美国国家航空航天局Feldman Andrew F.团队报道了大全球尺度植被对日降雨变率的敏感性。这一研究成果发表在2024年12月11日出版的国际学术期刊《自然》上。

据悉，在气候变化的背景下，降雨事件在全球范围内的发生越来越不频繁，但强度却越来越大，从而改变了与年降雨量无关的陆地植被的气候条件。然而，人们对日降雨变率的变化，是如何影响全球植被的光合作用和生长这一过程知之甚少。

本研究利用几种基于卫星的植被指数，结合指示光合作用和生长的野外观测结果，研究发现，全球年尺度植被指数对日降雨频率和强度敏感，而与年降雨量无关。具体而言，研究人员发现，基于卫星的植被指数，对42％的植被覆盖的地表日降雨量变化敏感。平均而言，植被对日降雨变率的敏感性，几乎与植被对年总降雨量的敏感度相同(95％)。

此外，研究结果显示，降水频率和强度的变化与年降雨量变化，具有相似的幅度和空间范围。总的来说，研究结果强调了日降雨量的变化及其趋势，正在影响全球植被的光合作用，对碳循环和粮食安全具有潜在的影响。

附：英文原文

Title: Large global-scale vegetation sensitivity to daily rainfall variability

Author: Feldman, Andrew F., Konings, Alexandra G., Gentine, Pierre, Cattry, Mitra, Wang, Lixin, Smith, William K., Biederman, Joel A., Chatterjee, Abhishek, Joiner, Joanna, Poulter, Benjamin

Issue&Volume: 2024-12-11

Abstract: Rainfall events are globally becoming less frequent but more intense under a changing climate, thereby shifting climatic conditions for terrestrial vegetation independent of annual rainfall totals. However, it remains uncertain how changes in daily rainfall variability are affecting global vegetation photosynthesis and growth. Here we use several satellite-based vegetation indices and field observations indicative of photosynthesis and growth, and find that global annual-scale vegetation indices are sensitive to the daily frequency and intensity of rainfall, independent of the total amount of rainfall per year. Specifically, we find that satellite-based vegetation indices are sensitive to daily rainfall variability across 42per cent of the vegetated land surfaces. On average, the sensitivity of vegetation to daily rainfall variability is almost as large (95per cent) as the sensitivity of vegetation to annual rainfall totals. Moreover, we find that wet-day frequency and intensity are projected to change with similar magnitudes and spatial extents as annual rainfall changes. Overall, our findings suggest that daily rainfall variability and its trends are affecting global vegetation photosynthesis, with potential implications for the carbon cycle and food security.

DOI: 10.1038/s41586-024-08232-z

Source: https://www.nature.com/articles/s41586-024-08232-z