»Climate
Vital Signs Included in Protocol
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Basic meteorology
Parks Where Protocol Will Be Implemented
- AMIS, BIBE, CAVE, FODA, GUMO, WHSA
Justification/Issues Being Addressed
Climate is the prevailing weather conditions in a given region averaged over a long series of years. Because of its crucial role in driving or regulating many biological and physical processes at the landscape scale, climate has been identified as a vital sign for all CHDN parks. Rainfall and temperature are the primary factors that limit an ecosystem's structure and function. Secondary limiting factors include long-term climate patterns: the length and intensity of weather events, seasons in which they occur, and amount of variability between and among years. Together, these dynamics greatly influence the types of plant species that occur, and where; the ways in which nutrients are cycled; and the relationships between soil, plants, and water availability. Accordingly, climate is a fundamental determinant of plant and animal distributions, productivity, and ultimately biodiversity (Rehfeldt et al. 2006). They can also affect the susceptibility of an ecosystem to disturbance.
Two climate-related meteorological conditions that have shown profound influence on Chihuahuan Desert systems are the intensity and persistence of rainfall, and the frequency and duration of prolonged periods of drought (Davey et al. 2007). Intense rainfall affects the transport and distribution of energy and materials through arid and semi-arid systems (Whitford 2002). Run-off also affects the hydrology and quality of aquatic systems such as the Rio Grande and Amistad International Reservoir. Prolonged drought often leads to diminished productivity in many species of plants and animals. Loss of vegetation cover, in turn, leads to greater vulnerability of soil erosion (Okin et al. 2006).
Long-term climate change generated by a proliferation of heat-storing (greenhouse) gasses in the earth’s atmosphere may have the most profound impact on ecological systems of any other human-induced stressor. Monitoring of basic meteorological measures over long-periods of time can indicate whether attributes of climate are changing at CHDN park units (Davey et al 2007). When monitoring of climate is co-measured with the phenology or productivity of plants or animals, the interpretation of observed meteorological trends is enhanced. For example, changes in climate that accelerate or expand growing seasons might be reflected by earlier onset of plant leaf-out or flowering, which in turn can influence plant-animal interactions (Schwartz and Reiter 2000, Marra et al. 2005, Cleland et al. 2007, Studer et al. 2007, Khanduri et al. 2008).