Measuring and Mapping Threats to a Wildlife Sanctuary in Southern India

Authors

  • N. BARVE,

    1. Ashoka Trust for Research in Ecology and the Environment, #659, 5th ‘A’ Main, Hebbal, Bangalore 560 024, India
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  • M. C. KIRAN,

    1. Ashoka Trust for Research in Ecology and the Environment, #659, 5th ‘A’ Main, Hebbal, Bangalore 560 024, India
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  • G. VANARAJ,

    1. Ashoka Trust for Research in Ecology and the Environment, #659, 5th ‘A’ Main, Hebbal, Bangalore 560 024, India
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  • N. A. ARAVIND,

    1. Ashoka Trust for Research in Ecology and the Environment, #659, 5th ‘A’ Main, Hebbal, Bangalore 560 024, India
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  • D. RAO,

    1. Ashoka Trust for Research in Ecology and the Environment, #659, 5th ‘A’ Main, Hebbal, Bangalore 560 024, India
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  • R. UMA SHAANKER,

    1. Ashoka Trust for Research in Ecology and the Environment, #659, 5th ‘A’ Main, Hebbal, Bangalore 560 024, India
    2. Department of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore 560 065, India
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  • K. N. GANESHAIAH,

    Corresponding author
    1. Ashoka Trust for Research in Ecology and the Environment, #659, 5th ‘A’ Main, Hebbal, Bangalore 560 024, India
    2. Department of Genetics and Plant Breeding, University of Agricultural Sciences, GKVK, Bangalore 560 065, India
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  • J. G. POULSEN

    1. Center for International Forestry Research, P.O. Box 6596, JKPWB, Jakarta 10065, Indonesia
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* * Address correspondence to K. N. Ganeshaiah, email kng@vsnl.com

Abstract

Abstract: Although conservation and management of tropical ecosystems requires that we understand the threats to these areas, there are no standardized methods to quantify threats to ecosystems. We used a geographic information system-based protocol with several physical and socioeconomic attributes to assess the threats to a protected area, a wildlife sanctuary in southern India. Physical attributes included threats from major and minor roads and the accessibility of an area (given as inverse of the slope of the area), and socioeconomic attributes included the number of human settlements and human, cattle, and sheep populations. We divided the sanctuary into 30-ha grids, and for each grid we computed three threat categories: (1) settlement-associated threat from humans, cattle, and sheep; (2) development-associated threat resulting from major and minor roads; and (3) accessibility-related threat caused by the steepness of the terrain. Combining all three threats, we derived a composite threat index for each grid and mapped five levels of threats in the sanctuary. We collected data on human activities, tree species richness, and diversity in the transects laid in areas corresponding to these five threat levels. Although the threat levels of the transects were strongly correlated with the human-related disturbance activities, the composite threat indices of the transects were negatively correlated with tree species richness, indicating that the threat values we derived served as a good surrogate of the actual threat experienced by the sanctuary. With appropriate modifications, the protocol developed here can be applied to other ecosystems as well.

Abstract

Resumen: La conservación y manejo de ecosistemas tropicales requiere que entendamos las amenazas a esas áreas. Sin embargo, no hay métodos estandarizados para cuantificar las amenazas a los ecosistemas. Utilizamos un protocolo basado en SIG con varios atributos físicos y socioeconómicos para evaluar las amenazas a un área protegida, un santuario de vida silvestre en el sur de India. Los atributos físicos incluyeron amenazas de caminos mayores y menores y accesibilidad de un área (como el inverso de la pendiente del área), y los atributos socioeconómicos incluyeron el número de asentamientos humanos y las poblaciones humanas, de ganado y ovejas. Dividimos al santuario en parcelas de 30 ha, y en cada parcela computamos tres categorías de amenaza: (1) amenaza de humanos, ganado y ovejas asociada con asentamientos, (2) amenaza asociada con desarrollo debido a caminos mayores y menores y (3) amenaza relacionada con accesibilidad debido a la pendiente del terreno. Combinando las tres amenazas, derivamos un índice compuesto de amenaza para cada parcela y mapeamos cinco niveles de amenaza en el santuario. Recolectamos datos sobre actividades humanas, riqueza y diversidad de especies de aves en los transectos ubicados en áreas correspondientes a estos cinco niveles de amenaza. Aunque los niveles de amenaza en los transectos estuvieron fuertemente correlacionados con actividades de perturbación humana, los índices compuestos de amenaza estuvieron correlacionados negativamente con la riqueza de especies de árboles lo que indica que los valores de amenaza que derivamos fueron buen sustituto de la amenazas que hay en el santuario. Con las modificaciones apropiadas, el protocolo desarrollado puede ser aplicado en otros ecosistemas.

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