Evaluating the impact of multi scenario land use change simulation on carbon storage at different scales: a case study of Pearl River Delta Urban Agglomeration

Abstract

Carbon storage in terrestrial ecosystems is crucial to advance carbon neutrality and support sustainable development. Extensive studies have explored the effect of land use change on carbon storage, especially urban expansion. As one of the world’s top urban agglomerations, the Pearl River Delta Urban Agglomeration (PRDUA) is facing a dramatic loss of carbon storage along with urbanization. Coordinating economic development and ecological protection and achieving low-carbon green development are urgently needed to alleviate the decline in urban carbon storage. Here, we quantified land use change in the historical period (2000, 2010, 2020) and in 2030 and then estimated carbon storage dynamics at different scales by combining the PLUS model and the InVEST model. We found that: (1) Construction land significantly increased simultaneously with considerable losses of farmland (2273.29 km2) and forestland (949.98 km2) from 2010–2020. In 2030, construction land will expand by 997.83 km2 (12.51%), 1419.97 km2 (17.79%), and 238.60 km2 (2.99%) under the natural growth (NG), urban expansion (UE), and low carbon development (LCD) scenarios, respectively. (2) Compared to 2020, carbon storage under the LCD will reach 6.51×108 Mg, with the lowest decline rate (0.35%). (3) At the city level, Shenzhen had the highest decline rate under various scenarios, followed by Zhuhai and Guangzhou. At the county scale, carbon storage followed the order NG > UE > LCD in 2000–2030. At the grid scale, carbon storage showed a declining trend from the central PRDUA region to marginal areas. Thus, comprehensive considering the multiscale effects of land use change on carbon storage was beneficial to formulate reasonable measures for specific areas. Differentiated development categories at different scales and low-carbon industrial upgrading should be implemented to maintain ecosystem services and achieve sustainable development.