Establishing priorities for restoration of riparian streams and meadows

Meadow degradation is an important problem throughout the Great Basin. Stream incision and associated declines in groundwater can lead to changes in plant species composition and even result in complete loss of meadow vegetation. The process of stream incision is controlled by a combination of sediment supply and flow regimes. Both of these controls are likely to be impacted by climate change through changes in fire frequency and hydrologic regime. Previous work in this area has shown that past climate change has played and important role in the formation and elimination of meadows in this region. As a result it is particularly important to look at the watershed level causes of current meadow conditions. It will not be possible to determine the landscape impacts of climate change without first understanding the landscape level controls on current conditions. We examined the relationships between watershed and reach level controls and stream incision and meadow degradation in 56 meadows throughout 5 mountain ranges in central Nevada. Watershed level variables such as watershed size and maximum height control the supply of water and sediment and the rate at which it is delivered to the meadow.  Reach level controls such as meadow architecture, channel slope, and the number of springs control water retention. Current meadow condition was measured by mapping vegetation communities, measuring incision, surveying knickpoints and terraces. Improved knowledge of these relationships can help up predict how regional scale changes like climate change will impact meadow condition.