Effects of Simulated Acid Rain on Growth and Physiological Characteristics of Ginkgo biloba L. Seedlings and on Chemical Properties of the Tested Soil -I. Seed Germination and Growth

인공산성우(人工酸性雨)가 은행(銀杏)나무(Ginkgo biloba L.) 유묘(幼苗)의 생장(生長), 생리적(生理的) 특성(特性) 및 토양(土壤)의 화학적(化學的) 성질(性質)에 미치는 영향(影響) -I. 종자발아율(種子發芽率)과 생장(生長)

Half-sib seeds and one-year-old seedlings of Ginkgo biloba were treated with various simulated acid rains (pH 2.0, pH 3.0, pH 4.0 and pH 5.0) to examine the effects of acid rain on seed germination and seedling growth. The seeds were sown in a pot ($4500cm^3$) containing one of three different soils (nursery soil, mixed soil and sandy soil) and the seedlings were grown in the same pots as the seeds. Simulated acid rain was made by diluting sulfuric and nitric acid solution ($H_2SO_4$: $HNO_3$ = 3:1, V/V) with tap water and tap water (pH6.4), and treated by 5mm each time for three minutes during the growing seasons (April to October 1985 and April to August 1986). Acid rain treatments were done three times per week to potted seeds and seedlings by spraying the solutions. The seed germination, seedling growth and physiological characteristics of potted seedlings were compared among three soil types as well as among the various pH levels. The results obtained in this study were as follows: 1. Seed germination of Ginkgo biloba decreased significantly at pH 2.0 level in the field test, and also at the levels of both pH 2.0 and pH 3.0 in the laboratory test, compared to that at control. 2. For two-year-old seedlings, total, top and root dry weights per seedling were significantly different among the three soil types and among the levels of pH, and shoot growth was different only among the levels of pH. 3. For one-year-old seedlings, height and total and stem-branch dry weights per seedling were significantly different among the levels of pH.

인공산성우(人工酸性雨)가 은행(銀杏)나무의 종자발아율(種子發芽率)과 유묘(幼苗)의 생장(生長)에 미치는 영향(影響)을 구명(究明)하기 위하여, 천연강우(天然降雨)를 차단(遮斷)하고 묘포토양(苗圃土壤), 혼합토양(混合土壤) 및 사질토양(砂質土壤)에 각각 분식(盆植)된 은행(銀杏)나무 종자(種字)와 유묘(幼苗)(1-0, half-sib)에 인공산성우(人工酸性雨)(황산(黃酸)과 질산(窒酸)을 3:1, v/v로 혼합(混合)하여 수돗물로 희석한 pH 2.0, 3.0, 4.0 및 5.0)와 수돗물(pH 6.4)을 생육기간중(生育期間中)(1985년(年) 4월(月) 28일(日)~10월(月) 19일(日) 및 1986년(年) 4월(月) 12일(日)~8월(月) 19일(日))에 주(週) 3회(回), 매회(每回) 5mm씩 처리(處理)하여 얻어진 결과(結果)는 다음과 같다. 1. 은행(銀杏)나무 종자(種字)의 발아(發芽)는 야외실험(野外實驗)에서는 pH 2.0 처리구(處理區)에서 발아율(發芽率)이 감소(減少)했으며, 실내실험(室內實驗)에서는 pH 2.0 및 3.0 처리구(處理區)에서의 발아율(發芽率)이 대조구(對照區)에 비하여 현저히 낮아졌다. 2. 2년생(年生)(1-1) 묘목(苗木)의 경우, 개체당(個體當) 건중량(乾重量), 지상부(地上部) 및 지하부(地下部) 건중량(乾重量)은 토양간(土壤間)에 그리고 pH 간(間)에 유의차(有意差)가 있었으며, 신초생장(新梢生長)은 pH 간(間)에만 유의차(有意差)가 인정(認定)되었다. 3. 1년생(年生)(1-0) 묘목(苗木)의 경우, 묘고(苗高), 개체당(個體當) 총건중량(總乾重量), 수간일지조(樹幹一枝條) 건중량(乾重量)이 pH 간(間)에 각각 유의성(有意性)이 인정(認定)되었다.