Riparian Zones Riparian zones hold particular importance for many Nevadans. The diversity of fish and wildlife, the quality and quantity of water resources, and a wide variety of outdoor recreation resources are strongly connected to presence and quality of riparian ecosystems. Riparian ecosystems occur in the full range of climate zones and landforms. Consequently, there are many varieties of riparian communities. Some are dominated by short or tall grass and grass-like species, by willows and other shrubs, by cottonwood, aspen and other trees, or by varying mixtures of trees, shrubs, grasses, and forbs. Healthy riparian zones play a vital role in commercial uses of rangeland ecosystems, for example, by providing abundant forage and shade for livestock. Recognizing the downward trend in conditions due to over-utilization of streamside vegetation and embankment erosion, the BLM and USFS launched a major initiative in the early 1990's to improve riparian management and protection. The BLM and the USFS monitor riparian areas on lands under their management. Using an assessment method called "proper functioning condition," (PFC) the BLM has performed site evaluations on 99 percent of the riparian areas and 33 percent of wetland meadow areas. In the PFC method, the hydrology, vegetation, channel erosion, sediment deposition, and land use features are evaluated to determine the overall physical condition in terms of the potential natural plant community and important resource values. Of 2,537 miles of riparian habitat mapped on BLM land, 753 were classified as "proper functioning condition" and 489 as "non-functional." Of the remainder, 495 miles were trending toward the desired condition, 321 miles trended downward, and the trend was not apparent in 475 miles. Wetland acres were also assessed. Of 34,327 acres, 8,962 were considered to be properly functioning, 476 acres trending up, 382 trending down, and on 1,400 the trend was not apparent. About 170 acres were classified as non-functional. The USFS has conducted extensive monitoring in the western and central mountains of Nevada as part of the preparation of ecological "scorecards" for riparian condition assessments. Though the data has not been centrally organized, general conclusions can be drawn based on scorecard development at almost 1000 sites. Steeper and higher elevation stream reaches tend to be more stable and well vegetated. Streams and meadows at lower elevations tend to be in unacceptable condition. However, trend in condition on USFS land is generally upward for a majority of all stream reaches. These generalizations include riparian sites in both forest and rangeland areas. Restoration of degraded riparian habitat is a primary objective in the Recovery Plan for the Lahontan Cutthroat Trout (150 page PDF File), prepared by the FWS in 1995. Because Lahontan cutthroat trout formerly inhabited northern Nevada lakes, rivers and headwater streams, restoration of degraded riparian habitat will be a regional effort involving many agencies, conservation organizations, ranch owners, and more. Extensive riparian zone restoration efforts on the Marys River and Trout Creek in northern Nevada have already occurred. Springs The wetland habitats identified in Table 3-12 as being less than 10 acres and between 10 and 40 acres (second and third columns) include a distinctive subset of riparian and aquatic habitats commonly called a spring. A spring occurs where deep or shallow groundwater flows naturally from bedrock or natural fill onto the land surface and forms a body of water. The source and subterranean pathway of water may be local or regional. Thousands of springs occur in a variety of landform settings throughout the state. Springs were important to emigrants crossing Nevada. Many have been developed to provide water for livestock, mining, wildlife, and public and domestic water supply. Gains in scientific knowledge about the relevance of spring habitats to biodiversity and the longevity of "ancient" water supply sources has drawn attention to spring conservation and management. Because springs are isolated and have unique environmental characteristics, aquatic and riparian plant, fish, and invertebrate (e.g., springsnail) diversity and endemism are high. Chimney Hot Springs in Nye County is a refuge for Railroad Valley springfish (Crenichthys nevadae). The Railroad Valley springfish was placed on the federal list of threatened species in 1986 due to habitat degradation related to water diversions, overgrazing, and exotic fish introductions. A majority of the 23 endangered or threatened fish species in Nevada survive only in unique spring habitats. Spring photo by Glenn Clemmer, 1989. Springfish photo by Peter Unmack, 1994. Like other water-associated habitats, dewatering, diversion works, channelization, and invasion of nonnative plants and animals have altered springs (U.S. Bureau of Land Management, 2001). Groundwater pumping has been found in some basins to depress spring flow. Field studies have found degraded habitat conditions, declines in sensitive plants and animal populations, and species extinctions. Similar to other wetlands, springs are intensively used. Livestock, including wild horses, and diversions, many for livestock watering, were the predominant disturbances found in one study of 511 northern Nevada springs (Sada, 1991). Concern exists that current protection and management attention is not sufficient to sustain the ecological site integrity and long-term water production of springs. Next Page -- Non-Native Flora and Fauna Back to Table of Contents