300 likes | 443 Views
Forest harvest effects on temperature of small headwater streams with and without riparian buffers. Steven M. Wondzell, Jack E. Janisch , William J. Ehinger, and Peter A. Bisson With help from: Alex Foster, Shannon Claeson, and Jeff Rickleffs.
E N D
Forest harvest effects on temperature of small headwater streams with and without riparian buffers Steven M. Wondzell, Jack E. Janisch, William J. Ehinger, and Peter A. Bisson With help from: Alex Foster, Shannon Claeson, and Jeff Rickleffs Janisch, J. E., Wondzell, S. M., and Ehinger, W. J. 2012. Headwater stream temperature: Interpreting response after logging, with and without riparian buffers, Washington, USA. Forest Ecology and Management 270:302-313.
Capitol Forest Willapa Hills G O O G L E E A R T H
Area: 1.1 - 7.6 ha Winter Q: 0.1 - 9.6; x = 2.1 l/s Summer Q: 0.0 - 1.8; x = 0.3 l/s
Temperature sensors at each wier
So…… for tiny headwater streams? Does forest harvest increase stream temperature? Do riparian buffers limit temperature increases?
Tpredicted= -0.23 + 1.18*Tcontrol+ 1.33*sin(2πj/365) + 1.59*cos(2πj/365) + є r2 = 0.9166
Capitol Forest Willapa Hills
Descriptive variables Elevation Area Aspect Gradient Depth Canopy+Topographicdensity Wetted channel Wetland area Streambed texture No direct measurement of Shade
Descriptive variables Elevation Area Aspect Gradient Depth Canopy+Topographicdensity Wetted channel Wetland area Streambed texture ?
Results Summary: • Some treated streams were significantly warmer, but… • On average, temperature increases were small • Trend did not match expectations for treatments, • Responses within treatments were highly variable • Temperature responses were correlated with • streambed texture, wetlands, and length of stream • Surface area exposure • Amount of hyporheic exchange
So…… for tiny headwater streams? Does forest harvest increase stream temperature? Do riparian buffers limit temperature increases?