Monday, 12 January 2009
Undercanopy and below ground microclimate patterns at the North Desert Village
Hall 5 (Phoenix Convention Center)
Undercanopy and below ground microclimate measurements are continuously being monitored at the North Desert Village (NDV) long-term residential landscape experiment site in Mesa, Arizona. In this report, annual patterns of above and below ground and surface temperatures and soil heat flux at 30 cm depth for the year 2007 were reported. Soil temperatures were recorded using copper constantan thermocouples. Soil heat flux measurements were made using HFP01SC-L Hukseflux self-calibrating soil heat flux plates. Air temperatures and percent relative humidity were recorded by Vaisala HMP230 probes. Data were recorded every 5 minutes and averaged hourly by fixed solar powered micrometeorological stations with a CR1000 datalogger that were located near the center of four of the five NDV treatment sites. The four treatment sites (average 6177 m2 area) with micrometeorological stations are called mesic (spray irrigated turf grass), oasis (a mixture of spray irrigated turf and drip irrigated trees and shrubs), xeric (drip irrigated trees and shrubs), and native (non-irrigated trees and shrubs). All landscape surfaces without turf grass are covered with 5 cm of light beige-colored decomposing granite mulch. Throughout the year, small differences in air temperature and percent relative humidity were observed at 2 m height. Differences in surface temperatures were most correlated to surface cover type, and soils underneath turf covered surfaces were generally cooler and demonstrated the greatest diel (24 hr) variation in soil heat flux. At the residential yardscape scale, landscape vegetation composition affects undercanopy microclimate mostly below 2 m height.