Forest Investment Account (FIA) - Forest Science Program
FIA Project Y073327

    Evaluation of fire site rehabilitation methods in terms of controlling erosion and sedimentation
 
Project lead: Scott, David
Contributing Authors: Scott, David F.; Forsyth, Kristen; Giest, Kelli; Thomson, Skye R.
Imprint: Kelowna, BC : University of British Columbia Okanagan, 2007
Subject: Forest Investment Account (FIA), Erosion, British Columbia, Fire, Sediment Control
Series: Forest Investment Account (FIA) - Forest Science Program
Description:
Strategic Fit Sustainability: Scientific information to inform policy, regulations and Forest and Range Practices Act requirements. Sustainability PAC research topic 1.6 Watershed function STUDY OBJECTIVES. Evaluate the functional and cost effectiveness of the more popular, probable and promising hillslope rehabilitation methods for severely burned forest watersheds. The project will contribute to guidelines for more effective rehabilitation and erosion prevention. STUDY DESIGN 1. On five different burned watershed/sites in the Kamloops Region of the Southern Interior of BC, replicated erosion plots have been laid out to test four possible rehabilitation treatments. The study aims to test the effectiveness of these treatments in reducing soil erosion. There are 3 replicates of the four treatments plus control (15 plots) in each of the five locations (45 plots in all), covering a fairly wide range of climatic, vegetation and lithological conditions. 2. The rehabilitation methods being tested are i.) wood-chip mulch, ii.) straw mulch, iii.) needle-fall (mulch) and iv.) seeding. 3. The dependent variable being measured is the mass of sediment trapped between visits (soil loss per unit contributing area). The independent variables that are measured are precipitation depth and intensity, and site variables that may influence the response of the plot to erosive forces, such as slope, soil properties (in particular water repellency) ground cover, including live plant cover (recovery). METHOD. The plots are clustered on steep hillslopes in severely burned sites. Treatments were allocated randomly to the plots which are 20 m long and 4 m wide. The bottom of earch plot is defined by a 3 m wide trap made of silt fence, that catches any soil loss off the plot. The sides of the plots are not bounded but the top of the plot is defined by a natural obstacle or slope break. The mechanism for soil erosion is overland flow, but we do not measure overland flow but rather the erosion that results. This makes the study easier and cheaper to establish and maintain, and directly measures the variable of interest. As the plots and equipment were easier & quicker to install we could establish more replicates on a greater variety of sites. Sites are visited periodically (interval adjusted to rainfall) to measure rainfall (tipping bucket rain gauge at each plot?) and soil loss in each plot. ANALYSIS. Sediment yield off the plots will be related to soil & site characteristics, treatment and precipitation. The most effective method is that with the lowest sediment yield (kg/m2) relative to the 'no action' option. Cost-effectiveness of each of the treatments will also be calculated.
Related projects:  FSP_Y051327FSP_Y062327

    Deliverables:

Technical Report (0.2Mb)

To view PDF documents you need Adobe Acrobat Reader, available free from the Adobe Web Site.

Updated August 16, 2010 

Search for other  FIA reports or other Ministry of Forests and Range publications.

Please direct questions or comments regarding publications to For.Prodres@gov.bc.ca