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  • 1
    Electronic Resource
    Electronic Resource
    The r.le programs for multiscale analysis of landscape structure using the GRASS geographical information system (1992)
    Springer
    Landscape ecology 7 (1992), S. 291-302 
    Details
    ISSN: 1572-9761
    Keywords: landscape structure ; software ; geographical information systems ; GIS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Geographical information systems (GIS) are well suited to the spatial analysis of landscape data, but generally lack programs for calculating traditional measures of landscape structure (e.g., fractal dimension). Standalone programs for calculating landscape structure measures do exist, but these programs do not enable the user to take advantage of GIS facilities for manipulating and analyzing landscape data. Moreover, these programs lack capabilities for analysis with sampling areas of different size (multiscale analysis) and also lack some needed measures of landscape structure (e.g., texture). We have developed the r.le programs for analyzing landscape structure using the GRASS GIS. The programs can be used to calculate over sixty measures of landscape structure (e.g., distance, size, shape, fractal dimension, perimeters, diversity, texture, juxtaposition, edges) within sampling areas of several sizes simultaneously. Also possible are moving window analyses, which enable the production of new maps of the landscape structure within windows of a particular size. These new maps can then be used in other analyses with the GIS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00131258
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming forest (1998)
    Springer
    Landscape ecology 13 (1998), S. 149-165 
    Details
    ISSN: 1572-9761
    Keywords: Forest fragmentation ; landscape pattern ; clearcutting ; logging roads ; watershed analysis ; Bighorn National Forest ; disturbance ; lodgepole pine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Remotely sensed data and a Geographic Information System were used to compare the effects of clearcutting and road-building on the landscape pattern of the Bighorn National Forest, in north-central Wyoming. Landscape patterns were quantified for each of 12 watersheds on a series of four maps that differed only in the degree of clearcutting and road density. We analyzed several landscape pattern metrics for the landscape as a whole and for the lodgepole pine and spruce/fir cover classes across these maps, and determined the relative effects of clearcutting and road building on the pattern of each watershed. At both the landscape- and cover class-scales, clearcutting and road building resulted in increased fragmentation as represented by a distinct suite of landscape structural changes. Patch core area and mean patch size decreased, and edge density and patch density increased as a result of clearcuts and roads. Clearcuts and roads simplified patch shapes at the landscape scale, but increased the complexity of lodgepole pine patches. Roads appeared to be a more significant agent of change than clearcuts, and roads which were more evenly distributed across a watershed had a greater effect on landscape pattern than did those which were densely clustered. Examining individual watersheds allows for the comparison of fragmentation among watersheds, as well as across the landscape as a whole. Similar studies of landscape structure in other National Forests and on other public lands may help to identify and prevent further fragmentation of these areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007919023983
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    A review of models of landscape change (1989)
    Springer
    Landscape ecology 2 (1989), S. 111-133 
    Details
    ISSN: 1572-9761
    Keywords: Models ; landscape change ; review
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Models of landscape change may serve a variety of purposes, from exploring the interaction of natural processes to evaluating proposed management treatments. These models can be categorized as either whole landscape models, distributional landscape models, or spatial landscape models, depending on the amount of detail included in the models. Distributional models, while widely used, exclude spatial detail important for most landscape ecological research. Spatial models require substantial data, now more readily available, via remote sensing, and more easily manipulated, in geographical information systems. In spite of these technical advances, spatial modelling is poorly developed, largely because landscape change itself is poorly understood. To facilitate further development of landscape models I suggest (1) empirical multivariate studies of landscape change, (2) modelling of individual landscape processes, (3) explicit study of the effect of model scale on model behavior, and (4) ‘scaling-up’ results of studies, on smaller land areas, that have landscape relevance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00137155
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  • 4
    Electronic Resource
    Electronic Resource
    The landscape ecology of large disturbances in the design and management of nature reserves (1992)
    Springer
    Landscape ecology 7 (1992), S. 181-194 
    Details
    ISSN: 1572-9761
    Keywords: disturbances ; nature reserves ; landscape ecology ; management
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Large disturbances such as fires and floods are landscape processes that may alter the structure of landscapes in nature reserves. Landscape structure may in turn influence the viability of species and the functioning of ecosystems. Past reserve design and management strategies have been focussed on species and ecosystems rather than on landscape-scale processes, such as disturbance. An essential feature of a natural disturbance regime is the variation in disturbance attributes (e.g., size, timing, intensity, spatial location). Although some past reserve management policies have included natural disturbances, perpetuating disturbance variation has not been the explicit goal of either reserve design or management. To design a reserve to perpetuate the natural disturbance process requires consideration of: (1) the size of the reserve in relation to maximum expected disturbance size, (2) the location of the reserve in relation to favored disturbance initiation and export zones and in relation to spatial variation in the disturbance regime, and (3) the feasibility of disturbance control at reserve boundaries, or in reserve buffers. Disturbance management possibilities are constrained by the design of the reserve and the reserve goals. Where a natural disturbance regime is not feasible, then it is important that the managed disturbance regime mimic historical variation in disturbance sizes and other attributes as well as possible. Manipulating structure on the landscape scale to restore landscapes thought to have been altered by historical disturbance control is premature given our understanding of spatial disturbance processes in landscapes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00133309
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    Longterm response of disturbance landscapes to human intervention and global change (1995)
    Springer
    Landscape ecology 10 (1995), S. 143-159 
    Details
    ISSN: 1572-9761
    Keywords: landscape change ; natural disturbance ; landscape structure ; GIS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The structure of landscapes subject to patch-forming catastrophic disturbances, or “disturbance landscapes”, is controlled by the characteristics of the disturbance regime, including the distribution of disturbance sizes and intervals, and the rotation time. The primary landscape structure in disturbance landscapes is the structure of the mosaic of disturbance patches, which can be described by indices such as patch size and shape. The purpose of this research was to use a geographical information system-based spatial model (DISPATCH) to simulate the effects of the initial density of patches on the rate of response to alteration of a disturbance regime, the effects of global warming and cooling, and the effects of fragmentation and restoration, on the structure of a generalized temperate-zone forested disturbance landscape over a period of 400 yr. The simulations suggest that landscapes require 1/2 to 2 rotations of a new disturbance regime to adjust to that regime regardless of the size and interval distributions. Thus alterations that shorten rotations, as would be the case if global warming increases fire sizes and decreases fire intervals, produce a more rapid response than do alterations that lengthen rotations, such as cooling and fire suppression. Landscape with long rotations may be in perpetual disequilibrium with their disturbance regimes due to a mismatch between their adjustment rate and the rate of climatic change. Landscapes with similar rotation times may have different structures, because size and interval distributions independently affect landscape structure. The response of disturbance landscapes to changing disturbance regimes is governed by both the number and size of patch births.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00133028
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    Attributes of reliable long-term landscape-scale studies: Malpractice insurance for landscape ecologists (1995)
    Springer
    Environmental monitoring and assessment 36 (1995), S. 1-25 
    Details
    ISSN: 1573-2959
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Monitoring long-term change in forested landscapes is an intimidating challenge with considerable practical, methodological, and theoretical limitations. Current field approaches used to assess vegetation change at the plot-to-stand scales and nationwide forest monitoring programs may not be appropriate at landscape scales. We emphasize that few vegetation monitoring programs (and, thus, study design models) are designed to detect spatial and temporal trends at landscape scales. Based primarily on advice from many sources, and trial and error, we identify 14 attributes of a reliable long-term landscape monitoring program: malpractice insurance for landscape ecologists. The attributes are to: secure long-term funding and commitment; develop flexible goals; refine objectives; pay adequate attention to information management; take an experimental approach to sampling design; obtain peer-review and statistical review of research proposals and publications; avoid bias in selection of long-term plot locations; insure adequate spatial replication; insure adequate temporal replication; synthesize retrospective, experimental, and related studies; blend theoretical and empirical models with the means to validate both; obtain periodic research program evaluation; integrate and synthesize with larger and smaller scale research, inventory, and monitoring programs; and develop an extensive outreach program. Using these 14 attributes as a guide, we describe one approach to assess the potential effect of global change on the vegetation of the Front Range of the Colorado Rockies. This self-evaluation helps identify strengthes and weaknesses in our program, and may serve the same role for other landscape ecologists in other programs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00546982
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    Paper (German National Licenses)
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  • 7
    Electronic Resource
    Electronic Resource
    Factors Influencing Succession: Lessons from Large, Infrequent Natural Disturbances (1998)
    Springer
    Ecosystems 1 (1998), S. 511-523 
    Details
    ISSN: 1435-0629
    Keywords: Key words: disturbance frequency; disturbance intensity; disturbance size; dispersal distance; landscape ecology; patch size; succession.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: ABSTRACT Disturbance events vary in intensity, size, and frequency, but few opportunities exist to study those that are extreme on more than one of these gradients. This article characterizes successional processes that occur following infrequent disturbance events that are exceptional in their great intensity or large size. The spatial variability in disturbance intensity within large, infrequent disturbances (LIDs) often leads to a heterogeneous pattern of surviving organisms. These surviving organisms dictate much of the initial successional pattern on large disturbances where the opportunities for seeds to disperse into the middle of the disturbance are limited. The traditional distinction between primary and secondary succession is insufficient to capture the tremendous variability in succession following LIDs. Disturbance size influences succession where long-distance colonization by propagules is important. Observations from LIDs suggest the following interrelated hypotheses about trends in succession with increasing distance from seed sources when disturbanceintensity is high: (a) initial densities of organisms will be lower; (b) nucleation processes, in which recovering patches serve as foci for additional colonization and expand spatially, will be more important; (c) competitive sorting will be less important relative to chance arrival in determination of community composition, and (d) community composition will be initially less predictable; and (e) the rate of recovery of community composition will be slower. Prediction of succession following LIDs without considering contingencies such as the abundance, types, and spatial distribution of residuals, and distance to seed sources is likely to be unsuccessful for large portions of the landscape. Abundance and spatial arrangement of survivors and arrival patterns of propagules may be the pivotal factors determining how succession differs between intense disturbances of large and small extent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100219900047
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    Paper (German National Licenses)
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