Department of Geographical Sciences, University of Maryland, College Park, MD 20742, United States of America.
Department EaRSLab-Earth Remote Sensing Laboratory, University of Évora, Évora, Portugal, iInstitute of Earth Sciences (ICT), Universidade de Évora, Évora, Portugal.
Sci Total Environ. 2023 Nov 1;897:165364. doi: 10.1016/j.scitotenv.2023.165364. Epub 2023 Jul 9.
Belowground components (biomass and soils) can stock as much carbon as the aboveground component of forest ecosystems. In this study, we present a fully-integrated assessment of the biomass budget and the three pools evaluated: aboveground (AGBD) and belowground biomass in root systems (BGBD) and litter (LD). We turned National Forest Inventory data, airborne Light Detection and Ranging (LiDAR) data actionable to map three biomass compartments at 25-m resolution over more than 2.7 million ha of Mediterranean forests in the South-West of Spain. We assessed distributions and balanced among the three modelled components for the entire region of Extremadura and specifically for five representative forest types. Our results showed belowground biomass and litter represent an important 61 % of the AGBD stock. Among forest types, AGBD stocks were the dominant pool in pine-dominated areas while its lowers contribution was found over sparse oak forests. The three biomass pools estimated at the same resolution were used to produce ratio-based indicators to highlight areas where the contribution of belowground biomass and litter can exceed AGBD and where carbon-sequestration and conservation practices should acknowledge belowground-oriented carbon management. The recognition and valuation of biomass and carbon stocks beyond the AGBD is a must step forward that the scientific community must support in order to properly assess living components of the ecosystem such as root systems sustaining AGBD stocks and to value carbon-oriented ecosystem services related to soil-water dynamics and soil biodiversity. This study aims at enforcing a change of paradigm in forest carbon accounting, advocating for a better recognition and broader integration of living biomass in land carbon mapping.
地下组分（生物量和土壤）可以储存与森林生态系统地上组分一样多的碳。在本研究中，我们对生物量预算和三个评估的碳库（地上生物量（AGBD）、根系地下生物量（BGBD）和凋落物（LD））进行了全面综合评估。我们利用国家森林清查数据和可用于绘制西班牙西南部超过 270 万公顷的地中海森林 25 米分辨率三个生物量组分的航空激光雷达（LiDAR）数据，对整个埃斯特雷马杜拉地区和五个有代表性的森林类型进行了评估。我们评估了整个地区和五个有代表性的森林类型中三个模型化组分的分布和平衡。结果表明，地下生物量和凋落物占地上生物量总储量的 61%。在森林类型中，地上生物量在以松树为主的地区占主导地位，而在稀疏的栎树林中占比较低。在相同分辨率下估计的三个生物量库被用来生成基于比率的指标，以突出地下生物量和凋落物贡献超过地上生物量的区域，以及应该承认地下导向的碳管理的碳固存和保护实践的区域。在以 AGBD 为基础的生物量和碳储量之外，认识和评估生物量和碳储量是科学社区必须支持的一个重要步骤，以便正确评估维持 AGBD 储量的根系等生态系统的活组分，并评估与土壤-水动态和土壤生物多样性有关的碳导向生态系统服务。本研究旨在加强森林碳核算的范式转变，倡导更好地认识和更广泛地整合土地碳测绘中的活生物质。
