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我这次到中国逗留了20天,在四川参观了几个华山松种植园,华山松及其天然林的生长下降很明显。中国林科院和四川省林科院对其原因进行了研究,其有关结论我认为是正确的。1) .酸雨:我们分析了降雨情况,但 pH 值无酸度。2) .喷稀硫酸试验:这种研究表明针叶无色,但针叶的基部变黄与自然色是不同的。3) .病害:通过试验之后,没有明确的病原真菌导致针叶变黄。也没得到明确的结果。4) .气候:病害主松树的范围限于海拔1200m-2000m 上,低于1170m 没有病害出现。
I have stayed in China for 20 days and visited several Huashan pine plantations in Sichuan. The growth of Huashan pine and its natural forests is obviously declining. The Chinese Academy of Forestry and the Sichuan Academy of Forestry conducted a study of its causes, and I think the relevant conclusions are correct. 1). Acid rain: We analyzed the rainfall but the pH was acid free. Spray dilute sulfuric acid test: This study shows that the needle is colorless, but the base of the needle is yellowed and the natural color is different. 3). Disease: After the test, no clear pathogenic fungi cause the needles to turn yellow. Did not get a clear result. 4). Climate: the main pine tree disease range limited to 1200m-2000m above sea level, less than 1170m no disease appears.