森林对温度的生物物理反馈对缓解全球气候变暖起着重要作用，但在不同纬度带间、不同近地表层间（气温和地温）的研究结果呈显著差异，驱动机理争议较大。现有陆地—大气交互模型把森林覆盖下垫面视为一个整体，尚未能清晰剖析森林内部能量流的传输（特别是林下空气和地表层间的分配），给科学、精细评估森林对气候的反馈调节作用带来较大困难。本课题拟基于配对实验原理选取具有纬度梯度的四个森林—非森林配对实验点作为研究基地，改进传统地表能量平衡方程，将森林覆盖地表划分成冠层、林下空气层、林下土壤层等垂直三部分，拆分林内垂直层之间的能量流再分配，构建能区分林下气温和地温对森林生物物理反馈响应的量化模型，揭示不同气候带两者对森林生物物理反馈的差异性响应规律，阐明森林水平覆盖和垂直结构异质性对森林生物物理反馈的调控机理，为精确模拟森林生物物理反馈过程提供新的研究方法，为应对未来气候变化、合理开展森林管理等提供科学依据。

The biophysical effects of forests on local temperature plays an important role in mitigating global warming, which differ greatly among latitudes and between different land surfaces (e.g. air temperature and soil surface temperature). The underlying mechanism also remains uncertain. However, most land-atmosphere models have limitations in presenting accurately the individual biophysical effects of forests on air temperature differences and soil temperature differences, as most land-atmosphere models mainly treat the forest and soil layers as a composite land surface. This might bring great difficulties in scientifically and accurately evaluate the biophysical feedbacks of forests on the climate. Focus on the above problems, this project will select four paired-sites (forest and non-forest) in different climate zones (mid-temperate zone, warm-temperate zones, subtropical zone and tropical zone) as the study areas, and improve the traditional land surface energy balance model by classifying the forest covered land surface into three vertical layers: canopy, understory air and surface soil, and decompose the understory energy fluxes redistributions among these three layers. We then establish a novel three-layer model to quantitatively estimate individual biophysical effects of forests on understory air and soil temperatures. Based on this, this project will reveal different drivers of forests’ biophysical effects on air temperature and soil temperature in the four climate zones and also reveal the mechanism of forest horizontal coverage and vertical structure heterogeneity in mediating the forests’ biophysical feedbacks. This project provides a new way in accurately modeling the forests’ biophysical effects on understory air and soil temperatures and also provide scientific basis for dealing with the climate change and making reasonable forestry management decisions in the future.