空间分辨率对总初级生产力模拟结果差异的影响

利用模型分析气候变化对陆地生态系统功能的影响,是当前全球变化生态学的研究热点,然而模型模拟不确定性来源之一就是空间异质性的问题。空间异质性是尺度的函数,基于气象和遥感数据驱动的生态系统过程模型（BEPS模型）,分别模拟2003-2005年中国生态系统通量观测与研究网络（ChinaFLUX）长白山站、千烟洲站、海北站及当雄站在1 km和8 km空间分辨率下的总初级生产力（GPP）的时间动态变化,并结合土地覆盖类型及叶面积指数(LAI)的差异,探讨两种空间分辨率输入数据对GPP模拟结果的影响。结果表明：① 差异性主要是由于8 km范围内混合像元导致LAI的不同,4个站点月均差异值分别为0.85、1.60、0.13及0.04;② 两种空间分辨率均能较好地反映各站点GPP的季节动态变化,与GPP观测值的相关性R²为0.79~0.97 (1 km)、0.69~0.97(8 km),月均差异值为11.46~29.65 gC/m²/month (1 km)、11.87~24.81 gC/m²/month (8 km);③ 4个通量站点在两种空间分辨率下的GPP月均差异值分别为14.43,12.05,4.79,3.22 gC/m²/month,不同空间分辨率的模拟结果在森林站的差异大于草地站,且生长季的差异大于非生长季。因此,模型在模拟大尺度、长时间序列GPP时,为了提高模型模拟效率,适度降低空间分辨率是可行的,但应尽量减小低空间分辨率对于森林生态系统以及生长季GPP模拟上的误差。     

Spatio-temporal Analysis of Water Supply Services in the Li River Basin

The water supply services of the Li River are essential for the ecological environment and local social development. Based on the InVEST model, we quantitatively analyzed the spatial and temporal distribution patterns of water supply services in the Li River Basin from 2000 to 2018 at multiple scales, including the raster, sub-basin, and regional scales, clarified the differences in water yield among different land use types, and explored the different stages of changes in the characteristics of water services. The results revealed four key aspects of this system. (1) The water supply service of Li River Basin showed a spatial distribution pattern of high in the north and low in the south, and the water yield gradually decreased from north to south. (2) Among the various land use types in Li River Basin, the average water supply capacity decreased in the following order: artificial surface, unused land, grassland, forest, cropland and wetland. (3) The average amounts of water services in the 18 sub-basins varied widely, with four sub-basins belonging to the high-value area for water supply services, eight in the middle-value area, and six in the low-value area. (4) From 2000 to 2010, the regions with large fluctuations in water supply services include the midstream region, Lipu River region, and the northern region of Gongcheng River; while from 2010 to 2018, the areas with large fluctuations were in the midstream region and Gongcheng River region. The results of this research increase our understanding of the water supply services in the Li River Basin and provide a critical scientific basis for the reverse compensation of a regional ecological compensation mechanism.     

The impact of spatial scale: exploring urban butterfly abundance and richness patterns using multi-criteria decision analysis and principal component analysis

ABSTRACT

Modelling changes in biodiversity have become a necessary component of smart urban planning practices. However, concepts such as biodiversity are often evaluated using area-based composite indices, the results of which are heavily reliant on specific parameters chosen. This paper explores the design and implementation of a butterfly biodiversity index by comparing two widely accepted modelling techniques: principal component analysis and spatial multi-criteria decision analysis (MCDA). A high degree of scale dependency has been demonstrated in previous studies exploring the use of area-based composite measures. To evaluate the impact of scale, each model was assessed at two different spatial resolutions. The outcomes were analyzed, mapped and compared using ordinary least squares, geographically weighted regression and global Moran’s I to evaluate relative biodiversity patterns across the City of Toronto, Canada. Findings indicate that the impact of spatial scale was significant, whereby the coarser resolution models were found to be more highly correlated with biodiversity, compared to the finer resolution models. The results of this study contribute to a growing body of literature that explores key conceptual questions regarding the robustness of GIS-based MCDA, the impact of scale in urban ecology studies, and the use of composite indices to manage spatial ecological data.     

Lithology-derived structure classification from the joint interpretation of magnetotelluric and seismic models

Magnetotelluric and seismic methods provide complementary information about the resistivity and velocity structure of the subsurface on similar scales and resolutions. No global relation, however, exists between these parameters, and correlations are often valid for only a limited target area. Independently derived inverse models from these methods can be combined using a classification approach to map geologic structure. The method employed is based solely on the statistical correlation of physical properties in a joint parameter space and is independent of theoretical or empirical relations linking electrical and seismic parameters. Regions of high correlation (classes) between resistivity and velocity can in turn be mapped back and re-examined in depth section. The spatial distribution of these classes, and the boundaries between them, provide structural information not evident in the individual models. This method is applied to a 10 km long profile crossing the Dead Sea Transform in Jordan. Several prominent classes are identified with specific lithologies in accordance with local geology. An abrupt change in lithology across the fault, together with vertical uplift of the basement suggest the fault is sub-vertical within the upper crust.     

闽东北沿海罗源县土地利用空间分布格局的 多尺度分析

在不同的空间尺度上,制约土地利用空间分布的影响因子及其影响程度并不相同,因此区域空间分布格局 分析应优先考虑制约空间分布的影响因子识别及其影响程度的尺度依赖性的研究。本文以闽东沿海的罗源县为研 究区域,采样统计方法与GIS 技术,选取20 个候选影响因子,研究了该县主要土地利用空间分布格局的影响因子 及其空间尺度相关性。研究表明模型的解释能力、影响因子及其影响系数均会随研究尺度发生不同程度的变化,回 归模型的解释能力以及主要影响因子的制约程度总体上均随研究尺度增大呈增强趋势。除受坡度、海拔高程等地 形条件的严格制约外,罗源县主要地类均在一定程度上受到人口因素以及若干可达性因素的影响。     

东江流域地表水功能区水质对土地利用的响应

以广东省东江流域2013年地表水功能区水质监测数据和Landsat8 OLI遥感影像为数据源,通过遥感信息提取、GIS空间分析和数理统计方法,对不同空间尺度河岸缓冲带土地利用结构与水体中的高锰酸盐指数（CODMn）、氨氮（NH3-N）和总磷（TP）进行相关性分析。结果表明：1）在水功能区中,开发利用区河岸带的城市化程度较高,水质状况相对较差;保护区、保留区、缓冲区河岸带用地类型以耕地和林地为主,水质状况明显优于开发利用区。2）耕地、林地和草地对水质具有正效应,水体和建设用地对水质具有负效应;同时,建设用地对水质影响作用最强,其次是水体和耕地。3）CODMn与耕地、林地、草地、建设用地的相关性远高于NH3-N和TP,3种水质指标与水体相关性都较大。4）耕地和草地与水质在小尺度范围内相关性最为显著;林地和建设用地与水质相关性随河岸缓冲带尺度增大而增大,水体与水质相关性随河岸缓冲带尺度不同呈波动性变化。     

黄河流域不同时间尺度干旱对ENSO事件的响应

利用黄河流域1963-2012年逐月气温和降水量数据,计算了各气象站点不同时间尺度的标准化降水蒸散指数(SPEI),通过对不同时间尺度SPEI与Niño 3.4区海洋表面温度距平(SSTA)的时空相关性进行分析,揭示不同时间尺度干旱对ENSO事件的响应及ENSO事件对黄河流域不同区域降水量和气温的影响。结果表明:(1)黄河流域1、3、6个月时间尺度的干旱在各时间段均有发生,12、24个月时间尺度的干旱主要发生在20世纪末和21世纪初的近20年。黄河上游和中游地区不同时间尺度的SPEI与SSTA均呈负相关关系,下游地区呈正相关关系。(2)黄河流域不同时间尺度的SPEI与SSTA相关性在空间分布上具有显著的差异性。久治站以上的黄河上游地区、中游地区的宁夏、内蒙古、陕西和山西的北部以及下游地区均呈正相关关系,其余地区呈负相关关系。全流域1、3、6、12个月和24个月时间尺度的相关性系数通过0.05显著性检验的站点占总站点数分别为14%、43%、61%、75%和44%。(3)ENSO事件强度与降水量在黄河上游地区的相关性较弱,在中游和下游地区呈显著的负相关性,强度增大时降水量下降,减弱时降水量上升。全流域ENSO事件强度与气温呈显著的正相关性,强度增大时温度有上升趋势。其中El Niño对气温有抬高的趋势,La Niña对气温有降低的趋势。     

流域水文模型对土壤数据响应的多尺度分析

流域水文模拟对输入数据空间详细程度的要求受流域面积大小的影响,而流域面积影响作用的定量描述有助于模拟时的数据选取.本文以美国Brewery Creek流域(约19.5 k㎡)为例,在逐级连续的汇流面积上,分析了SWAT模型基于1:2.4万的SSURGO和10m分辨率的SoLIM土壤数据模拟的径流量的差别随汇流面积的变化...     

咸海流域社会经济用水分析与预测

1960年以来咸海流域大规模的水土资源开发使得社会经济用水激增,致使至1990年咸海面积萎缩50%,引发咸海生态危机。目前对引起咸海生态危机的社会经济用水的时空变化特征和趋势尚不清楚。本文在整合了多途径获取的1960—2016年咸海流域国家/州级水资源和社会经济数据的基础上,利用系统动力学模型,仿真模拟和分析了1960—2016年咸海流域社会经济和用水时空变化特征,并多情景预测2016—2030年咸海流域社会经济用水。1960—2016年咸海流域人口增幅267%,GDP增幅1100%,社会经济用水量从410亿m³增长至910亿m³。咸海流域的工农业用水效益在1991年苏联解体后明显增加,但仍处于较低水平。对未来的情景预测表明：若延续现有社会经济用水效率、农作物种植面积持续扩张（S1）,至2030年咸海流域社会经济用水量达到962亿m³;而在滴灌普及率达到70%、种植面积不变的情景下（S10）,社会经济用水量降至681亿m³,可有效缓解咸海危机。     

青海湖沙柳河流域土壤水氢氧稳定同位素组成与土壤贮水量关系北大核心CSCD

氢氧稳定同位素技术和土壤贮水量是探究区域土壤水分特征的有效手段。基于青海湖沙柳河流域土壤水氢氧稳定同位素组成(δ2H和δ^(18)O)和土壤贮水量数据,分析其在流域的空间分布特征,探讨土壤水氢氧稳定同位素组成和土壤贮水量之间的相关性。结果表明:(1)沙柳河流域土壤水δ^(18)O值从西北向东南呈现富集—贫化—富集的趋势;土壤水d-excess值在流域南部最低,在流域东北部支流上游地区最高。(2)土壤贮水量在流域空间分布上表现为北高南低的趋势。(3)土壤水δ^(18)O值、d-excess值与土壤贮水量间存在分段线性关系。当0—30 cm各土层土壤贮水量≤30 mm时,各土层土壤贮水量与土壤水δ^(18)O值分别显著负相关、与d-excess值显著正相关。青海湖沙柳河流域自然地理环境和植被特征的空间差异导致其土壤水氢氧稳定同位素组成和土壤贮水量表现出明显的空间变异性。温度变化对土壤水氢氧稳定同位素组成与土壤贮水量之间的相关性影响是通过其对土壤蒸发作用的影响来实现的。     

Spatio-temporal Evolution and Flow of Water Provision Service Balance in Jinghe River Basin

Quantifying the whole process of ecosystem services from generation through transfer to use, and analyzing the balance between the supply and demand of regional ecosystem services are of great significance for formulating regional sustainable development strategies, realizing regional ecosystem management, and effective resource allocation. Based on the SWAT model, InVEST model, ArcGIS, and other software, this study analyzed the supply-demand balance of water provision services in Jinghe River Basin, a typical region located in the Loess Plateau, using multi-source data. This research then analyzed the spatial-temporal distribution pattern and spatial matching characteristics of the supply and demand of water provision services in Jinghe River Basin from 2000 to 2015. On this basis, a spatial flow model of water provision service was constructed, the flow rules (flow paths) of the water provision service were explored at the subwatershed scale, and the spatial scope of the supply area and benefit area were depicted. The results show that: (1) Water resource supply and demand in the Jinghe River basin both showed increasing trends from 2000 to 2015. (2) The supply-demand balance of water resources was generally up to the standard, however, there were significant differences between urban and rural areas. The supply-demand balances of the central urban areas of each county were relatively low, and even exceeded the supply in the lower reaches of the Jingyang River, such as Gaoling County, Qindu District, and Jingyang County. In rural areas, due to the small population and industrial distribution, coupled with a better ecological environmental base, the supply-demand balance was relatively high, such as Pengyang County, Lingtai County, Huachi County, Huanxian County, Ningxian County, and Zhenyuan County. (3) From 2000 to 2015, the spatial matching pattern of supply and demand in the Jinghe River Basin showed a trend of decline with fluctuations. In 2015, the supply-demand ratios of more than 60% of the subwatersheds showed trends of decline, and the proportion of under-supply area increased by 55.7% in 2015 compared with that in 2000. (4) The supply areas of water provision service in Jinghe River Basin are distributed in the upper reaches of the basin, and the benefit areas are Huating County, Chongxin County, Yongshou County, Chunhua County, Ganxian County, Liquan County, Qindu District, and others in the middle and lower reaches.     

山东省人口空间分布格局的多尺度分析

人口空间分布具有一定的尺度依赖性,从不同尺度上对人口空间分布格局进行分析,可以更确切、真实地揭示人口的空间分布规律,为制定区域发展规划、灾害评价、环境保护等提供科学依据。本文以山东省为研究区,运用空间自相关方法和统计相关分析方法,比较市级、县级、1 km三个尺度上人口分布的空间自相关性及其与环境—经济因子的统计相关性,试图探讨不同尺度下人口的空间分布模式及影响(指示)因素,从不同尺度揭示人口的空间分布格局特征。结果表明:①从不同尺度对人口的空间分布格局进行分析,可以得到从宏观到微观不同详细程度的信息。从市级尺度分析,可以得到山东省整体的人口空间分布特征;从县级尺度分析,可以得到山东省各市内部的人口空间分布特征;从1 km尺度分析,可以得到山东省各县内部的人口空间分布特征。②不同尺度上,人口的空间分布格局特征不同。市级和县级尺度上,人口分布受环境—经济因子的影响表现出与一些因子显著相关,而受空间集聚的作用较小;1 km尺度上,人口分布与环境—经济因子的相关性较小,而主要受空间集聚的作用,在县内部,人口往往集中分布于某一区域,呈现出典型的集聚分布模式。     

澜沧江流域农业灌溉需水的时空变化(英文)

Based on the data of eight meteorological stations from the 1950s to 2007, current cropping patterns, field water moisture management, we use the Mann-Kendall and the Re-scaled Range Analysis methods to research the changes of humidity and crop irrigation water requirements in the Lancang River Basin. The results show that the annual and dry season average temperatures significantly increased, and the dry season rainfall increased while wet season rainfall decreased. Evaportranspiration (ET0) increased during both dry and wet seasons at all stations except Dali, Jianchuan and Gengma, and the aridity-humidity index decreased at most of the stations. The turning points of weather factors, ET0, the arid-ity-humidity index, paddy irrigation requirements and total agricultural water requirements occurred from the 1960s to the 1990s. The spatial changing tendency of paddy irrigation quota increased with the increase of altitude and latitude, and the correlation coefficients are 0.513 and 0.610, respectively. The maximum value is observed in Weixi, while the minimum in Mengla.     

城市范围界定与标度律

标度律作为城市发展的重要规律之一,反映了城市经济活动产值、基础设施数量等要素随城市人口规模的变动情况,在城市研究领域引起了广泛讨论。但由于不同国家的城市统计数据对应的空间范围各不相同,导致标度律系数受城市边界范围选取影响很大。本文通过比较中、美两国统计数据对应的空间范围,并结合普查、城市统计年鉴和遥感数据,计算了不同空间范围对应的标度律系数。结果表明：① 不同空间尺度和数据源得到的标度律系数有较大差异。就空间尺度而言,市辖区比市域范围的数据更符合标度律模型,因为中国城市市域范围内还存在大量的非城市化地区,并不符合标度律模型的适用条件;就数据源而言,遥感数据比城市统计年鉴数据有更好的拟合优度;② 与美国城市相比,中国城市人口集聚带来的经济增长率更高（标度律系数更高）,市辖区人口每增加一倍,经济规模可增加122%,这一数字在美国是111%;而在家庭能源消耗（用水、用电）和土地利用方面,中国城市的效率更低;③ 从中国城市内部对比来看,大城市与中小城市在经济规模、土地利用方面的标度律（集聚效率）明显不同,人口集聚效应带来的大城市经济增长率、工资收入要远高于中小城市;能源消耗方面,中小城市比大城市更有效率。最后,本文还从建立更加有效的统计单元、传统统计数据与大数据结合、模型机制探索3个方面阐述了城市标度律未来可能的研究方向。     

Predicting 21st century global agricultural land use with a spatially and temporally explicit regression-based model

The extensive alteration of the earth's land cover during the anthropocene had widespread, and in some cases unknown, effects on terrestrial and atmospheric conditions and processes. Predicting future changes to the earth system therefore mandate a future-predicting framework of land use dynamics. However while future-predicting earth surface and atmospheric models tend to explicitly incorporate projected climatic conditions they all but ignore or overly simplify land use dynamics. As most surface and atmosphere dynamics models use gridded input datasets, and land use is a highly spatially-dynamic phenomena, a need clearly arise for spatially explicit representation of future land use dynamics. While a number of such datasets exists at regional and country scales, no fully gridded future-predicting global land use model and database has been reported to date. Here we present the Global Land Use Dynamics Model (GLUDM), a gridded and temporally explicit agricultural land use predictor. GLUDM calculates the relative area of a land use category (e.g. cropland) in each grid-cell by generating unique regression coefficients in each grid-cell based on local historic trends and global population dynamics. Spatial expansions or abandonment of agricultural land is simulated by propagating excesses or deficiencies in agricultural areas between neighboring grid-cells. This spatial connectivity is restricted by topographic, latitudinal and urban characteristics. A validation analysis shows that GLUDM corresponds well to observed land use distribution. GLUDM-predicted global cropland area dynamics between 2005 and 2100 are described herein. Globally, 18% increase in cropland area is predicted between 2005 and 2050 which corresponds very well to previous estimations. Following 2050, a general decrease in cropland area is predicted. The results reveal new insights about global cropland dynamics, demonstrating, for example, that changes in its spatial distribution will be highly heterogeneous, at both micro and macro scales, in some locations worldwide.     

Spatial-temporal patterns of vegetation dynamics and their relationships to climate variations in Qinghai Lake Basin using MODIS time-series data

Global warming has led to significant vegetation changes in recent years. It is necessary to investigate the effects of climatic variations（temperature and precipitation） on vegetation changes for a better understanding of acclimation to climatic change. In this paper, we focused on the integration and application of multi-methods and spatial analysis techniques in GIS to study the spatio-temporal variation of vegetation dynamics and to explore the vegetation change mechanism. The correlations between EVI and climate factors at different time scales were calculated for each pixel including monthly, seasonal and annual scales respectively in Qinghai Lake Basin from the year of 2001 to 2012. The primary objectives of this study are to reveal when, where and why the vegetation change so as to support better understanding of terrestrial response to global change as well as the useful information and techniques for wise regional ecosystem management practices. The main conclusions are as follows：（1） Overall vegetation EVI in the region increased 6% during recent 12 years. The EVI value in growing seasons（i.e. spring and summer） exhibited very significant improving trend, accounted for 12.8% and 9.3% respectively. The spatial pattern of EVI showed obvious spatial heterogeneity which was consistent with hydrothermal condition. In general, the vegetation coverage improved in most parts of the area since nearly 78% pixel of the whole basin showed increasing trend, while degraded slightly in a small part of the area only.（2） The EVI change was positively correlated with average temperature and precipitation. Generally speaking, in Qinghai Lake Basin, precipitation was the dominant driving factor for vegetation growth; however, at different time scale its weight to vegetation has differences.（3） Based on geo-statistical analysis, the autumn precipitation has a strong correlation with the next spring EVI values in the whole region. This findings explore the autumn precipitation is an important indicator     

中国人口省际流动重力模型的参数标定与误差估算

空间交互模型被广泛应用于地理要素关系强度的模拟,然而目前大量研究或建立在模型参数标定理想化、模式化的假设条件下,或是在暗箱中完成,由此导致模拟结果与实际的偏差却被严重低估。基于2015年中国春运期间人口省际流动的城市间O-D数据,在逐日、分市的研究精度下,实证推算人口流动重力模型变量的回归系数,探究模型代理变量影响效应的空间异质性,并评估重力模型在人口流动模拟上的误差。结果显示：① 重力模型参数标定的复杂性体现在交互对象代理变量影响程度的非对称性,和变量回归系数的空间异质性随研究精度加深显著加剧两个方面,因此模型参数标定的模式化将导致估算结果空间差异的趋势收敛;② 2015年春运期间中国人口省际流动距离衰减系数为1.970,在地级行政单元视角下,人口流出地距离衰减系数值域为0.712（驻马店）~7.699（乌鲁木齐）,人口流入地系数值域为0.792（三亚）~8.223（乌鲁木齐）;③ 应用重力模型模拟人口流动结果与实测流（百度迁徙数据）存在显著误差。就加权绝对平均误差而言,拟合总误差为85.54%,其中空间相互作用效应造成了86.09%的实测流与模拟流的最大误差,相对流出力、相对吸引力分别造成57.73%、49.34%的模型误差。因此,空间交互效应仍然是当前最难以模式化的因素。     

Multiscale Segregation: Multilevel Modeling of Dissimilarity—Challenging the Stylized Fact That Segregation Is Greater the Finer the Spatial Scale

A very large literature has explored the intensity of urban residential segregation using the index of dissimilarity. Several recent studies have undertaken such analyses at multiple spatial scales, invariably reaching the conclusion that the finer grained the spatial scale, the greater the segregation. Such findings, however, overstate the intensity of segregation at finer spatial scales because they fail to take into account an argument made by Duncan et al. some sixty years ago that indexes derived from fine-scale analyses must necessarily incorporate those from coarser scales, with the consequence that finer scale segregation is invariably overestimated. Moreover, most studies ignore stochastic variation that results in upward bias in the estimates of segregation. This article demonstrates the importance of a recently developed multilevel modeling procedure that identifies the “true” intensity of segregation at every level in a spatial hierarchy net of its intensity at other levels and also net of stochastic variation This is illustrated by both a simulated data set and an empirical study of an English city, with the latter raising important substantive issues regarding the interpretation of segregation patterns and the processes underlying them. Key Words: dissimilarity, multilevel modeling, scale, segregation.     

SWIM水文模型的DEM尺度效应

数字高程模型(DEM)极大地促进了分布式流域水文模型的快速发展。本文引入SWIM水文模型,以淮河上游长台关地区为研究区,将15种不同分辨率DEM数据输入水文模型,分析DEM分辨率对径流模拟的影响,并探讨最佳DEM分辨率选取及DEM分辨率对流域地形参数与径流模拟影响等问题。研究表明:(1)研究区水文模拟效果较理想DEM分辨率在90～120m之间,采用栅格面积与流域面积比值(G/A)小于0.05和"thousandmillion"经验公式作为DEM选取参考等均适用;(2)DEM分辨率下降,水文模拟纳希效率系数呈波动下降,分辨率超过250m后,虽纳希效率系数有所提高,但此时DEM已不能刻画真实流域特征从而造成假象;(3)15种分辨率DEM在水文极端事件模拟上差异较大,高纳希效率系数时不能较好地反映水文极端事件,尤其是峰值,而在枯水期15种DEM水文模拟效果均较好,DEM分辨率降低导致水文模型对降水等反应敏感。     

西鄂尔多斯半日花(Helianthemum soongoricum)种群结构和点格局分析

半日花(Helianthemum soongoricum)是古地中海区系的残遗种,是国家二级珍稀保护植物,种群数量和规模已非常有限。为了揭示半日花种群的结构和发展的空间规律,运用大小结构分析法将半日花种群分为3个龄级(Ⅰ级,d≤3cm;Ⅱ级,3cmd≤9cm;Ⅲ级,d9cm,d为植株体积(高度×冠幅)的立方根),并采用空间点格局分析中的O-ring统计方法研究了分布于西鄂尔多斯砾石质和石质生境的半日花种群的结构和不同发育阶段个体的空间格局及空间关联性。结果表明:(1)半日花个体主要集中在龄级Ⅱ,龄级Ⅰ和龄级Ⅲ的个体都较少,种群的更新受到限制;(2)半日花种群的空间分布格局与不同龄级间的空间关联性受生境条件的影响较大,并且对空间尺度表现出很强的依赖性。砾石质生境中的半日花种群及其各龄级在小尺度范围内呈聚集分布,随着尺度增大逐渐趋向于均匀分布,不同龄级间主要表现为(或接近于)负关联;石质生境中半日花种群及其各龄级在中小尺度呈聚集分布,随着尺度增加表现为随机分布,龄级Ⅲ与Ⅱ和龄级Ⅱ与Ⅰ之间的空间正关联或不关联关系更明显。这种差别与两种生境下的环境条件和群落结构有关;(3)半日花幼龄个体(龄级Ⅰ)在一定程度上受到了来自成年个体(龄级Ⅱ与Ⅲ)的竞争压力。研究结果对半日花的保护与利用具有一定的参考价值。