鼎湖山针阔叶混交林4种优势树种树干液流特征

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 鼎湖山针阔叶混交林4种优势树种树干液流特征 DOI: 10.5846/stxb201310202533 作者: 作者单位: 中国科学院华南植物园;中国科学院大学,中国科学院华南植物园;中国科学院大学,中国科学院华南植物园;中国林业科学研究院热带林业实验中心,中国科学院华南植物园,中国科学院华南植物园,中国科学院华南植物园 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31170375); 中国科学院知识创新工程重要方向项目(KZCX2-YW-GJ01); 广东省自然科学基金项目(9151008901000130) Sap flow characteristics of four dominant tree species in a mixed conifer-broadleaf forest in Dinghushan Author: Affiliation: South China Botanical Garden,Chinese Academy of Sciences,South China Botanical Garden,Chinese Academy of Sciences,South China Botanical Garden,Chinese Academy of Sciences,South China Botanical Garden,Chinese Academy of Sciences,South China Botanical Garden,Chinese Academy of Sciences,South China Botanical Garden,Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:运用Granier热消散式探针法,对鼎湖山自然保护区针阔叶混交林4种优势树种(马尾松、木荷、锥栗和广东润楠)的树干液流密度进行了长期连续观测,并同步监测林分的环境因子(光合有效辐射(PAR)、空气温度(T)、空气湿度(RH)、土壤含水量)。结果表明:(1)4种优势树种的边材面积(As)与胸径(DBH)均存在显著相关关系(P < 0.05);(2)各优势树种树干液流均呈现"昼高夜低"单峰曲线,且液流速率存在明显的季节性差异;(3)无论湿季还是干季,光合有效辐射(PAR)和水汽压亏缺(VPD) 均为控制蒸腾的主要驱动因子;(4) 4种优势树种湿季平均日蒸腾量高于干季,马尾松、木荷、锥栗、广东润楠湿季平均日蒸腾量分别为29.52、39.29、30.40、9.41 kgH2O/d,干季分别为20.91、24.84、24.26、8.43 kgH2O/d,干季和湿季的平均日蒸腾量(kgH2O/d)大小均为木荷>锥栗>马尾松>广东润楠,这种种间差异是由边材面积大小和树种本身的生物学特性共同决定的。 Abstract:The plant water use efficiency is not only crucial for plant to maintain a relatively high growth rate but also an important metric of water balance in forest ecosystem. Recent years, sap flow measurement has been widely used as a basis for assessing the water exchange between tree crown and ambient atmosphere for it can keep trees in natural condition without damaging the growth of trees. Many studies on trees' sap flow in single species plantations have been carried out across China, but the studies in natural forests are still few. We measured sap flow of four dominant tree species (Pinus manssoniana, Schima suerba, Castanopsis chinensis and Machilus kwangtungensis) in a mixed conifer-broadleaf natural forest in the Dinghushan Reserve of South China using the Granier's thermal dissipation probe method. The sap flow was measured daily in July and November, 2010, which represented the wet and dry seasons in the region, respectively. The environmental factors such as photosynthetically active radiation (PAR), air temperature (T), relative air humidity (RH) and soil moisture were also recorded. The aims of this study were (1) to investigate the characteristics of sap flow of four dominant tree species, (2) to estimate their relationships with the driving factors of transpiration, (3) and to compare the transpiration rates of different tree species calculated from sap flux density combing with trees' morphological characteristics. The results showed that sapwood area of the four dominant tree species had a significantly (P < 0.05) positive relationship with diameter at breast height (DBH). The coefficient of determination R2 of four trees species were 0.99、0.96、0.93、0.81 respectively. Sap flux density displayed an obvious pattern with higher values during daytime and also showed a significant seasonal variation with higher value in wet season. The average sap flow velocity of P. manssoniana, S. superba, C. chinensis and M. kwangtungensis were (10.07±1.47), (10.07±1.51), (12.20±1.73), (8.35±1.28) gH2O m-2 s-1 in wet season, and were (7.22±1.33), (6.41±1.15), (9.78±1.64), (7.37±1.34) gH2O m-2 s-1 in dry season. Contrast to previous study in Dinghushan Reserve of South China at an altitude of 50m, our research found that sap flow velocity displayed a significant variation along the gradient of altitude, which was induced by the differentiation of microenvironment and plant morphological characteristics. Partial correlation analysis indicated that photosynthetically active radiation (PAR) and vapor pressure deficiency (VPD) were the two main environmental factors determining the tree transpiration in both seasons. Transpiration of the four dominant tree species was much higher during the wet season than in the dry season. The average daily transpiration rates of P. manssoniana, S. superba, C. chinensis and M. kwangtungensis during the wet season were 29.52, 39.29, 30.40, 9.41 kgH2O/d, respectively, while those during the dry season the rates were 20.91, 24.84, 24.26 and 8.43 kgH2O/d, respectively. The order of the average daily transpiration was: S. superba > C. chinensis > P. manssoniana > M. kwangtungensis both in wet and dry seasons. Such difference in daily transpiration among tree species was mainly determined by the sapwood area and biological characteristics. 参考文献 相似文献 引证文献