Paired Watershed Timber Harvesting Research Study
Who Helped and Who Funded This Research?
The North Carolina Forest Service (NCFS) partnered with US Forest Service’s Eastern Forest Environmental Threat Assessment Center (EFETAC) to conduct this research study. Additional project or financial assistance came from NC State University, NC Department of Agriculture and Consumer Services, Watershed Science LLC, and Weyerhaeuser.
Where Did This Research Take Place?
Researchers evaluated three “pairs” of similar forested watersheds located in the NCSU Hill Demonstration Forest and the NC Department of Agriculture and Consumer Services Umstead Research Farm. These sites were located in the Neuse River Basin.
What Did Researchers Do?
Timber within one watershed of each pair was harvested using a clearcut logging method. The other watershed in each pair served as a non-harvested reference. Within each harvested watershed, loggers complied with the Forest Practice Guidelines Related to Water Quality (FPG’s) and followed appropriate voluntary BMPs. Streams were monitored for approximately 3 years before and after the timber harvest. The researchers recorded weather data, streamflow, soil characteristics, vegetation characteristics, and water quality factors.
What Did Researchers Find? (Some Quick Highlights)
- Stream discharge increased following the timber harvests. This illustrates the need for installing and maintaining BMPs!
- Small increases in nutrients and sediment were observed following harvest. However, these levels never exceeded N.C. water quality standards and returned to preharvest levels in less than 3 years!
- Partial harvesting within the buffer zone overstory provided more sunlight to the ground alongside the stream, which fostered the growth of more diverse ground cover and shrub vegetation. For the duration of the study, the stream water temperature never exceeded N.C.’s maximum allowable limit. Researchers recommended that the intent of leaving trees within the buffer should be to provide long-term vegetative structure, soil stability, and stream shade.
Where Can I Read More Details About the Findings?
- Four-page Summary Leaflet/Brochure
- Detailed Summary Report
- Final Grant Report
Boggs, J.L., Jones, D., Sun, G., McNulty, S.G., and Swartley, B. 2010. BMP effectiveness Monitoring Study – Phase II. Grant Final Report. US-EPA Non-Point Source (NPS) Pollution Control Grant through Section 319h of the Clean Water Act N.C. Department of Environment and Natural Resources Division of Water Quality. NC- DENR Contract EW 1683.
- Conference proceeding papers
Boggs, J.L., G. Sun, W. Summer, S.G. McNulty, W. Swartley, and E. Treasure. 2008. Effectiveness of streamside management zones on water quality: pretreatment measurements. American Water Resource Association: Summer Specialty Conference. June 30 – July 2, 2008, Virginia Beach, VA.
Boggs, J.L., G. Sun, S.G. McNulty, W. Swartley, E. Treasure, and W. Summer. 2009. Temporal and spatial variability in North Carolina piedmont stream temperature. In: Proceedings of 2009 American Water Resources Association Spring Specialty Conference. May 4-6, 2009. Anchorage, AK.
- Master of Science Theses
Dreps, C.L. 2011. Water storage dynamics and water balances of two piedmont North Carolina headwater catchments. Master of Science Thesis. North Carolina State University. pp 189.
Kuntukova, Y. 2011. Storm-event rainfall runoff response in Carolina slate belt and Triassic basin catchments. Master of Science Thesis. North Carolina State University. pp 114.
- Slide Shows
Effectiveness of Forestry Best Management Practices for Water Quality Protection in Headwater Catchments in the Falls Lake Watershed
- Peer-reviewed journal manuscripts
Boggs, J., G. Sun, and S. McNulty. 2016. Effects of timber harvest on water quantity and quality in small watersheds in the Piedmont of North Carolina. Journal of Forestry 114(1):27-40.
Boggs, J., G. Sun, J.-C. Domec, S.G. McNulty, and E. Treasure. 2015. Clearcutting upland forest alters transpiration of residual trees in the riparian buffer zone. Hydrological Processes 29:497-499.
Dreps, C., A.L. James, G. Sun, J.L. Boggs. 2014. Water balances of two Piedmont headwater catchments: Implications for regional hydrologic landscape classification. Journal of American Water Resources Association.
Boggs, J.L., G. Sun, D.G. Jones, S.G. McNulty. 2013. Effect of soils on water quantity and quality in Piedmont forested headwater watersheds of North Carolina. Journal of American Water Resources Association.