A GIS- based approach for participatory decision making in Mexico: a case study in the Sierra De Manantlan biosphere reserve
Oscar G. Cardenas-Hernandez and Luis M. Martinez Rivera
Instituto Manantlan de Ecología y Conservación de la Biodiversidad
Universidad de Guadalajara
Independencia Nacional # 151
Autlan, Jal. 48900, Mexico
Remotely sensed data have been utilized during most of the second half of this century (Rindfuss and Stern 1998), initially with the use of aerial photographs for military reconnaissance (since the 1940's), and subsequently (starting in the 1970's) with the use of satellite imagery for both civil and military objectives. Although some of this information has been put to use for certain social purposes such as forecast of crops, prediction of severe storms, and planning land development, remotely sensed information has not been a popular data source for social development research yet.
For many social scientists, deforestation and land-cover/use change, as well as road and building construction (development) are associated with variables such as government policies, land-tenure rules, distribution of wealth and power, market mechanisms, and social customs, "…none of which is directly reflected in the bands of the electromagnetic spectrum" (Rindfuss and Stern, 1998:2). However, remote sensing could play an important role in social science research by providing additional means of gathering contextual data, particularly in describing the biophysical context within which people live, work, and play. Additionally, remote sensing has the potential to supplement georeferenced social data by describing the characteristics of a certain area, including land-cover, soil moisture, and weather conditions.
In this context, remote sensing and GIS technology have proved to be valuable tools in the process of planning and management of natural resource, allowing the incorporation of multiple criteria for a better use of the environmental goods and services. This is particularly important in tropical developing countries, where environmental degradation has reached alarming proportions over the last decades because of the lack of planning of natural resources use and consumption. For instance, in the case of Mexico several authors have estimated different rates of deforestation for the country for the last 20 years (Repetto 1988, Castillo et al. 1989, Myers 1989, Toledo 1990, SARH 1990, Masera et al. 1992, WRI 1994, FAO 1995). Even though these studies describe different deforestation trends at national level, all of them coincide that there is much more deforestation in tropical areas, which are very rich in biodiversity, than in temperate zones.
Therefore, planning the use of land and natural resources to avoid environmental degradation in tropical mountainous areas in Mexico has become an important issue. The objective of this study consisted on developing a community-based plan for the sustainable management of natural resources in the ejido Zenzontla, a rural community located in the limits of the Sierra de Manantlan Biosphere Reserve (SMBR), a protected area located in western Mexico (Fig. 1). This community-based strategy was inscribed within the context of the Regional Sustainable Development Program (PRODERS) of the Mexican federal government, a program which defines policies and actions focused in the regional planning for a sustainable use and management of natural resources, incorporating local participation during the process.
In Mexico, like in many other developing countries, economic circumstances often create additional pressures to convert natural areas to alternative uses (Gerritsen 1998). Mexico's landscape has been modified as a result of several forces acting alone or in conjunction. These social, economical and political forces have affected the country's natural surroundings by modifying not only the traditional utilization of natural resources, but also changing people's perception of natural resources due to the application of policies aimed to increase or even change production systems (for example, the incorporation of commercial crops and livestock [primarily cattle]) into the environment (Barbier et al. 1994, Deininger and Minten 1999).
According to Barbier and Burgess (1996:204), "policies in Mexico's livestock and agricultural sectors affect deforestation by influencing the incentives to convert forest land for these economic activities, rather than maintain the forest for timber production, harvesting of non-timber products, tourism, watershed protection and other uses". These incentives include subsidies to agricultural products -fertilizers and pesticides--, price control for basic crops, and granting lands for new rural communities. Consequently, the comparative returns gained from converting forests to agriculture and livestock production is a major factor that influences the processes of deforestation and land-cover/use change in the country, even in protected areas such as the Sierra de Manantlán, a mountainous area located in western Mexico.