Multiscale analysis of the urbanization pattern of the Phoenix metropolitan landscape of USA: Time,space and thematic resolution

Investigating the ecological consequences of urbanization require knowledge of land-cover dynamics. Quantification of land-use/land-cover change in Phoenix, Arizona during the period of 1985–2005 using landscape metrics computed from Landsat-derived maps revealed temporal patterns of landscape composition and configuration. With accelerated urbanization the landscape as a whole became more fragmented ecologically and more complex compositionally and geometrically. However, the majority of individual patches became more compact in shape. Urban land covers, especially xeric residential, increased substantially and the desert decreased by 20%. Spatial and thematic resolution of data was shown to have large effects on the analysis of land-cover pattern. Our results, while agreeing in general with previously reported scaling relations with respect to changing spatial grain and extent, showed that scaling relations are also robust and consistent across thematic resolutions and time periods. Some metrics behaved unpredictably and some exhibited scale-free behavior. Compositional metrics, such as patch density, diversity, evenness, and largest patch index, were well correlated with vegetative cover, its spatial variation, and population density. Many of these correlations exhibited hump-shaped patterns with respect to increasing grain size, indicating a characteristic scale at approximately 500–1000 m. By simultaneously manipulating spatial and thematic resolutions, the importance of the Modifiable Area Unit Problem in relating landscape patterns to vegetation and socio-economic variables was also demonstrated. Additionally, highly variable desert vegetation due to precipitation variability poses a challenge for accurately quantifying urbanization pattern in arid environments. Choosing appropriate spatial, temporal and thematic resolutions is essential in meeting this challenge.     

Analysis of Eastern Mediterranean Oak Forests Over the Period 1965–2003 Using Landscape Indices on a Patch Basis

Although Eastern Mediterranean forests have been exploited for many years, the changing trends in the past 40 years require detailed investigations. Forests in the coastal zone of Lebanon are witnessing major changes mainly because of chaotic urbanisation. The study area at the coastal zone of Lebanon has 96% of its forest cover under oak coppice. The aim of this study is to investigate the applicability of landscape indices on oak forests especially their ability to detect changes between 1965 and 2003. It uses forest canopy closure as another indicator of forest destruction. The 1965 forest map was first checked for its accuracy before being used to extract patch delineations and canopy closures. Landcover types for 2003 were obtained by classifying a SPOT 5 satellite image. FRAGSTATS software was utilised on the 1965 map on a patch basis to calculate patch shapes and sizes. These indices and canopy closures data were investigated for correlation purposes with patterns of forest loss. The edge distances between forest patches in 1965 and new forest patches in 2003 were computed to analyze regeneration processes. Results show that although older forest patches have shown a 48% loss in area, total forest area reached 83%. Abandoned agricultural lands have become new forest. Smaller forest patches (< 40 ha) showed greater losses than large ones. Small and open forest patches recorded greater loss than large and dense patches. Shape indices show no correlation with forest loss. Clearance for agriculture covered 30% of the pre-existing forests, while urban developments accounted for just 4% of forest loss. This research highlights the great need for comprehensive studies of forests using landscape analyses. Such analyses help managers develop practical and relevant conservation measures.     

Changes in landscape structure of “yatsu” valleys: a typical Japanese urban fringe landscape

This study focuses on the ‘yatsu’ landscape of the southern Kanto Region, in central Japan. This agricultural landscape consists of narrow, branching valleys where rice is cultivated in irrigated paddies, and surrounding slopes and uplands devoted to a variety of landscape types, such as dry vegetable field, orchard, bamboo grove and coppice woodland. Two sites were selected, one with a long history of suburban development, and another just in the process of development. Changes in the landscape over a 30-year period, from 1960 to 1990, were identified and analyzed using aerial photographs and Geographical Information Systems (GIS) software. In the more intensively developed site, total forest area decreased while patch size of grassland, residences and bare ground increased together with the total number of patches. These changes in landscape element type were caused primarily by direct conversion of one type to another. In the less developed site, the total area and mean patch size of deciduous broad-leaved forest increased, and the total number of patches did not change. Changes at this site were caused mostly by the abandonment of traditional land management practices. The results of this study indicate that not only landscape element types, but also boundary types are influenced by urbanization. Of particular importance is the finding that the ecological function of boundaries is reduced by human intervention. This means that forest-floor herbaceous plants and woody plants with low dispersal capability will likely be adversely affected as residential development expands.     

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.     

Changes in the landscape structure of the Nagara River Basin, central Japan

A watershed is a structural and functional unit of a landscape consisting of various environments and sustaining a certain biodiversity. Conservation of watershed environments is important at both the regional and the national level. As a basis for conservation management, sufficient information about landscape structure should be provided for the whole terrestrial area of a watershed. In the present study, we reconstructed the former landscape structure and elucidated the changes in land use patterns during a period of about 80 years after 1900 (late Meiji era) in the Nagara River Basin, central Japan. We used three sets of maps for the analyses: old and modern topographical maps made in 1909, 1971 and 1992 by the Geographical Agency. Each map (ca. 18 km×22 km) was divided into 400 (20×20) grid cells, according to latitude and longitude. The dimension of each grid cell was about 1 km² (0.9 km×1.1 km). In each grid cell, all land-cover types were inventoried and the most dominant one was determined to be the dominant land-cover. The relative dominance (RD), frequency (FQ) and similarity index (SI) were calculated for analyses. The relative dominance of broad-leaved forest decreased, whereas those of conifer forest and residential areas increased throughout the whole study area during the 80-year period. However, regional differences in landscape change were found. In the upriver area, the relative dominance of broad-leaved forest decreased, while that of conifer forest increased. In the mid-river area, the relative dominance of conifer forest decreased, while that of broad-leaved forest increased. In the present study, we revealed the basic regional differences in landscape structure and their changes in the Nagara River Basin. Land use history with reference to socio-economics should be considered as an important factor affecting the present landscape structure.     

Factors affecting changes in landscape diversity in rural areas of the Fagus crenata forest region of central Japan

We compared landscape diversity in a primary forest site and a coppice forest site in rural area of the Fagus crenata forest region of central Japan. We focused on the factors affecting landscape diversity, with special reference to land ownership, and the relationship between changes in landscape diversity and the spatial distribution of landscape elements. We were able to identify two patterns that led to increased landscape diversity in the study sites. In the first, which was most apparent in the primary forest site, increased diversity resulted primarily from an increase in the number of landscape elements. In the other, which was seen in the coppice forest site, increased diversity resulted from a decrease in the difference between the numbers of grid squares dominated by each landscape element while the number of landscape elements remained unchanged. Land ownership also had different implications for the increase of landscape diversity. The changes in the Contagion Index, which decreased in private land and increased in the national forest, showed that private land contains many small patches while the landscape of the national forest consists of a few large, contiguous patches. Thus, an evaluation of changes in landscape structure requires measuring a variety of indexes in addition to the diversity.     

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.     

Nest distribution of magpies Pica pica sericea as related to habitat connectivity in an urban environment

Understanding the relationship between population dynamics and habitat connectivity is crucial for effective conservation and management of wildlife. In this study, we performed a graph-theoretical analysis to identify the relationship between nest distribution of the black-billed magpie Pica pica sericea and well-connected habitat patches. We analyzed 134 nest sites to determine environmental variables important for nesting magpies and identify habitat patches using a logistic model. Connectivity was estimated by Euclidean distance between habitat patches. A randomization procedure was implemented to verify the association between the nest distribution and the degree of habitat connectivity measured at multiple spatial scales. Preferred nesting habitat was areas close to the forest edge, containing more forest cover within 30 m of the nest. Connectivity analysis showed that the nest location was highly related to large clusters of habitat patches when patches are connected at large spatial scales. In addition, the nests in forest patches were close to grass patches with high connectivity. However, the size of habitat clusters adjacent to nests was much smaller than the average size of total habitat clusters across most scales, indicating that there are anthropogenic factors (e.g., effect of supplementary food in an urban matrix) affecting the distribution of magpie nests. Our results suggest that the distribution of magpie nests is related to landscape connectivity, which can be more clearly explained by taking into account the anthropogenic factors.     

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.     

Trajectory Analysis of Forest Cover Change in the Tropical Dry Forest of Burkina Faso,West Africa

Forest cover decline is one of the most important environmental issues in the tropics. The present study was carried out in Burkina Faso, West Africa, and aimed at assessing the trajectories of forest cover change and measuring landscape metrics of the trajectory classes in order to better understand the processes of change. Landsat and ASTER images acquired over a period of 30 years were used for cover change detection and the Fragstats package was used to compute landscape metrics with five unifying change classes. Results showed a substantial increase in cropland with concurrent decline in forest cover. Deforestation represented 63% of the Percentage of Landscape (PLAND) in 2006, while reforestation accounted for only 28%. Both of these classes had high Normalized Landscape Shape Index (NLSI) values, indicating that they were present as scattered small patches. The old cultivation (30-year permanent cropland) was aggregated (IJI ≈ 0) while deforestation exhibited highly interspersed patches. The old forest and old cultivation presented lower Area Weighted Fractal Dimension Index (FRAC_AM), but deforestation and reforestation had the higher FRAC_AM. These results confirmed that there was a high level of deforestation and fragmentation in southern Burkina Faso and justify the need for a proper management plan to ensure the sustainable use of forest resources.     

Assessing landscape change and biodiversity values of the Middle Vistula river valley, Poland, using BIO-SAFE

This paper deals with the relation between legally protected biodiversity and riverine ecotopes and with the assessment of biodiversity values of the Middle Vistula river valley (Poland). Furthermore, it describes the effects of landscape change on spatial distribution of ecotope patches and biodiversity values in Kazimierski Landscape Park. Biodiversity values were calculated using BIO-SAFE, a model meant to quantify biodiversity and to value ecotopes based on legally protected species. Dissimilarity indices depict high uniqueness of ecotope types regarding their species assemblages (e.g., river dunes, banks and bars). The actual biodiversity values of the river valley in Kazimierski Landscape Park are high in comparison with floodplains of lowland rivers in Western Europe. GIS analyses of remotely sensed ecotope maps show remarkable differences in number, acreage and patchiness of ecotopes for the years 1953 and 2003. The total number of patches increased by almost 44%. Side channels and floodplain lakes became fragmented. The average and total surface area of bush, forest and arable land increased, but decreased for bare soil, pioneer vegetation and grassland. These landscape changes indicate natural vegetation succession, intensification of agriculture and progressive impacts of river regulation. The Vistula river valley still represents high biodiversity values for higher plants, birds, herpetofauna and fish. However, current landscape changes negatively affect potential values for protected and endangered species. Assessments with BIO-SAFE can help to balance biodiversity conservation, river management and landscape planning.     

Relationships between urbanization and the oak resource of the Minneapolis/St. Paul Metropolitan area from 1991 to 1998

Urbanization was associated with loss and transformation of the oak forest in the Twin Cities (Minneapolis and St. Paul) metropolitan area (TCMA) over a recent 7-year interval. Between 1991 and 1998, urbanization increased based on several indicators: population density, area of developed land, and area of impervious surface—total impervious area and area within three classes of increasing degree of imperviousness (protected, affected, and degraded). We quantified relationships between changes in urbanization and changes in several parameters describing the oak forest at the scale of ecological subsection. Increased total and affected impervious area were strongly correlated with decreased area of oak forest when changes of the urbanization indicators and oak were expressed as percentages of the subsection area. Relationships were reversed when changes were expressed as percentages of the 1991 values. Increased population density was strongly correlated with increased loss in numbers and increased isolation of oak patches, but weakly correlated with loss of oak forest area. This is the first study to quantify relationships between changes in urbanization and changes in a specific forest cover type. Our results demonstrate complexities of urbanization impacts on a metropolitan forest resource, and highlight the importance of selected variables, spatial and temporal scales, and expressions of change when quantifying these relationships.     

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.     

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.     

Local and landscape scale variables impact parasitoid assemblages across an urbanization gradient

Urbanization is a major driver of land cover change worldwide, yet little is known about how urbanization affects beneficial arthropod communities. This study examined how local and landscape scale variables associated with urbanization influenced parasitic Hymenoptera abundance and diversity in residential and commercial properties along a rural to urban landscape gradient in Wisconsin. At a landscape scale, 300 m surrounding sites, land cover percentages were calculated for five cover classes: impervious cover, forest, grassland, agriculture, and urban green space. In addition, habitat diversity (Simpson's index) was calculated for the landscape surrounding study sites. At a local scale (within the boundaries of an individual property), flower diversity, flower area, tree density, and hardscape were measured and related to parasitoid abundance and diversity. During 2006 and 2007, parasitoids were sampled twice a month June-August using yellow sticky cards. Parasitoid abundance was a positive function of flower diversity, a local scale variable. The positive relationship between parasitoid abundance and flower diversity only occurred in areas containing high to moderate levels of urban development, suggesting parasitoids locally benefited from the increased availability of floral resources in urban but not rural sites. Parasitoid diversity decreased as impervious cover increased in the surrounding landscape. Parasitoid diversity decreased by approximately 10% in highly urbanized sites relative to rural sites, a pattern driven by several parasitoid families not detected in urban sites. These results suggest conservation strategies that focus on landscape variables at multiple scales can play an integral role in preserving beneficial arthropods across urban landscapes.     

景观干扰对乡村半自然生境植物多样性的 影响分析

乡村半自然生境植物多样性的影响分析,有助于推 动乡村生态景观高质量发展。村以下尺度乡村植物多样性研究 存在生境类型分析不全面、景观影响因子单一化、定量干扰机 制不深入等问题。在南京江宁西南部乡村地区,采用逐步回归 模型和广义加性模型,探讨了多种景观干扰对6类乡村半自然 生境植物多样性的影响,并提出了基于乡村植物多样性维持的 景观响应策略。结果表明：1)乡村景观格局、景观管理强度 和类型等对不同半自然生境植物多样性产生了显著影响,其综 合解释度约为10%~50%,小规模林斑、连接度高的半自然生 境、小面积池塘(<0.8hm2 )、茶田景观粗放管理方式、乡土 树种混交林等对植物多样性的正向促进作用显著;2)在所有显 著性指标中,斑块面积、斑块隔离度对各类半自然生境植物多 样性的影响最为突出,是驱动乡村植物多样性变化的重要景观 因素。     

上海城市绿地景观格局的分析研究

本文运用景观生态学的理论和方法,在遥感和地理信息系统（ＧＩＳ）技术的支持下,建立上海绿化景观地理信息系统,将不同大小面积的绿色缀块划分出四种景观类型,并以此为基础分析上海市区的绿化景观格局。上海市区的绿化景观以面积在５００ｍ＾２以下双块为主,它们不仅数量多,而且分布广,与城市居民的日常生活关系十分密切。     

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.     

Magnitude and Significance in Landscape Change

Landscape is organised in mosaics: sets of patches with a defined pattern of boundaries through which patches interact. Changes in patches cause changes in mosaics. Landscape change has two components: a quantitative one, referring to the areas in which changes happen, and a qualitative one, referring to the degree of similarity among the mosaics substituting each other. The quantitative component informs on the magnitude of the change: the total area in which landscape mosaics have changed; the qualitative one informs on the significance thereof: the ecological differences between the mosaics substituting each other. This paper presents an index for quantifying landscape change and for discriminating between magnitude and significance therein. It was tested by study of changes in the landscape mosaics in Madrid, Spain. Results show that the index developed is useful for this purpose. This enables objective comparison of different landscape changes presenting different combinations of magnitude and significance.     

The effectiveness of different conservation policies on the security of natural capital

The maintenance of ecosystem goods and services, i.e. natural capital, is the basic guarantee of environmental security that aims to evaluate the level of threats to the actual flux of natural capital. This research concerns a natural protected area in southern Italy and aims at (1) assessing the temporal dynamics of land-use and land-cover mosaics, and indirectly of the natural capital they support, using the economic valuation of ecosystem goods and services as surrogate; and (2) ascertaining whether all the past environmental conservation policies have fostered the natural capital, reducing or increasing its security. To these purposes, orthorectified aerial photos, referring to July 1954, 1987, 1997 and 2004, were used to analyze the landscape change trajectory and the consequent change of natural capital flux. Surprisingly the results showed that not all environmental conservation policies have played an equal role in fostering the maintenance of natural capital. This research highlighted that the recognition of the natural value of a site according to the European Directives is not sufficiently effective for the conservation of the natural capital, while the presence of a local management authority setting some limits on human activities that cause landscape changes, can increase the security of natural capital. This is of particular relevance considering that in each European partner country there is a great number of areas that are recognized for their natural value but that, at the moment, are not protected at a local level with any measure aimed at mitigating human impact.