## 5 Conclusions  
In this study, we analyzed the spatial effects of different climate-influencing factors on carbon sinks in the ecological space in the B-T-H region using NPP data. Additionally, by using spatial econometric models, the specific climate factors influencing carbon sequestration were identified. We then quantitatively analyzed the contributions of different interannual climate factors to the spatial patterns of carbon sequestration within ecological spaces and spatial spillover effects. The results indicate the following:  
Figure 6: Spatial distribution and scale of “Three Zone Space”.  
1. A significant increasing trend in NPP from 2000 to 2020 in ecological regions of the B-T-H area, with clear regional and agglomeration characteristics. Therefore, it is advised to proactively adjust land use and climate policies to promote sustainable NPP growth. When implementing ecological spatial governance, it is crucial to consider the interactive effects of urban agglomeration and the surrounding areas and strengthen cooperative governance between regions;
2. Spatial regression models, especially the SDM, showed the best fit for this study, indicating the presence of both endogenous and exogenous interactions in the model. Under the fixed effect condition, annual precipitation did not have a significant impact on spatial-scale carbon sequestration in the ecological spaces. However, interannual temperature, evaporation, and relative humidity showed a positive effect on carbon sequestration. Annual sunshine duration, ground temperature, and wind speed had a negative impact on carbon sequestration. Considering the spatial autocorrelation of NPP, when building carbon sequestration simulation models, a larger geographic region should be considered, including both the target area and its neighboring spaces, to improve the accuracy of the models;
3. Various climate factors not only have direct effects on carbon sequestration patterns locally, but they also exhibit spatial spillover effects. Annual average temperature, evaporation, and relative humidity enhanced carbon sequestration locally but reduced regionally. In contrast, annual sunshine duration and ground temperature negatively affected carbon sequestration locally but enhanced regionally. Annual wind speed had a negative effect on NPP both at local and regional scales. Considering the direct and indirect effects of specific climate factors, reasonable recommendations can be made for urban agglomeration and addressing climate change, such as improvement in land use structures and solar and wind resources development.  
Conceptualization, X.W. and K.W.; methodology, Y.Z.; software, X.W.; validation, Y.X. and J.G.; formal analysis, X.W.; investigation, Y.Z.; resources, Y.Z.; data curation, Y.X.; writing--original draft preparation, X.W.; writing--review and editing, X.W.; visualization, Y.X.; supervision, Y.Z.; project administration, K.W.; funding acquisition, Y.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Beijing Municipal Education Commission through the Innovative Transdisciplinary Program \"Ecological Environment of Urban and Rural Human Settlements\", grant number GJJXZ10105.  
The data of the current research are available from the corresponding author on request.  
The authors declare no conflict of interest.