酸雨指標作物之研究-利用模擬方式評估兩種篩選方法

Abstract

選定14種臺灣主要農作物為酸雨指作物篩選材料，探討兩種簡易篩選方法：一、酸性緩衝力指數，再用稀鹽酸滴定經研磨後葉片組纖均質液，用以了解對酸沉降的緩衝力。二、葉表酸鹼度測定，將不同酸度之模擬酸雨噴施葉片後，以平面酸鹼度電極奉測定葉表酸鹼度變，用以瞭解葉表對酸根離子的中和力。試驗結果顯示，緩衝力指數和葉片斑點面積極關係數達0.73，顯然可作為評估葉片傷害的指標。相反的，葉表酸度變化因作物間表層臘質的差異及其他因素干擾，無法顯示出和葉片傷害的一致性。 Foliage buffering capacity index (BCI) and leaf surface pH were measured in 14 major crops of Taiwan. Plants were exposured to simulated acid rain (pH7.0, 3.5，3.0 and 2.5) in greenhouse. The experimental results indicated that leaves had a capacity to neutralize acid rain. Crop species differed in their capacity to buffering specific levels of acidic input, with similar BCI levels differ in folilar necrosis ( r= 0.73 ). Leaf surface pH is not a proper screening method for acid rain indicator, because of the multifactural response of epicuticular waxs with acid rain.