Change of Needle Contact Angles due to Artificial Acid Rain Treatment

인공산성우 처리에 따른 침엽의 접촉각 변화

Artificial acid rain(pH 3.0, 4.0 and 5.0) and ground water(pH 6.5) were treated on the potted seedlings of Pinus rigida and Pinus koraiensis to examine its effects on the contact angles on needle surface. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water(pH 6.5) was used as control. Artificial acid rain was sprayed to the pots two times per week for growing season, one time per week for winter seasons. About 5mm of artificial acid rain was treated each time from late April, 1992 to early October, 1993. Contact angles on the needle surface were measured and compared among the treatments. The results were summarized as follows. Contact angles between needle surface and water droplet decreased with decrease of pH values of artificial acid rain. Measuring and comparing contact angles might be very effective criteria for early diagnosis of acid rain injury in the field.

리기다소나무와 잣나무 유묘에 인위적으로 산도를 조절한 인공산성우(pH 3.0, 4.0 및 5.0)와 지하수(pH 6.5)를 1992년 4월부터 1993년 8월까지, 생육기간 중에는 주 2회, 겨울철은 주 1회 1회 5mm의 강도로 처리하였다. 인공산성우를 처리하면서 수종별 침엽의 접촉각(contact angle)을 조사 비교하여 얻은 결과는 다음과 같다. 침엽의 표면과 물방울이 이루는 접촉각을 측정한 결과, 처리산성우의 산도수준이 높을수록 엽령이 높을수록 접촉각의 크기는 낮아졌다. 침엽의 접촉각을 측정 비교하는 방법은 야외에서 침엽수류에 대한 산성우 피해의 조기판단을 위한 매우 효과적인 기준이라 판단된다.