Savannas constitute a mixture of trees and shrub patches with a more continuous herbaceous understory. The contribution of this biome to the soil organic carbon (SOC) and above-ground biomass (AGB) carbon (C) stock globally is significant. However, they are frequently subjected to land use changes, promoting increases in CO emissions. In Uruguay, subtropical wooded savannas cover around 100,000 ​ha, of which approximately 28% is circumscribed to sodic soils (i.e., subtropical halophytic wooded savannas). Nevertheless, there is little background about the contribution of each ecosystem component to the C stock as well as site-specific allometric equations. The study was conducted in 5 ​ha of subtropical halophytic wooded savannas of the national protected area Esteros y Algarrobales del Río Uruguay. This work aimed to estimate the contribution of the main ecosystem components (e.g., soil, trees, shrubs, and herbaceous plants) to the C stock. Site-specific allometric equations for the most frequent tree species and shrub genus were fitted based on basal diameter (BD) and total height (H). The fitted equations accounted for between 77% and 98% of the aerial biomass variance of and . For shrubs ( sp.), the adjusted equation accounted for 86% of total aerial biomass. C stock for the entire system was 116.71 ​± ​11.07 ​Mg⋅ha, of which 90.7% was allocated in the soil, 8.3% in the trees, 0.8% in the herbaceous plants, and 0.2% in the shrubs. These results highlight the importance of subtropical halophytic wooded savannas as C sinks and their relevance in the mitigation of global warming under a climate change scenario.

中文翻译：

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乌拉圭盐生树木稀树草原的碳储量估算：生态系统方法


稀树草原由乔木和灌木丛组成，林下有更连续的草本植物。该生物群落对全球土壤有机碳 (SOC) 和地上生物量 (AGB) 碳 (C) 库的贡献是显着的。然而，它们经常受到土地用途变化的影响，导致二氧化碳排放量增加。在乌拉圭，亚热带树木繁茂的稀树草原面积约为 100,000 公顷，其中约 28% 为钠质土壤（即亚热带盐生树木稀树草原）。然而，关于每个生态系统组成部分对碳库的贡献以及特定地点的异速生长方程的背景知识很少。该研究在乌拉圭 Esteros y Algarrobales del Río 国家保护区 5 公顷的亚热带盐生树木稀树草原中进行。这项工作旨在估计主要生态系统组成部分（例如土壤、树木、灌木和草本植物）对碳库的贡献。根据基径（BD）和总高度（H）拟合最常见树种和灌木属的特定地点异速生长方程。拟合方程解释了 和 的空中生物量方差的 77% 到 98%。对于灌木( sp.)，调整后的方程占气生总生物量的86%。整个系统的碳库为116.71 ± 11.07 Mg·ha，其中90.7%分配在土壤中，8.3%分配在树木中，0.8%分配在草本植物中，0.2%分配在灌木中。这些结果强调了亚热带盐生树木稀树草原作为碳汇的重要性及其在气候变化情景下减缓全球变暖的相关性。