气候过渡带针阔混交林水文过程对林火干扰的响应

Increased human activity-induced climate warming enhances the frequency of fire disaster. Forest fire is a major driving factor of ecosystem succession and material cycle. Forest fire could lead to drastic changes in forest structure, and exerts a great influence on the ecology service function of forest ecosystem. At present, the response of forest ecosystem hydrological processes to fire disturbance is still unclear. This study takes the coniferous and broadleaved mixed forest located in transition zone between southern subtropical and temperature forest as research object. The research will be conducted in a forest land disturbed by accidental fire. Though comparing the rainfall partitioning pattern, detecting the chemical element characteristics of rainfall fractions and monitoring the transpiration feature of fire sample plots and control sample plots, we are aimed at revealing the influencing mechanism of fire disturbance on rainfall partitioning and related chemical element migration characteristics, as well as water consumption of tree transpiration. The performance of this project will expand our understanding of the ecohydrological characteristics of forest ecosystem disturbed by fire, and enhance our comprehensive analytical and predictive ability of hydrological-ecological-economic system.

人类活动加剧引起的气候变暖造成全球范围内火灾发生频率提高。林火是生态系统演替和物质循环的重要驱动因子，可以导致森林结构发生剧烈变化，对森林生态系统的生态服务功能产生重大影响。然而，当前森林生态系统水文过程对火烧干扰的响应格局尚不清楚。本研究拟以我国北亚热带-暖温带过渡区的针阔混交林为研究对象，利用人为意外所形成的火烧林地，通过对比火烧林地与对照林地的降水分配情况及分配过程中的化学元素，并监测其蒸腾特征，揭示火烧干扰对森林生态系统降水分配、化学元素迁移特征以及蒸腾的影响机制。本项目的开展将有助于深入理解火烧干扰后的森林生态系统生态水文特征，提升对全球变化背景下水文-生态-经济系统的综合分析与预测能力。

气候变暖加剧导致的林火增多显著改变着森林结构，使森林生态系统的生态服务功能发生剧烈的变化，然而目前鲜有研究关注火烧干扰对森林水文过程的影响。本研究以我国北亚热带-暖温带过渡区的针阔混交林为研究对象，利用人为意外所形成的火烧林地，通过对比火烧林地与对照林地的降水分配情况，以期揭示火烧干扰对森林生态系统水文过程的影响。研究显示，修正Gash模型在未火烧和火烧的样地中均具有很好的适用性。尽管火烧改变了林冠截留的组分构成，但两个主要成分仍旧占据最大的份额。火烧使得穿透雨比值增高，树干茎流和林冠截留的比值降低。此外，对于两种树种，火烧会降低麻栎树干茎流的产量和汇流率，但会使马尾松树干茎流的产量和汇流率略有提升。通过对森林水文过程对火烧干扰的响应的分析，有助于提升全球变化背景下水文平衡的理解。