美国蒙大拿大学Maneta Marco课题组报道了美国西部受土壤表面温度限制的低海拔森林范围。该项研究成果发表在2024年11月19日出版的《自然—地球科学》上。
据悉，气候变化和干扰威胁着全球的森林生态系统。预测森林未来分布的能力需要了解再生的限制因素。森林冠层可以缓冲近地表气温和水汽压力差的极端情况，森林冠层因野火等干扰而持续损失，可能加剧气候对自然再生的限制。
该研究团队将实验、经验和基于模拟的证据结合起来，表明土壤表面温度限制了美国西部低海拔森林的范围。模拟的潜在土壤表面温度预测了低海拔森林树线的位置，显示了与现场和实验室研究一致的温度阈值。
高分辨率历史和未来地表温度图显示，目前森林的107000-238000km2超过了森林再生的临界热阈值，预计到2050年这一面积将增加一倍以上。土壤表面温度是低海拔地区幼苗存活的重要物理控制因素，随着气候变暖，这可能会对美国西部森林的范围产生越来越大的限制。
附：英文原文
Title: Low-elevation forest extent in the western United States constrained by soil surface temperatures
Author: Holden, Zachary A., Dobrowski, Solomon Z., Swanson, Alan, Hoylman, Zachary, Lyons, Drew, Warren, Allen, Maneta, Marco
Issue&Volume: 2024-11-19
Abstract: Climate change and disturbance threaten forested ecosystems across the globe. Our ability to predict the future distribution of forests requires understanding the limiting factors for regeneration. Forest canopies buffer against near-surface air temperature and vapour pressure deficit extremes, and ongoing losses of forest canopy from disturbances such as wildfire can exacerbate climate constraints on natural regeneration. Here we combine experimental, empirical and simulation-based evidence to show that soil surface temperatures constrain the low-elevation extent of forests in the western United States. Simulated potential soil surface temperatures predict the position of the low-elevation forest treeline, exhibiting temperature thresholds consistent with field and laboratory studies. High-resolution historical and future surface temperature maps show that 107,000–238,000km2 (13–20%) of currently forested area exceeds the critical thermal threshold for forest regeneration and this area is projected to more than double by 2050. Soil surface temperature is an important physical control on seedling survival at low elevations that will likely be an increasing constraint on the extent of western United States forests as the climate warms.
DOI: 10.1038/s41561-024-01577-0
Source: https://www.nature.com/articles/s41561-024-01577-0