Humans have transformed most of the terrestrial surface by changing the land use and land cover, impacting ecosystems, depleting water resources, degrading the soil and changing the climate. To study the extent of land use changes, we scientists use satellites, informing us of where and how much of the land we have changed. This does not, however, tell us why we are changing the land use, what are our motivations, and the characteristics of the people causing such changes all around the world. To study the reasons behind land use change, researchers from different disciplines perform field studies all around the world. In the last decades, researchers have published hundreds of local-scale studies on land use change. An overview of these studies was, until now, not available.
In our recent study published in Environmental Research Letters (full article and video abstract available free of charge), we reviewed 315 peer-reviewed studies on local land use change, and synthesized the objectives, attitudes and abilities of the people changing the land use. We collected information on 758 different decision-makers from all around the world. Our study shows, that the objectives behind land use change are diverse, and that survival is the main reasons behind changing the land use (followed by economic objectives). The main result of the study however, is the typology of different decision-making types.
Using clustering, we identified six distinct types of decision makers, with different objectives, wealth, land size and tenure security. The most common type reported in the literature is the survivalist, whose main objective is survival. This is the poorest decision making type, and most commonly associated with deforestation. The subsistence-oriented smallholder is still mostly focusing on survival, however tries to obtain economic gains from land use change. He or she also mostly causes deforestation, but has a much higher rate of agricultural intensification. The market-oriented smallholder has two equal objectives behind changing the land use: survival and economic gain. This decision-making type mostly results in agricultural intensification, and owns the smallest amount of land.
The professional commercialist follows, a relatively wealthy type that mostly intensifies the land use, but also has the highest reforestation rate among all types. The professional intensifier represents large-scale farmers that mostly focus on economic gains, and are least likely to diversify the land use. As the name implies, professional intensifiers mostly intensify the land use. The final type we identified from the literature is the eco-agriculturalist. This is the only type where lifestyle plays a considerable role in changing the land use. The eco-agriculturalists have a high appreciation of the environment and are reported in more recent studies.
We furthermore studied how decision-making evolves over time. Survival and livelihood become less important, and people who change the land use focus more on economic gains, while also developing higher environmental awareness. Additionally, people changing the land use tend to increase their wealth and have more secure land tenure.
Our results can help to explain land use change trajectories, and present the first step to more explicit representation of decision-making in land use models. Most importantly, we demonstrate how valuable local case studies are. They contain immense knowledge on the people behind land use change and without them we are unable to explain the complex causes behind such changes.