River influences on riparian climate: Colorado River, Glen Canyon
Stanitski-Martin D and Stevens LE. 1995. River influences on riparian climate: Colorado River, Glen Canyon. Bulletin of the Ecological Society of America. 76(3):390
Rivers influence riparian climate and vegetation ecotones. We measured diel and seasonal gradients of temperature (T), relative humidity (RH), and net radiation (Q*) in the cold, stenothermic Colorado River immediately below Glen Canyon Dam, Arizona. Mean predawn and midday ranges of June T (14.9 to 31.1 degrees C), RH (57.4 to 21.7%), and Q* (0.0 to 660.8 W/m2) at river level shifted non-linearly over a 15m elevational gradient to: 20.4 to 39.4 degrees C, 38.2 to 21.0%, and -4.5 to 423.2 W/m2 ,respectively. December ranges were: 1.0 to 8.1 degrees C, 73.3 to 41.9%, and -77.1 to 6.1 W/m2 at river level, and 1.3 to 8.1 degrees C, 68.8 to 46.4%, and -3.5 to 7.9 W/m2 , respectively. T and RH explain 68% of sandbar willow xylem water potential (xwp) variance, and xwp is correlated with growth (r2 = 0.54, p<0.001). Multivariate analyses revealed strong correlation of T, RH, and Q* with time of day, season, distance from, and elevation over, the river. Interactions between climatic variables create thresholds of improved growth conditions that correspond with riparian ecotone position.
- Type
- Journal Article
- Authors
- Stanitski-Martin, Diane; Stevens, Lawrence
- Units
- GRCA
- Keywords
- Climate, Climatology, Ecology, Flow, Glen Canyon, Glen Cnyon Dam, IAR, Outflow, Riparian, Wetland/Riparian