 0.11, about 20% that of 1974. It can be concluded that landscape change and suitable habitat play an important role in protecting mammal diversity.     

The influence of forest management on landscape structure in the cool-temperate forest region of central Japan

Comprehension of historical changes in landscape and forest management will provide valuable insights into current ecosystems and biodiversity and will support future management decisions and conservation strategies. This study clarified changes in the forest landscape of the cool-temperate forest region of central Japan from 1947 to 1997. We used a geographic information system to reconstruct past forest landscapes at four times (1947, 1962, 1975, and 1997) based on interpretation of aerial photographs and landscape metrics calculated using the FRAGSTATS software for spatial pattern analysis. Our results showed that secondary forests, the dominant land use in 1947, decreased greatly in area and became more fragmented, whereas coniferous plantations, which occupied approximately 20% of the total land area in 1947, became the dominant land use (almost 40% of the total land) by 1997. The young coniferous plantations have been established at increasing elevations over time and were mainly created by conversion of secondary forest until 1975. The number of young coniferous plantations and their patch spacing depended on the type of forest management. In the study area, landscape structure changed in response to changes in management of national forests, especially the expansion of afforestation in the 1950s and 1960s and changes in harvesting systems.     

Integrating time and the third spatial dimension in landscape structure analysis

Over the last decades, landscape metrics have been increasingly used to describe and analyse landscape structure. This article highlights some limitations of standard landscape structure analysis approaches and examines four major developments in this field: ways of integrating the height dimension of surface and vegetation into landscape metrics, the delineation of ‘meaningful’ landscape units comprising the relief, the problem of relating pattern and scale, and the challenges posed by the analysis of the temporal dimension of landscapes. We demonstrate that (1) the integration of height information and gradients into the approach of landscape metrics is both necessary and possible by means of using digital elevation models from remote sensing and novel analysis techniques, (2) the delineation of 3-D landscape units has enormous potential and (3) there are useful methodical extensions for two-dimensional objects in spatiotemporal investigations of landscapes, namely for analysing land use change and for exploring the interrelations between landscape diversity and species diversity.     

蓝绿空间景观格局对城市热岛的影响

城市热岛是城市环境中的典型问题。景观指数影响范围的空间异质性很少被理解。为了解决这个问题,拟采用多尺度地理加权回归模型(MGWR)来分析景观指数,归一化差值植被指数(NDVI)与地表温度(LST)之间的相互关系。结果显示,和普通最小二乘法回归和地理加权回归相比较,MGWR揭示了不同景观指数的空间影响尺度,具有更接近真实值的拟合效果。增加绿地和水体景观百分比及NDVI能够很好地缓解LST,其他景观指数则与LST的关系在不同的位置呈现正或负相关,需在特定位置进行优化才能有效地缓解LST。总的来说,形状简单且聚集分布的较大绿地斑块和形状复杂且较小的绿地斑块,以及在大多数情况下形状复杂、连通性强的水体景观更利于缓解LST。     

Scale-dependent habitat relations of birds in riparian corridors in an urbanizing landscape

As the amount of urbanization in the landscape surrounding a riparian zone increases, local riparian vegetation structure and composition change in complex ways. The impact of increasing urbanization on birds in and around riparian zones will depend on their differential sensitivity to local- versus landscape-scale habitat variation. Thus, our principal objective was to determine which spatial scale has a greater association with the distribution of each bird species using riparian corridors in a landscape mosaic comprised of anthropogenic land uses and undeveloped native shrublands in coastal southern California. We surveyed 137 points in riparian vegetation along an urbanization gradient, and used logistic regression and information theory to select best supported models describing the distribution of each of 52 bird species. Models based only on local-scale vegetation variables were best supported for 19 species, whereas landscape-scale (amount of urbanization within a 1000-m radius) models were best supported for 13. Ten species were best described by models combining local- and landscape-scale variables, and 10 had no well-supported models. Within guilds, woodland and riparian-dependent species appeared to respond to local vegetation variables whereas shrubland species appeared more sensitive to landscape context. Likewise, insectivores were more likely to be associated with variation in local-scale variables. In contrast to other studies, Neotropical migrants were not sensitive to increasing urbanization. Provided that local vegetation remains in good condition, our results suggest that riparian bird species may persist even in areas with extensive urbanization.     

"生态城市设计"专题系列之六区域尺度的城市化与生态效应:地理信息系统的应用

本文探讨如何应用地理信息相关技术以及空间化的景观生态学量化方法,来分析城市与区域空间形式的变化及不同生态效应之间的复杂关系。结合地理信息技术及景观生态学有关斑块、廊道、基质(patch-corridor- matrix)所组成的土地嵌合体理论(land mosaic),以台北盆地东半部基隆河流域为个案对城市与区域空间形式进行演算,包含了斑块紧密性程度、城市斑块形状及景观碎形向度等景观生态指针的应用;配合可视化空间资料的呈现,以此来掌握不同程度的城市及自然景观形式在时间与空间上的变化与分布状况,并衡量其生态影响的相关性及程度。     

An analysis of tree mortality in southern California using high spatial resolution remotely sensed spectral radiances: a climatic change scenario

The value of remotely sensed data for ecological monitoring and modeling studies that address landscape changes due to climatic change is widely recognized. However, these data can be collected at a variety of spatial resolutions which was significant implications in terms of the information that can be derived from the data. Most readily available remotely sensed data tend to have ground resolutions substantially greater than the size of individual plants so pixels may contain a mixture of vegetation types, background cover, illumination intensity and shadow. These mixtures make it difficult to evaluate fine-scale vegetation dynamics. This paper examines the potential utility of high spatial resolution remotely sensed data for assessing vegetation condition within a climatic change context. The drought in southern California that started in 1987 and the associated increase in tree mortality due to bark beetle infestations, provided the climatic change scenario for the study. A possible consequence of anthropogenically induced climatic change is the occurrence of more intense and prolonged droughts in some regions leading to greater mortality rates for susceptible vegetation species. Studies of present-day patterns and processes of vegetation mortality associated with droughts may help to identify future consequences of hypothesized climatic changes. High spatial resolution (0.5 m) reflected spectral radiances were collected over the Cuyamaca State Park in southern California and related to levels of bark beetle infestations that increased during the drought years. The results from this demonstration project indicated that high spatial resolution remotely sensed data allow investigators to isolate individual plants from the scene background and are likely to provide valuable information for assessing vegetation condition. The characteristics of the reflected spectral radiances and their geostatistical properties may be potential indicators of differences in vegetation condition. These data are also likely to be valuable for determining biophysical quantities required in models of ecosystem function and for monitoring key species that may be particularly sensitive to climatic change (indicator species).     

珠三角基塘景观格局演变特征及驱动 因素研究——以佛山顺德区为例

基塘系统作为一种水陆相互作用的人工复合农业生态系统,是珠三角地区乡土景观的重要组成部分。近年来,随着城镇化的快速发展,基塘系统的景观格局发生巨大改变,其农业生产功能和生态功能逐渐退化。以佛山顺德区为例,基于1979—2020年的Landsat遥感影像进行ENVI解译,在此基础上利用9个景观指数研究区域基塘景观格局的演变规律,并对其驱动因素进行分析。结果表明,1979—2020年,顺德区基塘、耕地和林地向建设用地转化明显,整体景观呈现非均衡化趋势分布;基塘景观的破碎度不断增加,优势度和团聚程度下降,部分基塘逐渐萎缩。驱动因素分析结果表明,人文因素是影响顺德区景观格局变化的主要因素,具有负向效应的空间推动作用。     

Developing a land-cover classification to select indicators of forest ecosystem health in a rapidly urbanizing landscape

As moderate-sized cities become more urbanized, ecosystems are altered by land-use change. Key ecological services, such as clean air and water, drought and flood protection, soil generation and preservation, and detoxification of wastes are disrupted, risking the health and welfare of society. An understanding of ecosystem responses to urbanization is necessary to evaluate and balance short-term needs with long-term sustainability goals. Our main objective was to develop a land management and planning tool using a land-cover classification to select landscape indicators of ecosystem health near Columbus, GA. Spearman's Rho correlations were calculated to compare landscape and field-based indicators. Results suggest there are significant inverse correlations between ‘percent forest land-cover’ and ‘population, housing, and road densities’; ‘tree species richness’ and ‘forest patch density’; ‘percent urban land-cover’ and ‘lichen species richness’; ‘lichen incidence’ and ‘forest perimeter-area fractal dimension’. Overall, there were 152 significant urban/biological correlations obtained from this assessment (Rho ≥ |0.50| and p ≤ 0.10). Such a tool could prove useful to land managers and environmental planners by providing a quick and simple method to assess broad areas of land in a single analysis.     

Planning an ecological network of Xiamen Island (China) using landscape metrics and network analysis

Most Chinese municipal governments and urban planners have attempted to conserve and create urban greenspace in response to rapid urbanization. It is a major task for urban landscape planners to construct an effective and harmonious urban ecological network and maintain a sustainable urban development environment. In this paper, the present situation and a recent greenway augment plan of Xiamen Island were assessed using a series of landscape metrics. The results showed that the recent greenway augment plan could improve the present greenway system considerably. The improvements were indicated by decrease in patch density, and increase in total class area and edge density on the patch level, landscape diversity, landscape evenness and landscape connectivity on the landscape level. On the basis of these analyses, a number of alternative planning scenarios were designed by using network analysis methods for improving the ecological network of Xiamen Island. An alternative planning scenario was proposed to decrease the degree of landscape fragmentation, increase the shape complexity of greenway patches and enhance the landscape connectivity. The results indicated that methods which integrate landscape metrics with network analyses could not only quantitatively assess the present situation and the rationality of planning for urban greenway systems, but also facilitate the design of planning scenarios for urban ecological networks, enabling them to meet the principles of conformity, harmony, circulation, safety, diversity and sustainability. The principles and methods of landscape ecology, and the greenway concepts that have originated in the West can be useful for Chinese landscape planning and can be applied to greenway development in China.     

Landscape metrics in the analysis of urban land use patterns: A case study in a Spanish metropolitan area

Urban growth patterns are characteristic of spatial changes that take place in metropolitan areas (MA). They are particularly prominent in more recently formed MAs, such as those in certain locations in Spain, where the structure of the traditional city has undergone sweeping changes. Given the capacity of spatial metrics to characterize landscape structure, these metrics can be a valuable instrument to identify growth patterns in MAs and to evaluate possible urban growth options, based on spatial characteristics.This article focuses on a medium-sized MA (Granada, Spain), and explores the use of spatial metrics to quantify changes in the urban growth patterns reflected in three future scenarios (2020). The scenarios were simulated with a model based on cellular automata, which reproduced three urban growth processes (aggregation, compaction, and dispersion) and four urban growth patterns (aggregated, linear, leapfrogging, and nodal). The scenarios were evaluated with metrics that quantified changes in the spatial characteristics of urban processes. Thus, for example, the NP and AREA_MN allowed us to characterize the decreased aggregation of high-density residential land uses in one scenario (S1) and the linear growth patterns in industrial land uses in another scenario (S2). In this way, spatial metrics were found to be useful for the evaluation of urban planning.