不同抚育技术对杉木幼林生长及群体结构的影响

对不同幼林抚育技术对杉木幼林生长和群体结构的影响进行定位研究 ,结果表明 :抚育技术对杉木保存率和生长有较大的影响。块状抚育和全垦抚育可提高杉木的保存率 ,而不抚育的杉木保存率则最低。树高和抽梢高基本上表现出块状抚育 >全垦抚育 >带状抚育 >劈草抚育 >不抚育 ,并且在后期更为明显 ;地径则基本上表现出全垦抚育 >块状抚育 >带状抚育 >劈草抚育 >不抚育。方差分析的结果表明抚育技术对地径的影响大于树高。多重比较表明 :除了不抚育外 ,其他 4种抚育技术均能有效地促进杉木生长 ,它们之间并没有多大的差异。块状抚育、全垦抚育、带状抚育和劈草抚育的总单株生物量分别为不抚育的 3 4 6、3 4 0、3 15和 1 11倍 ;块状抚育、全垦抚育、带状抚育、劈草抚育和不抚育的根 茎比分别为 0 1992、0 193 1、0 1673、0 3 5 75和 0 2 680。这可能是劈草抚育和不抚育的杉木对地下营养空间激烈竞争的一种适应现象。抚育技术对杉木群体树高和地径结构有一定的影响 ,尤其是对地径结构

THE EFFECT OF TENDING METHODS ON GROWTH AND POPULATION STRUCTURE OF YOUNG CHINESE FIR PLANTATION

In this paper,the effects of tending methods on growth and population structure of young Chinese fir plantation have been studied.The results showed that preserving rate and growth of Chinese fir were greatly affected by tending methods.Block tending and overall tending were favourable to elevate survival rate,but non\|tending was lowest.Tree height and sprout height basically showed block tending>overall tending>strip tending>chopping tending>non\|tending,and this kind of trend became more significant in later period;The basal diameter basically showed overall tending>block tending>strip tending>chopping tending>non\|tending.The results of variance analysis showed that the effect of tending on basal diameter was larger than on height.The results of multiple comparison showed that other four tending methods can effectively promote Chinese fir growth except non\|tending,and there were no difference among them.The biomass per tree of block tending,overall tending,strip tending and chopping tending was 3 46,3 40,3 15 and 1 11 times as much as that of non\|tending,respectively.Ratios of root/stem of block tending,overall tending,strip tending,chopping tending and non\|tending was 0 1992,0 1931,0 1673,0 3575 and 0 2680,which be a kind of adaptive phenomenon that Chinese fir competes for underground nutritional space with vegetation under chopping tending and non\|tending.The structures of height and basal diameter of Chinese fir population were certainly affected by tending methods,especially basal diameter structure.