Coupling spatial-temporal changes and driving factors of carbon stock for the Wuhan metropolitan area using the PLUS-InVEST-GeoDectetor model.

Focusing on the spatiotemporal variations in carbon stock and its driving factors in metropolitan areas serves not only as a crucial approach to promoting high-quality and sustainable development under the expansion of metropolitan development but also as a significant component of achieving urban carbon neutrality. This study used the PLUS-InVEST-GeoDectetor model to set natural development (Q1), ecological protection (Q2) and cultivated land protection (Q3) scenarios to analyze the spatiotemporal changes in carbon stock in the Wuhan metropolitan area; the results were combined with land use and multifactor analysis to reveal the key driving factors. The results show that the Q2 and Q3 scenarios have a significant inhibitory effect on the expansion of construction land in metropolitan area, with a slight negative trend (a net decrease of 0.43 Tg) from 2000 to 2020; furthermore, the carbon sink function revealed a risk of accelerated degradation in the future. Carbon stock in the metropolitan area was high in the northeast and low in the west and gradually evolved symmetrically around the high value area along the Yangtze River from 2000 to 2035. Compared with that in 2020, the carbon stock in the metropolitan area in 2035 decreased by 3.94 Tg (Q1), 1.16 Tg (Q2) and 5.24 Tg (Q3) when coupled with the three scenarios, and the Q2 scenario effectively inhibited the loss of carbon stock. In addition, the expansion of construction land in the metropolitan area from 2000 to 2020 caused significant conversions of cultivated land and woodland, and led to a significant loss of carbon stock. The order of importance of the factors driving the spatial differentiation of carbon stock in the metropolitan area was land use > slope > elevation > NDVI, and there was a positive synergistic relationship between the factors. This study is conducive to promoting the optimization of urban land use patterns, the high-quality development of metropolitan areas, and the realization of the concept of better city life.