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79 results found
The distribution and abundance of many plants and animals are influenced by the spatial arrangement of suitable habitats across landscapes. We derived habitat maps from a digital land cover map of the ~178,000 km2 Chesapeake Bay Watershed by using a spatial filtering algorithm. The regional amounts…
Author(s): Kurt H. Riitters, R.V. O'Neill, K.B. Jones
Keywords: landscape ecology, wildlife habitat, spatial statistics, risk assessment, scale
Source: Biological Conservation 81(1997) 191-202
Year: 1997
We analyzed historical and current vegetation composition and structure in 49 sample watersheds, primarily on National Forests, within six river basins in eastern Oregon and Washington. Vegetation patterns were mapped from aerial photographs taken from 1932 to 1959, and from 1985 to 1992. We…
Author(s): J.F. Lehmkuhl, P.F. Hessburg, R.L. Everett, M.H. Huff, R.D. Ottmar
Keywords: Historical vegetation, landscape pattern, insect and disease hazard, range of variation, scale, forest health, disturbance, fire suppression, Oregon, Washington, Cascades, Blue Mountains
Source: Gen. Tech. Rep. PNW-GTR-328. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 88 p. (Everett, Richard L.; team leader; Eastside forest ecosystem health assessment; Hessburg, Paul F., science team leader and tech. ed., Volume III: assessment.)
Year: 1994
Parameterization of subgrid-scale variability in snow accumulation and melt is important for improvements in distributed snowmelt modelling. We have taken the approach of using depletion curves that relate fractional snowcovered area to element-average snow water equivalent to parameterize the…
Author(s): C. H. Luce, D. G. Tarboton
Keywords: distributed snow models, subgrid variability, scale, snow-cover patterns, snow water equivalent
Source: Hydrological processes. 18(8): 1409-1422
Year: 2004
Restoration projects are often developed with little consideration for understanding their effects on wildlife. We contend, however, that monitoring treatment effects on wildlife should be an integral component of the design and execution of any management activity, including restoration. Thus, we…
Author(s): William M. Block, Alan B. Franklin, James P. Ward, Joseph L. Ganey, Gary C. White
Keywords: wildlife, monitoring, status and trends, restoration effects, experiments, quasi-experiments, scale
Source: Restoration ecology. 9(3): 293-303
Year: 2001
Summary - Appropriate temporal and spatial scales vary between rehabilitation objectives. A scale appropriate within a physical or biological context might not be appropriate within a political or social context. For example, corporations and stockholders consider quarterly profits and losses to…
Author(s): Robert R. Ziemer
Keywords: PSW4351, watercourse restoration, scale, environmental, erosio
Source: In: Rutherfurd, Ian, and Rebecca Bartley, eds. Second Australian Stream Management Conference proceedings: The challenge of rehabilitating Australia's streams, 8-11 February 1999, Adelaide, South Australia. Cooperative Research Centre for Catchment Hydrology, Department of Civil Engineering, Monash University, Clayton, Victoria, Australia. p. 749-753.
Year: 1999
We demonstrate a method to evaluate the degree to which a meta-model approximates spatial disturbance processes represented by a more detailed model across a range of landscape conditions, using neutral landscapes and equivalence testing. We illustrate this approach by comparing burn patterns…
Author(s): Brian R. Miranda, Brian R. Sturtevant, Jian Yang, Eric J. Gustafson
Keywords: equivalence, fire model, meta-model, neutral landscape, scale
Source: Landscape Ecology. 24: 587-598.
Year: 2009
Landscape ecology is based on the premise that there are strong links between ecological pattern and ecological function and process. Ecological systems are spatially heterogeneous, exhibiting consid-erable complexity and variability in time and space. This variability is typically represented by…
Author(s): Eric J. Gustafson
Keywords: spatial pattern, index, indices, spatial heterogeneity, patchiness, landscape ecology, scale, geostatistics, autocovariation, spatial models
Source: Ecosystems. Vol. 1 no. 1.:p. 143-156. (1998)
Year: 1998
Forest management practices imposed at one spatial scale may affect the patterns and processes of ecosystems at other scales. These impacts and feedbacks on the functioning of ecosystems across spatial scales are not well understood. We examined the effects of silvicultural manipulations…
Author(s): Swee May Tang, Eric J. Gustafson
Keywords: Forest management planning, scale, spatial pattern, forest birds, timber harvest, fragmentation, landscape metrics
Source: Landscape and Urban Planning 39 (1997) l-9
Year: 1997
Estimates of air pollution removal by the urban forest have mostly been based on mean values of forest structure variables for an entire city. However, the urban forest is not uniformly distributed across a city because of biophysical and social factors. Consequently, air pollution removal function…
Author(s): Francisco J. Escobedo, David J. Nowak
Keywords: air quality, scale, heterogeneity, Santiago de Chile, urban forest structure
Source: Landscape and Urban Planning. 90: 102-11.
Year: 2009
The continuing degradation of United States surface waters by excessive nutrient loads has motivated the establishment of nutrient criteria for streams, lakes, and estuaries as a means to protect aquatic resources. Nutrient criteria have been established based on ecoregional differences,…
Author(s): James D. Wickham, Kurt H. Riitters, Timothy G. Wade, K. Bruce Jones
Keywords: Clean Water Act (CWA), eutrophication, nitrogen, phosphorus, scale, variance component analysis
Source: Landscape Ecology (2005) 20:791–798
Year: 2005