| 引用本文: | 张成,陈文波.基于生境-生物一体化视角的鄱阳湖草洲景观连通度研究.湖泊科学,2023,35(4):1380-1396. DOI:10.18307/2023.0432 |
| Zhang Cheng,Chen Wenbo.Landscape connectivity of grassland in Lake Poyang from the integrated perspective of habitat and biology. J. Lake Sci.2023,35(4):1380-1396. DOI:10.18307/2023.0432 |
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| 基于生境-生物一体化视角的鄱阳湖草洲景观连通度研究 |
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张成1,2,3, 陈文波1
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1.东华理工大学测绘与空间信息工程学院, 南昌 330013;2.江西农业大学国土资源与环境学院, 南昌 330045;3.江西农业大学南昌市景观与环境重点实验室, 南昌 330045
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| 摘要: |
| 分析景观连通度动态变化特征是研究景观生态过程的重要途径,也是维持区域生物多样性的重要手段。本文以鄱阳湖草洲为研究对象,立足于影响景观连通度的生境(水位变化)与生物(物种扩散)一体化视角,在识别不同水位梯度下草洲生境范围和斑块组成的基础上,利用景观格局指数分析不同水位梯度下草洲景观结构连通度的变化特征,通过基于图论的景观连通度方法对草洲景观功能连通度分别进行不同水位梯度和不同扩散距离下的情景模拟,并剖析景观结构连通度与功能连通度的相关关系。结果表明:(1)鄱阳湖草洲呈现“水落滩出、水进草退”的景观特征,草洲生境同时面临水体的淹没效应和分割效应。随着水位的增加,草洲分布范围不断缩小,大斑块破碎与小斑块消失并存。(2)从水位变化过程来看,随着水位的增加,草洲斑块的面积不断萎缩、形状趋于简单、密度减小、破碎化程度加剧,草洲景观结构连通度下降。此外,随着水位的增加,草洲斑块在生态功能上的链接数减少、难以连接的独立组分增加、连接的可能性降低,草洲景观功能连通度降低。(3)从物种扩散过程来看,物种扩散距离对草洲景观功能连通度具有绝对正向作用,随着扩散距离的增加,草洲景观功能连通度显著增大。(4)相关性分析结果显示,表征功能连通度水平的Flux指数(F)与表征结构连通度水平的斑块密度(PD)、边缘密度(ED)呈现显著的正相关关系;可能连接度指数(PC)与最大斑块指数(LPI)和凝聚度(COHESION)的正相关性最显著,而与周长面积分维数(PAFRAC)呈负相关;链接数(NL)与LPI、ED、COHESION呈负相关,且相关系数随着物种扩散距离的增大而增大。研究结果可为鄱阳湖草洲生境的保护和管理提供科学参考。 |
| 关键词: 鄱阳湖 草洲 水位变化 物种扩散 景观连通度 |
| DOI：10.18307/2023.0432 |
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| 基金项目:国家自然科学基金项目(42261021,41961036)资助。 |
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| Landscape connectivity of grassland in Lake Poyang from the integrated perspective of habitat and biology |
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Zhang Cheng1,2,3, Chen Wenbo1
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1.College of Surveying and Spatial Information Engineering, East China University of Technology, Nanchang 330013, P. R. China;2.College of Land Resource and Environment, Jiangxi Agricultural University, Nanchang 330045, P. R. China;3.Key Laboratory of Landscape and Environment, Jiangxi Agricultural University, Nanchang 330045, P. R. China
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| Abstract: |
| Analyzing dynamic changes of landscape connectivity is an important way to study landscape ecological process, and an important method to maintain regional biodiversity. Taking the grassland of Lake Poyang as an example, based on the integrated perspective of habitat (water level change) and biology (species dispersal), this study firstly identified the range and composition of grassland patches under different water levels. Then, landscape pattern indices were used to analyze the dynamics of grassland structural connectivity at different water levels. We also applied the graph theoretical approach to analyze the changes of grassland functional connectivity with different water levels and compared scenarios for different dispersal distances. Finally, we further discriminated the correlation between landscape structural connectivity and functional connectivity. The results showed as follows: (1) The grassland presented the characteristics of “expanding when water falls while retreating when water rises”. The grassland patches faced both the segmentation effect and the inundation effect of water. With the increase of water level, the distribution of grassland was gradually shrinking, and the fragmentation of large patches and the disappearance of small patches coexisted. (2) From the perspective of water level change, with the water level increased from 7.54 m to 17.17 m, the patch area shrank, the patch shape tended to be simple, the patch density decreased, the patch fragmentation aggravated, and then grassland structural connectivity decreased progressively. Meanwhile, with the increase of water level, the number of links between patches decreased, the number of components increased, the probability of connectivity decreased, and then grassland functional connectivity decreased significantly. (3) From the perspective of species dispersal, the species dispersal distance had an absolutely positive impact on landscape functional connectivity. With the increase of dispersal distance, grassland functional connectivity increased dramatically. (4) The correlation results between structural connectivity indices and functional connectivity indices indicated that flux index (F) had a significant positive relationship with patch density (PD) and edge density (ED), and probability of connectivity (PC) had a strong significant positive relationship with largest patch index (LPI), COHESION, while a negative correlation with PAFRAC. The number of components (NC) had a negative relationship with LPI, ED, COHESION, and the correlation coefficients became much larger with the increase of dispersal distance. This study provides theoretical guidance for the conservation and management of grassland habitat in Lake Poyang. |
| Key words: Lake Poyang grassland water level change species dispersal landscape connectivity |
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