除草布在崖柏回归初期幼林抚育中的应用

The application of weeding cloth in sapling tending of Thuja sutchuenensis Franch.at the initial stage of reintroduction

在重庆市开州区马云林场崖柏回归试验基地,采用随机区组实验设计,布设覆盖单层、双层除草布和无覆盖的田间试验。通过对不同处理下崖柏的存活率、树高、地径、冠幅、冠层结构、根系垂直分布、地上和地下生物量及其分配、枝叶养分含量以及杂草盖度的调查,研究不同处理方式的控草效果及其对崖柏幼树生长和发育的影响,为回归初期崖柏种群维护措施的制定提供参考。结果表明:1)覆盖单层和双层除草布的杂草盖度分别为5%和3%,无覆盖的杂草盖度为87%;2)覆盖单层和双层除草布的崖柏存活率均在95%以上,无覆盖的仅65%,覆盖与无覆盖差异显著,覆盖单层和双层除草布的差异不显著;3)崖柏大部分生长指标和冠层结构指标、崖柏地上和地下生物量、根系分布深度和崖柏嫩枝叶氮含量等指标均为:覆盖单层和双层除草布>无覆盖,覆盖单层和双层除草布的差异不显著;4)除草布的控草效果和对崖柏存活和生长的促进作用与除草布的特殊结构和功能有关。由此可见,在崖柏回归初期,地表覆盖除草布既能有效控制杂草,又能提高崖柏的存活率和促进崖柏幼树的生长,同时还可降低人工除草成本;覆盖单层和双层除草布的差异不显著,选用覆盖单层除草布的方式即可获得理想的抚育效果。

A field experiment of uncovered(control),covered single-layer and double-layer weeding cloth was conducted with randomized block design in Thuja sutchuenensis reintroduction experimental base of Mayun Forest Farm,Kaizhou District,Chongqing.We investigated the survival rate,height,ground diameter,crown width,canopy structure,vertical distribution of roots,biomass and its aboveground and belowground allocation,branch and leaf nutrient contents of T.sutchuenensis saplings as well as weed coverage.We examined the effects of weeding cloth on weed control and the growth and development of the saplings,aiming to provide scientific basis for the population maintenance of T.sutchuenensis at the initial stage of reintroduction.Our results showed that:(1)Weed coverage with single-layer and double-layer weeding cloth was 5% and 3%,respectively,and 87% for the control.(2)The survival rate of saplings covered with single-layer and double-layer weeding cloth was more than 95%,without significant difference between them.The survival rate of uncovered was only 65%,with significant difference between the uncovered and covered weeding cloth.(3)Most growth and canopy structure indices,aboveground and belowground biomass,root distribution depth of trees and nitrogen content in the branches and leaves of T.sutchuenensis saplings covered with single-layer and double-layer weeding cloth performed better than those of uncovered samplings.There were no significant differences between single-layer and double-layer.(4)The weed control effect and the promotion effect on the survival and growth of T.sutchuenensis saplings were correlated to the special structure and function of weeding cloth.In conclusion,the use of weeding cloth can effectively inhibit weed growth,improve the survival rate and growth of T.sutchuenensis,and reduce the cost of artificial weeding and tending at the initial stage of reintroduction.There was no significant difference in the impacts between single-layer and double-layer weeding cloth.Therefore,the ideal tending effect can be obtained by covering with single-layer weeding cloth.