杉木水分利用效率对混交和气象因子的响应  

Responses of water use efficiency of Chinese fir to mixed planting and meteorological factors

作　　者：王筱迪 张杰铭 姜姜[1] 刘自强 WANG Xiaodi;ZHANG Jieming;JIANG Jiang;LIU Ziqiang(Key Laboratory of Soil and Water Conservation and Ecology Restoration,Co-lnnovation Center of Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京林业大学南方现代林业协同创新中心江苏省水土保持与生态修复重点实验室,南京210037 [2]南京水利科学研究院水文水资源与水利工程科学国家重点实验室,南京210029

出　　处：《应用生态学报》2023年第12期3232-3238,共7页Chinese Journal of Applied Ecology

基　　金：中国博士后科学基金项目(2022M720693);国家自然科学基金项目(42007182)资助。

摘　　要：我国现存的杉木人工林普遍是树种组成单一、林分密度不合理、生产力低下的低效人工林,在改善低效人工林方面通常采取引入阔叶树种的营林措施。本研究以江西官山林场杉木纯林和杉楠混交林为对象,基于树轮δ^(13)C稳定同位素方法量化植物内禀水分利用效率(iWUE)及其对气象因子的响应,分析引入楠木对低效杉木人工林林木质量的提升效应。结果表明:纯林中的杉木断面积生长量为0.23 cm^(2),高于混交林杉木的0.19 cm^(2);杉木纯林树轮δ^(13)C和iWUE分别为-27.4‰和52.9%,低于混交林的-26.7‰和62.8%。杉木纯林δ^(13)C对年均降水和年均相对湿度的变化更敏感,杉木混交林δ^(13)C则与气象因子的相关性不明显;杉木纯林iWUE与年均温度、年均大气CO_(2)浓度和年均最高温度呈正相关,与年均降水和年均相对湿度呈负相关,而杉木混交林iWUE仅与年均大气CO_(2)浓度呈正相关。表明杉木纯林对气候的响应较杉木混交林更敏感。Chinese fir in China are generally inefficient plantations with single species, unreasonable stand density, and low productivity. The introduction of broadleaved species is usually adopted as a strategy to improve Chinese fir plantations. Taking the pure forests and mixed forests of the Guanshan Forest Farm in Jiangxi Province as example, we quantified the intrinsic water-use efficiency(iWUE) of trees based on the stable isotope carbon method, as well as its response to meteorological factors, and investigated the improvement of stand quality after introducing Phoebe zhennan into Chinese fir plantation. The results showed that the basal area increment was 0.23 cm^(2) in pure forest, being higher than that of 0.19 cm^(2) in mixed forest. The δ^(13)C and iWUE of pure forest were-27.4‰ and 52.9%, respectively, being lower than those of-26.7‰ and 62.8% in the mixed forest. Tree δ^(13)C in pure forest was more sensitive to changes in mean annual precipitation and mean annual relative humidity, while that in mixed forest was not significantly correlated with meteorological factors. Pure forest iWUE was positively correlated with mean annual temperature, mean annual atmospheric CO_(2) concentration, and mean annual maximum temperature, and negatively correlated with mean annual precipitation and mean annual relative humidity, while mixed forest iWUE was positively correlated with mean annual atmospheric CO_(2) concentration only. Our results indicated that pure forests was more sensitive to climate than mixed forests.

关 键 词：杉木 稳定碳同位素 内禀水分利用效率 气象因子 

分 类 号：S791.27[农业科学—林木遗传育种]