Land use mapped

Overmars wanted to develop methods to identify and integrate factors which are important in the land use system, so that he could use these to describe and model the complex land use system in San Mariano.

Changes in land use have major consequences for the global environment because, for example, they affect the climate and ecosystem functions. Land use changes do not influence all regions in the world to the same extent. Much of the land in the Philippines was deforested during the last century due to intensive commercial timber activities and the expansion of agriculture.

The study was carried out on a part of San Mariano, situated in the northeast of the Philippines. There an area of 48,000 hectares has changed from a thinly-populated forested area into an area with intensive rice and maize cultivation that is home to 4000 families. The large-scale commercial timber felling has now stopped. The expansion of the agricultural area and small-scale (illegal) timber felling are now the most important changes in land use.

Combination of methods

The improved insights into the land use system in San Mariano are the consequence of a combination of analysis methods. Qualitative information is used to describe land use processes in the area. Quantitative data are used to analyse the land use system at the household level and spatially. Both deductive and inductive research methods were used. The use of these different methods is a standard approach for stimulating the development of methodological theory.

Some scientists claim that the time is ripe for an overarching theory of land use change. It is unlikely that a theory will be found which is acceptable for all of the disciplines involved with the research. An overarching theory of land use is still a long way off. Overmars thinks that for the time being it is more productive to develop theories of parts of the system.

Koen Overmars’ research was funded by NWO.