In Maine, streams draining watersheds of less than 300 acres have no buffer or shade requirements under state law . The objective of the headwater stream project is to evaluate the effectiveness of different riparian management practices for maintaining water temperature, water quality, aquatic habitat, and aquatic and riparian biodiversity.

Study Design

The study focuses on fifteen first order streams located in the industrial forests of western Maine.  On each stream, a 500-m study segment was established.  After one year of pre-harvest data collection, each stream was assigned to one of five treatment groups (3 streams per treatment group):  No streamside buffer 11-m Buffer 23-m Buffer Partial cut harvest zone Control (No Harvesting)  Following a year of pre-harvest data collection, harvest zones were established adjacent to 300-m of the stream channel on both sides of the stream.

Aerial views of the harvested treatments

Important Results

• Mean weekly maximum temperature increased 2.0-3.4°C in streams without a buffer and 0.1-2.3°C in streams with an 11-m buffer during the first three post-harvest years (2002-2004). No temperature change was detected in 23-m buffer treatment streams or in partial-cut streams as a result of the harvest.

• No changes in pH, conductivity, dissolved oxygen, and turbidity were observed following the timber harvest in any treatment groups including streams harvested without a buffer. The study design required best management practices (BMPs) to be used during harvest operations and adherence to the BMPs was critical in preventing changes in water quality.

• Following the timber harvest, concentrations of chlorophyll-a increased 3-14 fold in streams without a buffer and 5 fold in streams with an 11-m buffer. No post-harvest changes in chlorophyll-a were observed in the 23-m or partial-harvest treatment group. Concentrations of orthophosphate remained very low (<0.007ppm) in all streams regardless of harvest treatment.

• In the study streams, periphyton species richness ranged from 26-53 species. There were no obvious differences in species richness among treatment groups. The dominant species in both the harvested and unharvested portions of the stream was Achnanthes minutissima.

• Macroinvertebrate communities were dominated by the order Diptera which made up between 42-64% of the taxa. Macroinvertebrate species richness at the study streams ranged from 29-53 species. There were no obvious differences in species richness among treatment groups.

For more information, download the following documents or contact Ethel Wilkerson.

Publications

Hagan, J.M., S. Pealer, and A.A. Whitman. 2006. Do small headwater streams have a riparina zone defined by plant communities.  Canadian Journal of Forest Research. 36:2131-2140.

Wilkerson, E., J.M. Hagan, D. Seigel, and A.A. Whitman. 2006. The Effectiveness of Different Buffer Widths for Protecting Headwater Stream Temperature in Maine.  Forest Science. 52(3):221-231.

LeDoux, C.B. and E. Wilkerson. 2006. A case study assessing opportunity cost and ecological benefits of streamside management zones and logging systems for eastern hardwood forests.  US Forest Service, Northern Research Station, Research Paper NRS-1.

Wilkerson, E., J.M. Hagan, D. Seigel, and A.A. Whitman. 2004.  The effectiveness of different buffer widths for protecting temperature in headwater streams.  University of Maine, Cooperative Forestry Research Unit, CFRU RR-04-01, 7pp.

Posters and Presentations

Ecology and Management of Headwater Streams

Significant Seasonal Waters Workshop

Sponsered by Maine Forest Service, October 25, 2006

Changes in macroinvertebrate communities following timber harvest.

Maine Water Conference 2006

Water quality in headwater streams following timber harvest

Maine Water Conference 2005

Harvest induced temperature changes on headwater streams: How much protection is enough?

Maine Water Conference 2004