[A-CG35] グローバル炭素循環の観測と解析

[ACG35-02] Combining GEDI, Landsat forest cover loss maps, and airborne remote sensing, to improve understanding of central Africa tropical forest regrowth and carbon sequestration

*David Roy¹、Herve Kashongwe²、Myung Cho ²、David Skole ³、Jean-Robert Bwangoy ⁴ (1.Center for Global Change and Earth Observations & Department of Geography, Michigan State University, East Lansing, MI 48823, USA、2.Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI 48823, USA、3.Global Observatory for Ecosystem Services & Department of Forestry, Michigan State University, East Lansing, MI, 48823, USA、4.Department of Natural Resource Management, Faculty of Agronomy, University of Kinshasa, Kinshasa, Democratic Republic of Congo)

キーワード：central Africa tropical forest regrowth , carbon sequestration, satellite mapping, field work

Nearly half of the world’s tropical forests are secondary forests, i.e., they are regrowing after being disturbed, and if left to regrow, provide a low-cost mechanism for carbon sequestration and an effective pathway to help mitigate climate change. Recent published research estimated that regrowing tropical forests mitigated 26% of the emissions that occurred due to forest loss and degradation. Tropical forest regrowth rates are poorly quantified and conventional ground-based assessment is extraordinarily challenging. The NASA Global Ecosystem Dynamics Investigation (GEDI) LiDAR is the first space-borne laser sensor designed to measure vegetation height, and combined with satellite maps of the location and occurrence of forest cover loss (FCL), provide new opportunities to quantify forest regrowth. New NASA GEDI science team funded research is presented to quantify forest regrowth in secondary forests in Mai Ndombe Province, in the Democratic Republic of the Congo (DRC), located in the largest REDD+ project in the DRC. A protocol to identify GEDI observations containing homogeneous regrowing tree stands by examination of 8 cm airborne digital imagery, with targeted field-based species inventory undertaken by expert DRC forest officers, is presented. Different tropical forest tree species have different regrowth rates and dry wood densities, and so have different carbon sequestration potential. A forest regrowth chrono-sequence derived using the GEDI relative height product combined with 30 m Landsat-based maps to locate and date FCL is presented. The implications for quantification of the carbon sequestration of regrowing forest in central Africa are discussed.