随着城镇化进程的加快,南京市面临着人口快速增长与土地资源有限之间的矛盾。文章通过构建人口和土地城镇化的测度指标,运用耦合协调度模型分析二者的协调程度及其时空演变特征。结果显示,2007-2021年,南京城镇化率从76.8%增至86.9%,显示出农村人口向城镇转移的趋势。建成区面积从577.44 km 2增至868.28 km^(2),增幅50.37%。人口与土地城镇化的耦合协调度在新型城镇化政策实施后显著改善。文章提出统筹区域协调发展、优化城乡功能格局、强化规划引领作用、实现包容多元的城镇化等优化路径,以实现南京市人口与土地城镇化的协调发展,提升城市的可持续性和居民的生活质量。
In sharp contrast to Western urbanization models, the distinctive feature of China's rapid urbanization lies in the production of space. This is not only a crucial entry point for comprehending China's urbanization path but also provides a new orientation for global urban studies.
Beak deformation,known as avian keratin disorder(AKD),can impair feeding and preening of birds,reducing their survival.This disorder is apparently caused by Poecivirus infection,although to date,the viral origin has been corroborated in only a few North American bird species.Considering that fruit-eating birds can track spatiotempo-ral variations in fruit abundance and that AKD may have a viral origin,the incidence of this disease can be expected to increase withflocking by birds.Therefore,we evaluated if austral thrushes(Turdus falcklandii)were attracted to urban areas when exotic plants offered fruits and ifflocking of thrushes in urban areas increased the spread of AKD in this species in a Patagonian town.Wefitted GPS loggers on some individuals with normal beaks in rural areas and found that they visit the town in fall.Through point count censuses,we recorded greater abundances of thrushes with normal and deformed beaks during fall–winter in urban sites than in rural sites.However,the abun-dance of birds with AKD declined more(78–87%)than that of individuals with normal beaks(44–52%)during the transition from fall–winter to spring–summer.In urban zones in our study area,fruits of exotic species ripen during fall,attracting austral thrushes from rural sites.Nevertheless,such an attraction for food resources may be an ecological trap for this species,as the increase in incidence of AKD in urban areas may drastically reduce the survival of birds during the most unfavorable period of the year.
Cristian Andres GOROSITOAlex Edward JAHNVictor Rodolfo CUETO
Rapid urbanization has caused significant changes along the urban-rural gradient,leading to a variety of landscapes that are mainly shaped by human activities.This dynamic interplay also influences the distribution and characteristics of trees outside forests(TOF).Understanding the pattern of these trees will support informed decision-making in urban planning,in conservation strategies,and altogether in sustainable land management practices in the urban context.In this study,we employed a deep learning-based object detection model and high resolution satellite imagery to identify 1.3 million trees with bounding boxes within a 250 km^(2)research transect spanning the urban-rural gradient of Bengaluru,a megacity in Southern India.Additionally,we developed an allometric equation to estimate diameter at breast height(DBH)from the tree crown diameter(CD)derived from the detected bounding boxes.Our study focused on analyzing variations in tree density and tree size along this gradient.The findings revealed distinct patterns:the urban domain displayed larger tree crown diameters(mean:8.87 m)and DBH(mean:43.78 cm)but having relatively low tree density(32 trees per hectare).Furthermore,with increasing distance from the city center,tree density increased,while the mean tree crown diameter and mean tree basal area decreased,showing clear differences of tree density and size between the urban and rural domains in Bengaluru.This study offers an efficient methodology that helps generating instructive insights into the dynamics of TOF along the urban-rural gradient.This may inform urban planning and management strategies for enhancing green infrastructure and biodiversity conservation in rapidly urbanizing cities like Bengaluru.
Tao JiangMaximilian FreudenbergChristoph KleinnV.P.TewariB.N.DiwakaraNils Nolke
