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5 resultados encontrados para: AUTOR: Hellier, A
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1.
Artículo
Carbon emissions from land-use change: an analysis of causal factors in Chiapas, Mexico
Castillo Santiago, Miguel Ángel ; Hellier, A. (coaut.) ; Tipper, R. (coaut.) ; De Jong, Bernardus Hendricus Jozeph (coaut.) ;
Clasificación: AR/333.75137 / C3
Contenido en: Mitigation and Adaptation Strategies for Global Change Vol. 12, no. 6 (2007), p. 1213-1235 ISSN: 1381-2386
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SIBE Campeche
ECO040003163 (Disponible)
Disponibles para prestamo: 1
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SIBE Chetumal
ECO030004801 (Disponible)
Disponibles para prestamo: 1
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SIBE San Cristóbal
ECO010010810 (Disponible)
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SIBE Tapachula
ECO020012075 (Disponible)
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SIBE Villahermosa
ECO050003768 (Disponible)
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Resumen en: Inglés |
Resumen en inglés

This study examines the correlation between deforestation, carbon dioxide emissions and potential causal factors of land-use change within an area of 2.7 million ha in Chiapas, southernMexico between 1975 and 1996. Digitized land-use maps and interpreted satellite images were used to quantify land-use changes. Geo-referenced databases of population and digitized maps of roads and topography were used to determine which factors could be used to explain observed changes in landuse. The study analyzed the relationship between carbon emissions during this period and two types of possible causal factors: ‘predisposing’ factors that determine the susceptibility of a particular area of forest to change (slope, distance to agriculture and roads, land tenure) and ‘driving’ factors representing the pressures for change (population density, poverty).

The correlated factors were combined in risk matrices, which show the proportion of vulnerable carbon stocks lost in areas with defined social, economic and environmental characteristics. Such matrices could be used to predict future deforestation rates and provide a verifiable evidence-base for defining baseline carbon emissions for forest conservation projects. Based on the results of the analysis, two matrices were constructed, using population density as the single most important driving factor and distance from roads and distance from agriculture as the two alternatives for the predisposing factors of deforestation.


2.
- Artículo con arbitraje
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3.
Artículo
*Solicítelo con su bibliotecario/a
Application of the climafor approach to estimate baseline carbon emissions of a forest conservation project in the Selva Lacandona, Chiapas, Mexico
De Jong, Bernardus Hendricus Jozeph ; Hellier, A. (coaut.) ; Castillo Santiago, Miguel Ángel (coaut.) ; Tipper, R. (coaut.) ;
Clasificación: AR/333.75137 / A6
Contenido en: Mitigation and Adaptation Strategies for Global Change Vol. 10, no. 2 (2005), p. 265-278 ISSN: 1381-2386
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SIBE Campeche
ECO040002470 (Disponible)
Disponibles para prestamo: 1
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SIBE Chetumal
ECO030001237 (Disponible)
Disponibles para prestamo: 1
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SIBE San Cristóbal
ECO010004676 (Disponible)
Disponibles para prestamo: 1
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SIBE Tapachula
ECO020008246 (Disponible)
Disponibles para prestamo: 1
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SIBE Villahermosa
ECO050002505 (Disponible)
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Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

We present a methodology for testing and applying a regional baseline for carbon (C) emissions from land-use change, using a spatial modelling approach (hereafter called the Climafor approach). The methodology is based on an analysis of causal factors of previous land-use change(Castillo et al. 2005). Carbon risk matrices constructed from the spatial correlation analysis between observed deforestation and driving factors (Castillo et al. 2005), are used to estimate future carbonemissions within acceptable limits for a forest conservation project. The performance of two risk matrices were tested by estimating carbon emissions between 1975 and 1996 from randomly selected sample plots of sizes varying from 1,600 to 10,000 ha and comparing the results of the observed emissions from these sample plots with the model estimations. Expected emissions from continued land-use change was estimated for the community applying the risk matrices to the current land cover. The methodology provides an objective means of constructing baseline scenarios including confidence intervals, using the sum of variances of the various data sources, such as measured carbon densities, classification errors, errors in the risk matrices, and differences between the model prediction and observed emissions of sample plots due to sample size. The procedures applied in this study also give an indication of the impact of the variance in the various data sources on the size of the confidence intervals, which allows project developers to decide what data sources are essential to improve his baseline. The modelling approach to estimate the deforestation pattern is based on readily available cartographic and census data, whereas data on carbon densities are required to assess the potential for forest conservation projects to offset carbon emissions.


4.
- Artículo con arbitraje
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5.
Artículo
*En hemeroteca, SIBE-San Cristóbal
Use of indigenous knowledge for rapidly assesing trends in biodiversity: a case study from Chiapas, Mexico
Hellier, Augustine ; Newton, Adrian C. (coaut.) ; Ochoa Gaona, Susana (coaut.) ;
Clasificación: AR/333.95 / H4
Contenido en: Biodiversity and Conservation Vol. 8, no. 7 (October 1999), p. 869-889 ISSN: 0960-3115
Bibliotecas: San Cristóbal , Villahermosa
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SIBE San Cristóbal
27026-20 (Disponible)
Disponibles para prestamo: 1
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SIBE Villahermosa
VER000044 (Disponible)
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Nota: En hemeroteca, SIBE-San Cristóbal
Resumen en: Inglés |
Resumen en inglés

In order to evaluate the usefulness of rapid surveys of indigenous knowledge for as- sessing trends in biodiversity, a case study was undertaken in two rural communities, Juznajab and Muquenal, in Chiapas, Mexico. This involved the use of a variety of rapid rural appraisal (RRA) and participatory rural appraisal (PRA) techniques, including semi-structured interviews, transect walks and participatory mapping. These approaches were used in conjunction with analysis of land use maps and aerial photographs to evaluate recent changes in vegetation cover and abundance of utilised species. In both communities, the extent of forest cover was considered by local people to have declined substantially in recent decades, with an annual decline in forest cover of 0.3% and 0.6% estimated by local people in Juznajab and Muquenal, respectively. Results from RRA in- dicated that this has been accompanied by signi®cant declines in the abundance of useful species. In Juznajab 60% and 79%, and in Muquenal 96% and 85% of plants and animal species, respectively, were considered to have declined within living memory. These declines appear to result from over- utilization as well as habitat changes. For example, most of the tree species used for timber and the animal species used for meat were considered to have declined substantially in both communities. These results indicate that indigenous knowledge is potentially a valuable source of information about biodiversity trends, which could be assessed during Rapid Biodiversity Assessments and incorporated into the process of resource management by local communities. However, the con- tradictions recorded between assessments of vegetation change by local people and data obtained from other sources indicates the need for caution in the use of indigenous knowledge for this purpose.