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4 resultados encontrados para: AUTOR: Dickson, Rebecca
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Resumen en: Inglés |
Resumen en inglés

Land system science axiomatically addresses social–environmental systems by integrating the dynamics of land uses (social) and land covers (environment), invariably including the use of remote sensing data and often, spatially explicit models of land change. This kind of research is illustrated through the Southern Yucatán Peninsular Region project (1997–2008) aimed at understanding, predicting, and projecting spatially explicit land change in a region with juxtaposed land uses-agriculture and a biosphere reserve. The successes of the project, its contributions to contemporary land system science, and the organizational mechanisms that fostered the research are identified as well as various corrections, which if applied, may have refined and extended the project's goals. Overall, the project demonstrates the kind of integrated research required to advance understanding of a social-environment system and the team-based methods used in the process.


Resumen en: Inglés |
Resumen en inglés

Land system science axiomatically addresses social– environmental systems by integrating the dynamics of land uses (social) and land covers (environment), invariably including the use of remote sensing data and often, spatially explicit models of land change. This kind of research is illustrated through the Southern Yucata´ n Peninsular Region project (1997–2008) aimed at understanding, predicting, and projecting spatially explicit land change in a region with juxtaposed land uses-agriculture and a biosphere reserve. The successes of the project, its contributions to contemporary land system science, and the organizational mechanisms that fostered the research are identified as well as various corrections, which if applied, may have refined and extended the project’s goals. Overall, the project demonstrates the kind of integrated research required to advance understanding of a social-environment system and the team-based methods used in the process.


3.
- Artículo con arbitraje
A step-wise land-cover classification of the tropical forests of the Southern Yucatán, Mexico
Schmook, Birgit Inge ; Palmer Dickson, Rebecca (coaut.) ; Sangermano, Florencia (coaut.) ; Vadjunec, Jacqueline (coaut.) ; Eastman, J. Ronald (coaut.) ; Rogan, John (coaut.) ;
Contenido en: International Journal of Remote Sensing Vol. 32, no. 4 (February 2011), p. 1139–1164 ISSN: 0143-1161
Resumen en: Inglés |
Resumen en inglés

Analysis of land-cover change in the seasonal tropical forests of the Southern Yucatan, Mexico presents a number of significant challenges for the fine-scale land-cover information required of land-change science. Subtle variation in mature forest types across the regional ecocline is compounded by vegetation transitions following agricultural land uses. Such complex mapping environments require innovation in multispectral classification methodologies. This research presents an application of a step-wise maximum likelihood/In-Process Classification Assessment (IPCA) procedure. This hybrid supervised and unsupervised classification methodology allows for exploration of underlying characteristics of Landsat Thematic Mapper (TM) imagery in tropical environments. Once spectrally separable classes have been identified, field data then determine the ecological definition of vegetation types with special attention paid to areas of unknown or mixed classes. A post-field assessment re-classification using the Dempster-Shafer method reduced the original 25 spectral classes to 14 ecologically distinctive classes, providing the fine-tuned land-cover distinctions that are required for both environmental and socioeconomic research questions. The overall map accuracy was 87% with an average per-class accuracy of 86%. Per-class accuracy ranged from as low as 45% for pasture grass to a high of 100% for tall-stature evergreen upland forest, low and medium-stature semi-deciduous upland forest and deciduous forest.


4.
- Artículo con arbitraje
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Resumen en: Inglés |
Resumen en inglés

The southern Yucatán contains the largest expanse of seasonal tropical forests remaining in Mexico, forming an ecocline between the drier north of the peninsula and the humid Petén, Guatemala. The Calakmul Biosphere Reserve resides in the center of this region as part of the Mesoamerican Biological Corridor. The reserve’s functions are examined in regard to land changes throughout the region, generated over the last 40 years by increasing settlement and the expansion and intensification of agriculture. These changes are documented from 1987/1988 to 2000, and their implications regarding the capacity of the reserve to protect the ecocline, forest habitats, and butterfly diversity are addressed. The results indicate that the current landscape matrix serves the biotic diversity of the reserve, with several looming caveats involving the loss of humid forests and the interruption of biota flow across the ecocline, and the amount and proximity of older forest patches beyond the reserve. The highly dynamic land cover changes underway in this economic frontier warrant an adaptive management approach that monitors the major changes underway in mature forest types, while the paucity of systematic ecological and environment–development studies is rectified in order to inform policy and practice.