Net loss of biomass predicted for tropical biomes in a changing climate

Tropical ecosystems store over half of the world’s aboveground live carbon as biomass, and water availability plays a key role in its distribution. Although precipitation and temperature are shifting across the tropics, their effect on biomass and carbon storage remains uncertain. Here we use empirical relationships between climate and aboveground biomass content to show that the contraction of humid regions, and expansion of those with intense dry periods, results in substantial carbon loss from the neotropics. Under a low emission scenario (RCP4.5) this could cause a ~14.4–23.9 Pg C (6.8–12%) net reduction of aboveground live carbon from 1950–2100. Under a high emissions scenario (RCP8.5), net carbon losses could double across the tropics ~28.2–39.7 Pg C (13.3–20.1%). The contraction of humid regions in South America accounts for ~40% of this change. Climate mitigation strategies could prevent half of the carbon losses and help maintain the natural tropical net carbon sink., This dataset contains the input data, and partial and final results from Uribe et al. (2023).,热带生态系统以生物量（biomass）形式储存了全球超过一半的地上活体碳，而水分可利用性对其分布起着关键调控作用。尽管热带地区的降水与温度均发生了变化，但二者对生物量与碳储量的影响仍尚不明确。本研究借助气候与地上生物量含量间的经验关系，证实了湿润区域的收缩与强干旱期区域的扩张，将导致新热带区出现大规模碳损失。在低排放情景（RCP4.5）下，1950年至2100年间该区域的地上活体碳净储量或将减少约14.4~23.9 Pg C（占比6.8%~12%）。在高排放情景（RCP8.5）下，整个热带地区的碳净损失量将翻倍，达到约28.2~39.7 Pg C（占比13.3%~20.1%）。南美洲湿润区域的收缩贡献了该变化总量的约40%。气候减缓策略可避免半数碳损失，有助于维持热带地区自然碳汇的净固碳能力。本数据集包含Uribe等人（2023年）研究中的输入数据、部分结果与最终结果。