Sagehen Experimental Forest past, present, and future: An evaluation of the fireshed assessment process

This research investigates the fireshed assessment process with a thorough evaluation of past, present and future fire characteristics at Sagehen Experimental Forest (Sagehen). The past fire regime was determined through a dendrochonological fire scar reconstruction of lower elevation Jeffrey pine-mixed conifer stands within Sagehen. Mean composite fire return interval for the study area was 2.2 years from 1700 to 2006. The mean composite fire return interval was significantly longer during the suppression period (1924 to 2006) than during the pre-settlement (1700 to 1859) and settlement (1860 to 1923) periods. A superposed epoch analysis found significant correlation to warmer and wetter conditions three years prior to fire events pre-settlement.;Present fire hazard and potential fire behavior was modeled to better understand the complexity of available data and resulting fire behavior metrics to assess potential SPLAT treatment scenarios for Sagehen. The ability of the input data to represent current vegetation and fuel characteristics does impact potential fire behavior (fire type, flame length and fireline intensity) and probable fuel treatments on the landscape. The effectiveness of six SPLAT designs was compared to assess the outcome of the fireshed process. All six treatment plans effectively reduced potential fire behavior. Two of the treatments preformed better than the remaining four.;Finally, future forest growth was modeled from 2005 to 2055 to assess long term effectiveness of one of the SPLAT designs. Fuel treatment effectiveness is expected to last at least 25 years and up to 50 years based on maximum and mean flame length and fireline intensity. The xeric conditions at Sagehen may partially explain the longevity of fuel treatment effectiveness. The complexity of the landscape at Sagehen provided a unique experience to assess the effectiveness of both the fireshed process and SPLATs. Findings from this research should be of interest to forest managers and scientists working to reduce fire severity at the landscape-scale.