粉煤灰复田立地上杨,柳,榆,刺槐根系的分布和生长特点

针对粉煤灰复田立地（利用电厂粉煤灰填充采煤塌陷区，在其上再覆３０ｃｍ土壤）营造人工林的可行性和造林树种选择等问题，调查了该立地上生长的４—５年生欧美杨、旱柳、白榆和刺槐人工林根系的分布及生长特点。结果表明：四树种根系分布深达１８０ｃｍ以下，水平延伸达８ｍ。在粉煤灰层中，各树种根系均能正常生长，其中根系长度和根系重量分别占总量的６８％和８７％以上。在３０ｃｍ厚表层土壤中，根系长度和重量分别低于总量的３０％和１３％。欧美杨、旱柳、白榆和刺槐的根系总长度和总重量分别为每株４９．２４、２９．４５、２５．４２、６８．０８ｋｍ和７．４５、７．５４、１０．０５、１３．３７ｋｇ。

DISTRIBUTION AND GROWTH CHARACTERISTICS OF THE ROOT SYSTEMS OF POPLAR,WILLOW,ELM AND LOCUST ON SITE OF RENEWED LAND BY FINE ASH OF COAL

Aiming at the feasibility of conducting plantation on the site of renewed land by powder of coal(the coalpits filled with the fine coal ash from electri factory, then covered with soil layer of 30cm)and the selection of appropriate tree species, investigation on the distribution and growth characteristics of root-system of 4-5-yearold plantations of P.Xeuramericana, Salix matsudana,Ulmus pumila and Robinia pseudoacacia were carried out. The results are as follows:1. Root-system of all the 4 tree species can grow normally and the distribution depth can reach over 180cm in the soil, of which the weight and length of the root in the ash amount to 68% and 87% of the total,and those in the 30cm soil layer, 32% and 13%,respectively; and me horizontal root range around 8m.2.The total root length and weight of the poplar,willow,elm and locust are:49.29,29.45,25.42 and 68.08 km/plant,and 7.45,7.54,10.05 and 13.37kg/plant respectively.