Climate Change and the Chihuahuan Desert (U.S. National Park Service) Chihuahuan Desert Network parks contain 247 miles of the Rio Grande, as well as the confluence of the Devils, the Pecos, and the Rio Grande in Amistad National Recreation Area. The condition of these rivers within CHDN parks is greatly influenced by drivers and stressors occurring across the landscape in areas located well beyond park boundaries. Climate change may have direct and indirect effects on streamflow and water quality. As temperature and precipitation patterns affect the abundance, type, and distribution of vegetation cover in watersheds, changes in flood magni­tude and duration, sediment loads, and water chemistry will likely occur. CHDN monitoring of water quality, channel morphology, macroinvertebrates, and stream discharge will allow park: managers to address proximate issues occurring within park boundaries and will also provide an index of overall watershed condition. Climatic changes are predicted to provide exotic plant species with new opportunities for invasion. Because they fragment native ecosystems, displace native plants and animals, and alter ecosystem function, invasive exotics represent one of the most serious threats to natural ecosystem integrity. They can also alter fire regimes by causing fires to burn more swiftly or intensely, or even introducing fire to systems that did not evolve with it. Several climate models predict that climate change will result in more frequent and extreme droughts that could episodically reduce water availability and soil moisture. An increase in exotic invasions, in combination with the decreasing soil moisture that may accompany climate change, could set the stage for fires with the potential to dramatically impact desert and aquatic ecosystems. CHDN will be monitoring the distribution of invasive plants as part of monitoring for uplands and seeps and springs. CHDN will also implement a protocol to provide park managers with data on early detection of these species, which should allow them to deal with invasive exotic plants effectively in the face of climate change.