Relationship of field and LiDAR estimates of forest canopy cover with snow accumulation and melt

摘要: At the Priest River Experimental Forest in northern Idaho, USA, snow water equivalent (SWE) was recorded over a period of six years on random, equally-spaced plots ~4.5 ha small watersheds (n=10). Two were selected as controls and eight treatments, with two randomly assigned per treatment follows: harvest (2007) followed by mastication (2008), prescribed fire alone (2006), (2006) salvage (2007). Canopy closure using digital hemispherical camera, measured Polyvinyl chloride (PVC) tube before after treatments. In addition, canopy densities derived from LiDAR datasets taken at beginning end study compared to photos. The objectives 1) assess changes accumulation melt result cover, 2) compare photograph method for quantifying cover changes. A Before-After/Control-Impact (BACI) analysis conducted examine how reduction due treatments influenced melt. BACI assesses an experimental design which measurements are made both control impacted units Such is often used account natural temporal variations that occur regardless applied. Within framework, mixed-effects models tested where Before/After Control/Impact considered fixed effects while variable year kept random effect. results showed there effect SWE received thinning operation no snowmelt detectible. Field estimates significant applied thinned estimates, although correlated (p = 0.66, 0.58, 0.77, 0.62, Treatments 1, 2, 3, 4, respectively) field had significance statistical models. Some mildly violated assumptions normality equal variance, so further work needed order correct these violations.