摘要
本文引入聚集度指数和平均拥挤度———平均密度系数的方法，研究了杨树灰斑病的空间分布型。通过ＣＡ、Ｍ／Ｍ和Ｉｗａｏ方法测定的结果表明，在不同病情下，具有不同的空间分布型；当病情指数低于４时为均匀分布；４～１５时，呈聚集分布；１５以上时由聚集分布趋于随机分布。同时本文给出了不同精度和不同病情指数下的抽样数目。
Spatial distribution of Coryneum populinum was studied through crowding index and coefficient of mean crowdiness-mean density methods. The result shows that different spatial distribution appears in stands of various density. The pattern is a uniform disttribution when damage index is less than 4; or aggregation distribution while damage index is 4-15; or random distribution if damage index is larger than 15. This paper also provided for precision and number of samples in each case.
出处
《辽宁林业科技》
1999年第1期28-30,共3页
Liaoning Forestry Science and Technology
