|| 要旨トップ | 目次 |||日本生態学会第57回全国大会 (2010年3月，東京) 講演要旨|
Sabina vulgaris is a decumbent habit shrub with adventitious roots (ARs for short). Involving water supply from ARs (traced by 0.5% acid fuchsine), leaf water potential (ψleaf), transpiration rate (Tr), stomatal conductance (gs), and leaf area were estimated, and seasonal water-use properties were discussed.
At daytime, water supply from ARs just flowed to the tip part of decumbent stems in both moist summer and dry spring. At night, water from ARs was supplied to restore water deficit in different organs both basal and distal to ARs. Moreover in dry spring, the water from ARs also flowed into neighboring root system, which proved the possibility of hydraulic redistribution of soil water. Drought-resistant characteristics of S. vulgaris can be described as: in drought condition, (1) ψleaf decreased with soil water potential (ψleaf at predawn) to maintain sufficient driving force for water absorption; (2) gs and leaf area were significantly small relative to moist condition to achieve unchanged Tr in unit leaf area and protect from water loss; (3) the existence of ARs and hydraulic redistribution between roots can potentially provide more effective absorption and usage of soil water.