Rangeland Fragmentation Creates Consequences for Human and Ecological Processes, Say Colorado State Researchers

Nearly 25 percent of the earth’s land mass is dominated by rangeland landscapes which support the livelihoods of more than 20 million people and provide habitats for some of the world’s large wildlife populations. Socio-cultural and climate changes are fragmenting these regions, and the resulting consequences for humans and ecological processes are being explored by Colorado State University scientists. Those findings are included in a new book, "Fragmentation in Semi-Arid and Arid Landscapes – Consequences for Human and Natural Systems."

Colorado State scientists argue that a mainstream view – exclusivity of land use promotes human well-being and sustains natural processes – is flawed in the case of dry grazing lands. Researchers examined the effect of fragmentation on dryland pastoral systems throughout the world by exploring the concept of fragmentation, the ecological processes interrupted by fragmentation and the social drivers and consequences of fragmented landscapes in places as diverse as Australia, Africa, the United States and Central Asia. The varied human responses to these changes also are explored by researchers.

The effects of fragmentation on people as well as their roles in driving it emerge as a critical part of understanding global change.

The savannas in these regions produce a significant proportion of the world’s livestock, and the biggest risk that herders face is climate variability. The movement of animals allows livestock and wildlife to access forage and water that is unevenly distributed in space and varies over time. Private land ownership and agricultural intensification is advantageous in wet environments, but the same efforts restrict the movements of people, livestock and wildlife across drier landscapes, limiting access to resources that fluctuate over time.  

Scientists argue that there are several ways public policy can support local efforts to adapt to fragmentation. Public policy can help improve returns to pastoralism by increasing accessibility both to markets and price information. The crucial component to a public policy in this matter needs to allow for access to heterogeneity of landscapes which is important for people worldwide who live in these rangelands.

The book is edited by Kathleen Galvin, chairwoman of the Department of Anthropology at Colorado State and senior research scientist at the university’s Natural Resource Ecology Laboratory, or NREL; Tom Hobbs, NREL senior research scientist; Robin Reid, the incoming director of the Center for Collaborative Conservation at Colorado State; and Roy Behnke, an anthropologist at the Macaulay Institute in Scotland.