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1.
城市街道是城市空间的基本单元,承载着多元的城市生活。本研究基于手机APP共享的健身数据,以街道线性体育活动为研究对象,从健康视角认知街道空间属性和特征。运用VGI-GIS的方法,在信息矢量化和可视化的基础上,从时间和空间2个维度,对城市街道的健康服务功能进行描述。基于运动热点空间的分布格局,研究在空间集聚、建成环境和人群收入3个层面上进行分析。结果表明,街道的空间连续性对健身活动有促进作用,大型公园和高校对健身活动有巨大的吸引力,公交站点对健身活动有多方面的影响,不同收入阶层健身活动差异明显。多元化的热点空间模式为提升街道的健康性提供了因地制宜的可能性。以健康为导向的城市设计探索采用临时封闭街道,在商业和办公区域周边增设户外体育设施等措施,提升街道的健康服务功能。  相似文献   

2.
基于电子导航地图POI的北京城区绿色空间服务半径分析   总被引:1,自引:0,他引:1  
近年来,电子导航地图中的兴趣点(Point of Interest,POI)在城市地理与城市生态研究方面越来越受到重视。城市绿色空间对其居民的生产生活服务作用十分重要,城市绿地系统的配置是否科学对城市生态系统服务供需情况有着重要影响。利用北京城区五环以内的POI数据,采用核函数模拟出城市居民生产生活在空间分布上强弱程度的热力图,对该区域绿色空间实体不同半径服务区内的热力特征进行耦合分析。研究表明:北京市五环以内绿色空间实体500、750 m和1000 m典型服务半径的覆盖面分别占总面积的77.99%、91.55%和97.46%,从服务供给角度表现出空间分布格局相对均匀;但在绿色空间500 m服务半径内,仅覆盖了POI热力图中极高密度区中51.19%的地区,高密度区中54.78%的地区,中密度区中66.21%的区域,从服务需求角度表现出绿色空间分布格局明显不均衡。研究认为城市绿色空间在POI热度较高区域的主要商圈、人流密集区域匹配明显不足,需要通过增加绿地或疏解POI集中程度来缓解绿色空间供需矛盾。  相似文献   

3.
4.
The shy-bold continuum is a fundamental axis of behavioral variation in humans and at least some other species, but its taxonomic distribution and evolutionary implications are unknown. Models of optimal risk, density- or frequency-dependent selection, and phenotypic plasticity can provide a theoretical framework for understanding shyness and boldness as a product of natural selection. We sketch this framework and review the few empirical studies of shyness and boldness in natural populations. The study of shyness and boldness adds an interesting new dimension to behavioral ecology by focusing on the nature of continuous behavioral variation that exists within the familiar categories of age, sex and size.  相似文献   

5.
Wastelands are likely to host a significant part of urban floristic diversity but have received limited attention because they are not considered interesting green zones. Here, we explore the potential role of wastelands in maintaining urban biodiversity to help define effective urban management plans. We quantified floristic diversity in 98 wasteland sites of Hauts-de-Seine, one of the most densely populated areas in France, and characterized the environmental parameters and spatial distribution of sites to identify some of the factors that influence plant species composition and to explore the impact of urban environment on the floristic interest of wastelands. Their floristic richness represented 58% of the total richness observed in the whole study area. Site richness depended on site area (the largest sites were the richest) and site age, with a maximum in sites of intermediate age (4–13 years). In the largest sites only (>2,500 m2), the floristic distance among sites was positively correlated with geographic distance, which suggests that migration of species among large sites partly controls local floristic composition. In contrast, the environmental distance among sites was not correlated with floristic distance. Finally, we showed that the presence of collective and individual dwellings within 200 m of a wasteland decreased its floristic rarity, whereas the presence of rivers or ponds increased it. We derive several recommendations to optimize the management of wastelands with respect to conservation of urban biodiversity.  相似文献   

6.
在北京分布的受胁鸟类主要分布在平原区,而平原区为城市发展的主要区域,因此,在城市管理中融入受胁鸟类保护的内容十分必要。以北京市平原区分布的24种受胁鸟类为研究对象,以鸟类对栖息地的需求为分类依据,结合国家土地利用分类标准,采用人工目视解译法,在北京市平原区的高清卫星影像图上识别出5类一级鸟类栖息地和17类二级鸟类栖息地,得到北京市平原区鸟类栖息地分布图。使用24种受胁鸟类的空间分布模型掩膜鸟类栖息地分布,得到24种受胁鸟类的预测空间分布,叠加之后获得受胁鸟类丰富度分布格局,结果显示,水域是受胁鸟类丰富度最高的栖息地。将受胁鸟类丰富度分布格局与北京市国家级和市级自然保护区分布叠加进行空缺分析,结果显示:1)北京市的自然保护区多分布在山区,不能有效保护受胁鸟类;2)受胁鸟类的保护与平原区的城市建设、绿地管理关系密切。采用分区统计方法,计算各类栖息地中分布的平均鸟类种类数,作为栖息地保护行动优先级指标,得出湖泊、水库、坑塘、滩地、沼泽地等湿地区域是具有最高保护优先级的栖息地类型,在保护实践资源充足的情况下,应对各类栖息地开展综合保护。该研究首次为北京城市区域受胁鸟类保护提出空间参考和管理建议。  相似文献   

7.
城市生态空间多元综合识别研究——以杭州市为例   总被引:1,自引:0,他引:1  
张亮  岳文泽 《生态学报》2019,39(17):6460-6468
城市生态空间是维护城市生态安全和提供持续生态服务的基本保障。以杭州市为研究区,从城市生态斑块的自然、人工以及自然-人工交互的属性特征3个方面选取了12个评价因子建立辨识指标体系,采用空间加权叠加的方法评价生态空间强度并识别核心型、辅助型、底线型生态空间和非生态空间4种类型。研究表明:(1)建立的辨识体系较好地反映了城市生态空间分布情况,适用于城市生态空间识别;(2)核心生态空间以林地为主要用地类型,集中分布在城市西翼,辅助型生态空间围绕核心生态空间周边。两类生态空间分别占总面积的21.28%、20.33%。(3)杭州市生态空间在分布上呈现出局部聚集的特征。以北部余杭区分布最为集中,且斑块连通度较高。城市不同区域生态空间分布特征具有较大差异性,针对其空间分布与生态功能提出不同的管理建设措施,能够为研究区未来的生态基础设施建设与维护提供科学依据。  相似文献   

8.
We herein describe the synthesis of novel 3-(het)aryl-pyrrolo[2,3-b]pyrrolizin-8(1H)-ones starting from commercial (het)aryl-acetonitriles. A more convergent route was also described through the first synthesis of ethyl 3-amino-4-bromo-1H-pyrrole-2-carboxylate 17. The antiproliferative activities of these compounds were tested toward various cell lines and one of them 10k shows interesting cytotoxic properties, although it was less potent than our lead compound in thiophene series 1k.  相似文献   

9.
南宁市几个功能区的植被群落结构特征分析   总被引:5,自引:0,他引:5  
借助数量分析技术分析了广西南宁市植被结构特征。结果表明:(1)主要的绿化乔木有45种,灌木24种。这些植物基本上代表了南宁市绿化植物的主体,但在生物量比重等方面,还是少数种类占主要优势,亟待调整。(2)绿地植被群落的平均胸径与密度成极显著负相关,显示城市植被与自然植被的相似性,而总冠幅盖度与总密度和综合重要值之间成极显著正相关,则显示了城市人工植被的特殊性;(3)绿地面积与胸径成显著正相关,而与密度、冠幅盖度成极显著与近显著的负相关,与重要值成负相关,则显示空间资源对群落特征的影响与自然植被是相似的;(4)聚类分析与主分量分析反映了人工绿地的群体特征,分类结果与功能区划分基本一致,个别样地则不一致;无论格局多样化,还是格调较为均一的绿色景观,均反映了人文美学价值取向对绿地建设的影响;(5)整体上看,南宁市植被结构还存在较大的优化空间。  相似文献   

10.
Many microbes are important symbiotes of human. They form specific microbiota communities, participate in various kinds of biological processes of their host and thus deeply affect human health status. Metagenomic sequencing has been widely used in human microbiota study due to its capacity of studying all genetic materials in an environment as a whole without any extra need of isolation or cultivation of microorganisms. Many efforts have been made by researchers in this area trying to dig out interesting knowledge from various metagenome data. In this review, we go through some prominent studies in the metagenomic area. We summarize them into three categories, constructing taxonomy and gene reference, characterization of microbiome distribution patterns, and detection of microbiome alternations associated with specific human phenotypes or diseases. Some available data resources are also provided. This review can serve as an entrance to this exciting and rapidly developing field for researchers interested in human microbiomes.  相似文献   

11.
A large share of construction material stock (MS) accumulates in urban built environments. To attain a more sustainable use of resources, knowledge about the spatial distribution of urban MS is needed. In this article, an innovative spatial analysis approach to urban MS is proposed. Within this scope, MS indicators are defined at neighborhood level and clustered with k‐mean algorithms. The MS is estimated bottom‐up with (a) material‐intensity coefficients and (b) spatial data for three built environment components: buildings, road transportation, and pipes, using seven material categories. The city of Gothenburg, Sweden is used as a case study. Moreover, being the first case study in Northern Europe, the results are explored through various aspects (material composition, age distribution, material density), and, finally, contrasted on a per capita basis with other studies worldwide. The stock is estimated at circa 84 million metric tons. Buildings account for 73% of the stock, road transport 26%, and pipes 1%. Mineral‐binding materials take the largest share of the stock, followed by aggregates, brick, asphalt, steel, and wood. Per capita, the MS is estimated at 153 metric tons; 62 metric tons are residential, which, in an international context, is a medium estimate. Denser neighborhoods with a mix of nonresidential and residential buildings have a lower proportion of MS in roads and pipes than low‐density single‐family residential neighborhoods. Furthermore, single‐family residential neighborhoods cluster in mixed‐age classes and show the largest content of wood. Multifamily buildings cluster in three distinct age classes, and each represent a specific material composition of brick, mineral binding, and steel. Future work should focus on megacities and contrasting multiple urban areas and, methodologically, should concentrate on algorithms, MS indicators, and spatial divisions of urban stock.  相似文献   

12.
The knowledge that potential guanine quadruplex sequences (PQs) are non-randomly distributed in relation to genomic features is now well established. However, this is for a general potential quadruplex motif which is characterized by short runs of guanine separated by loop regions, regardless of the nature of the loop sequence. There have been no studies to date which map the distribution of PQs in terms of primary sequence or which categorize PQs. To this end, we have generated clusters of PQ sequence groups of various sizes and various degrees of similarity for the non-template strand of introns in the human genome. We started with 86 697 sequences, and successively merged them into groups based on sequence similarity, carrying out 66 clustering cycles before convergence. We have demonstrated here that by using complete linkage hierarchical agglomerative clustering such PQ sequence categorization can be achieved. Our results give an insight into sequence diversity and categories of PQ sequences which occur in human intronic regions. We also highlight a number of clusters for which interesting relationships among their members were immediately evident and other clusters whose members seem unrelated, illustrating, we believe, a distinct role for different sequence types.  相似文献   

13.
陈阳  张琳琳  马仁锋  李冠  卓跃飞  徐忠国 《生态学报》2022,42(24):9971-9980
城市居民的绿色空间可达性是衡量城市基础设施公平分配的指向标,关乎城市民生福祉。以宁波为研究区,基于高德地图路径规划Application Programming Interface(API)测度了绿色空间可达性,融合多源数据模拟了人口空间分布,分析了绿色空间可达性与人口分布的空间匹配状态,并采用地理探测器探讨其影响因素。研究表明:(1)宁波绿色空间可达性由各区中心向郊区衰减,高可达性空间占比不高,反映了绿色服务供给不足的现状。高可达性空间集中于三江口、鄞州新城、北仑城区和镇海老城区,低可达性空间则主要分布在东部郊区、西部山区和南部农业区。(2)宁波居民的绿色空间可达性在空间上表现为市中心高人口密度-高可达性和郊区低人口密度-低可达性的空间匹配特征,在规模上仅不及半数的居民享有15min绿色空间可达性,在乡镇尺度上呈现显著的城区—郊区二元类型分异。(3)城市居民绿色空间可达性受多重影响因子驱动,按照重要性依次为区位特征、人类活动、开发强度、社会经济和地形条件。  相似文献   

14.
汪淼  陈振杰  周琛 《生态学报》2023,43(13):5347-5356
城市绿色开敞空间是城市公共空间的重要组成部分,合理配置城市绿色开敞空间对城市宜居环境建设至关重要。空间可达性常用于评价公共服务设施空间布局的合理性,两步移动搜索法即是一种直观、运算简便、应用广泛的可达性计算方法,但该方法未考虑需求主体之间的差异性。本研究以南京市中心城区为例,利用手机信令数据提取需求者属性特征以及空间分布,通过分类细化需求主体改进搜索策略,改善两步移动搜索法传统研究未考虑不同群体差异性、统计数据滞后、空间尺度粗等弊端。结果表明,南京市中心城区绿色开敞空间可达性呈现出明显的空间分异特征,江南主城可达性总体比江北新区高,低值区集中在人口密度高、绿色开敞空间资源规模小的中心城区周边;不同人群的绿色开敞空间可达性总体格局相似,但在数值上老年人可达性均值是其他年龄段的14.60%,工作人群可达性均值是居住人群的86.02%,老年人作为弱势群体在享受绿色开敞空间服务中被边缘化。研究结果可为优化南京市绿色开敞空间布局提供科学依据,也可为其他公共服务设施可达性评价提供借鉴。  相似文献   

15.
The sequencing of the human genome led to many insights into gene organization and structure. One interesting observation was the high frequency of bidirectional promoters characterized by two protein encoding genes whose promoters are arranged in a divergent or "head-to-head" configuration with less than 2000 base pairs of intervening sequence. Computational estimates published by various groups indicate that nearly 10% of the coding gene promoters are arranged in such a manner and the extent of this bias is a unique feature of mammalian genomes. Moreover, as a class, head-to-head promoters appear to be enriched in specific categories of gene function. Here we review the structure, composition, genomic properties and functional classifications of genes controlled by bidirectional promoters and explore the biological implication of these features. This article is part of a Special Issue entitled: Chromatin in time and space.  相似文献   

16.
郭振  胡聃  李元征  秦文翠 《生态学报》2014,34(1):201-209
城市道路系统是人类活动最为频繁的场所之一,研究路网空间特征与相关环境指标的关系,可为定量分析城市建设过程对城市生态环境的影响以及为城市基础设施规划管理提供方法。对北京市五环内各级道路抽样调查及面向对象的高分辨率遥感影像识别,建立道路空间信息数据库,运用TM影像反演获得地表温度(LST)及归一化植被指数(NDVI),研究4种不同分析网格下城市路网特征与两者的空间相关性。结果表明,在较大分析网格下(4×4),路网空间指标与LST mean及NDVI mean相关性显著;中等网格下,除LST与NDVI的平均值外,路网空间指标还可与两者最小值建立相关性;在较小窗口下(32×32),除平均值与最小值,还可建立特定道路指标与LST max及NDVI max的联系;各路网指标中,单位面积道路总长与LST及NDVI相关性最强;加权道路结点数在8×8和32×32网格分析中,与NDVI的相关性高于该指标未加权值,而结点指标均不适合与LST max建立联系;在各分析网格下,4项道路指标均与NDVI mean呈极显著负相关,表明道路绿地建设规模还不足以对NDVI的强度及分布产生较大影响。  相似文献   

17.
李锋  王如松 《生态学报》2003,23(9):1929-1936
城市绿地是城市自然生态系统的重要组成部分,具有重要的生态服务功能。以扬州市为例,依据社会—经济—自然复合生态系统理论和生态规划原则,参照国内外有关标准进行了规划,构建了“内环绿带、近郊绿带和外围大环境绿色屏障”三环绿带的布局结构,并从绿化覆盖率、人均绿地、人均公共绿地、绿地结构、绿地均匀度、本地种优势度6个指标分阶段进行了具体规划,应用多边形综合指标法对规划结果进行了评价与预测。结果表明:2000年扬州市区绿地系统生态服务功能一般,2005年也一般,2010较好,2020年优良。为了达到规划的预期目标,扬州市必须通过法律、经济、行政、社会、技术等手段加强后期的实施、监督与管理,从生态学角度提出了绿地系统建设的生态对策。城市生态建设应多元化而不应仅“唯绿地论”,城市绿地建设应体现城市特色,同时考虑其建设成本和维护管理费用等问题。  相似文献   

18.
Green space has been identified as a modifiable feature of the urban environment and associations with physiological and psychological health have been reported at the local level. This study aims to assess whether these associations between health and green space are transferable to a larger scale, with English cities as the unit of analysis. We used an ecological, cross-sectional study design. We classified satellite-based land cover data to quantify green space coverage for the 50 largest cities in England. We assessed associations between city green space coverage with risk of death from all causes, cardiovascular disease, lung cancer and suicide between 2002 and 2009 using Poisson regression with random effect. After adjustment for age, income deprivation and air pollution, we found that at the city level the risk of death from all causes and a priori selected causes, for men and women, did not significantly differ between the greenest and least green cities. These findings suggest that the local health effects of urban green space observed at the neighbourhood level in some studies do not transfer to the city level. Further work is needed to establish how urban residents interact with local green space, in order to ascertain the most relevant measures of green space.  相似文献   

19.
城市绿地的净生态系统CO2交换量(NEE)受多种环境因素控制,定量分析NEE的环境响应机制对评估绿地生态系统固碳效益、优化城市绿地布局有重要意义。本文应用2009、2010年位于东莞市植物园内的涡度相关CO2通量定位观测资料,分析了光合有效辐射(PAR)、土壤温度(Ts)、饱和水汽压差(VPD)、降水及周边不同下垫面类型对NEE的影响。结果表明:NEE绝对值随PAR的升高而增加,PAR超过光饱和点(约为1500μmol photons·m-2·s-1)后,NEE绝对值呈回落趋势;生态系统呼吸(Reco)随Ts升高而增加,在温度较低时,Reco对Ts的敏感性较强(10℃时,Lloyd-Taylor方程的Q10=1.8),随着温度升高,敏感性下降(30℃时,Q10=1.43);VPD通过影响植物气孔导度对CO2交换产生作用,相同温度下,随着VPD升高,气孔导度增大,呼吸释放与光合固定的CO2量均增加;降水能增加土壤湿度进而使Reco增大,25℃时,降水后的Reco比降水前增加15.8%;测站东北和西南方的绿地范围较大,当东北和西南部是主要贡献区时,NEE绝对值较大,表明增加城市绿地能有效提高城市固碳效益。  相似文献   

20.
Within urban green spaces, tree species diversity is believed to correlate with aboveground biomass, though there is some disagreement within the literature on the strength and directionality of the relationship. Therefore, we assessed the relationship between the biodiversity of woody species and the aboveground biomass of woody plant species in the tropical, coastal city of Haikou in southern China. To accomplish this, we obtained comprehensive tree and site data through field sampling of 190 urban functional units (UFUs, or work units) corresponding to six types of land uses governmental‐institutional, industrial‐commercial, park‐recreational, residential, transport infrastructure, and undeveloped area. Based on our field data, we investigated the relationship between tree species diversity and aboveground biomass using multiple regression, which revealed significant relationships across all five types of land uses. Aboveground biomass in green spaces was also correlated with anthropogenic factors, especially time since urban development, or site age, annual maintenance frequency by human caretakers, and human population density. Among these factors, maintenance is the strongest predictor of aboveground biomass in urban green space. Therefore, this study highlights the critical role of maintenance of urban green space in promoting both aboveground biomass and woody biodiversity in urban ecosystems and, consequently, on urban ecosystem services. Our findings contribute to a deeper understanding of the ecosystem services provided by communities of woody plant species in urban areas.  相似文献   

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