Middle-range theories of land system change

Change in land-use—the purposes and activities through which people interact with land and terrestrial ecosystems— is a key process of global environmental change. Understanding the dynamics of land-use change is central for designing strategies to address sustainability challenges and human-altered environments around the world. However, the theories about land-use changes are disconnected from each other; there is no grand, integrated theory that ties the field together.

A journal article by Rachael Garrett and coauthors in Global Environmental Change synthesizes the ideas from current land-use theories to show that middle-range theories, or generalizations that can describe chains of causal mechanisms to explain a range of phenomena and the conditions that trigger, enable or prevent these causal chains, provide a path towards generalized knowledge of land systems. 

The authors map out the main theories of land-use changes, plot the trajectory of the land’s intensifying expansion and present theories behind land-use and market integration to demonstrate the versatility of land-use theory. Later delving into how middle-range theories can be used as a tool, they describe how the theories can formulate key processes of land-use change and the conditions under which these processes manifest. Such middle-range theories provide a constructive path towards more generalized knowledge of human-environment systems. 

The authors advocate for middle-range theories to be more widely used in the field, arguing that the theories not only enhance the study of land-use change systems, but also that the ideas behind middle-range theories could be applied to other land and social-ecological systems to further enrich research and development.