土壤水分逆境對果樹生理之影響

Physiological Effects of Soil Moisture Stress in Fruit Crops

土壤水分的變化因全球氣候變遷而逐漸極端化，對多年生果樹之生長與生理有立即性與持續性的雙重作用。果樹作物或可藉由形態與生理的改變，提高根系自土壤吸收水分的效率與減少樹冠水分蒸散量，或可利用滲透調節維持樹體水勢與基本生理活力，或可降低生長量以減少水分需求，來適應不同程度之乾旱逆境。另一方面，藉由根組織形態與發生部位的改變以維持根系之功能，或經由生理與形態的調控維持地上部與地下部基本機能的平衡狀態，來適應淹水逆境。本文試探討土壤水分對果樹作物生理與生長發育之影響，以了解果樹作物於土壤水分逆境下之可能生長模式，作為未來因應氣候變遷果園土壤水分管理之參考。 Soil moisture fluctuates toward the extreme in recent years due to the global climate change. Consequently, the growth and physiology of perennial fruit crops may not only be instantly but also persistently affected by such trend. Many fruit trees can tolerate or adapt to various severities of drought stress by morphological and physiological changes to increase soil water absorption efficiency or reduce canopy transpiration rate, by osmotic adjustment to maintain tree water status and physiological function, or by reducing growth to conserve water use. On the other hand, many fruit trees can also tolerate or adapt to various degrees of waterlogging by changing morphology of root tissue and occurring site to maintain root function, or by morphological and physiological adjustments to balance the physiological functions between root and canopy. This review focuses on the effects of soil moisture stress on fruit tree development and physiology to understand the possible growth model. The information integrated here faciliates future water management in orchard to cope with global climate change.