Accurate prediction of forest carbon sequestration potential requires a comprehensive understanding of tree growth relationships. However, the studies for estimating carbon sequestration potential concerning tree growth relationships at fine spatial-scales have been limited. In this paper, we assessed the current carbon stock and predicted sequestration potential of Lushan City, where a region has rich vegetation types in southern China, by introducing parameters of diameter at breast height (DBH) and tree height in the method of coupling biomass expansion factor (BEF) and tree growth equation. The partial least squares regression (PLSR) was used to explore the role of combined condition factors (e.g., site, stand, climate) on carbon sequestration potential. The results showed that (1) in 2019, the total carbon stock of trees in Lushan City was 9.22 × 10⁵ t, and the overall spatial distribution exhibited a decreasing tendency from northwest to south-central, and the carbon density increased with elevation; (2) By 2070, the carbon density of forest in Lushan City will reach a relatively stable state, and the carbon stock will continue to rise to 2.15 × 10⁶ t, which is 2.33 times of the current level, indicating that Lushan forest will continue to serve as a carbon sink for the next fifty years; (3) Excluding the effect of tree growth, regional forest carbon sequestration potential was significantly influenced on site characteristics, which achieved the highest Variable Importance in Projection (VIP) value (2.19) for slope direction. Our study provided a better understanding of the relationships between forest growth and carbon sequestration potential at fine spatial-scales. The results regarding the condition factors and how their combination characteristics affect the potential for carbon sequestration could provide crucial insights for Chinese carbon policy and global carbon neutrality goals.

Land use/land cover (LULC) change driven by land use policy always leads to dramatic change in carbon storage and sequestration, especially in a rapidly urbanizing region. However, few studies explored the influences of land use polices on carbon storage and sequestration in a rapidly urbanizing region. Through Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, the spatial-temporal pattern of carbon storage altered by LULC transformation and its linkage with land use policies were analyzed in five periods (1990–1995, 1995–2000, 2000–2005, 2000–2010, 2010–2015) in the Yangtze River Delta (YRD) Region. The results indicated that: (1) the carbon storage in the YRD was substantially altered by continuous LULC transformation, totally decreased by 1.49 × 10⁷ Mg during 1990–2015. (2) The total amount of carbon storage increased from 2.91 × 10⁹ Mg in 1990 to 2.95 × 10⁹ Mg in 1995, and then decreased to 2.90 × 10⁹ Mg in 1995–2015. Thus, the total economic value of carbon storage increased approximately from 467.42 million dollars in 1990 to 472.99 million dollars in 1995, and then decreased to 465.01 million dollars in 2015. (3) The carbon storage and sequestration were influenced by LULC transformation driven by land use policies in five periods: large areas of grassland converted to woodland in 1990–1995 led by Forest Law, then clustered areas of cropland converted to built-up land in 1995–2015 around large cities of YRD Region led by Land Management Law and Development Plans, and finally, the conversion of cropland to built-up land was decreased and scattered in the entire region influenced by land use polices led by early stage of ecocivilization construction. The study can facilitate to develop regional land use policy for carbon storage conservation and carbon neutrality in a rapidly urbanizing region.

Many forests have suffered serious economic losses and ecological consequences of pine wilt disease (PWD) outbreaks. Climate change and human activities could accelerate the distribution of PWD, causing the exponential expansion of damaged forest areas in China. However, few studies have analyzed the spatiotemporal dynamics and the factors driving the distribution of PWD-damaged forests using continuous records of long-term damage, focusing on short-term environmental factors that influence multiple PWD outbreaks. We used a maximum entropy (MaxEnt) model that incorporated annual meteorological and human activity factors, as well as temporal dependence (the PWD distribution in the previous year), to determine the contributions of environmental factors to the annual distribution of PWD-damaged forests in the period 1982–2020. Overall, the MaxEnt showed good performance in modeling the PWD-damaged forest distributions between 1982 and 2020. Our results indicate that (i) the temporal lag dependence term for the presence/absence of PWD was the best predictor of the distribution of PWD-damaged forests; and (ii) Bio14 (precipitation in the driest month) was the most important meteorological factor for affecting the PWD-damaged forests. These results are essential to understanding the factors governing the distribution of PWD-damaged forests, which is important for forest management and pest control worldwide.

Transboundary environmental problems caused by urban expansion and economic growth cannot be solved by individual cities. Successful intercity environmental cooperation relies on the clear identification and definition of the rights and obligations of each city. An Ecosystem services (ES) approach not only budgets the ES supply and demand of a city, but also defines the spatial relationships between Services Provisioning Areas (SPA) and Services Benefiting Areas (SBA). However, to date, quantitative studies integrating ES budgets and spatial relations have been scarce. This study integrates ecosystem services supply–demand budgeting with flow direction analysis to identify intercity environmental cooperation in the highly urbanized Yangtze River Delta (YRD) region of China for water-related ecosystem services (flood protection, erosion regulation and water purification). The results demonstrated that there were significant spatial mismatches in the supply and demand of three water-related ES among 16 core cities in the YRD region: five to six cities in the southern part of the region had significant service surpluses, while ten to 11 cities in the north–central part had significant service deficits. We then went on to offer definitions for Ecosystem Services Surplus City, Ecosystem Services Deficit City and Ecosystem Services Balance City, as well as Service Provisioning City, Service Benefiting City and Service Connecting City in which to categorize cities in the YRD Region. Furthermore, we identified two intercity cooperation types and two non-cooperation types. This framework can be used to promote ecological integration in highly urbanized regions to advance sustainable development.