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Population structure and spatial pattern analysis of Quercus aquifolioides on Sejila Mountain,Tibet,China 被引量:2
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作者 Zhiqiang Shen Jie Lu +4 位作者 Min Hua Xiaoqin Tang Xingle Qu Jingli Xue Jiangping Fang 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第2期400-409,共10页
Understanding population structure provides basic ecological data related to species and ecosystems.Our objective was to understand the mechanisms involved in the maintenance of Quercus aquifolioides populations.Using... Understanding population structure provides basic ecological data related to species and ecosystems.Our objective was to understand the mechanisms involved in the maintenance of Quercus aquifolioides populations.Using a 1 ha permanent sample plot data for Q.aquifolioides on Sejila Mountain,Tibet Autonomous Region(Tibet),China,we analyzed the population structure of Q.aquifolioides by combining data for diameter class,static life table and survival curve.Simultaneously,the spatial distribution of Q.aquifolioides was studied using Ripley’s L Function in point pattern analysis.The results showed:(1) Individuals in Q.aquifolioides populations were mainly aggregated in the youngest age classes,that accounted for94.3% of the individuals; the older age classes had much smaller populations.Although the youngest age classes(ClassesⅠ and Ⅱ) had fewer individuals than Class Ⅲ,the total number of individuals in classes Ⅰ and Ⅱ was also greater than in classes Ⅳ to Ⅸ.In terms of tree height,fewsaplings,more medium-sized saplings and few large-sized trees were found.The diameter class structure of Q.aquifolioides populations formed an atypical ‘pyramid’type; the population was expanding,but growth was limited,tending toward a stable population.(2) Mortality of Q.aquifolioides increased continuously with age; life expectancy decreased over time,and the survivorship curve was close to a Deevey I curve.(3) The spatial distribution pattern of Q.aquifolioides varied widely across different developmental stages.Saplings and medium-sized tree showed aggregated distributions at the scales of 0–33 m and 0–29 m,respectively.The aggregation intensities of saplings and medium-sized trees at small scales were significantly stronger than that of large-sized trees.However,large-sized trees showed a random distribution at most scales.(4) No correlation was observed among saplings,medium-and large-sized trees at small scales,while a significant and negative association was observed as the scale increased.Strong competition was found among saplings,medium-and large-sized trees,while no significant association was observed between medium-and largesized trees at all scales.Biotic interactions and local ecological characteristics influenced the spatial distribution pattern of Q.aquifolioides populations most strongly. 展开更多
关键词 point pattern analysis Population structure Quercus aquifolioides Sejila Mountain Spatial distribution pattern
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Spatial pattern analysis and associations of different growth stages of populations of Abies georgei var.smithii in Southeast Tibet,China 被引量:3
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作者 SHEN Zhi-qiang LU Jie +1 位作者 HUA Min FANG Jiang-ping 《Journal of Mountain Science》 SCIE CSCD 2016年第12期2170-2181,共12页
Abies georgei var.smithii is an important plant species in Southeast Tibet,China.It has high ecological value in terms of biodiversity protection,as well as soil and water conservation.We analyzed the spatial pattern ... Abies georgei var.smithii is an important plant species in Southeast Tibet,China.It has high ecological value in terms of biodiversity protection,as well as soil and water conservation.We analyzed the spatial pattern and associations of A.georgei var.smithii populations at different growth stages by using Ripley's L function for point pattern analysis.The diameter structure was a nearly reverse 'J' shape.The amount of saplings and medium-sized trees accounts for a large part of the entire population,suggesting a high regeneration rate and an expanding population.In the transition from saplings to medium trees or to large trees,saplings show a significant aggregation distribution at small scales,while medium trees and large trees show a random distribution.There are significant inverse associations between saplings and medium trees and large trees at small scales,while there are no obvious associations between medium trees and large trees.The natural regeneration was affected by interspecific competition,and it was also affected by intraspecific competition.The joint effects of biological characteristics and environmental factors contribute to the spatial distribution pattern and associations of this A.georgei var.sm ithii population. 展开更多
关键词 Southeastern Tibet Abies georgei var.smithii point pattern analysis Distribution pattern Spatial association
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Effect of Quadrat Shape on Spatial Point Pattern Performance of Haloxylon ammodendron
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作者 Shaohua Wang Longwei Dai 《Open Journal of Ecology》 2024年第1期66-76,共11页
In this study, we investigated the natural growth of Haloxylon ammodendron forest in Moso Bay, southwest of Gurbantunggut Desert. Random sample analysis was used to analyze the spatial point pattern performance of Hal... In this study, we investigated the natural growth of Haloxylon ammodendron forest in Moso Bay, southwest of Gurbantunggut Desert. Random sample analysis was used to analyze the spatial point pattern performance of Haloxylon ammodendron population. ArcGIS software was used to summarize and analyze the spatial point pattern response of Haloxylon ammodendron population. The results showed that: 1) There were significant differences in the performance of point pattern analysis among different random quadrants. The paired t-test for variance mean ratio showed that the P values were 0.048, 0.004 and 0.301 respectively, indicating that the influence of quadrat shape on the performance of point pattern analysis was significant under the condition of the same optimal quadrat area. 2) The comparative analysis of square shapes shows that circular square is the best, square and regular hexagonal square are the second, and there is no significant difference between square and regular hexagonal square. 3) The number of samples plays a decisive role in spatial point pattern analysis. Insufficient sample size will lead to unstable results. With the increase of the number of samples to more than 120, the V value and P value curves will eventually stabilize. That is, stable spatial point pattern analysis results are closely related to the increase of the number of samples in random sample square analysis. 展开更多
关键词 Spatial point pattern Random Quadrat Quadrat analysis Quadrat Shape
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Research on the Development Pattern Optimization of China’s Central Plains Urban Agglomeration from the Perspective of Historical and Cultural Resources
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作者 Guangyuan Feng Jingxiang Zhang +3 位作者 Zhen Zhou Handong Wang Jiale Zu Zeyu Zhou 《Journal of Civil Engineering and Architecture》 2025年第8期373-380,共8页
China is one of the countries with the longest history in the world.The protection and development of historical and cultural resources is an issue worthy of attention in the fields of economic geography and urban-rur... China is one of the countries with the longest history in the world.The protection and development of historical and cultural resources is an issue worthy of attention in the fields of economic geography and urban-rural planning at the present stage.This study takes the Zhongyuan Urban Agglomeration,which is rich in historical and cultural heritage,as a specific case,analyzes the characteristics of the spatial-temporal distribution pattern of its historical and cultural resources.The results show that the distribution structure of historical and cultural element resources within the Zhongyuan Urban Agglomeration presents significant regional agglomeration and combination characteristics.In response to the analysis results,the study formulates an optimization strategy for the regional development pattern supported by the protection and development of historical and cultural resources,and initially proposes a matching spatial development pattern plan and policy recommendations for coordinated development. 展开更多
关键词 Historical and cultural resources regional development pattern point pattern analysis central plains urban agglomeration
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基于奇异平面空间染色镶嵌的空间点模式识别与特征提取
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作者 刘菁 朱渭宁 《深圳大学学报(理工版)》 北大核心 2026年第1期101-109,共9页
为扩展空间点可识别模式的多样性,基于空间染色模型(spatial chromatic model,SCM),分析奇异空间染色镶嵌的空间染色码与空间点模式之间的对应关系,发现空间码的数值大小及统计特征可指示空间点的分布模式.该方法不仅能识别点模式中常... 为扩展空间点可识别模式的多样性,基于空间染色模型(spatial chromatic model,SCM),分析奇异空间染色镶嵌的空间染色码与空间点模式之间的对应关系,发现空间码的数值大小及统计特征可指示空间点的分布模式.该方法不仅能识别点模式中常见的随机、聚类等特性,也能识别共线、共圆、对称等特殊模式,且有利于将点模式识别与SCM的其他空间分析功能结合,在一个统一框架内完成实体与空间关系的分析与处理.研究结果可为空间点模式识别提供新的理解思路与分析方法. 展开更多
关键词 模式识别 空间点模式 空间染色模型 聚类分析 奇异空间 计算几何
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基于MSPA技术和InVEST模型的杭州市生态安全格局构建 被引量:1
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作者 张权 张舟 +2 位作者 刘晶晶 宋润泽 杨朝辉 《环境科学》 北大核心 2026年第1期494-505,共12页
经济发展和城市化进程的加快导致区域生态安全面临着重大挑战.以杭州市为研究对象,通过计算生态系统服务重要性,叠加MSPA(最小累积阻力模型)分析的核心区,识别出潜在的生态源地;然后引入InVEST模型的生境质量结果,筛选出最终的生态源地... 经济发展和城市化进程的加快导致区域生态安全面临着重大挑战.以杭州市为研究对象,通过计算生态系统服务重要性,叠加MSPA(最小累积阻力模型)分析的核心区,识别出潜在的生态源地;然后引入InVEST模型的生境质量结果,筛选出最终的生态源地;最后选取6类阻力因子分别赋予不同权重,构建综合阻力面,并采用linkage mapper工具提取出生态廊道和生态夹点,构建杭州市生态安全格局.结果表明:(1)杭州市最终的生态源地面积为3 008.64 km^(2),占杭州市面积的22%,生态源地分布合理,特别是西南方向连通性强,有利于物种迁移.(2)通过LM工具提取出15条生态廊道,总长333.4 km,连接不同生态源地,廊道宽度设定在50 m,以保持林地占比最高,从而促进生物迁徙和生态功能的有效发挥.(3)识别出24处待修复关键区域,包括11处核心保护类、3处诊断提升类、8处重点修复类和2处源地贯通区.研究可为杭州市生态廊道修建提供关键区域识别和重点区域修复提升提供科学指导. 展开更多
关键词 形态空间格局分析(MSPA) InVEST模型 linkage mapper(LM)工具 生态廊道 生态夹点
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Effects of grazing disturbance of spatial distribution pattern and interspecies relationship of two desert shrubs 被引量:6
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作者 Lei Zhang Yong Gao +4 位作者 Jinrong Li Chao Zhang Minyu Li Zhao Hu Xiangxin Cui 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第2期507-518,共12页
Grazing significantly affects the distribution,growth,and productivity of shrubs.In this study,we evalu-ated the effects of grazing disturbance on the spatial distri-bution patterns and interspecific relationships of ... Grazing significantly affects the distribution,growth,and productivity of shrubs.In this study,we evalu-ated the effects of grazing disturbance on the spatial distri-bution patterns and interspecific relationships of two desert shrubs,Ammopiptanthus mongolicus and Sarcozygium xan-thoxylon.Three types of grazing conditions were considered,including enclosed area(EA),seasonal rotational grazing area(SRGA),and grazing area(GA)(100 m×100 m),in the West Ordos Nature Reserve of Inner Mongolia,China.The results showed that A.mongolicus and S.xanthoxylon populations were uniformly distributed at a small scale,and the distribution in EA and SRGA became gradually ran-dom.In GA,A.mongolicus population showed aggregated distribution but S.xanthoxylon population showed random distribution at a small scale. Moreover, both A. mongolicus and S. xanthoxylon populations at the 5-7 m scale showed random distribution. At the small and intermediate scales, the two species showed positive interspecific relationships of GA. However, no interspecific relationship was noted between the two species in EA and SRGA. A significant positive relationship (P < 0.01) was noted between the two species at 2-9 m and a negative relationship (P < 0.01) at 13-17 m scales in GA. Positive relationship (P < 0.01) was noted between the two species at 6-13 m scales and a sig-nificant negative relationship (P < 0.01) at 14-24 m scales in SRGA. The two species of desert shrubs showed posi-tive interspecific relationships at the small scale, and they showed negative relationships as the interspecific compe-tition intensified in the presence of grazing disturbance. When the grazing intensity exceeds a certain threshold, the interspecific relationships become weak. Therefore, moder-ate grazing would facilitate interspecific competition and species succession, whereas excessive grazing would disrupt natural competition causing desertification ultimately. 展开更多
关键词 Extending point pattern analysis GRAZING Interspecific relationships Unmanned aerial vehicle(UAV)
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Spatial patterns of Picea crassifolia driven by environmental heterogeneity and intraspecifi c interactions 被引量:4
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作者 Changxing Zhao Weijun Zhao +8 位作者 Ming Jin Jiqiang Zhou Feng Ta Lei Wang Wenbo Mou Longju Lei Jinrong Liu Junlin Du Xinglin Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期949-962,共14页
Research on the spatial patterns of tree populations is critical for understanding the structure and dynamic processes of forests.However,little is known about how the underlying drivers shape these patterns and speci... Research on the spatial patterns of tree populations is critical for understanding the structure and dynamic processes of forests.However,little is known about how the underlying drivers shape these patterns and species interactions in forest systems.In this study,spatial point pattern analysis investigated the combined eff ects of intraspecifi c interactions and environmental heterogeneity on the spatial structure and internal maintenance mechanisms of Picea crassifolia in the Qilian Mountain National Nature Reserve,China.Data were obtained from a 10.2-ha dynamic monitoring plot(DMP)and sixteen 0.04-ha elevation gradient plots(EGPs).Under complete spatial randomness,both mature trees and saplings in the DMP demonstratedlarge-scale aggregation with negative correlations.In EGPs,saplings were clustered in small mesoscales,mature trees were randomly distributed,and the interactions of saplingstrees at all elevations were not correlated.By eliminating the interference of environmental heterogeneity through the inhomogeneous Poisson process,saplings in the DMP and EGPs were clustered in small scales and trees randomly distributed.Intraspecifi c associations were negatively correlated,in the DMP and at low elevations,and no correlations in high elevations of EGPs.In the vertical scale,saplings showed a small-scale aggregation pattern with increase in elevation,and the aggregation degree fi rst decreased and then increased.The interactions of saplings-trees and saplings–saplings showed inhibitions at small scales,with the degree of inhibition gradually decreasing.Spatial patterns and associations of adults–adults did not change signifi-cantly.The results revealed that intraspecifi c interactions and environmental heterogeneity regulated the spatial patterns of P.crassifolia at small and large scales,respectively.Environmental heterogeneity might be the most decisive factor aff ecting the spatial patterns of saplings,while trees were more aff ected by intraspecifi c interactions.Moreover,competition between trees in this area could be more common than facilitation for the growth and development of individuals. 展开更多
关键词 Picea crassifolia Spatial point pattern analysis Intraspecifi c interactions Environmental heterogeneity
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Spatial analysis and structure of a cross-timber stand in the TallGrass Prairie Preserve (Pawhuska, Oklahoma)
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作者 José Ramón Arévalo 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第1期47-52,共6页
I analyzed the spatial distribution and structure of trees in a cross timber forest in the Tallgrass Prairie Preserve (Pawhuska, Oklahoma, USA). I mapped and measured diameter of all stems, saplings (〉1.5 m tall)... I analyzed the spatial distribution and structure of trees in a cross timber forest in the Tallgrass Prairie Preserve (Pawhuska, Oklahoma, USA). I mapped and measured diameter of all stems, saplings (〉1.5 m tall) and dead trees in a 4-ha plot. The stand was dominated by Quercus stellata and Q. marilandica. In total, I mapped 7,636 trees, consisting of 6,785 Q. stellata, 846 Q. marilandica, 2 Celtis occidentalis, 1 Fraxinus pensilvanica and 2 Prunus americana. For saplings, I mapped 54 Q. stellata and 21 Q. marilandica. The size class distribution of the two dominant species did not differ. The dominant mortality class was “standing dead”, while I only found saplings less than 2 m tall. The spatial distribution of the species indicated segregation in the use of the environment, generating a clumped univariate distribution of stems of the same species within radii of 30 m, but repulsion outside 30 m. This segregation can be explained by the different ecological requirements of each species. 展开更多
关键词 CONSERVATION point pattern analysis Quercus stellata Q.marilandica size class distribution
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Regeneration Characteristics and Spatial Pattern of <i>Platycladus orientalis</i>in Mount Tai, China
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作者 Wenhui Li Xiyue Zhao +2 位作者 Jinli Bian Ruiqiang Liu Ruiqiang Ni 《Open Journal of Ecology》 2021年第3期276-286,共11页
Platycladus orientalis is one of the main tree species in Mount Tai, and its sustainable development is of great significance to the protection and development of the forest ecological environment of Mount Tai. In thi... Platycladus orientalis is one of the main tree species in Mount Tai, and its sustainable development is of great significance to the protection and development of the forest ecological environment of Mount Tai. In this study, a representative sample plot of Platycladus orientalis with a size of 30 m * 20 m was selected on Mount Tai. The growth and distribution of the parent trees and seedlings of Platycladus orientalis were investigated in the sample plots. The results showed that both the mother cypress trees and seedlings inside the plot present an aggregated distribution pattern within a certain scale, which conforms to the distribution of most natural communities;and the mother cypress can promote seedlings within a certain scale. Although Platycladus orientalis has good natural regeneration ability, it is difficult to succeed in understory regeneration solely relying on natural fertility, and it is not conducive to the long-term stable development of forest stands. Therefore, the thinning of Platycladus orientalis and the adjustment of the forest stand structure and artificial promotion of natural regeneration can not only reduce operating costs, but also conform to the idea of forest near-natural management and maintain sustainable forest development. 展开更多
关键词 Platycladus orientalis Understory Regeneration point pattern analysis Community Structure Intraspecific Relationship
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黑龙江省森林-城镇交界域火灾分布格局及高发区域时空动态辨识 被引量:1
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作者 关如泓 焦珂伟 +5 位作者 常禹 吕秋爽 李凯莉 郭文华 周思羽 刘志华 《生态学报》 北大核心 2025年第13期6349-6359,共11页
人口增加和城市扩张导致森林-城镇交界域的范围不断扩大,独特的火源条件、可燃物结构及气候变暖导致交界域内的火灾风险急剧上升,严重破环生态环境,威胁人民生命财产安全,研究交界域内火灾发生的空间分布及其驱动因子,能够满足交界域火... 人口增加和城市扩张导致森林-城镇交界域的范围不断扩大,独特的火源条件、可燃物结构及气候变暖导致交界域内的火灾风险急剧上升,严重破环生态环境,威胁人民生命财产安全,研究交界域内火灾发生的空间分布及其驱动因子,能够满足交界域火灾管理和预防策略制定的实际需求。基于黑龙江省1980—2009年的森林火灾数据,采用点格局分析方法,构建交界域内人为火、雷击火的空间分布与驱动因子之间的关系,识别火灾高发区域,分析火灾发生密度的时空动态变化。结果表明:黑龙江省交界域平均林火发生密度为0.0028次km^(-2)a^(-1),气候、植被和地形因子对人为火和雷击火的发生均具有较强的驱动作用;人为火和雷击火的发生具有明显的时空异质性,主要集中于大兴安岭、小兴安岭及黑龙江省东南部。火灾高发区域主要位于北部和东北部的森林地带,近年来并未显著扩张。本研究发展的森林-城镇交界域火灾分布格局及高发区域时空动态辨识方法可有效地评估交界域火灾发生风险,为火灾预防和管理提供科学依据。 展开更多
关键词 森林-城镇交界域 空间点格局分析 林火 时空动态 高发区域
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神农架南坡小叶青冈+曼青冈林木质残体空间分布及地形关联
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作者 刘明伟 赵常明 +7 位作者 陈聪琳 徐凯 徐文婷 熊高明 葛结林 邓滢 申国珍 谢宗强 《生态学报》 北大核心 2025年第5期2374-2385,共12页
木质残体(WD)是森林生态系统的重要组成部分,对群落结构、营养循环、碳储存和生态系统生产力具有重大贡献。以神农架南坡小叶青冈+曼青冈常绿阔叶林为研究对象,把WD分径级Ⅰ(2.5 cm≤d<7.5 cm)、径级Ⅱ(7.5 cm≤d<12.5 cm)、径级... 木质残体(WD)是森林生态系统的重要组成部分,对群落结构、营养循环、碳储存和生态系统生产力具有重大贡献。以神农架南坡小叶青冈+曼青冈常绿阔叶林为研究对象,把WD分径级Ⅰ(2.5 cm≤d<7.5 cm)、径级Ⅱ(7.5 cm≤d<12.5 cm)、径级Ⅲ(d≥12.5 cm),分析群落各径级和各存在形式WD的物种组成、径级结构、空间分布格局及地形关联。结果发现:(1)该群落WD物种组成丰富,共有54种,隶属于25科40属,其中毛黄栌、球核荚蒾和曼青冈的WD数量最多,总体和各存在形式径级结构呈倒“J”型,数量上径级Ⅰ>径级Ⅱ>径级Ⅲ。(2)WD总体空间分布格局随着尺度的增加聚集程度逐渐降低。径级Ⅰ分布趋势与总体类似,径级Ⅱ表现为在整个尺度上聚集和随机分布交替变换,径级Ⅲ主要以随机分布为主;枯立木和倒木分布趋势与径级Ⅰ类似,但倒木从聚集到随机分布的变化发生在更小尺度内;枯桩分布趋势与径级Ⅱ类似,不过聚集与随机分布交替的波动幅度更为平缓。(3)不同径级和不同存在形式WD分布在缓坡地形中的比例较高,物种与地形关联结果显示物种与山脊和沟谷地形之间关联性较显著,与缓坡和陡坡地形无显著关联。研究表明,先锋物种正逐渐被淘汰,该群落处于演替阶段中后期;WD空间格局的形成主要受密度制约、生境过滤和个体自然衰老的影响;缓坡地形是群落中环境条件相对较好的区域,适宜大部分物种的繁殖生长。研究揭示了WD在亚热带北缘常绿阔叶林群落中的数量特征及分布规律,为探索该地区植被演替、地形对生态过程的影响提供了科学依据。 展开更多
关键词 物种组成 点格局分析 群落演替 生境过滤 分布规律
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随机分布条件下种群空斑对点格局分析结果的影响
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作者 李聿泽 王鑫厅 +5 位作者 李海兵 范静宇 姜超 刘芳 李素英 梁存柱 《生态学杂志》 北大核心 2025年第3期1021-1028,共8页
点格局分析是种群格局研究过程中最重要、最常用的方法。种群空斑是影响点格局分析结果的重要因素,其对点格局分析结果的影响关乎种群格局研究结论的可靠性;因此,探讨空斑如何影响点格局分析结果具有重要意义。以随机分布格局为对象,在5... 点格局分析是种群格局研究过程中最重要、最常用的方法。种群空斑是影响点格局分析结果的重要因素,其对点格局分析结果的影响关乎种群格局研究结论的可靠性;因此,探讨空斑如何影响点格局分析结果具有重要意义。以随机分布格局为对象,在5 m×5 m的研究区域内,通过模拟实验设置低、中、高3种密度,选择具有累积效应的K(r)函数和去除累积效应的成对相关函数g(r),在非屏蔽与屏蔽2种情况下,探讨空斑面积的变化如何影响点格局分析结果。结果表明:(1)随着空斑半径的增加,无论K(r)函数还是g(r)函数,在3种密度条件下,空斑达到一定面积时,开始对点格局分析结果产生影响:种群格局由原来的随机分布1种格局类型经过2种格局类型的过渡后转变为3种格局类型共存;(2)空斑对点格局分析结果的影响,K(r)函数和g(r)函数之间存在差异;(3)空斑对点格局分析结果的影响,对于同一分析方法,不同密度条件下,亦存在一定差异;(4)空斑对点格局分析结果的影响,可以通过屏蔽空斑加以规避,且K(r)函数的规避效果比g(r)函数好。 展开更多
关键词 空斑 点格局分析 K(r)函数 g(r)函数 屏蔽
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基于点格局的柠条固沙群落物种空间关联分析
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作者 张力 杨新国 +4 位作者 王磊 张雪 曲文杰 刘荣国 张波 《草地学报》 北大核心 2025年第6期1886-1893,共8页
多样生态过程导致了种群的空间格局变化,进而影响了物种之间的空间关联。从单一固沙灌木构成向灌草复合植被结构的自然演替,系旱区人工固沙植被系统长期管理的目标之一。本文使用点格局分析方法研究腾格里沙漠东南缘30~40年柠条固沙群... 多样生态过程导致了种群的空间格局变化,进而影响了物种之间的空间关联。从单一固沙灌木构成向灌草复合植被结构的自然演替,系旱区人工固沙植被系统长期管理的目标之一。本文使用点格局分析方法研究腾格里沙漠东南缘30~40年柠条固沙群落中柠条和优势草本,以及优势草本之间的空间关系。结果显示:以空间分布关系为指示,柠条(Caragana korshinskii)固沙群落中,柠条种内关系以竞争为主,优势草本植物在小尺度上共生,大尺度上竞争关系占优;柠条与优势草本的空间关系相对复杂,多偏向无相关性。30~40年的柠条固沙群落灌草植被配置依然具有很强的随机性,以灌草间强种间关系为指示的稳定群落构建,尚存不小的距离。植被演替的趋势仍有很大的不确定性。 展开更多
关键词 荒漠草原 柠条 优势草本 点格局分析 空间关联性
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安宁河谷云南松种群年龄结构及点格局分析
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作者 李金桓 刘守江 +2 位作者 余宇首 王自豪 陈曦 《生态科学》 北大核心 2025年第3期135-141,共7页
为了保护作为当地荒山造林,水土保持先锋树种的云南松,探究其种群年龄结构、空间格局、不同生长阶段格局、种间空间关系,以及分布格局的影响因素,本文设置1公顷样地,并采用胸径代替年龄的方法,记录种群年龄结构。点格局采用g(r)成对相... 为了保护作为当地荒山造林,水土保持先锋树种的云南松,探究其种群年龄结构、空间格局、不同生长阶段格局、种间空间关系,以及分布格局的影响因素,本文设置1公顷样地,并采用胸径代替年龄的方法,记录种群年龄结构。点格局采用g(r)成对相关函数,并采取具有不同生态意义的模型对其进行模拟。结果显示年龄结构呈倒“J”型;基于完全随机模型的所有个体格局在1—3m小尺度上聚集强度高,中大尺度逐渐趋于随机、均匀分布。基于异质泊松模型和泊松聚块模型在0—1m上聚集,其余尺度上完全随机;基于完全随机模型不同生长阶段的树都表现出在小尺度上聚集,在其他尺度上趋于随机、均匀分布。而基于异质泊松在不同生长阶段表现出聚集尺度减小,程度降低,甚至完全随机分布;种间空间相关性表现出小树幼树、中树幼树在小尺度上负相关,中树小树在小尺度上正相关,在其余尺度上不相关。大树幼树中大尺度上负相关,大树小树无关,中树大树于1m处负相关。结论:云南松种群更新良好,但受火干扰、阳生灌草的竞争面临着更新困难的问题。总的种群格局以及不同生长阶段的格局表明,种群受到扩散限制、生境异质的作用。各生长阶段有相关关系但不密切,是生境异质、人为干扰、扩散限制等多因素共同导致的。 展开更多
关键词 云南松 点格局分析 年龄结构 空间分布
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武夷山温性针叶林粗木质残体沿海拔梯度的空间点格局
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作者 倪婉龙 常冰冰 +4 位作者 张锦琳 黎棕仁 林文俊 邹向飞 游巍斌 《中南林业科技大学学报》 北大核心 2025年第11期66-77,共12页
【目的】探究武夷山国家公园温性针叶林内森林粗木质物残体空间格局及其沿山地海拔变化规律,为山地针叶林地被层可持续经营和生态保护提供科学依据。【方法】以位于武夷山4个海拔梯度(1300、1400、1500、1600 m)上的温性针叶林为研究对... 【目的】探究武夷山国家公园温性针叶林内森林粗木质物残体空间格局及其沿山地海拔变化规律,为山地针叶林地被层可持续经营和生态保护提供科学依据。【方法】以位于武夷山4个海拔梯度(1300、1400、1500、1600 m)上的温性针叶林为研究对象,在对林内CWD全面普查的基础上;采用点格局方法分析温性针叶林在各海拔中不同特征(存在形式、腐烂等级和径级)CWD的空间格局及其空间关联性。【结果】1)各海拔上不同径级CWD数量特征均为径级Ⅰ>径级Ⅱ>径级Ⅲ;2)枯立木数量占比随海拔上升而增加,而倒木、大枯枝和树桩未呈现相同规律;3)CWD在小尺度(0~4 m)内多呈聚集分布,且该聚集格局的尺度随海拔升高而扩大;4)腐烂等级Ⅰ与腐烂等级Ⅱ的CWD空间关联性随海拔上升逐渐由正空间相关转化为不相关;径级Ⅰ与径级Ⅱ在小尺度上表现为正相关关系,且随着海拔增加其空间相关的尺度也增大。【结论】武夷山温性针叶林CWD在聚集分布尺度、存在形式(特别是枯立木)、不同腐烂等级和径级的空间关联性上均存在沿海拔梯度的依赖格局,研究结果为揭示森林CWD的空间分布特征沿海拔梯度的响应规律提供了新的视角的同时,亦为武夷山温性针叶林森林地被层CWD碳库的海拔格局研究奠定基础。 展开更多
关键词 粗木质残体 点格局分析 海拔 空间关联性
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景观格局对河流水质影响的时空尺度效应及阈值研究
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作者 徐佳妮 邬建红 +6 位作者 杨紫清 邢梦潇 王成 刘东鑫 何圣嘉 张方方 姜培坤 《环境科学学报》 北大核心 2025年第12期394-404,共11页
研究景观格局与水质的关系有助于优化景观规划,并为水质保护提供理论依据.然而,由于水质对景观格局的响应存在尺度依赖性和非线性特点,目前对此关系的理解仍不充分.本研究以青山湖流域为例,选取26个监测点测定河流总氮(TN)、硝态氮(NO_(... 研究景观格局与水质的关系有助于优化景观规划,并为水质保护提供理论依据.然而,由于水质对景观格局的响应存在尺度依赖性和非线性特点,目前对此关系的理解仍不充分.本研究以青山湖流域为例,选取26个监测点测定河流总氮(TN)、硝态氮(NO_(3)^(-)-N)、铵态氮(NH_(4)^(+)-N)、总磷(TP)和溶解氧(DO),采用相关性分析、冗余分析和非参数突变点分析,定量评估不同时空尺度上景观格局对河流水质的影响,并识别沿景观梯度引起水质突变的关键景观阈值.结果表明:①研究区内TN、NO_(3)^(-)-N、TP和DO浓度在枯季显著高于洪季,TN、TP和NH_(4)^(+)-N浓度呈现显著的空间变异性(p<0.05).②景观格局对枯季水质变化的解释率比洪季高3.0%~7.8%.在枯季,子流域尺度景观格局对水质变化的解释力强于缓冲区尺度,而洪季则相反,表明水质响应具有明显的尺度差异性,景观调控应结合多尺度协同施策.③在子流域尺度,建设用地占比(PLAND3)和耕地散布分裂程度(IJI2)是影响枯季水质的关键景观因子;而在缓冲区尺度,林地散布分裂程度(IJI1)和林地聚集度指数(AI1)对洪季水质影响显著.④当子流域尺度PLAND3>12.6%、IJI2<82.5%时,河流水质恶化的风险显著增加.综上,本研究揭示了景观格局对水质的时空尺度效应及关键的景观阈值特征,为中国东部丘陵源头小流域水环境管理与景观规划提供了科学依据. 展开更多
关键词 景观格局 水质 非参数突变分析 尺度效应 阈值
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珍稀濒危水生植物靖西海菜花的种群空间格局与种内关联性 被引量:2
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作者 李峻峰 高鸿灿 +3 位作者 殷根深 梁梓煜 杨晓虹 翟书华 《生态学杂志》 北大核心 2025年第7期2150-2156,共7页
为了解珍稀濒危水生植物靖西海菜花(Ottelia acuminata var.jingxiensis)的种群动态、生存能力及其对环境的适应性,本研究以分布于河池澄江河和百色靖西鹅泉河的靖西海菜花种群为对象,采用点格局分析方法,对靖西海菜花各级株丛的空间格... 为了解珍稀濒危水生植物靖西海菜花(Ottelia acuminata var.jingxiensis)的种群动态、生存能力及其对环境的适应性,本研究以分布于河池澄江河和百色靖西鹅泉河的靖西海菜花种群为对象,采用点格局分析方法,对靖西海菜花各级株丛的空间格局及空间关联性进行研究。结果表明:两个样地内的靖西海菜花种群Ⅲ级株丛占比均高于Ⅰ级和Ⅱ级株丛占比;喀斯特地貌的水环境使靖西海菜花种群出现特殊的分布模式,两个样地内的靖西海菜花种群均表现小尺度下为聚集分布,随着尺度的增大,聚集程度由聚集分布转变为随机分布或均匀分布;两个样地内的Ⅰ级株丛与Ⅱ级株丛、Ⅲ级株丛皆表现为在小尺度下正关联,大尺度下负关联;靖西海菜花种群中幼苗严重不足,其种群更新正处于负增长阶段,在小尺度下植株呈聚集分布,且各等级间互利依赖是靖西海菜花种群适应其生长环境的一种生存策略。 展开更多
关键词 靖西海菜花 点格局分析 空间分布格局 种内关联性
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Spatial Structure and Development of Tourism Resources based on Point Pattern Analysis: A Case Study in Hainan Island, China 被引量:4
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作者 ZHANG Tongyan WANG Yingjie +2 位作者 WANG Yingying ZHANG Shengrui YU Hu 《Journal of Resources and Ecology》 CSCD 2022年第6期1058-1073,共16页
Tourism resources are the basic materials of tourism development, and they also provide the support for regional tourism spatial competition. The development of tourism depends on the degree to which tourism resources... Tourism resources are the basic materials of tourism development, and they also provide the support for regional tourism spatial competition. The development of tourism depends on the degree to which tourism resources are utilized, and it is of great guiding significance for their development and utilization to study their spatial structure. Based on a large sample of data on tourism resources, and starting from the characteristics of multi-type,multi-level and multi-combination, this paper puts forward a framework and method for analyzing the spatial structure of tourism resources. Taking Hainan Island as an example, this paper describes the spatial structure of tourism resources in Hainan Island by using the method of point pattern analysis, identifies the tourism resource development zones, and puts forward some suggestions for the development of tourism resources. The results are as follows:(1) The characteristic scale of the spatial structure of tourism resources in Hainan Island is 30.5 km, and there are significant differences in the distributions of all kinds of tourism resources.(2) Through the spatial structure map of tourism resources, the tourism resource development zones are identified, including three tourist central city levels, “one horizontal and three vertical” tourist belts and four tourist combination areas.(3) By combing the distribution of tourism resources and the development zones in Hainan Island, the cross-border characteristics of the tourism resources and development zones are obvious. In order to give full play to the spatial combination and superposition effect of tourism resources, a change from a single isolated development mode to the overall combined development between regions is suggested. On the provincial scale, it is relatively accurate to describe the spatial structure of tourism resources for point data with a large sample size. However, the method of point pattern analysis can not only accurately describe the spatial structure of tourism resources, but it can also provide reference for other types of regional spatial analyses. The research results provide a scientific basis for the spatial planning of regional tourism resources and have practical significance for the development of regional tourism. 展开更多
关键词 tourism resources spatial structure development area point pattern analysis method Hainan Island China
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黄河源东部祁连圆柏种群动态及空间分布
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作者 刘蕴 勾晓华 +3 位作者 纪泽延 李轩 王子博 杨开轩 《兰州大学学报(自然科学版)》 北大核心 2025年第6期779-788,共10页
利用种群生态学和点格局分析方法,对黄河源森林优势树种祁连圆柏种群动态和空间分布格局进行系统性研究.结果表明,祁连圆柏年龄结构完整,属于增长型种群,更新能力随海拔升高而增强;存活曲线接近Deevey-Ⅲ型,表明幼龄期死亡率偏高;动态... 利用种群生态学和点格局分析方法,对黄河源森林优势树种祁连圆柏种群动态和空间分布格局进行系统性研究.结果表明,祁连圆柏年龄结构完整,属于增长型种群,更新能力随海拔升高而增强;存活曲线接近Deevey-Ⅲ型,表明幼龄期死亡率偏高;动态指数显示其对外界干扰高度敏感,时间序列预测未来种群动态更新趋势良好;在0~1 m尺度上呈聚集分布,更大尺度上为随机分布.祁连圆柏种群在研究区具有一定增长潜力,分布模式在不同空间尺度上存在差异,且对环境变化反应灵敏,预示着种群未来有良好的发展趋势. 展开更多
关键词 祁连圆柏 黄河源 种群动态 点格局分析
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