The primary objective of this project is to understand how long-term climate variability and change influence the structure and function of desert streams via effects on hydrologic disturbance regimes. Climate and hydrology are intimately linked in arid landscapes; for this reason, desert streams are particularly well suited for both observing and understanding the consequences of climate variability and directional change. Researchers will 1) determine how climate variability and change over multiple years influence stream biogeomorphic structure (i.e., prevalence and persistence of wetland and gravel-bed ecosystem states) via their influence on factors that control vegetation biomass, and 2) compare interannual variability in within-year successional patterns in ecosystem processes and community structure of primary producers and consumers of two contrasting reach types (wetland and gravel-bed stream reaches). Arid regions are characterized by high interannual variation in precipitation, and these climate patterns drive the overall disturbance regime (in terms of flooding and drying), which influences the geomorphic structure and nutrient status of desert stream ecosystems. Embedded within the multi-annual hydrologic regime, flash floods scour stream channels and initiate a series of rapid successional changes by benthic algae, aquatic and wetland plants, and macroinvertebrates at short time scales (i.e., within a year). An important goal of this research is to understand cross-scale interactions: i.e., how long-term climate variability and change guide the interactions among slow (biogeomorphic change) and fast (postflood succession) features and processes characteristic of desert stream ecosystems.
|Effective start/end date||8/1/09 → 9/30/13|
- NSF: Directorate for Biological Sciences (BIO): $449,298.00