补植木荷对湿地松林林木生长及林分碳密度的影响

Effects of Replanting Schima superba on the Tree Growth and Carbon Density of Pinus elliottii Plantations

探究补植木荷对湿地松林林木生长及林分碳密度的影响可为湿地松纯林提高林分稳定性及功能的改造提供参考依据。以江西省吉水县23年生受灾湿地松林为研究对象,于2013年选择立地条件相似且地域相邻地块分别设置补植(补植1年生木荷)和对照(纯林)配对固定样地,2013年和2021年对5组配对固定样地进行样地调查与样品测定。采用配对样本T检验,分析湿地松林补植木荷后对林木生长及不同组分碳密度的影响。结果表明,1)补植木荷8 a后,湿地松的平均胸径显著高于对照样地(P<0.05),其平均胸径及平均单株材积的增长量分别比对照样地提高了27.27%和63.92%。2)乔木层、凋落物层、土壤层的碳密度及林分总碳密度分别比对照样地提高了62.01%、108.66%、40.09%和41.31%,而林下植被层碳密度则减少了12.75%,其中凋落物层碳密度和林分总碳密度提高显著(P<0.05)。3)补植样地的乔木层、植被(乔木层+林下植被层+凋落物层)碳密度及林分总碳密度8 a间的增长量均显著高于对照样地(P<0.05)。因此,补植木荷能够有效促进湿地松林林木生长及显著提高林分碳密度。

Exploring the effect of replanting Schima superba on tree growth and stand carbon density of Pinus elliottii plantations can provide reference for improving the stability and function of P.elliottii pure plantations.Taking the 23-year-old P.elliottii plantations damaged by freezing disaster in Jishui County,Jiangxi Province as the research object,in 2013,the plots with similar site conditions and geographical adjacent plots were selected to set up the paired fixed plots of replanting(replanting one-year-old seedlings of S.superba)and control(pure plantation).In 2013 and 2021,five pairs of fixed plots were investigated and measured.The effects of replanting S.superba on the tree growth and carbon density of different components were analyzed by paired sample T test.The results showed that 1)After 8 years of replanting S.superba,the average DBH of P.elliottii was significantly higher than that of the control plots(P<0.05),and the average DBH and average individual volume increased by 27.27%and 63.92%,respectively.2)Compared with the control plots,the carbon density of the tree layer,litter layer,soil layer and total carbon density of the stand increased by 62.01%,108.66%,40.09%and 41.31%,respectively,while that of understory vegetation layer decreased by 12.75%,and the carbon density of litter layer and total carbon density of the stand increased significantly(P<0.05).3)The increments of carbon density of the tree layer,vegetation(tree layer+understory vegetation layer+litter layer)and total carbon density in 8 years were significantly higher than those in control plots(P<0.05).Therefore,replanting S.superba can effectively promote the growth of P.elliottii plantations and significantly increase carbon density.