[Measurement of Efficiency， Total Volume Prediction， and Resource Allocation for China's Forest Carbon Sink]

In the context of the challenge posed by climate change and the pursuit of the "dual carbon" goals， accurately assessing the efficiency of forest carbon sinks in various regions， identifying the reasons behind efficiency differences， and accordingly proposing effective resource allocation pathways are of great significance for promoting coordinated regional development， improving resource utilization efficiency， and achieving carbon sequestration and emission reduction. Based on provincial data from China spanning from 2004 to 2021， a three-stage DEA model was constructed to measure the forest carbon sink efficiency of 30 provinces and municipalities， and a regional difference analysis was conducted. Simultaneously， a prediction model based on GAN and KOA-CNN-BiLSTM-Attention was established to forecast the total carbon sink targets that each region intends to achieve by 2030， and scenarios were set up to enhance the accuracy of the model. Based on the three-stage theory， further improvements were made to the inverse DEA model to discuss the resource allocation path planning schemes for various regions to achieve their predicted carbon sink targets. In particular， feedback was provided on the current input redundancies and deficiencies in each region. The results showed that： ① Although China's forest carbon sink efficiency showed a trend of growth， it was still at a moderately low level overall. Moreover， there were significant regional differences. Regions with higher efficiency levels were mainly distributed in the southwest and northeast， while those in North China had lower levels and require attention. The remaining regions fell in between and still had room for development. ② The core reasons for the differences in forest carbon sink efficiency among regions were natural resource endowments （including forest resources and natural conditions） and the degree of concern for forestry （including policy support and resource allocation preferences）. Scientific management and operation played a reinforcing role in enhancing the forest carbon sink capacity of the regions. ③ The northeast and southwest regions have made significant contributions in terms of total forest carbon sink. Nationally， the total forest carbon sink is expected to increase by 7% to 30% by 2030， and the forest carbon sink will continue to play a crucial role in carbon emission reduction and sequestration. ④ Each region needs to make incremental improvements in at least one input area. Land input will be the main challenge in achieving future carbon sink targets and is also a key limiting factor for the current level of forest carbon sink efficiency. In the long run， Heilongjiang and Inner Mongolia have the best prospects for forest carbon sink development. The research can provide decision-making references for governments and related industries in pursuing the "dual carbon" goals and help enhance carbon sequestration efficiency and resource allocation efficiency.