Since most buffer strip areas have limited disturbance from farming it allows for a shelter to hide year round for many of the species including insects, birds, and mammals. When buffers run into and follow riparian areas along stream beds it is important to have larger vegetation like trees and shrubs that shade the water from the open sun. The water is then able to be cooler allowing for greater fish production and other aquatic plants and other biota to thrive in a less disturbed environment. This area of vegetation following a body of water is noted as a riparian zone. These buffer areas often incorporate large trees that protect stream banks from excessive erosion and shade aquatic areas. The shade provided by the larger trees reduces water temperatures and light intensity from ultraviolet light. Debris including leaves and branches that fell from trees, often contain aquatic invertebrates important to the structure of the water following the "River Continuum" concept. Since the riparian zones contain a larger variety of plants the overall diversity is much greater as well. With more photosynthesis and higher amounts of available water plant primary production can increase in turn creating more potential food for the wildlife. The USDA shows that grassed waterways of less than 5% slopes for a chosen waterway will greatly reduce velocity of draining water within the land. The Natural Resources Conservation Service (NRCS) offers the use of an online Soil survey to view the area of land to be planted and examine slope and soil drainage. As viewed by the Natural Resources Conservation Service, soil drainage is the number one priority for location of certain grasses. Poorer drainage causes less infiltration of water into the soil as groundwater recharge causing ponding and flooding of surrounding crops. Higher drainage becomes more droughty which hinders the establishment of certain grasses good for waterways. Medium soil drainage becomes the most suitable for planting. Determining exact grasses and seed amounts to plant follows specifications of a local NRCS Field Office Technical Guide and the Contour Buffer practice standard while taking practice on land and regional environmental conditions into consideration. The NRCS has shown contour strip cropping provides the greatest effectiveness when slopes of the area are within 4-8%. For greater success in lowering the erosion, contour strips on the slopes need to follow the contours of the landscape. Row crops like corn, legumes, or soybeans should alternate strips of small grains or forages to successfully limit erosion and slowing or capturing the runoff of fertilizers and pesticides. Tests from the NRCS have shown that the smaller tighter rooted grasses and hays provide more surface cover to prevent rain and wind erosion while slowing runoff, increasing infiltration, and trapping sediment from the high erosive row crops.