立地因子影响桉树人工林土壤质量及材积量的机制  

Mechanism of site factors affecting soil quality and volume of Eucalyptus plantations

作　　者：王珮璇 何春 吴秦展 陈虎[5] 陈利军 祝玲月 刘森 杨章旗 唐健 吴立潮[1,2] WANG Peixuan;HE Chun;WU Qinzhan;CHEN Hu;CHEN Lijun;ZHU Lingyue;LIU Sen;YANG Zhangqi;TANG Jian;WU Lichao(Key Laboratory of Soil and Water Conservation and Desertification Combating in Hunan Province,Central South University of Forestry&Technology,Changsha 410004,Hunan,China;Key Laboratory of Cultivation and Protection for Non-wood Forest Trees of Ministry of Education,Central South University of Forestry&Technology,Changsha 410004,Hunan,China;Qipo Forest Farm,Nanning 530000,Guangxi,China;Daguishan Forest Farm,Hezhou 542899,Guangxi,China;Guangxi Forestry Research Institute,Nanning 530002,Guangxi,China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210018,Jiangsu,China)

机构地区：[1]中南林业科技大学水土保持与荒漠化防治湖南省高等学校重点实验室,湖南长沙410004 [2]中南林业科技大学经济林培育与保护省部共建教育部重点实验室,湖南长沙410004 [3]国有七坡林场,广西南宁530000 [4]国有大桂山林场,广西贺州542899 [5]广西林业科学研究院,广西南宁530000 [6]中国科学院南京土壤研究所,江苏南京210018

出　　处：《中南林业科技大学学报》2022年第3期80-91,125,共13页Journal of Central South University of Forestry & Technology

基　　金：国家“十三五”重点研发计划项目(2016YFD0600505)。

摘　　要：【目的】桉树是重要的用材林树种,因其速生的优点在巴西、印度等地被大面积人工种植。根据前人对其他用材林的研究表明林木的生长不仅受土壤理化性质的影响,立地因子的影响同样也是十分显著的。然而,目前对桉树人工林的研究主要集中在土壤物理、化学或生物学性质的研究,鲜有学者探讨立地因子对其的影响。立地因子如何影响桉树人工林的土壤质量及其材积量尚不明确。本文旨在了解立地因子对桉树人工林土壤质量和材积量的影响。【方法】在中国桉树主产区广西的3个主要桉树种植区设置108个样地,以降水量、海拔、坡向、坡度4个立地因子为变量,测定30个土壤理化生指标用以评价土壤质量(SQI),最后结合冗余分析、随机森林模型和结构方程模型对立地因子、SQI及材积量之间的关系进行分析,探究最优的立地条件及立地因子影响桉树人工林土壤质量和材积量的机制。【结果】海拔和坡度是影响土壤特性的主要立地因子。随着海拔和坡度的增大SQI与材积显著降低。而降水量只表现出与SQI的显著负相关关系。南坡向的SQI和材积均显著高于其他坡向。海拔和坡度主要是通过对土壤物理性质的饱和持水量,化学性质的全磷和生物特性的微生物生物量磷的显著负向影响从而对SQI和材积产生间接的负向影响。【结论】低海拔,低坡度,南坡向的立地因子条件有利于桉树人工林的可持续经营。【Objective】Eucalyptus is an important timber forest species that has been planted on a large scale in Australia and Brazil due to its fast-growing advantages.According to previous studies on other timber forests,the growth of Eucalyptus is not only influenced by soil physical and chemical properties,but also by site factors.However,studies on Eucalyptus plantations have mainly focused on soil physical,chemical and biological factors,but few scholars have explored the effect of site factors on Eucalyptus plantations.At present,it is not clear how site factors affect the soil quality and wood volume of Eucalyptus plantations.To understand the effects of site factors on soil quality and volume of Eucalyptus plantations.【Methods】Three main Eucalyptus planting areas in Guangxi,the main Eucalyptus producing area in China,were taken as the sample plots,and four site factors including precipitation,altitude,slope direction and slope were used as variables.108 sample plots were selected,and 30 soil physical,chemical and biological indexes were measured to evaluate the soil quality(SQI).Finally,redundancy analysis,random forest model and structural equation model were used to analyze the correlation between site factors,SQI and volume,and to explore the optimal site conditions and the mechanism of site factors affecting soil quality and volume of Eucalyptus plantations.【Results】The results showed that elevation and slope were the main stand factors affecting soil properties.SQI and wood volume decreased significantly with the increase of elevation and slope.In contrast,precipitation only showed a significant negative correlation with SQI.The SQI and wood volume were significantly higher in the south slope than the other slopes.Elevation and slope had an indirect negative effect on SQI and wood volume mainly through the significant negative effects on saturated water holding capacity of the soil,total phosphorus and phosphorus of microbial biomass.【Conclusion】The site factors of low altitude,low slope and so

关 键 词：桉树人工林 立地因子 土壤质量评价(SQI) 随机森林模型 冗余分析 结构方程模型 

分 类 号：S792.39[农业科学—林木遗传育种]