北美红杉无性系培育模型及其对初植密度、海拔高度的响应

Clonal cultivation model of Sequoia sempervirens and its response to the initial planting density and altitude

以北美红杉无性系为研究对象,通过调查833株/hm2(株行距3 m×4 m)、1 111株/hm2(株行距3 m×3 m)、1667株/hm2(株行距2 m×3 m)3个初植密度以及550～1 800 m海拔范围内造林生长参数的变化规律,试图揭示初植密度与海拔高度两项造林关键因素对北美红杉生长特征的影响规律,期望为高级用材北美红杉引种造林设计提供理论依据。结果表明:(1)一种较好的生根培养基为MS+1.5 mg/LNAA+0.1 mg/L6-BA;(2)初植密度对试验株树高生长影响不大,1 111株/hm2和1 667株/hm2水平之间树高生长差异不显著。地径生长量随着初植密度的加大先升后降,当初植密度为1 406株/hm2(相当于2.6 m×2.6 m的株行距)时,地径发育情况最优,生长量在4.65 mm左右;(3)北美红杉各生长量参数随海拔增大先升后降,当海拔高度为1 096 m(考虑高海拔造林1 000～1 800 m范围)时,树高生长情况最优;当海拔高度为680 m左右时,地径发育情况最优。当海拔高度超过最佳值时,海拔的增加则会对北美红杉的发育起到一定程度的抑制作用,导致其生长量呈现逐渐减少趋势。

Use Sequoia sempervirens clones for research object,through the survey of 833 plants/hm2,1 111 plants/hm2,1 667 plants/hm2 at the beginning of three planting density and afforestation in the 550~1 800 m above,tries to reveal the early planting density and the altitude afforestation of two key factors on the influence of Sequoia sempervirens growth characteristics,expect to provide advanced wood Sequoia sempervirens introduction afforestation design theory basis.The results showed that:(1)a good rooting medium for MS+1.5 mg/LNAA+0.1 mg/L6-BA;(2)the early planting density has a little influence on the test tree height growth,1 111 plants/hm2 and 1 667 plants/hm2 level no significant difference between tree height growth.Ground diameter increment as the planting density increased at first and lowered later at the beginning of the original planting density of 1 406 plants/hm2,ground diameter growth,the optimal growth at around 4.65 mm;(3)the Sequoia sempervirens growth parameters increases with altitude at first and lowered later when the altitude of 1096 m;when the altitude is around 680 m,it is the best in the area;When the altitude of more than the best value,the increase in altitude will have a degree of dampening effect on the development of Sequoia sempervirens,leading to a gradual decline in growth.