Multi-year throughfall reduction enhanced the growth and non-structural carbohydrate storage of roots at the expenses of above-ground growth in a warm-temperate natural oak forest

作者：Cuiju Liu, Zhicheng Chen, Shirong Liu, Kun‐Fang Cao, Baoliang Niu, Xiaojing Liu, Xiaomin Gao · 发表于：Forest Ecosystems · 年份：2023 · DOI：10.1016/j.fecs.2023.100118 · 被引用次数：24 · 研究领域：Plant Water Relations and Carbon Dynamics、Forest ecology and management、Tree-ring climate responses

The more frequent occurrence and severer drought events resulting from climate change are increasingly affecting the physiological performance of trees and ecosystem carbon sequestration in many regions of the world. However, our understanding of the mechanisms underlying the responses and adaption of forest trees to prolonged and multi-year drought is still limited. To address this problem, we conducted a long-term manipulative throughfall reduction (TFR, reduction of natural throughfall by 50%–70% during growing seasons) experiment in a natural oriental white oak (Quercus aliena var. acuteserrata Maxim.) forest under warm-temperate climate. After seven years of continuous TFR treatment, the aboveground growth in Q. aliena var. acuteserrata started to decline. Compared with the control plots, trees in the TFR treatment significantly reduced growth increments of stems (−14.2%) and leaf area index (−6.8%). The rate of net photosynthesis appeared to be more susceptible to changes in soil water in trees subjected to the TFR than in the control. The TFR-treated trees allocated significantly more photosynthates to belowground, leading to enhanced growth and nonstructural carbohydrates (NSC) storage in roots. The 7-year continuous TFR treatment increased the biomass, the production and the NSC concentration in the fine roots by 53.6%, 153.6% and 9.6%, respectively. There were clear trade-offs between the aboveground growth and the fine root biomass and NSC storage in Q. aliena var....