China's megacities are undergoing a critical transition from incremental expansion to stock optimization in order to achieve high-quality spatial development.However,the complex interactions among land use,populat...China's megacities are undergoing a critical transition from incremental expansion to stock optimization in order to achieve high-quality spatial development.However,the complex interactions among land use,population,and economy involved in this transition remain underexamined,particularly with respect to human-land relationships in suburban areas.From an incremental-stock-decremental perspective,this paper develops a construction land-population vitality discriminant matrix.Using land use data(CNLUCC),population data(World Pop),and nighttime light data(DMSP-OLS),the paper examines the spatiotemporal characteristics of human-land spatial development patterns in Beijing's suburban areas from 2000 to 2020 and analyzes the underlying formation mechanisms across different periods.The findings show that:(1)From 2000 to 2020,land use in Beijing's suburban areas shifted from incremental expansion to quantitative reduction and qualitative improvement,while population vitality continued to increase and was not constrained by a reduction in land supply.(2)The suburban plain area,strongly influenced by the central city,evolved from free-form expansion to preferential point-like incremental development.In contrast,the ecological conservation zone exhibited the coexistence of incremental and decremental spaces,with population vitality growing increasingly stronger.The suburban areas gradually formed an urban-rural integration pattern in which urban areas led rural development,and the plain area facilitated the development of the ecological conservation zone.(3)Incremental development was primarily shaped by urban master plans and major project initiatives.Incremental-contraction patterns reflect human-land mismatches resulting from uncontrolled sprawl,disorderly construction,and population outflow.Decremental development was mainly driven by land reduction policies,including the demolition of illegal structures,the phasing-out of inefficient industrial land,and pilot programs for intensive land use.Decremental-growth patterns,supported by intensive land use and collective land marketization policies,contributed to a more balanced human-land relationship and fostered high-quality economic and population growth.This paper highlights the critical role of policy-driven strategies in guiding sustainable urban development and enhances our understanding of how to achieve efficient and balanced human-land development in suburban areas.It offers insights applicable to other megacities undergoing similar transitions.展开更多
Broadleaf-Korean pine forests exhibit high species richness and distinctive species composition, which are currently becoming more dominant among natural forests in Changbai Mountains of northeastern China. Understand...Broadleaf-Korean pine forests exhibit high species richness and distinctive species composition, which are currently becoming more dominant among natural forests in Changbai Mountains of northeastern China. Understanding the ecological process of restored vegetation is quite important for ecosystem reconstruction. Distinguishing stand development stages and analyzing the dynamic spatial patterns could provide insights into significant community coexistence mechanisms. In the present study, eight permanent study areas were established according to the substituting space for time method in Changbai Mountains of north-eastern China. The optimal division method was used to quantify the successional series into different stand development stages, and the point pattern analysis method(L(r) function) was used to analyse the dynamic changes in spatial patterns and interspecific associations. Our results suggested that:(1) The stand development process was divided into five stages: the first three stages were poplar-birch secondary forests in different stages of recovery, the fourth stage was thespruce-fir mixed forest, and the last stage was the primary broadleaf-Korean pine forest;(2) The spatial pattern showed an aggregated distribution at a small scale and changed to a random distribution as the scale increased in poplar-birch secondary forests, but the spatial pattern appeared to be randomly distributed in spruce-fir mixed forest and broadleafKorean pine forest;(3) The interspecific associations between pioneer species and climax species changed from negative to positive among the different stand stages, and environmental resources were shared among these species. Interspecific differences in shade tolerance among the tree species were key determinants of forest dynamics and structure. Our study is vital to the understanding of the forest development;thus, the spatial change features should receive greater attention when forest management is being planned and restoration strategies are being developed for the Changbai Mountains.展开更多
基金supported by the National Natural Science Foundation of China(No.52478036,No.42301217)the Humanities and Social Science Fund of Ministry of Education of China(No.23YJAZH215)the Beijing Natural Science Foundation(No.8232002)。
文摘China's megacities are undergoing a critical transition from incremental expansion to stock optimization in order to achieve high-quality spatial development.However,the complex interactions among land use,population,and economy involved in this transition remain underexamined,particularly with respect to human-land relationships in suburban areas.From an incremental-stock-decremental perspective,this paper develops a construction land-population vitality discriminant matrix.Using land use data(CNLUCC),population data(World Pop),and nighttime light data(DMSP-OLS),the paper examines the spatiotemporal characteristics of human-land spatial development patterns in Beijing's suburban areas from 2000 to 2020 and analyzes the underlying formation mechanisms across different periods.The findings show that:(1)From 2000 to 2020,land use in Beijing's suburban areas shifted from incremental expansion to quantitative reduction and qualitative improvement,while population vitality continued to increase and was not constrained by a reduction in land supply.(2)The suburban plain area,strongly influenced by the central city,evolved from free-form expansion to preferential point-like incremental development.In contrast,the ecological conservation zone exhibited the coexistence of incremental and decremental spaces,with population vitality growing increasingly stronger.The suburban areas gradually formed an urban-rural integration pattern in which urban areas led rural development,and the plain area facilitated the development of the ecological conservation zone.(3)Incremental development was primarily shaped by urban master plans and major project initiatives.Incremental-contraction patterns reflect human-land mismatches resulting from uncontrolled sprawl,disorderly construction,and population outflow.Decremental development was mainly driven by land reduction policies,including the demolition of illegal structures,the phasing-out of inefficient industrial land,and pilot programs for intensive land use.Decremental-growth patterns,supported by intensive land use and collective land marketization policies,contributed to a more balanced human-land relationship and fostered high-quality economic and population growth.This paper highlights the critical role of policy-driven strategies in guiding sustainable urban development and enhances our understanding of how to achieve efficient and balanced human-land development in suburban areas.It offers insights applicable to other megacities undergoing similar transitions.
基金supported by the National Natural Science Foundation of China (Grant No. 31400540, 31300538)
文摘Broadleaf-Korean pine forests exhibit high species richness and distinctive species composition, which are currently becoming more dominant among natural forests in Changbai Mountains of northeastern China. Understanding the ecological process of restored vegetation is quite important for ecosystem reconstruction. Distinguishing stand development stages and analyzing the dynamic spatial patterns could provide insights into significant community coexistence mechanisms. In the present study, eight permanent study areas were established according to the substituting space for time method in Changbai Mountains of north-eastern China. The optimal division method was used to quantify the successional series into different stand development stages, and the point pattern analysis method(L(r) function) was used to analyse the dynamic changes in spatial patterns and interspecific associations. Our results suggested that:(1) The stand development process was divided into five stages: the first three stages were poplar-birch secondary forests in different stages of recovery, the fourth stage was thespruce-fir mixed forest, and the last stage was the primary broadleaf-Korean pine forest;(2) The spatial pattern showed an aggregated distribution at a small scale and changed to a random distribution as the scale increased in poplar-birch secondary forests, but the spatial pattern appeared to be randomly distributed in spruce-fir mixed forest and broadleafKorean pine forest;(3) The interspecific associations between pioneer species and climax species changed from negative to positive among the different stand stages, and environmental resources were shared among these species. Interspecific differences in shade tolerance among the tree species were key determinants of forest dynamics and structure. Our study is vital to the understanding of the forest development;thus, the spatial change features should receive greater attention when forest management is being planned and restoration strategies are being developed for the Changbai Mountains.
