Unawong Weerapong, Yaemphum Siriphong, Nathalang Anuttara, Chen Yajun, Domec Jean-Christophe, Tor-Ngern Pantana
Center of Excellence on Hazardous Substance Management, Chulalongkorn University, Bangkok, 10330, Thailand.
Graduate School, Chulalongkorn University, Bangkok, 10330, Thailand.
Sci Rep. 2022 Apr 27;12(1):6882. doi: 10.1038/s41598-022-10988-1.
Large-scale abandoned agricultural areas in Southeast Asia resulted in patches of forests of multiple successions and characteristics, challenging the study of their responses to environmental changes, especially under climatic water stress. Here, we investigated seasonal variation in leaf water status and drought tolerance of dominant tree species in three multi-aged tropical forests, ranging from 5 to > 200 years old, with contrasting soil moisture in Thailand. Seasonal variation in leaf water status differed among the forests with trees in young and intermediate sites demonstrating larger differences between seasons than the old-growth forest. Although vulnerability to embolism curves revealed that trees in old-growth forest were potentially more sensitive to declining leaf water status than others, they were predicted to lose < 5% of their hydraulic capacity as opposed to 13% for the trees in the younger sites. Our results suggest that the responses to water stress of tree species in different forest ages greatly vary with a tendency of trees in younger sites to be more resilience than those in older sites. Such information would benefit the selection of tree species that could adapt well to specific environments, thus improving the strategies for managing forests of different ages under a warmer future.
东南亚大规模的废弃农业区形成了具有多种演替阶段和特征的森林斑块，这对研究它们对环境变化的响应提出了挑战，尤其是在气候性水分胁迫的情况下。在此，我们调查了泰国三片不同树龄（5年至200多年）、土壤湿度各异的热带森林中优势树种叶片水分状况的季节变化和耐旱性。不同森林中叶片水分状况的季节变化存在差异，幼龄和中年林分的树木季节间差异比老龄林更大。尽管栓塞脆弱性曲线显示老龄林中的树木可能比其他树木对叶片水分状况下降更敏感，但预计老龄林中树木损失的水力传导率不到5%，而幼龄林分中的树木则为13%。我们的结果表明，不同林龄的树种对水分胁迫的响应差异很大，幼龄林分中的树木比老龄林分中的树木更具恢复力。这些信息将有助于选择能很好适应特定环境的树种，从而改进在未来气候变暖情况下不同林龄森林的管理策略。
