The Experts below are selected from a list of 10770 Experts worldwide ranked by ideXlab platform
Thomas R. Loveland - One of the best experts on this subject based on the ideXlab platform.
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Ecoregions and Ecoregionalization: Geographical and Ecological Perspectives
Environmental Management, 2004Co-Authors: Thomas R. Loveland, James M. MerchantAbstract:Ecoregions, i.e., areas exhibiting relative homogeneity of ecosystems, are units of analysis that are increasingly important in environmental assessment and management. Ecoregions provide a holistic framework for flexible, comparative analysis of complex environmental problems. Ecoregions mapping has intellectual foundations in both geography and ecology. However, a hallmark of Ecoregions mapping is that it is a truly interdisciplinary endeavor that demands the integration of knowledge from a multitude of sciences. Geographers emphasize the role of place, scale, and both natural and social elements when delineating and characterizing regions. Ecologists tend to focus on environmental processes with special attention given to energy flows and nutrient cycling. Integration of disparate knowledge from the many key sciences has been one of the great challenges of Ecoregions mapping, and may lie at the heart of the lack of consensus on the “optimal” approach and methods to use in such work. Through a review of the principal existing US ecoregion maps, issues that should be addressed in order to advance the state of the art are identified. Research related to needs, methods, data sources, data delivery, and validation is needed. It is also important that the academic system foster education so that there is an infusion of new expertise in ecoregion mapping and use.
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Using an Ecoregion Framework to Analyze Land-Cover and Land-Use Dynamics
Environmental Management, 2004Co-Authors: Alisa L. Gallant, Terry L Sohl, Thomas R. Loveland, Darrell E. NaptonAbstract:The United States has a highly varied landscape because of wide-ranging differences in combinations of climatic, geologic, edaphic, hydrologic, vegetative, and human management (land use) factors. Land uses are dynamic, with the types and rates of change dependent on a host of variables, including land accessibility, economic considerations, and the internal increase and movement of the human population. There is a convergence of evidence that Ecoregions are very useful for organizing, interpreting, and reporting information about land-use dynamics. Ecoregion boundaries correspond well with patterns of land cover, urban settlement, agricultural variables, and resource-based industries. We implemented an ecoregion framework to document trends in contemporary land-cover and land-use dynamics over the conterminous United States from 1973 to 2000. Examples of results from six eastern Ecoregions show that the relative abundance, grain of pattern, and human alteration of land-cover types organize well by ecoregion and that these characteristics of change, themselves, change through time.
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Landscape Trends in Mid-Atlantic and Southeastern United States Ecoregions
Environmental Management, 2003Co-Authors: Jerry A Griffith, Stephen V Stehman, Thomas R. LovelandAbstract:Landscape pattern and composition metrics are potential indicators for broad-scale monitoring of change and for relating change to human and ecological processes. We used a probability sample of 20-km × 20-km sampling blocks to characterize landscape composition and pattern in five US Ecoregions: the Middle Atlantic Coastal Plain, Southeastern Plains, Northern Piedmont, Piedmont, and Blue Ridge Mountains. Land use/land cover (LULC) data for five dates between 1972 and 2000 were obtained for each sample block. Analyses focused on quantifying trends in selected landscape pattern metrics by ecoregion and comparing trends in land cover proportions and pattern metrics among Ecoregions. Repeated measures analysis of the landscape pattern documented a statistically significant trend in all five Ecoregions towards a more fine-grained landscape from the early 1970s through 2000. The ecologically important forest cover class also became more fine-grained with time (i.e., more numerous and smaller forest patches). Trends in LULC, forest edge, and forest percent like adjacencies differed among Ecoregions. These results suggest that Ecoregions provide a geographically coherent way to regionalize the story of national land use and land cover change in the United States. This study provides new information on LULC change in the southeast United States. Previous studies of the region from the 1930s to the 1980s showed a decrease in landscape fragmentation and an increase in percent forest, while this study showed an increase in forest fragmentation and a loss of forest cover.
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detecting trends in landscape pattern metrics over a 20 year period using a sampling based monitoring programme
International Journal of Remote Sensing, 2003Co-Authors: Jerry A Griffith, Terry L Sohl, Stephen V Stehman, Thomas R. LovelandAbstract:Temporal trends in landscape pattern metrics describing texture, patch shape and patch size were evaluated in the US Middle Atlantic Coastal Plain Ecoregion. The landscape pattern metrics were calculated for a sample of land use/cover data obtained for four points in time from 1973-1992. The multiple sampling dates permit evaluation of trend, whereas availability of only two sampling dates allows only evaluation of change. Observed statistically significant trends in the landscape pattern metrics demonstrated that the sampling-based monitoring protocol was able to detect a trend toward a more fine-grained landscape in this ecoregion. This sampling and analysis protocol is being extended spatially to the remaining 83 Ecoregions in the US and temporally to the year 2000 to provide a national and regional synthesis of the temporal and spatial dynamics of landscape pattern covering the period 1973-2000.
Édson Luis Bolfe - One of the best experts on this subject based on the ideXlab platform.
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Cerrado Ecoregions: A spatial framework to assess and prioritize Brazilian savanna environmental diversity for conservation
Journal of environmental management, 2018Co-Authors: Edson Eyji Sano, Ariane A. Rodrigues, Éder De Souza Martins, G. M. Bettiol, Mercedes M. C. Bustamante, Amanda Silva Bezerra, Antônio F. Couto, Vinicius Vasconcelos, Jéssica Schüler, Édson Luis BolfeAbstract:The Brazilian Cerrado is the second largest biome in Latin America, extending over more than 200 million ha and hosts some of the most intensive agricultural activities for grain and beef production in the world. Because of the biodiversity richness and high levels of endemism, Cerrado is considered one of world's hotspot for biodiversity conservation. The objectives of this study are three-fold: to present a comprehensive division of Cerrado into different Ecoregions that reflect the environmental heterogeneity within the biome; to analyze the Ecoregions in terms of biophysical characteristics, protected areas, environmental liability in riparian permanent protection areas along watercourses, and priorities for biodiversity conservation; and to rank the Ecoregions in terms of endangerment for biodiversity conservation and restoration. A previous study that delineated 22 Ecoregions using geomorphology, vegetation, soil, geology, and plant diversity maps was revised using topography, vegetation, precipitation, and soil maps. Our new ecoregion map consists of 19 units that are unique in terms of landscape characteristics and has been adjusted to the current official boundary map of Cerrado. Some of the Ecoregions consist of only one geomorphological compartment, whereas others are heterogeneous, consisting of up to eight compartments. Ferralsols comprise the dominant soil type in 14 of the Ecoregions. The percentage of protected areas within Ecoregions ranges from 1.7% to 51.5%. The most endangered ecoregion, where land use change critically threatens habitat integrity, is the Depressao Carstica do Sao Francisco (states of Bahia, Minas Gerais, and Piaui), where environmental liability along riparian permanent protection areas amounts to 85.6% of the total area. Our proposed ecoregion map provides a spatial framework for regional and local assessments to improve decision-making processes to reconcile conservation and restoration planning, sustainable agriculture, and provision of ecosystem services. Besides de adjustment of the previous Cerrado's ecoregion map to the official biome boundary (relevant for the implementation of public policies of conservation as those regulated by the Brazilian Forest Code), the new analyses of the ecoregion map represent a substantial improvement in comparison to the ones conducted by the previous study in 2003. In addition, current web resources allow us to make all the information used or derived from this study available to other users. This opens the possibility of additional improvements of our findings by the scientific community or to be used effectively by decision makers.
Charles B Halpern - One of the best experts on this subject based on the ideXlab platform.
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area burned in alpine treeline ecotones reflects region wide trends
International Journal of Wildland Fire, 2016Co-Authors: Alina C Cansler, D F Mckenzie, Charles B HalpernAbstract:The direct effects of climate change on alpine treeline ecotones – the transition zones between subalpine forest and non-forested alpine vegetation – have been studied extensively, but climate-induced changes in disturbance regimes have received less attention. To determine if recent increases in area burned extend to these higher-elevation landscapes, we analysed wildfires from 1984–2012 in eight mountainous Ecoregions of the Pacific Northwest and Northern Rocky Mountains. We considered two components of the alpine treeline ecotone: subalpine parkland, which extends upward from subalpine forest and includes a fine-scale mosaic of forest and non-forested vegetation; and non-forested alpine vegetation. We expected these vegetation types to burn proportionally less than the entire ecoregion, reflecting higher fuel moisture and longer historical fire rotations. In four of eight Ecoregions, the proportion of area burned in subalpine parkland (3%–8%) was greater than the proportion of area burned in the entire ecoregion (2%–7%). In contrast, in all but one ecoregion, a small proportion (≤4%) of the alpine vegetation burned. Area burned regionally was a significant predictor of area burned in subalpine parkland and alpine, suggesting that similar climatic drivers operate at higher and lower elevations or that fire spreads from neighbouring vegetation into the alpine treeline ecotone.
Glenn E. Griffith - One of the best experts on this subject based on the ideXlab platform.
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Ecoregions of the Conterminous United States: Evolution of a Hierarchical Spatial Framework
Environmental Management, 2014Co-Authors: James M. Omernik, Glenn E. GriffithAbstract:A map of ecological regions of the conterminous United States, first published in 1987, has been greatly refined and expanded into a hierarchical spatial framework in response to user needs, particularly by state resource management agencies. In collaboration with scientists and resource managers from numerous agencies and institutions in the United States, Mexico, and Canada, the framework has been expanded to cover North America, and the original Ecoregions (now termed Level III) have been refined, subdivided, and aggregated to identify coarser as well as more detailed spatial units. The most generalized units (Level I) define 10 Ecoregions in the conterminous U.S., while the finest-scale units (Level IV) identify 967 Ecoregions. In this paper, we explain the logic underpinning the approach, discuss the evolution of the regional mapping process, and provide examples of how the Ecoregions were distinguished at each hierarchical level. The variety of applications of the ecoregion framework illustrates its utility in resource assessment and management.
Darrell E. Napton - One of the best experts on this subject based on the ideXlab platform.
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Using an Ecoregion Framework to Analyze Land-Cover and Land-Use Dynamics
Environmental Management, 2004Co-Authors: Alisa L. Gallant, Terry L Sohl, Thomas R. Loveland, Darrell E. NaptonAbstract:The United States has a highly varied landscape because of wide-ranging differences in combinations of climatic, geologic, edaphic, hydrologic, vegetative, and human management (land use) factors. Land uses are dynamic, with the types and rates of change dependent on a host of variables, including land accessibility, economic considerations, and the internal increase and movement of the human population. There is a convergence of evidence that Ecoregions are very useful for organizing, interpreting, and reporting information about land-use dynamics. Ecoregion boundaries correspond well with patterns of land cover, urban settlement, agricultural variables, and resource-based industries. We implemented an ecoregion framework to document trends in contemporary land-cover and land-use dynamics over the conterminous United States from 1973 to 2000. Examples of results from six eastern Ecoregions show that the relative abundance, grain of pattern, and human alteration of land-cover types organize well by ecoregion and that these characteristics of change, themselves, change through time.
