<正>在分析几种削度方程的基础上建立了改进的四参数Sohumacher方程作为杨树削度方程，并编制了江苏杨树二元材种出材率表。经对不同立地条件下的杨树林分出材量的估计实验，表明该方程适合江苏省杨树生长，为进一步编制全省杨树二元材种出材率表提供了理论与实验方法。结合计算机理论造材方法，模拟林木生长规律，提高了编制材种出材量表的效率，保证了营林设计的材种出材量精度。提出的理论与方法可用于江苏杨树的收获估计。对提高杨树的科学经营管理水平具有重要的意义。

This paper studied on the status of litter collected in different phases from 2002 to 2003 in December at reclamation and non reclamation pure Phyllostachys edulis stands by means of fixed monitoring in Luxi forest region, Fuyang county, Zhejiang province, P. R. C. ANOVA results showed that the dry weight of litter in reclamation Ph. edulis stands was more significantly reduced than that in non reclamation one in summer or in winter, It indicated that the average dry weight of litter in non reclamation one was 1.65~5.74 times than that of reclamation’s stands in winter. It also appeared similar variation characteristics for nutrient of litter in different Ph. edulis stands: The order of nutrient content or storage of litter in reclamation stands was as follow: c(Ca)>c(K)>c(Mg)>c(N)>c(P), it indicated that nutrient content or storage range from 0.16~3.3 g/kg and 0.20~4.50 kg/hm2, respectively. Whereas non reclamation stands was as follows:c(Ca)>c(K)>c(N)>c(Mg)>c(p), the nutrient content ranged from 0.20~5.10 g/kg while nutrient storage was from 0.70~ 29.10 kg/hm2, respectively. Not only the amount of letter covered on soil surface greatly reduced, but also nutrient storage was significantly lower after reclamation in Ph. edulis stands. Thus sufficient attention should be paid to soil management for reclamation to restrict steady improvement of potential soil fertility.