摘要
樟子松(Pinus sylvestris var.mongolica)是辽西北半干旱区主要的人工林造林树种,准确估算其蒸腾耗水量对樟子松人工林的科学管理具有重要意义。该研究采用基于多点(不同规格)TDP探针研究30年生樟子松树干液流的径向变化特征及其对树木蒸腾耗水量的影响。结果表明:樟子松树干液流在径向上存在较大的差异且随着季节的变化径向模式也会发生变化。在8月,樟子松树干液流呈现明显的单峰径向模式,在距最外侧边材15 mm处达到峰值,而在10月,樟子松径向模式表现出较大的差异,从边材的外侧到心材逐渐下降。基于液流径向变化,估算出30年生樟子松在8月和10月日蒸腾量分别在25.32–27.45和14.05–16.49 kg之间,其中,边材外侧0–20 mm的蒸腾量占据了整株蒸腾量的绝大部分。通过单点估算樟子松整株蒸腾量会产生较大误差,误差最高可达133.22%。樟子松各深度(5、15、25 mm)的液流通量密度之间存在显著的关联性,每个深度的液流通量密度与基于边材面积加权平均的液流通量密度之间的线性方程拟合度较好,通过转换方程可以达到使用单点来估算整株蒸腾量的目的。光合有效辐射对樟子松各深度的液流影响最大,但不同深度的液流对气象因素的响应程度不同,因此不能以单深度的液流通量密度受气象因素的影响程度来预估气象因素对整株蒸腾耗水量的影响。
Aims Pinus sylvestris var.mongolica is one of the key afforestation species in the semi-arid region of western Liaoning Province.Precise estimation of its transpiration is crucial for the scientific management of these plantations.Methods This study utilized multi-point TDP probes with different probe sizes to examine the radial pattern of sap flow in 30-year-old P.sylvestris var.mongolica on sandy terrain,and to explain the factors affecting transpiration.Important findings Results revealed significant differences in the radial pattern of sap flow within the plantation,which also varied across seasons.In August,the sap flow exhibited a distinct unimodal radial pattern,peaking at 15 mm depth from sapwood.However,in October,the radial pattern showed a significant difference,presenting a gradual decline from the outer sapwood towards the heartwood.Based on radial sap flow changes,the daily transpiration of 30-year-old P.sylvestris var.mongolica in August and October was estimated to be between 25.32–27.45 and 14.05–16.49 kg,respectively.The transpiration from the outer 0–20 mm of the sapwood accounted for a substantial majority of the whole tree’s transpiration.Estimation of the entire P.sylvestris var.mongolica transpiration based on a single point could lead to significant errors,with the highest error reaching up to 133.22%.There was a notable correlation between sap flux densities at different depths(5,15,25 mm)out of sapwood,and a satisfactory linear fit was observed between sap flux density at various depths and weighted mean sap flux density on a sapwood area basis.Thus,a single-point estimation of individual tree transpiration can be achieved using conversion equations.The most significant effect on sap flow at different depths in P.sylvestris var.mongolica was from photosynthetically active radiation.However,the response degree of sap flow at different depths to meteorological factors were different,implying that meteorological influences on whole-tree transpiration cannot be predicted based on the
作者
童郁强
吴梦鸽
王玲
赵实
韩叙
张彤
刘静
秦胜金
董英豪
魏亚伟
周永斌
TONG Yu-Qiang;WU Meng-Ge;WANG Ling;ZHAO Shi;HAN Xu;ZHANG Tong;LIU Jing;QIN Sheng-Jin;DONG Ying-Hao;WEI Ya-Wei;ZHOU Yong-Bin(College of Forestry,Shenyang Agricultural University,Shenyang 110866,China;Research Station of Liaohe-River Plain Forest Ecosystem,Chinese Forest Ecosystem Research Network,Changtu,Liaoning 112500,China;Liaoning Forestry Development Service Center,Shenyang 110036,China;and 4College of Life and Health,Dalian University,Dalian,Liaoning 116622,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2024年第9期1118-1127,共10页
Chinese Journal of Plant Ecology
基金
中国科学院战略性先导科技专项(XDA23070103)
国家林业和草原局林草科技创新平台运行补助项目(2020132029和2021132053)。
关键词
树干液流
樟子松
人工林
径向变化
蒸腾
气象因子
sap flow
Pinus sylvestris var.mongolica
plantation
radial variation
transpiration
meteorological factor
