粤港澳大湾区生态系统格局变化与模拟

快速城市化是导致粤港澳大湾区生态系统时空格局变化的主要驱动力之一,模拟生态系统变化趋势对于优化区域土地利用格局、防控城市化的生态风险具有重要意义。以2000、2005、2010、2015、2018年5期土地利用数据,分析该区域生态系统格局演变,并运用CA-Markov模型模拟2025年的生态系统格局。研究结果表明:(1)2018年大湾区的森林、农田和城镇为主要生态系统类型,分别占区域总面积的53.99%、22.67%和14.51%。(2)2000—2018年农田、森林、湿地面积分别下降了1983、740、278 km~2,城镇和草地面积分别上升了2896、103 km~2,城镇面积增长的主要途径是对周围农田、林地和湿地的侵占,草地面积增长是因为管理经营不善导致部分林地退化为草地。(3)大湾区的景观多样性和均匀度下降,景观正在向小斑块趋势发展,空间连通性下降,破碎度增加。(4)模拟2025年的生态系统格局发现,与2018年相比,城镇面积增长了609 km~2,农田和森林分别减少了309 km~2和316 km~2。基于大湾区生态系统格局变化与模拟发现,快速城市化区域中,落实耕地保护红线和生态保护红线制度、保护重要生态空间完整性,对于降低城市化的生态风险具有重要作用。     

闽三角城市群生态安全格局构建及城镇扩展模拟

在快速城镇化背景下,构建生态安全格局并探讨城镇用地扩展格局已成为保障区域生态安全和缓解生态保护与土地开发矛盾的重要手段。以闽三角城市群为例,基于景观安全格局原理和ArcGIS空间分析法,从综合水安全、生物保护安全、地质灾害安全以及游憩安全四个方面叠加构建"底线安全格局-缓冲安全格局-最优安全格局"三种不同安全水平的综合生态安全格局;然后结合SLEUTH模型,将不同生态安全格局情景作为约束条件融入其排除图层,对研究区2015-2030年的城镇用地空间扩展进行多情景模拟。研究表明：①底线安全格局、缓冲安全格局以及最优安全格局的面积为9305.51、7576.28、3482.73 km²,分别占闽三角城市群总面积的36.89%、30.03%、13.81%;②三种生态安全格局情景模拟下城镇用地均呈增长趋势,但增长速度均小于历史用地的增长速度,高安全格局约束下的新增城镇用地面积和增长速度均最小,表明将生态安全格局作为城镇发展的约束条件,在城镇土地开发中能够增强对生态空间的保护力度,维护区域生态安全,控制城镇蔓延。相关研究成果可为城镇开发边界管控与国土空间规划的编制提供技术支撑与决策辅助。     

Simulation of urban expansion and encroachment using cellular automata and multi-agent system model—A case study of Tianjin metropolitan region,China

The combination model of cellular automata and multi-agent system were used in this paper for simulating spatio-temporal dynamics of urban expansion and its encroachment on other lands at the regional scale. The human system(contain authorities and residents) and their behavior, the landscape system and its behavior as well as the inter actions between them were all simulated in this paper. The behavior of human system is established based on multi-agent system, the authority agent and the resident agent were both regarded as abstract entities. The cellular automata is embedded into the model for simulating the spontaneous urban growth. The impact of neighbor cells were considered so that the expansion of urban lands can be limited near the existed urban lands. Moreover, the rural residential lands have higher probability to convert to urban lands if they were close to the cities or towns. Simulation of urban expansion is undertaken on the time series from 2000 to 2020 for Tianjin metropolitan region, the largest open coastal city in northern China. The results show that Tianjin’s urban lands focus on the epitaxial expansion around the central city accompanied with the growing exurb expansion distributing in multiple districts and counties. The croplands are taken the most area of the land-use types, 1764.03 km² are converted to urban lands, and more than one fourth of the rural residential lands are changed to urban lands in 2000–2020. The urban development and the cropland protection should be both taken into account to minimize the threats on food security and ecological environment.     

Organic Carbon Storage in China's Urban Areas

China has been experiencing rapid urbanization in parallel with its economic boom over the past three decades. To date, the organic carbon storage in China''s urban areas has not been quantified. Here, using data compiled from literature review and statistical yearbooks, we estimated that total carbon storage in China''s urban areas was 577±60 Tg C (1 Tg  = 10¹² g) in 2006. Soil was the largest contributor to total carbon storage (56%), followed by buildings (36%), and vegetation (7%), while carbon storage in humans was relatively small (1%). The carbon density in China''s urban areas was 17.1±1.8 kg C m⁻², about two times the national average of all lands. The most sensitive variable in estimating urban carbon storage was urban area. Examining urban carbon storages over a wide range of spatial extents in China and in the United States, we found a strong linear relationship between total urban carbon storage and total urban area, with a specific urban carbon storage of 16 Tg C for every 1,000 km² urban area. This value might be useful for estimating urban carbon storage at regional to global scales. Our results also showed that the fraction of carbon storage in urban green spaces was still much lower in China relative to western countries, suggesting a great potential to mitigate climate change through urban greening and green spaces management in China.     

内蒙古大兴安岭林草交错带景观动态分析

为加强对林草交错带生态系统的科学管理,进一步促林草资源保护与合理利用,迫切需要摸清交错带景观本底并分析其时空动态演化趋势。以大兴安岭林草交错带为研究对象,选取2000、2010年Landsat 5 TM影像和2018年Landsat 8 OLI影像,利用面向对象的决策树分类算法建立3期土地利用数据集,据此分析土地利用动态变化与景观格局演变特征,然后利用状态转换模拟模型STSM模拟研究区2025年的土地利用数据。结果表明：（1）2010年林地、草地、耕地、湿地、人工表面、盐碱地及荒漠和过火区面积占比分别为46.93%、31.66%、5.02%、13.73%、1.08%、1.55%和0.04%;2018年分别为46.89%、31.69%、4.99%、13.72%、1.15%、1.54%和0.02%。（2）景观尺度上,2010-2018年间林地面积减少43.55 km²,破碎化程度加剧、景观完整性降低、景观构成愈发复杂;草地面积增加38.11 km²,其景观完整性升高。（3）在现行趋势下,预测2025年研究区林地、草地、人工表面和过火区面积分别增加92.27、183.21、66.2 km²和10.25 km²;耕地、湿地和盐碱地及荒漠面积分别减少184.2、2.89 km²和164.84 km²。林火频发是导致研究区林地面积减少的主因,模拟的过火区面积增加提醒森林管理部门要严控林区用火风险并增强火灾扑救能力建设。后期"天然林保护"工程和"退牧还草"政策的实施是生态环境改善的主因。在制定区域发展战略时,需要充分平衡农业生产与城市扩张之间的竞争性,满足区域耕地红线的基本要求。     

山东半岛城市扩展模式与生态足迹的关系

理解城市扩展模式与生态足迹动态之间的关系是区域可持续性研究的重要内容,对实现城市可持续发展具有重要指导意义。然而,目前对这二者关系探索的实证研究较少。以山东半岛城市群为例,掌握其2000—2010年的城市扩展模式与生态足迹动态特征,并探索二者之间的关系。采用景观扩展指数和生态足迹模型对研究区的城市扩展模式和生态足迹动态进行计算。在此基础上,将该区44个县划分为4种类型,用相关分析法对城市扩展模式和生态足迹动态的关系进行探索。结果表明,2000—2010年山东半岛城市群的城市用地面积增量加了1.2×10~5hm~2,增幅为19.4%。44个县均体现出边缘型扩展面积最大,生态赤字增加的特点,平均赤字增量为1.26 hm~2/人。垦利等27个县的外延式扩展面积与生态赤字增加量存在较显著的正相关关系,在济阳等17个县中,二者未呈现出相关关系。建议垦利、淄博和青岛等地区在未来城市发展中,控制飞地型和边缘型扩展面积总量,发展清洁能源,遏制化石能源足迹的增长趋势。     

最大可允许填海面积模拟——厦门西海域案例研究

填海造地在解决海岸带地区发展空间短缺问题的同时,严重损害了人类赖以生存和发展的海洋与海岸带生态系统。如何控制大规模填海造地是我国面临的重大课题。构建了估算海湾最大可允许填海造地面积的分析框架和模型。填海造地的各种收益和成本,包括环境和生态成本被系统性地量化并嵌入到框架和模型之中。模型的估算结果可以为实施控制填海造地的约束机制提供科技支撑。利用建立的框架和模型对厦门西海域模拟的结果显示:当贴现率为4.5%时,厦门西海域最大可允许填海面积是89.44 hm2,其面积至少应该保持在44.52 km2;即便是使用8%的高贴现率,最大可允许填海面积也只占规划填海面积的35.83%;如果采用更加重视环境与生态效益的低贴现率2%,则厦门西海域最大可允许填海面积是0。     

平顶山新区生态用地的识别与安全格局构建

生态用地对城市生态安全具有重要意义,关键性生态用地的识别与安全格局的构建是实现城市精明增长和生态保护的重要途径。以河南省平顶山新区为例,结合GIS(Geographic Information System)空间技术,分析得到基于水资源安全、地质灾害规避、生物多样性保护三种单一过程的生态用地,进而综合叠加并重分类为理想型、缓冲型和底线型三类生态用地,并以底线型生态用地为源,现状土地覆被为阻力因子,应用最小累积阻力模型构建了平顶山新区生态用地的安全格局。结果表明:新区内最小生态用地,即底线型生态用地的面积为88.44 km2,占研究区总面积的29.35%;缓冲型和理想型生态用地的面积分别为22.28 km2和43.87 km2。确定了三种安全水平的生态用地范围、"源"与外部联系的辐射道、"源"间连接的生态廊道、关键的生态节点等。关键性生态用地综合安全格局的构建,旨在为研究区城市生态规划和城镇空间布局规划等提供科学参考。     

Seasonal patterns in space use of Black Sparrowhawks Accipiter melanoleucus in an urban environment

Capsule: Urban Black Sparrowhawk males hunt mostly within 2.27?km of their nest during the breeding season (‘home range’ of 16.15?km²) and increased the distance slightly to 2.43?km outside of the breeding season (18.56?km²). We found high individual variation within and between six global positioning systems tagged breeding males, but no significant seasonal differences in the urban environment of Cape Town, South Africa.     

Open Space Loss and Land Inequality in United States' Cities, 1990–2000

Urban growth reduces open space in and around cities, impacting biodiversity and ecosystem services. Using land-cover and population data, we examined land consumption and open space loss between 1990 and 2000 for all 274 metropolitan areas in the contiguous United States. Nationally, 1.4 million ha of open space was lost, and the amount lost in a given city was correlated with population growth (r(272) = 0.85, P<0.001). In 2000, cities varied in per capita land consumption by an order of magnitude, from 459 m²/person in New York to 5393 m²/person in Grand Forks, ND. The per capita land consumption (m²/person) of most cities decreased on average over the decade from 1,564 to 1,454 m ²/person, but there was substantial regional variation and some cities even increased. Cities with greater conservation funding or more reform-minded zoning tended to decrease in per capita land consumption more than other cities. The majority of developed area in cities is in low-density neighborhoods housing a small proportion of urban residents, with Gini coefficients that quantify this developed land inequality averaging 0.63. Our results suggest conservation funding and reform-minded zoning decrease per capita open space loss.     

A bottom-up modeling of metabolism of the residential building system in China toward 2050

This study predicted the metabolic process of the residential building system in China toward 2050 by addressing the detailed provincial patterns and urban–rural disparity and the characterizing metabolisms of building materials in detail. The results show that after a rapid growth during 1980–1990, the in-use stocks of residential buildings in China are expected to slow down in around 2030, reaching 75 billion m² in 2050. Urban regions will account for 80% of total stocks, and provinces in the eastern and southern coastal areas will have the largest share. As demolition lags construction, the end-of-life residential buildings will continue to grow steadily with huge urban–rural and provincial differences, reaching 1.4 billion m² by 2050. Regarding the metabolism of building materials, the inflow of most materials will decrease after 2030, while the outflow will increase steadily toward inflow. Based on the recycling outlook of construction and demolition waste and the corresponding environmental benefit, it is indicated that under the Chinese government's ambitious planning and vigorous promotion, prior to the middle of the century, the building system has the potential to transition to a sustainable future that meets residents’ housing needs with a remarkable decreasing input of raw materials thereby notably decreasing pressures on the environment, which will significantly benefit the goal of carbon neutrality in China.     

Urban expansion dynamics and natural habitat loss in China: a multiscale landscape perspective

China's extensive urbanization has resulted in a massive loss of natural habitat, which is threatening the nation's biodiversity and socioeconomic sustainability. A timely and accurate understanding of natural habitat loss caused by urban expansion will allow more informed and effective measures to be taken for the conservation of biodiversity. However, the impact of urban expansion on natural habitats is not well‐understood, primarily due to the lack of accurate spatial information regarding urban expansion across China. In this study, we proposed an approach that can be used to accurately summarize the dynamics of urban expansion in China over two recent decades (1992–2012), by integrating data on nighttime light levels, a vegetation index, and land surface temperature. The natural habitat loss during the time period was evaluated at the national, ecoregional, and local scales. The results revealed that China had experienced extremely rapid urban growth from 1992 to 2012 with an average annual growth rate of 8.74%, in contrast with the global average of 3.20%. The massive urban expansion has resulted in significant natural habitat loss in some areas in China. Special attention needs to be paid to the Pearl River Delta, where 25.79% or 1518 km² of the natural habitat and 41.99% or 760 km² of the local wetlands were lost during 1992–2012. This raises serious concerns about species viability and biodiversity. Effective policies and regulations must be implemented and enforced to sustain regional and national development in the context of rapid urbanization.     

Urban expansion and its consumption of high-quality farmland in Beijing,China

China faces the challenge of using limited farmland to feed more than 1.3 billion people. Accelerated urbanization has exacerbated this challenge by consuming a large quantity of high-quality farmland (HQF). It is therefore essential to assess the degree to which urban expansion has preferentially consumed HQF, and discern the mechanism behind this. We found urban areas in Beijing to expand at speeds of 48.97 km²/year, 21.89 km²/year, 62.30 km²/year and 20.32 km²/year during the periods 1986–1995, 1995–2000, 2000–2005 and 2005–2020, respectively. We developed an indicator of HQF consumption due to urban expansion, representing the ratio of HQF consumed to its proportion of overall farmland, and found its values were 2.21, 1.57, 1.99 and 1.10 for 1986–1995, 1995–2000, 2000–2005 and 2005–2020, respectively. Thus, although HQF has been overrepresented in the farmland consumed by Beijing's urbanization, this phenomenon has decreased over time. Centralized expansion has contributed greatly to consumption of HQF. Topography and distances to urban and water bodies determine the relative consumption of HQF in urbanization.     

时空变化视角下北京市湿地优先保护格局

气候变化通过改变湿地水文过程等影响湿地的空间分布,城市化进程加剧了湿地破碎化程度并导致湿地生境退化,构建连续的湿地生态保护网络体系有利于应对气候变化和城市发展带来的负面影响、提高生物多样性保护水平。北京市现有湿地空间分布呈现斑块面积小、破碎化程度高等特点,为优化湿地保护区格局并应对气候变化和城市发展对北京市湿地生物多样性的影响,基于系统保护规划方法,以Marxan作为空间优化模型,结合PLUS模型和MaxEnt模型,模拟预测北京市湿地优先保护格局、识别湿地保护空缺并构建湿地分级保护区格局。研究表明:2020年北京市湿地存在80.15km²的保护空缺、2035年和2050年优化后湿地保护区占比分别为87.54%和85.95%,在满足本研究预设的生物多样性保护目标的前提下符合北京市湿地保护规划对湿地保护率的要求。为最优化资源分配,综合时空变化对湿地保护区空间分布的影响,构建了湿地分级保护区格局,将湿地保护区分为湿地永久保护区、湿地一级临时保护区和湿地二级临时保护区三个等级,以期为北京市分期建设湿地保护区、优化湿地生态保护网络体系和保护湿地生物多样性提供依据。     

Tree Productivity Enhanced with Conversion from Forest to Urban Land Covers

Urban areas are expanding, changing the structure and productivity of landscapes. While some urban areas have been shown to hold substantial biomass, the productivity of these systems is largely unknown. We assessed how conversion from forest to urban land uses affected both biomass structure and productivity across eastern Massachusetts. We found that urban land uses held less than half the biomass of adjacent forest expanses with a plot level mean biomass density of 33.5 ± 8.0 Mg C ha^-1. As the intensity of urban development increased, the canopy cover, stem density, and biomass decreased. Analysis of Quercus rubra tree cores showed that tree-level basal area increment nearly doubled following development, increasing from 17.1 ± 3.0 to 35.8 ± 4.7 cm² yr^-1. Scaling the observed stem densities and growth rates within developed areas suggests an aboveground biomass growth rate of 1.8 ± 0.4 Mg C ha^-1 yr^-1, a growth rate comparable to nearby, intact forests. The contrasting high growth rates and lower biomass pools within urban areas suggest a highly dynamic ecosystem with rapid turnover. As global urban extent continues to grow, cities consider climate mitigation options, and as the verification of net greenhouse gas emissions emerges as critical for policy, quantifying the role of urban vegetation in regional-to-global carbon budgets will become ever more important.     

Variation in demographic patterns and population structure of raccoons across an urban landscape

Raccoons (Procyon lotor) are considered synanthropic, with high densities reported from urban landscapes. However, little information is available on population density and demography within the urban matrix. To better understand how urban land-use patterns influence raccoon density and demographic patterns, we sampled raccoons at multiple, replicated sites across an urban landscape. Density differed by land-use type (F_2,17 = 4.66, P = 0.027): urbanized sites, = 4.96 ± 2.64 raccoons/km², range = 1.25–10.00 raccoons/km²; urban open sites, = 14.84 ± 6.35 raccoons/km², range = 3.00–29.25 raccoons/km²; rural open sites, = 15.50 ± 4.66 raccoons/km², range = 13.00–20.25. Although we found no clear patterns in sex ratio, reproductive condition, or body condition, we observed differences in age structure among urban open, rural open, and urbanized sites. The most striking difference was the absence of older animals at urbanized sites and relatively low numbers of young individuals at urban open sites. Raccoons were the dominant mesocarnivore in open fragments, but less so in the urban matrix. Spatial variation in density across urban landscapes is likely influenced by site level differences in abundance of anthropogenic resources and differences in habitat quality. Furthermore, the association between changes in land-use and population age structure may have reflected different mortality sources across the landscape. Our results illustrate that wildlife species considered synanthropic may have complex relationships with urban landscapes. © 2012 The Wildlife Society.     

Carbon Flux of an Urban System in México

We estimated vertical and lateral fluxes of carbon for the isolated coastal city of Ensenada (Baja California, México). In 2005, the city had a resident population of about 261,000, with tourism adding about 1.5%; it occupied an area of roughly 68 square kilometers (km²). Carbon (C) export was estimated at 400 gigagrams of carbon per year (Gg C/yr); notable sources to the atmosphere were combustion engines (42%), cement production (38%), water heating and cooking (7%), and human respiration (6%). Solid waste (6%) was exported for burial, but efflux to the bay was minor (about 0.1 Gg C/yr). Local deposition was limited to sewage sludge (about 2 Gg C/yr), asphalt, and extremely low primary production. Remote fluxes driven by local demand could be estimated only for electricity (61 Gg C/yr), but local flux from cement and other industrial production might be attributed largely to external demand. The urban system output to the atmosphere was about 6.4 kilograms of carbon per square meter per year (kg C/m²/yr), or roughly 23.6 kg/m²/yr in CO₂ equivalence. By comparison, net ecosystem productivity in the surrounding watershed has been estimated at 0.04 kg C/m²/yr, so the city's atmospheric output of C might be balanced by productivity over about 11,000 km² of the surrounding ecosystems. Between 2000 and 2005, C output increased faster than population growth, particularly from engine fuels.     

Living in the suburbs: Space use by vervet monkeys (Chlorocebus pygerythrus) in an eco‐estate,South Africa

We examined vervet monkey (Chlorocebus pygerythrus) space use using GPS/UHF telemetry data from 10 vervet monkeys across six troops over 9 months within a 420 ha suburban eco‐estate. We documented a mean home range of 0.99 km² (95% MCP) and 1.07 km² (95% KDE) for females (n = 6), 1 km² (95% MCP) and 1.50 km² (95% KDE) for males (n = 4) and 0.87 km² (95% MCP) and 1.12 km² (95% KDE) for troops (n = 6), respectively, indicating that males and larger troops had larger home ranges. These relatively small home ranges included shared territorial boundaries and high home range overlap. Vervet monkey movements indicated higher morning activity levels, and habitat selection indicated significantly more use of golf course, urban residential and forest, thicket and woodland areas, and avoidance of wetland, grassland and shrub, and urban built‐up areas. Our results suggest that modified habitat use by vervet monkeys is a consequence of behavioural facilitation to access highly available food resources, thereby facilitating their persistence in green spaces in urban areas of South Africa. Conflict management is dependent on the conservation of sufficient natural habitats and food resources, to minimise their dependence on anthropogenic supplementary food resources and consequently reduce human–monkey conflict.     

辽宁中部城市群城市增长时空格局及其驱动力

基于1988、1992、1997、2000和2004年5期Landsat TM卫星遥感影像数据,采用GIS空间分析和景观格局分析的方法,分析了辽宁中部城市群城市增长的时空格局特征,并对其驱动力进行了探讨.结果表明: 1988-2004年间,辽宁中部城市群城市面积持续增加,增长强度逐渐增强, 城市面积由812.55 km²增至1345.86km², 平均增长速率为32-96 km²·a^-1;1997年以后,城市增长强度迅速增大,以1997-2000年的城市扩展强度最大;辽宁中部城市群的城市增长主要集中在中部城镇密集带.1988-1997年,研究区城市面积的增长速度较慢,空间结构紧凑,以边缘增长和填充增长为主;1997-2004年,城市面积增长较快,表现为扩散的城市增长格局和复杂的城市斑块形状,以开发区的飞地式增长和扩散增长为主.非农业人口增长、经济增长、城市群城市空间的相互吸引、工业发展与开发区建设政策等因素是辽宁中部城市群城市空间快速增长的主要驱动力.     

滨海半城市化地区景观格局演变——以厦门市集美区为例

基于厦门市集美区1987-2007年5期TM/ETM⁺遥感影像数据,选取斑块类型水平和景观水平上的景观指数,定量研究了半城市化地区的景观发育过程及其时空动态特征.结果表明：研究区景观格局演变具有快速性、不稳定性、异质性和过渡性特征;1987-2007年间,研究区城市建设用地面积的增长最快,由2.7 km²增至29.1 km²,年均增长率13%,但仍然不是优势景观,其扩展主要通过侵占农用地和吸纳农村建设用地实现,并呈现出“飞地式”特征和复杂的空间形态;农村建设用地面积增加了2.3倍,年均增长率6.2%,其空间扩展呈现出无序和分散的特征;城市和农村的扩展导致农用地面积减少了42%,并呈破碎化趋势;受城市化影响,半城市化地区的整体景观在快速复杂的转变中趋于破碎化,景观异质性增强.