Richards J H, Caldwell M M
Department of Range Science and the Ecology Center, Utah State University, 84322-5230, Logan, UT, USA.
Oecologia. 1987 Oct;73(4):486-489. doi: 10.1007/BF00379405.
Diel soil water potential fluctuations reflected daytime depletion and nocturnal resupply of water in upper soil layers. Transpiration suppression experiments demonstrated that water absorption by roots caused the daytime depletion. The soil water potential data and experimental results suggest that at night water absorbed from moist soil by deeper roots is transported to and lost from roots into drier upper soil layers. The deeper roots appear to absorb and transport water both day and night. Implications for the efficiency of deep roots and water storage, nutrient uptake and water parasitism in upper soil layers are discussed.
昼夜土壤水势波动反映了上层土壤白天水分的消耗和夜间的水分补给。蒸腾抑制实验表明，根系吸水导致了白天的水分消耗。土壤水势数据和实验结果表明，夜间较深根系从湿润土壤中吸收的水分被输送到较干燥的上层土壤层，并从根系中流失。较深根系似乎在白天和夜间都能吸收和运输水分。文中讨论了深根效率以及上层土壤层中水分储存、养分吸收和水分寄生的相关问题。
