Evaluation on relative carbon efficiency of regional planning land use structure

To study the impacts of planning land use structure on carbon storage of terrestrial ecosystem, data envelopment analysis was introduced. The relative carbon efficiency of land use structure in general land use planning (2006-2020) was appraised in Jiangsu Province and its 13 cities, which carbon efficiency of land use structure was DEA efficient; 38.64%, 38.64% and 46.15% of 13 cities were DEA efficient in 2005, 2010 and 2020, respectively; Besides Jiangsu provincial level, 23.08%, 30.77% and 38.46% of 13 cities was DEA efficient in 2005, 2010 and 2020, respectively. Excessive constructive land was the key reason of inefficiency, redundant forest land and agrarian land also had contribution to it. It concludes that planning is efficient to some extent, and to the inefficient cities, it is primary to utilize constructive land economically and intensively. As to forest land and agrarian land, it is inadvisable to reduce the ratios because of their functions of food security and carbon sink, and the best choice is to carry out good practice to increase carbon sink and improve their contribution to ecosystem carbon storage.