滨海沙地木麻黄低效防护林生长特性的研究

STUDY ON GROWTH CHARACTERISTICS OF LOWER-EFFECTIVE PROTECTION FOREST OF CASUARINA SPP.ON COASTAL SANDY SOIL

从木麻黄生长量、生物产量、生长发育规律和直径分布状况等方面,探明滨海沙地低效防护林生长特性。木林黄低效林的树高、胸径和材积和生物量均显著低于正常林,连年生长量和平均生长量一开始就小于正常林,并随着年龄的增长这种差距愈加显著,生长高峰期比正常林提前1～4年,且生长高峰的持续时间较短,林分数量成熟龄比正常林提高3～4年。低效林的径级分布结构不合理,林木株数的直径分布呈偏态分布,与正常林相比径级分布的高峰向前推移,降低了林木商品材的经济出材率。

Growth characteristics of lower-effective protection forest of Casuarina in the castal sandy soil were re- searched in the aspect of growth,biological yield,growth regularily and diameter distribution.Tree height,diameter at breast height,volume and biomass of these stands were obviously lower than the normal.Current annual increment and average increment from beginning of growth were less than the normal,and the differences would be more and more with ages.Growth peak period came 1-4years earlier than the normal and shorter in time duration.The age of quantitative mature was 3-4 years earlier than the normal.Diameter class of the lower-effective stands abnormally distributed,and the peak of distribution shifted ahead,that reduced the percentage of out-turn.