摘要
为探索适宜大小的林窗改造模式,在川中丘陵区高密度的柏木人工纯林中,选择人为砍伐形成的不同大小林窗样地36个,研究光热环境、植物生长和多样性随林窗大小的变化.结果表明:疏伐后,林窗内光合有效辐射和气温显著升高(P<0.05),空气湿度和土壤相对含水量显著降低(P<0.05),光合有效辐射和气温随林窗面积的增大而增加,空气湿度和土壤相对含水量随林窗面积的增加而降低.疏伐后,林窗内乔木高度、胸径、郁闭度和冠幅较未疏伐对照样地更新层显著提高(P<0.05),灌木高度和盖度、草本层盖度和枯落物层厚度显著提高(P<0.05),单位面积柏木蓄积量和单株柏木材积较未疏伐对照样地更新层显著增加(P<0.05),不同林窗大小之间,植物生长指标随面积的增加呈单峰型变化,峰值出现在90-110 m2林窗内.疏伐后,林窗内植物种数、属数和科数增加,乔木、灌木和草本种数增多,物种丰富度指数和多样性Shannon-Wiener指数显著提高(P<0.05),中林窗内植物区系组成最复杂,植物物种多样性最丰富.林窗和非林窗植物共有种为6-9种,相似系数在30.43%-36.73%之间.可见林窗式疏伐促进了林下植物的更新,90-110 m2的中林窗效果更为明显.
In order to explore the appropriate size of gap reconstruction model, 36 artificial forest gaps of different sizes were chosen for field investigation from a high-density pure cypress plantations in the hilly region of central Sichuan.The change of ecological factors; plant growth and diversity in the different size of gaps were monitored. The results showed that after thinning, the photosynthetic active radiation （PAR） and air temperature increased significantly （P 〈 0.05）, while air humidity and soil moisture increased significantly （P 〈 0.05） in the gaps. With the increase of gap size, the PAR and air temperature increased, but air humidity and soil moisture decreased. Compared with those of the control, the height, DBH, shade density, crown width of arbor after thinning significantly improved （P 〈 0.05）. The shrub height, shrub coverage, herbaceous coverage and litter layer thickness all increased significantly （P 〈 0.05）. Compared with the control plots of non-thinning updated layer, the thinning plots had significantly increased cypress volume in unit area and volume per cypress （P 〈 0.05）. Growth index of different size vegetations showed single peak change varying with gap size, with the peak appearing in the gap size of 90-110 m2. Number of species, genera, families and trees, shrubs, herbaceous species all elevated after thinning. Species richness and Shannon-Wiener index significantly increased （P 〈 0.05）. The middle forest gaps had the most complex floristic composition and the richest plant diversity. Between gaps and non-gaps, there were 6 - 9 common species with 30.43-36.73% similarity coefficient. The results indicated that forest thinning promotes the understory plant update, most effective with middle gaps of 90-110 m2.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2014年第6期971-977,共7页
Chinese Journal of Applied and Environmental Biology
基金
国家科技支撑计划课题(2011BAC09B05)
四川科技支撑计划项目(2010NZ0 049)资助~~
关键词
川中丘陵区
柏木人工林
林窗
疏伐
植物多样性
蓄积量
central Sichuan hilly region
cypress plantation
gap
thinning
plant diversity
volume
