Close Window

Old growth forests and alpine meadows shift to shrub-dominated ecosystems in southwest China’s Himalayan mountains

Jodi Brandt, University of Wisconsin-Madison, jsbrandt@wisc.edu (Presenter)
Volker Radeloff, University of Wisconsin-Madison, radeloff@wisc.edu

China is undergoing massive land cover and land use change, threatening the exceptional diversity of Northwest Yunnan, a biodiversity hotspot in the remote Chinese Himalayans. We used a time-series of Landsat imagery and Support Vector Machines to detect change from 1975 to 2009 in the two most biodiverse and threatened ecosystems: old-growth forests and alpine meadows. We found that China’s forest protection policies have led to decreased logging rates and overall increasing forest cover from 1975 to 2009. However, despite the national logging ban, old-growth forest clearing accelerated, especially in areas dominated by ecotourism. The new forests are mostly shrub and pine monocultures, and are not on a trajectory towards high-diversity forest stands. In the alpine region (>3800m), prior to 1990, alpine meadows were resilient to land cover change despite a variety of policy, climate, and land use changes. However, between 1990 and 2009, 39% of meadows were invaded by native shrubs, suggesting a regime shift and a non-equlibrium grassland ecosystem. Initial shrub establishment in the meadows was triggered by declining snowfall, and, ironically, burning prohibitions designed to prevent forest fires. However, shrubs did not spread rapidly until increasing stressors, including warming temperatures and overgrazing, led to a sudden grass-to-shrub shift. Our research shows that rapid development may pose inherent risks to forest biodiversity given that our study area arguably represents a “best-case scenario” for balancing development with maintenance of biodiversity given strong forest protection policies and an emphasis on ecotourism development. We also highlight that multiple factors, including climate change, policy, and land use practices, interact with each other in highly coupled social-ecological systems and can precipitate rapid shifts in vulnerable alpine ecosystems, a situation that is probably not unique to our study area, and which has serious ramifications for global biodiversity, livelihoods, regional hydrology, and climate regulation.

Presentation: 2011_Poster_Brandt_118_184.ppt (3644k)

Presentation Type:  Poster

Session:  Global Change Impact & Vulnerability   (Tue 11:30 AM)

Associated Project(s): 

  • Radeloff, Volker: Land Use and Land Cover Change in Southwest China's Himalayan Mountains and the implications for alpine meadows, forest ecosystems, and avian biodiversity ...details

Poster Location ID: 118

 


Close Window