Responses of macroinvertebrate communities to long?term flow variability in a Sonoran Desert stream
ثبت نشده
چکیده
Current global models predict a hotter and drier climate in the southwestern United States with anticipated increases in drought frequency and severity coupled with changes in flash flood regimes. Such changes would likely have important ecological consequences, particularly for stream and riparian ecosystems already subject to frequent hydrologic disturbance. This study assessed the potential response of aquatic macroinvertebrates to interannual variation in hydrology in a spatially intermittent desert stream (Sycamore Creek, AZ). We compiled data on the recovery of macroinvertebrate communities following spring floods, with successional sequences captured 11 times over a 16-year period (1983–1999). This period encompassed a transition from perennial to intermittent flow in this system, and included a record drought in 1989–1990. Results show that while the size of floods initiating sequences had little explanatory power, changes in macroinvertebrate community structure during postflood succession were closely associated with antecedent flooding and drought. Year-to-year differences in benthic communities integrated taxon-specific responses to antecedent disturbance, including differential resistance to channel drying, use of hyporheic refugia, and variable rates of recovery once stream flow resumed. The long-term consequences of drying on community structure were only evident during later stages of postflood succession, illustrating an interaction between flood and drought recovery processes in this system. Our observations highlight the potential for predicted climate changes in this region to have marked and long-lasting consequences for benthic communities in desert streams.
منابع مشابه
Statistical model of daily flow in arid and semi arid regions
Abstract Stochastic model for synthetic data generation is not available for daily flows of intermittent streams. Such a model is required in the planning and operation of structures on an intermittent stream for purposes where short time flow fluctuations are important. In this study a model is developed for such a case. The model consists of four steps: determination of the days on which fl...
متن کاملLarge-scale climatic phenomena drive fluctuations in macroinvertebrate assemblages in lowland tropical streams, Costa Rica: The importance of ENSO events in determining long-term (15y) patterns
Understanding how environmental variables influence the distribution and density of organisms over relatively long temporal scales is a central question in ecology given increased climatic variability (e.g., precipitation, ENSO events). The primary goal of our study was to evaluate long-term (15y time span) patterns of climate, as well as environmental parameters in two Neotropical streams in l...
متن کاملImportance of neutral processes varies in time and space: Evidence from dryland stream ecosystems
Many ecosystems experience strong temporal variability in environmental conditions; yet, a clear picture of how niche and neutral processes operate to determine community assembly in temporally variable systems remains elusive. In this study, we constructed neutral metacommunity models to assess the relative importance of neutral processes in a spatially and temporally variable ecosystem. We an...
متن کاملRemote Sensing of Sonoran Desert Vegetation Structure and Phenology with Ground-Based LiDAR
Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of ...
متن کاملSpatio-Temporal Variability in Benthic Macroinvertebrate Communities in Headwater Streams in South Korea
Comprehensive research on the structural and functional variability of benthic macroinvertebrate communities within headwater streams is limited, despite the fact that the majority of streams within a watershed are headwater streams that form the primary link between terrestrial and aquatic ecosystems. Therefore, we investigated the structure and function of benthic macroinvertebrate communitie...
متن کامل