The number of directions in which patches should be connected. Greenspace spatial characteristics and human health in an. Using landscape metrics to analyze microscale soil. The zonal level of the landscape metrics calculation, rather than the focus area defined by the data set, has so far only been implemented in a few tools patch analyst incorporates the functionality to calculate some landscape metrics in a hexagonal grid and marxan we propose the zonalmetrics toolbox. Incsim application for landscape metrics calculation zoz. With the process of habitat loss, patch and edge density both increased linearly from 1800 to 2000. Number of disjunct core areas per hectare of total landscape area. Table 1 list of the 49 classlevel c and 54 landscapelevel l landscape structure metrics calculated for the analysis see mcgarigal et al. In most cases, redundant metrics will be very highly or even perfectly correlated. Furthermore, mean patch size represents the average condition.
Patch size distribution can be summarized at the class and landscape levels in a variety of ways e. An overview of their use in landscape research evelin uuemaa department of geography, institute of ecology and earth sciences, university of tartu. In this section, each metric computed in fragstats is described. Title landscape metrics for categorical map patterns version 1. Behavior of classlevel landscape metrics across gradients. To examine the behavior of landscape metrics, we generated arti. Among two shape metrics, landscape shape index continuously increased with habitat loss.
Patch density, size and variability metrics fragstats computes several simple statistics representing the number or density of patches, the average size of patches, and the variation in patch size at the class and landscape levels table 1. An opensource pythonic library to compute landscape metrics martiboschpylandstats. Mean patch size and overestimation of other ones e. In contrast, patch density is a function of total landscape area. As resolution changes, these two metrics show almost identical scaling functions across the two paradigms, even though they were. Connectivity refers to the degree to which a landscape facilitates or impedes ecological flows e. Exploring the influence of urban form on landuse efficiency. Zonalmetrics a python toolbox for calculating landscape. Class metrics are computed by landscape classmetrics are computed by landscape class e.
These factors were interpreted as composite measures of average patch compac tion, overall image texture, average patch shape, patch perimeterarea scaling, number of attribute classes, and largepatch densityarea scaling. Edge metrics usually are best considered as representing landscape configuration, even though they are not spatially explicit at all. Landscape metrics analysing patches with patch analyst. The behavior of landscape metrics commonly used in the. In this report, each metric calculated by fragstats is described in terms of its ecological application and limitations. A limited n mber of metrics are a ailablelimited number of metrics.
Metrics are grouped into patch, class, and landscape indices. Our objective was to model the relationship among deer density, landscape metrics, and harvest density of deer in tn, usa. Relationships between fire severity and postfire landscape. Landscape metrics as a framework to measure the effect. The fire resulted in a complex mosaic of fire patches and foreststructure changes. Comparison of landscape metrics for three different level. Digital images were an appropriate tool because they can generate data very quickly. Jul 03, 2019 the minimum value of lsi is always equal to 1 when either the class is maximally compact at the class level or the landscape consists of a single patch at the landscape level. If a border patch is a patch type of code 34, then its label must be 34. The potential introduction of artificial patch edges when the analysis is performed by simply cutting the analyzed layer with statistical zones. The current software version includes metrics on all available levels, namely patch. The final video in the series provides an example of how landscape metrics can be applied in the context of a umam assessment.
However, the maximum density of patches of a single class is attained when every other. It describes the fragmentation the landscape, however, does not necessarily contain information about the configuration. Patches in the border must be set to the negative of the appropriate patch type code. However, the relationship between deer density and specific landscape indices is unclear. Fragstats user guidelines version 3 the main metrics connectivity background. Using raster based image classifications in arcgis in conjunction with the freely available patch analyst to better understand patchiness and connectivity in the landscape. Contrary to expectations, average patch density and richness were also nearly. Patch density pd measures the number of patches per area fig. Np, edge density ed, largest patch index lpi, euclidean nearest. A patch truncation effect cutoffs by zone borders may cause underestimation of the value of some metrics e.
This metrics are statistical coefficients that contain information about the size, amount or strength of one characteristic in a fragment of categorized satellite image. Jan 15, 2020 landscape and harvest indices are frequently used to represent whitetailed deer odocoileus virginianus density. Within each group, metrics are ordered in logical fashion according to the aspect of landscape structure measured. At the last stage, several landscape metrics such as number of patch. Of course, if total landscape area is held constant, then patch. Cushman1,3 1department of natural resources conservation, holdsworth natural resources center, university of massachusetts, amherst, massachusetts 01003, usa. A possible explanation for this is that the smaller natural green space patches have been occupied while larger patches will be preserved in the process of urban construction, the additional cultivated green space patches have a larger area, and the smaller patches will be aggregated into larger patches in green space system planning. Area metrics are measured by patch density pd and mean patch size mps. Calculates a variety of landscape metrics, on binary rasters, for polygons or points with a buffer distance. Oct 01, 20 using raster based image classifications in arcgis in conjunction with the freely available patch analyst to better understand patchiness and connectivity in the landscape. Connectivity increases in a nonlinear fashion as the proportion map occupied by a given patch. Quantifying the speed, growth modes, and landscape pattern. Many of these measures are very similar, and can be considered as highly correlated.
A factor analysis of landscape pattern and structure metrics. In the large patches, the fragmentation, density, area and richness, and connectivity metrics were critical to multiple esvs. The border can be any width and provides information on patch type adjacency for patches on the edge of the landscape. Github makes it easy to scale back on context switching.
The movingwindow approach indicates that the majority of areas in the landscape were unchanged in mean patch size, whereas mean and median patch size increased according to landscape level measures. Raster layer, stack, brick or a list of rasterlayers. The first six factors explained about 87% of the variation in the 26 landscape metrics. Relationships among whitetailed deer density, harvest, and. If an argument is not provided, automatically all possibilities are selected. Correlation analysis between landscape metrics and water. Oct 15, 2015 to capture the synoptic characteristics of the green space system in 2005 and green space planning in 2020, the natural and cultivated green space patch types were merged into one green space patch type. Cushman1,3 1department of natural resources conservation, holdsworth natural resources center, university of. Landscape diversity and forest edge density regulate stream. Table 1 list of the 49 classlevel c and 54 landscape level l landscape structure metrics calculated for the analysis see mcgarigal et al.
We investigated the relationship between land use parameters and fragstatsbased landscape metrics edge density, patch density, mean shape index, mean euclidean nearest neighbour index, contagion, patch richness density and shannons diversity index and nutrientorganicmatterbased water quality indicators bod 7 and cod kmno4 values, totaln and totalp concentrations in water in 24. These factors were interpreted as composite measures of average patch compaction, overall image texture, average patch shape, patch perimeterarea scaling, number of attribute classes, and large patch density area scaling. It describes the fragmentation the landscape, however, does not necessarily contain information about the configuration or composition of the landscape. The movingwindow approach allows examination of the quantitative and spatial variability of landscape pattern, producing a more nuanced description of forest pattern when compared to whole landscape or patch based metrics. To quantify the landscape metrics, computer programs have been developed same as fragstats mc garical and marks 1994. Spatial pattern of urban growth using remote sensing and. This is one method metrids help show where forest habitat corridors might be located. Landscape structure was assessed based on four landscape metrics percentage, density, connectance, and shape applied to two landcover types, forest fragments maps in the lefthand column and agricultural patches maps in the right hand column. The raster version also computes several nearest neighbor metrics. This index measures the perimetertoarea ratio for the landscape as a whole. Landscape and fragmentation analysis patch analyst patch.
Patch density and splitting index are a simple and more sophisticated metric of the aggregation aspect of configuration, while the landscape shape index and contiguity index describe the shape. Incsim application for landscape metrics calculation incsim is a application that enables perform calculation of landscape metrics over categorized raster and vector data. In combination with class area landscape metrics, these make it possible to quantify the spatial extent and rate of urban growth over time. Largest patch density corresponds to the area of the largest patch of the corresponding patch type divided by total landscape area, in similar area unities. Integrating landscape metrics and hydrologic modeling to. For these reasons, mean patch size is probably best interpreted in conjunction with total class area, patch density or number of patchesand patch size variability. The result of landscape pattern analysis with landscape level metrics is presented in table 2. Quantifying the speed, growth modes, and landscape pattern changes of urbanization. Alternatively, two landscapes could have the same number of patches and total landscape area and thus have the same patch density. Landscape structure affects the provision of multiple. The application of landscape metrics in landscape planning should receive particular attention because of the complexity of the impacts of landscape structural changes on the provision of ecosystem services are complex. This confirms the importance of selecting metrics that indicate a diversity of aspects of landscape.
Computer software program produced by the authors at the university of massachusetts, amherst. The simplest measure of configuration is patch size, which represents a fundamental attribute of the spatial character of a patch. Read rendered documentation, see the history of any file, and collaborate with contributors on projects across github. Gyrate has a zero value when the patch consists of only one pixel. For example, at the landscape level, patch density pd and mean patch size. Of course, if total landscape area is held constant, then patch density and number of patches convey the same information. For example, the number or density of patches may determine the number of subpopulations in a spatiallydispersed population, or metapopulation, for species exclusively associated with that habitat type. Mean selected patch metrics showing general landscape. Harvest is another metric often used to estimate deer density. Planning of green space ecological network in urban areas. Research article behavior of classlevel landscape metrics across gradients of class aggregation and area maile c. Patch and landscape metrics conservation design workshop st. Landscape metrics as a framework to measure the effect of. These metrics usually are best considered as representing.
In other words, lpi equals the percentage of the landscape comprised by the largest patch. Core area density measure of relative distribution of core areas. Sep 24, 20 this four part video series provides a brief overview of landscape ecology, as well as terms and concepts often discussed as part of the uniform mitigation assessment methods location and. Landscape level gyrate is equal to the mean distance between each cell and the centroid of that patch. Connectivity increases in a nonlinear fashion as the proportion map occupied by a given patch type p increases. You can use these to further threshold the patches that might be too small to matter. N\ is the number of patches and \a\ is the total landscape area in square meters. Most landscape metrics either directly incorporate patch size information or are affected by patch size. Metrics studied include patch richness, class area proportion, patch number and density, mean patch size, shape, radius of gyration, contagion, edge contrast, nearest neighbor distance, and proximity. Landscape metrics are computed for the entire landscape. Quantifying urban growth patterns in hanoi using landscape. According to the previous literature, four landscape metrics are selected to describe the spatial features of urban landscape. Fragstats user guidelines version 3 the main metrics.
Assessing the relationship between surface urban heat islands. A limited n mber of metrics are a ailablelimited number of metrics are available. Determination of landscape structure, quantifying changes in this structure and determination of the structure of the landscape, with regard to the evaluation of. Traditional landscape metrics, such as the number of patches np, the patch density pd, the largest patch index lpi, and the landscape shape index lsi, were usually used in the related studies to characterize the spatial structures of landscape patches.
While landscape level structural complexity also tended to increase, the shape of individual patches became increasingly regular. Landscape metrics as indicators of river water quality at. Behavior of classlevel landscape metrics across gradients of. These factors were interpreted as composite measures of average patch compac tion, overall image texture, average patch shape, patch perimeterarea scaling, number of attribute classes, and large patch density area scaling. Patch density has the same basic utility as number of patches as an index, except that it expresses number of patches on a per unit area basis that facilitates comparisons among landscapes of varying size. Digital photos were converted into bimodal images and seven landscape metrics were analyzed. In addition to its direct interpretive value, class area in absolute or relative terms is used in the computations for many of the class and landscape metrics. We suggest that these factors can be represented in a simpler way by.
A meaningful interpretation of landscape metrics is possible only when the limitations of each measure are fully understood, the range of attainable values is known, and the user is aware of potential shifts in the range of values due to characteristics of landscape patches. The relationship between habitat loss and fragmentation. Landscape metrics analysing patches with patch analyst for. The simplest measure of configuration is patch size, which represents a fundamental attribute of the spatial character of a. Spatial pattern analysis program for categorical and continuous maps. List all available landscape metrics depending on the provided filter arguments. Reaches its maximum if every cell is a different patch. Density, nesting success and predation rates are all equally relevant indications of habitat suitability.
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