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Wed January 8, 2014
Dr. Brody Sandel, Aarhus University – Topography and Forest Clearing
In today’s Academic Minute, Dr. Brody Sandel discusses why forests are becoming increasingly restricted to sloped terrain.
Brody Sandel is an assistant professor at Aarhus University in Denmark where he works with both the Econinformatic and Biodiversity Group and the Center for Massive Data Algorithmics. His research examines the distributions of plants (especially grasses) and animals (particularly mammals) and how these respond to global changes, both ancient and recent. He holds a Ph.D. from the University of California at Berkeley.
Dr. Brody Sandel – Topography and Forest Clearing
Humans change the landscape we live in. Forests have dwindled in many regions, as we harvest them or clear them for agriculture and construction. We are studying patterns of human land use, changes in forests and how the physical terrain determines these. To do this, we are using high-resolution satellite data that reveal the dynamics of global tree cover through time.
Across the world, there is a clear effect of topography on tree cover wherever there is heavy human land use. When forests are under pressure from clearing or harvest, they often remain only on sloped terrain. This pattern is strongest in developed countries, which have been particularly efficient at removing forests from fertile, flat areas. The better the economy, the better the political organisation, and the more orderly societal conditions are in a country, the more efficient the population has been at restricting forests to steep areas, reflecting their lower utility and value.
This process is accelerating in some regions. In the Amazon, for example, land use demands are increasing rapidly. As a result, formerly large continuous forests are likely to be divided up into smaller patches on hill or mountain slopes. At the same time, many societies around the world are now increasingly replanting trees, just as forests are naturally regrowing in areas that have been abandoned as people move to the cities. These dynamics also occur particularly in steep areas.
These results have mixed implications for conservation. On one hand, it suggests that forests remnants will increasingly be divided into small fragments where slopes are found. On the other hand, mountainous areas often provide many habitat types supporting high biodiversity, so the conservation of forests in these areas can be particularly valuable.