Hydrologic and Vegetal Responses to Fuelwood Harvest and Slash Disposal in aPinyon Pine and Juniper Dominated Grassland

摘要

Woodlands dominated by pinyon pine (Pinus spp.) and juniper (Juniperus spp.)species have expanded both in aerial extent and density during the last century and now occupy 8 to 12 million hectares in the western United States. Accelerated erosion has been observed in many of these former grass and shrublands that are now dominated by pinyon pine and junipers. The objective of this research project was to determine the effects of fuelwood harvesting and slash disposal of a pinyon pine and juniper woodland on understory plant responses, runoff, sediment concentration, and bedload. Five plots (25 x 12 meters) were located in each of four blocks and contained runoff subplots, which were 21.1 x 3.6 meters with a drop box, flume, and sediment sampler at the bottom. Calibration was conducted during 1988. Treatments were applied in 1989 and 1991. Vegetation responses, runoff, sediment concentration, and bedload were measured each monsoon season through 1999 for a total of 10 years.