BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

Tilling green wood chips intothe soil can temporarily makenutrients unavailable to plantsand disrupt successfulvegetative establishment. Usewood chips that have beenaged for at least six months orpreferably one year.Physical soil treatments such as soil loosening, ripping, and tilling initiate therestoration of compacted soils. These treatments improve soil aeration andwater infiltration and can be executed mechanically or by hand. No mechanicaltreatment should take place within the drip line of trees, where tree roots areencountered, or in Stream Environment Zones (SEZs) without first obtainingapproval from the permitting and regulatory authority. Also avoid physicaltreatments when the soil is saturated as further damage to soil structure canoccur.Soils in the Lake Tahoe Region are typically nutrient poor and have limitedwater holding capacity. Adding organic soil amendments, such as compost, drywood chips or other organic material to soils provides nutrients, aeration, andincreases the rate that water can infiltrate into and move through the soil (i.e.Ksat).5.2.2 SOIL STABILIZATIONAs part of the soil restoration process, stabilizing loose or unstable soils witherosion control Best Management Practices (BMPs) protects the soil fromerosion until vegetation becomes established. These BMPs provide physical orchemical means to keep soil particles together and prevent their mobilizationand transport to Lake Tahoe. These practices, which include mulch, erosioncontrol blankets, tackifiers, soil binders, and hydromulches, may also help soilsretain moisture, moderate soil temperature fluctuations, and suppress weeds,thereby improving conditions for seed germination and vegetationestablishment. On challenging sites, such as steep slopes, vegetation is oftensupplemented by mechanical and engineered slope stabilization techniques suchas riprap and retaining walls.5.3 VEGETATIONVegetation physically protects the soil surface and holds soil particles in placewith roots. It intercepts raindrop impact, slows surface runoff, and regulatessoil moisture through shade and transpiration. Restoring vegetation on exposeddisturbed soils greatly reduces soil erosion and sediment loading to LakeTahoe. Revegetation of disturbed soils begins with selecting appropriatevegetation for the project.5.3.1 VEGETATION SELECTIONPlants native to the Lake Tahoe Region tolerate nutrient-poor soils, harshwinters, and a short growing season. When used for revegetation, native plantsmay need water and nutrients to become established, but can thrive with nolong term irrigation and minimal to no addition of fertilizer. Adapted plantsare not indigenous to the region, but have evolved under similar climates orconditions.CHAPTER 5: Soil and Vegetation ManagementTRPA BMP HandbookPage 5-4 2012