Influence of photosynthetic active radiation on sap flow dynamics across forest succession stages in Dinghushan subtropical forest ecosystem

作者：Jianqiang Huang, Fasih Ullah Haider, Wanxuan Huang, Shizhong Liu, Brian Njoroge Mwangi, Vincent Suba, Lindsay Sikuku, Xuli Tang, Qianmei Zhang, Guowei Chu, Deqiang Zhang, Juxiu Liu, Ze Meng, Dennis Otieno, Yuelin Li · 发表于：Heliyon · 年份：2024 · DOI：10.1016/j.heliyon.2024.e37530 · 被引用次数：6 · 研究领域：Plant Water Relations and Carbon Dynamics、Forest ecology and management、Horticultural and Viticultural Research

With the intensification of global change, forests are subjected to varying degrees of drought or high-temperature stress, which has an indelible impact on the growth of trees. However, knowledge on the response of sap flow to environmental changes in different types of forests is still rare, especially in China's subtropical forest ecosystem. Consequently, studying how different tree species regulate their sap flow in response to shifting environmental conditions is essential for understanding forest transpiration, water use efficiency, and drought stress resilience. Therefore, this study aimed to investigate the sap flow dynamics of seven tree species in five forest plots, i.e., pine forest (PF), two types of mixed conifer-broadleaf forests (MF1+MF2), monsoon evergreen broadleaved forest (MEBF), and montane monsoonal evergreen broad-leaf forest (MOBF) at Dinghushan National Reserve in Southern China, using the heat dissipation probe technique and synchronous environmental factor recordings. Results demonstrated a significant influence of photosynthetic active radiation (PAR) on sap flow across all tree species, with mean PAR values ranging from over 1200 to 425 μmol m −2 s −1 , establishing it as the principal driving factor. This observation underscores the heightened responsiveness or sensitivity of tree species to variations in PAR as the forest undergoes development and maturation. The correlation between vapor pressure deficit (VPD) and tree sap flow decreased as succe...