目标树经营对杉檫混交林生长及天然更新影响研究

以通山县大幕山林场国家储备林为研究对象,按蓄积采伐强度设置对照(0%)、低强度(15.7%)、中强度(27.0%)、高强度(36.0%)、超高强度(45.6%)5个处理建立20块固定样地,对杉檫混交林目标树经营成效进行了监测。结果表明:作业样地2020年与2019年相比,目标树平均胸径生长量增加0.52 cm/年,单位面积蓄积生长量增加4.38 m³/(hm²·年);同时,2020年4种采伐强度作业样地平均每100 m²天然更新树种数6.25个,新增天然更新株数21株,而对照样地每100 m²天然更新树种数仅3个,新增天然更新株数仅12株。由此可见,目标树经营既促进了林木胸径生长,增加了林分蓄积量,同时又改善了林下天然更新,增加了物种多样性,可为国家储备林项目营林措施的选择提供有力支撑。

Preliminary Effects of Future-Crop-Tree Management on Growth and Natural Regeneration of Mixed Forests of Cunninghamia lanceolate and Sassafras tzumu

Taking Damushan National Reserve Forest in Tongshan County as the research object,20 permanent plots were set up for monitoring impacts of future-crop-tree management(FCT management)on forests of Cunninghamia lanceolate and Sassafras tzumu.The plots were established according to thinning intensity of stand volume:comparative plot(0%),low intensity(15.7%),medium intensity(27.0%),high intensity(36%)and very high intensity(45.6%).The monitoring results in thinned plots after 1 year showed that in comparison with those in 2019,the average DBH of FCT in the plots has increased 0.52 cm·a^-1 and the unit volume has increased 4.38m³/hm²·a.Meanwhile,in the plots with different thinning intensity,on average 6.25 kinds of species and 21 new seedlings appeared per 100 m²;in the comparative plots,only 3 kinds of species and 12 new seedlings were found,respectively.Obviously,FCT management can not only promote the tree growth and increase the stand volume,but also improve vegetation regeneration under trees and increase species diversity,which provides strong support for selection of treatments of National Reserve Forests project.