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我国拥有丰富的经济林资源,一些产品的产量居世界的首位。如:油茶、油桐、乌桕、生漆、栗、枣、梨等。占世界第二位的有苹果、核桃等。但是,我国经济林产品的平均亩产量却很低。如:苹果亩产不足意大利的五分之一,梨为日本的四分之一强,柑桔为日本的五分之一强,核桃仅为美国的二十分之一。原因是我国低产园面积大,现有结果油茶中,亩产茶油5公斤以下的占70%以上,油桐林亩产油7公斤以下的占60%以上,栗、枣、核桃等
China has abundant economic forest resources and the output of some products ranks first in the world. Such as: Camellia, tung tree, black beans, raw lacquer, chestnut, dates, pears and so on. The world’s second place with apples, walnuts and so on. However, the average yield per mu of forest products in China is very low. Such as: less than one-fifth of Italy’s apple production per mu, pear is a quarter strong in Japan, citrus is more than a fifth of Japan, Walnut is only one-twentieth of the United States. The reason is that the area of low-yielding garden in our country is large. The existing result of Camellia oleifera is that more than 70% of the tea yield is less than 5 kg per mu, while the oil yield is less than 60 kg per acre.