日本落叶松人工林种群自然稀疏规律的研究

Study on the Natural Thinning of Population in Man-made Japanese Larch Forest.

一、前言日本落叶松(Larix kaempferi)原产日本。种群地理分布范围为北纬35°20′—38°10′,东经136°45′—140°30′,海拔高度为1000—2800m。1900年引入我国,以其较强的适应性“定居”下来,而且生长速度在抚顺地区远比长白落叶松(L.olgensis var.changpaiensis)、兴安落叶松(L.gmelinii)为快;我国黑龙江、吉林、辽宁、山东、山西、陕西、北京、河南、河北、江西、湖北、四川以及新疆等地都有人工栽培,而以吉林、辽宁东部栽培面积较大,在年平均气温2.5—12.0℃、年降水量500—1400mm 的水热条件下能正常生长。

According to the principles and methods in plant genecology,natural thinning process ofJapanese larch population is analysed.The natural differentiations of trees in man-made Japa-nese larch forest is most intensive before 16 years of age,with an annual withering mortality larger than 3.5%.There are four peaks of natural thinning in the natural developmentprocess during 6—26 years of age,appearing at 9,13,17,20 years respectively.The GrayGM(1,1)model was applied to fit the natural thinning process of Japanese larch popula-tion.Fitness results show a higher accuracy and can be used for the prediction of futurepopulation densities.