National Park Service

Mojave Desert I&M Network (MOJN)

Spring Vegetation

Saratoga Springs at Death Valley National Park
Saratoga Springs at Death Valley National Park

There are currently no publicly-available documents or other products pertaining to this monitoring topic

For more information contact: Nicole Hupp

Importance/Issues

Spring riparian areas in MOJN parks are some of the most significant habitats for maintaining biological diversity and one of the most threatened habitats in MOJN parks. In MOJN parks, as elsewhere in the arid west, human land-use practices such as livestock grazing, water diversion, groundwater withdrawal, mining, removal of beaver, and introduced invasive species have radically altered ecological processes and led to losses in riparian productivity and biodiversity (National Research Council 1992, Kauffman et al. 1997, Brussard et al. 1998). In many MOJN riparian areas, plant communities are now dominated by non-native tamarisk (Tamarix spp.), a phreatophyte that accesses groundwater more easily and tolerates saline soils better than native plant species. A significant number of species of special concern are associated with riparian habitat in MOJN parks, including the Southwestern willow flycatcher (Empidonax traillii extimus), least Bell's vireo (Vireo bellii pusillus), and the relict leopard frog (Rana onca).

Preliminary Monitoring Objectives

  • How stable are riparian plant communities through time as measured by species composition, abundance, and structure? Are major shifts in dominant vegetation observed?
  • Is the areal extent of MOJN park riparian plant communities declining?
  • What are the trends in abundance and composition of targeted invasive plant species in MOJN riparian communities?
  • Are changes in vegetation cover, composition, and structure correlated with long-term changes in discharge or stream flow rates?
  • Are changes in native vegetation communities associated with changes in exotic plant species cover and species composition?

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Last Updated: February 17, 2017 Contact Webmaster