Our studies have clearly shown infiltration, runoff, erosion, groundwater recharge, and nutrient transport to be heterogeneous and difficult to predict due to such factors as soil water repellency, preferential flow, soil type, plot condition and vegetative cover. We have also examined colloid nutrient transport as a mechanism for the cycling of particle- reactive chemicals that may influence lake and tributary ecology in the Sierra Nevada. Such forms may well represent a previously unrecognized significant source of mobile nutrients in the Sierra Nevada. Recent research considers the effects of wildfire and various biomass management strategies in the Lake Tahoe Basin and eastern Sierras on ecosystem response and discharge water quality. Of specific interest are the effects of fire suppression, controlled burning, and mechanical harvest on changes in soil compaction, water repellency, preferential flow, overland/litter interflow, plot condition, and vegetative cover.
