scholarly journals Constructing and optimizing urban ecological network in the context of rapid urbanization for improving landscape connectivity

2021 ◽  
Vol 132 ◽  
pp. 108319
Author(s):  
Xinxin Huang ◽  
Haijun Wang ◽  
Luyi Shan ◽  
Fengtao Xiao
Keyword(s):  
Landscape Connectivity ◽  
Ecological Network ◽  
Rapid Urbanization

scholarly journals Assessing the Impact of Urban Expansion on Surrounding Forested Landscape Connectivity across Space and Time

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 359
Author(s):  
Zhouqiao Ren ◽  
Jianhua He ◽  
Qiaobing Yue
Keyword(s):  
Landscape Connectivity ◽  
Urban Expansion ◽  
Landscape Fragmentation ◽  
Sustainable Urban Development ◽  
Delayed Response ◽  
Conservation Practices ◽  
Rapid Urbanization ◽  
Dynamic Landscapes ◽  
The Impact ◽  
Over Time

Landscape connectivity is important for all organisms as it directly affects population dynamics. Yet, rapid urbanization has caused serious landscape fragmentation, which is the primary contributor of species extinctions worldwide. Previous studies have mostly used spatial snap-shots to evaluate the impact of urban expansion on landscape connectivity. However, the interactions among habitats over time in dynamic landscapes have been largely ignored. Here, we demonstrated that overlooking temporal connectivity can lead to the overestimation of the impact of urban expansion. How much greater the overestimation is depends on the amount of net habitat loss. Moreover, we showed that landscape connectivity may have a delayed response to urban expansion. Our analysis shifts the way to understand the ecological consequences of urban expansion. Our framework can guide sustainable urban development and can be inspiring to conservation practices under other contexts (e.g., climate change).

Changes in ecological networks and eco-environmental effects on urban ecosystem in China’s three typical urban agglomerations

2020 ◽  
Author(s):  
Ying Fang ◽  
Jing Wang ◽  
Jingjing Liu ◽  
Zehui Li
Keyword(s):  
Ecosystem Services ◽  
Human Activities ◽  
Carbon Stock ◽  
Quality Index ◽  
Urban Ecosystem ◽  
Ecological Networks ◽  
Ecological Network ◽  
Rapid Urbanization ◽  
Urban Agglomerations ◽  
Ecosystem Carbon

<p>Rapid urbanization caused a massive loss of natural habitats and seriously changed urban natural ecosystems. Ecological network, a spatial concept of ecosystems, maps the most valuable areas that provide multiple ecological goods and services for human demands. Ecological network has long been adopted worldwide for improving urban ecological environment under the scenarios of rapid urbanization. However, Little researches focused on changes in ecological networks and their effects on urban ecosystem. It is important to investigate the trends in ecological network changes, clear its relationship with human activities and policies for guiding sustainable economic and social development. The study aimed to analyze the relationship between the changes in ecological networks and human activities, regional policies as well as environmental changes, and to establish new ecological networks that meet the human demands of ecosystem services, in China’s three typical urban agglomerations, including Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), and Pearl River Delta (PRD) from 2000 to 2015.This study used the variation of habitat quality index, ecosystem carbon stock, PM<sub>2.5</sub> and supply-demand of ecosystem services to measure the eco-environmental effects of ecological network changes under complex physical and socio-economic circumstances. Meanwhile, it established the new ecological networks based on the human-being demand of ecosystem services calculated by real-time population distribution, accessibility, and land development index, trying to optimize the land spatial patterns and ecosystem management in urban agglomerations. The results showed that a lot of areas of ecological networks had vanished into dryland, urban land and other developed land from 2000 to 2015, resulting from urban expansion, industrial development and regional land policies. The degradation in ecological networks caused a significant increase of PM<sub>2.5</sub> and decrease of habitat quality index and ecosystem carbon stock. And the spatial imbalance in the supply-demand of ecosystem services was shrinking to varying degrees, due to different regional ecological protection policies. There were regional spatial differences in the establishment of new ecological networks. However, the closer to central cities of each agglomerations, the human demands of ecosystem services and the need of strengthening the preservation ecosystems were more critical. This study contributes to the identifying the role of human activities on ecological processes and provides a scientific reference for the use of ecological network as the basis of the regional development plans. It is necessary to relieve the dilemma between the urban growth and ecosystem protection.</p>

scholarly journals Spatio-Temporal Dynamics of Landscape Connectivity and Ecological Network Construction in Long Yangxia Basin at the Upper Yellow River

Land ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 265 ◽  
Author(s):  
Fangning Shi ◽  
Shiliang Liu ◽  
Yi An ◽  
Yongxiu Sun ◽  
Shuang Zhao ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Yellow River ◽  
Landscape Connectivity ◽  
Natural Habitat ◽  
Cultivated Land ◽  
Landscape Resistance ◽  
Ecological Network ◽  
Natural Habitats ◽  
Yellow River Valley ◽  
Upper Yellow River

Analyzing multi-scale changes in landscape connectivity is an important way to study landscape ecological processes and also an important method to maintain regional biodiversity. In this study, graph-based connectivity was used to analyze the dynamics of the connectivity of natural habitats in the Long Yangxia basin of upper Yellow River valley from 1995 to 2015. We used the core areas of the nature reserves as the source regions to construct ecological networks under different thresholds, so as to identify key areas that can maintain overall landscape connectivity. The results showed that, from 1995 to 2015, the landscape connectivity in the study area increased for the first 10 years, and, since 2005, has declined. On a spatial scale, we found that both the connectivity of the ecological network and the length of the corridor increased with landscape resistance. Our analysis demonstrates the importance of the natural habitat in the southern part of the study area where connectivity was higher, as well as the sensitivity of connectivity of the northern area to human activities. Both large and medium patches contribute greatly to the overall landscape connectivity, while attention needs to be paid to the protection and management of small patches as they played “stepping stone” roles in maintaining and improving landscape connectivity. The proportions of landscape types that served as corridors, listed in order of their contribution to connectivity, were grassland, forestland, wetland and cultivated land. This suggests that, in addition to focusing on the protection of grassland and forest land, the reasonable planning and utilization of wetland and cultivated land will also have an impact on landscape connectivity. In addition, the protection of and improvement in habitats in the Sanjiangyuan Nature Reserve is of great significance to enhance landscape connectivity. Our study provides a scientific basis to support and improve regional landscape connectivity and biodiversity conservation over the next decade.

scholarly journals Promoting landscape connectivity of highly urbanized area: An ecological network approach

2021 ◽  
Vol 125 ◽  
pp. 107487
Author(s):  
Shuang Wang ◽  
Maoquan Wu ◽  
Mengmeng Hu ◽  
Chen Fan ◽  
Tao Wang ◽  
...  
Keyword(s):  
Landscape Connectivity ◽  
Network Approach ◽  
Ecological Network ◽  
Urbanized Area

scholarly journals Identifying Ecological Corridors and Networks in Mountainous Areas

2021 ◽  
Vol 18 (9) ◽  
pp. 4797
Author(s):  
Di Zhou ◽  
Wei Song
Keyword(s):  
Landscape Connectivity ◽  
Effective Means ◽  
Ecological Networks ◽  
Habitat Destruction ◽  
Spatial Pattern Analysis ◽  
Cultivated Land ◽  
Ecological Network ◽  
Network Efficiency ◽  
Mountain Areas ◽  
Ecological Corridors

Since the 1950s, human activities have been driving economic development and land changes, hindering the conservation of biological habitats and landscape connectivity. Constructing ecological networks is an effective means to avoid habitat destruction and fragmentation. Mountain areas are hotspots of biological habitats and biodiversity; however, the pace of urbanization in mountain areas is also accelerating. To protect an ecosystem more effectively, it is necessary to identify ecological corridors and ecological networks. Therefore, based on the Minimal Cumulative Resistance model and taking Chongqing in China as an example, the identification of potential ecological corridors and the construction of an ecological network in Chongqing were realized using the Linkage Mapper software. The results were as follows: (1) From 2005 to 2015, the patch area of cultivated land and grassland in Chongqing decreased by 0.08% and 1.46%, respectively, while that of built-up areas increased by 1.5%. The fragmentation degree of cultivated land was higher, and the internal connectivity of forestry areas was worse. (2) In total, 24 ecological sources were selected, and 87 potential ecological corridors and 35 ecological nodes were generated using the Morphological Spatial Pattern Analysis and the Conefor2.6 software. The total length of the ecological network in Chongqing is 2524.34 km, with an average corridor length of 29.02 km. (3) The overall complexity and network efficiency are high, but the spatial distribution of ecological corridors is uneven, especially in the southwest of Chongqing.

scholarly journals The Effects of Rapid Urbanization on Forest Landscape Connectivity in Zhuhai City, China

2018 ◽  
Vol 10 (10) ◽  
pp. 3381 ◽  
Author(s):  
Nan Cui ◽  
Chen-Chieh Feng ◽  
Dan Wang ◽  
Jianfei Li ◽  
Luo Guo
Keyword(s):  
Environmental Protection ◽  
Landscape Connectivity ◽  
Scientific Evidence ◽  
Urban Forests ◽  
Forest Landscape ◽  
Theoretic Approach ◽  
Rapid Urbanization ◽  
Graph Theoretic ◽  
Comprehensive Information ◽  
Protection Strategies

Urban forests can provide the necessary ecosystem services for their residents and play an important part in improving the urban environment. Forest landscape connectivity is a vital indicator reflecting the quality of the ecological environment and ecological functions. Detecting changes in landscape connectivity is, therefore, an important step for providing sound scientific evidence for the better urban planning. Using remote sensing images of a study area in Zhuhai City in 1999, 2005, 2009 and 2013, the dynamic forest landscape connectivity of Zhuhai city can be evaluated based on a graph-theoretic approach. The aims of our study were to discover and interpret the effect of rapid urbanization on forest landscape connectivity. The construction of ecological corridors helps us specifically compare the landscape connectivity of three parts of urban forests. On the basis of functional landscape metrics, the correlation of these metrics and patch area was discussed in order to comprehensively identify the key patches. The analysis showed that the total areas of forestlands reduced from 1999 to 2009 and then increased from 2009 to 2013, and the same trend was found in overall forest landscape connectivity. To improve the overall landscape connectivity, construct urban ecological network and appropriately protect biodiversity in the future, the existing important patches with large areas or key positions should be well protected. This study revealed that urbanization reduced the area of key patches and consequently reduced the forest landscape connectivity, which increased while the patch areas increased due to the environmental protection policy. Functional connectivity indicators could provide more comprehensive information in the development of environmental protection strategies.

scholarly journals Analysis of Forest Landscape Restoration Based on Landscape Connectivity: A Case Study in the Yi River Basin, China, during 2015–2020

Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 904
Author(s):  
Ziqi Bian ◽  
Lyuyi Liu ◽  
Shengyan Ding
Keyword(s):  
Landscape Connectivity ◽  
Landscape Management ◽  
Forest Landscape ◽  
Landscape Restoration ◽  
Forest Patches ◽  
Rapid Urbanization ◽  
Forest Landscape Restoration ◽  
The Status ◽  
Ecological Conservation

Landscape connectivity has widely been recognized as one of the key objectives in studies of forest landscape management, ecological conservation and construction. Protecting virgin forests and afforesting marginal cropland are two long-term ecological projects in China. However, along with rapid urbanization and industrialization in China, the relationship between landscape connectivity and forest landscape restoration (FLR) has not been fully explored. The emergent question concerns whether the connectivity of a restored forest landscape could benefit the local flora and fauna. We evaluated the status of FLR in the Yi River watershed based on remote sensing images during 2015–2020. The forest landscape connectivity (FLC) was investigated using landscape connectivity indicators, applying the theory of landscape connectivity. We also examined the variations of FLC under different landform types (hills and low mountains) according to distance threshold values ranging from 100 m to 20,000 m. The most appropriate distance thresholds for analyzing FLC in hills and low mountains are 500 m and 100 m, respectively. The results showed that in this period, the FLC in low mountains was increased, whereas that of hills was decreased. The contributions for reforested patches on the improvement of the FLC were evaluated. In hills, patches that made “very high” and “high” contributions to improve the FLC occupied 15.6% of the total reforested area, whereas the proportion in low mountains was 25.5%. The results indicated that although rainfed cropland patches have been converted to forest patches, some of them have made small contributions to the FLC. Through this case study, we hope to have confirmed that landscape connectivity analysis could be used as a criterion for selecting important patches in the planning of FLR. Moreover, we have introduced this implementable method for future ecological restoration management programs.

scholarly journals Graph-based multi-attribute decision making: impact of road fencing on ecological network

2015 ◽  
Vol 10 (2) ◽  
pp. 105-111
Author(s):  
Andrius Kučas
Keyword(s):  
Patch Size ◽  
Landscape Connectivity ◽  
Decision Support Techniques ◽  
Conservation Priorities ◽  
Minimum Length ◽  
Habitat Patch ◽  
Ecological Network ◽  
Habitat Patches ◽  
The Road ◽  
Spatial Graph

Conservation and transport decision makers must deal with many competing criteria in order to find the optimal connectivity of habitat patches in order to maximize organisms’ ability to traverse the landscape successfully. Thus, there is an increasing interest in prioritization of habitat patches by their contribution to overall landscape connectivity. Many different indices can be used to quantify structural and functional landscape connectivity. However, landscape connectivity indices alone do not clearly define conservation priorities for habitat patches. In this study priority values for each available habitat patch were calculated using multiple criteria spatial decision support techniques. As criteria for prioritization, spatial graph-based element properties (habitat patch size, number of corridors connected to a habitat patch, etc.) were characterized for each habitat patch. Graph-based connectivity rules for each habitat patch within a landscape (in conjunction with largest patch size, maximum number of corridors with a minimum length connected to a habitat patch, etc.) were defined and applied. Each criterion’s importance was assessed. Criteria-based ranking of habitat patches within a graph better indicated exact critical habitat patches than connectivity index alone, especially when changes in network occur. Simulations in the case study of Lithuania showed that barriers (road fences to keep animals off the road) without prompt establishment of animal crossings may realign complexes of an ecological networks by reducing the importance of adjacent and increasing the importance of more distant patches. Such distant patches may become essential, and can sometimes be the only elements preserving the realigned ecological network.

Modeling and protecting global ecological networks

2021 ◽  
pp. 2150046
Author(s):  
Xinmiao Sun ◽  
Ruiqi Li
Keyword(s):  
Trophic Level ◽  
Human Activities ◽  
Degree Distribution ◽  
Small World ◽  
Volterra Model ◽  
Local Network ◽  
Ecological Network ◽  
Rapid Urbanization ◽  
Local Networks ◽  
Quantitative Changes

With the rapid urbanization worldwide and ever-increasing impacts of human activities since at least 200 years ago, we are now facing a harsh situation of our biosphere. Building a global-level network model on ecological systems is of great importance, which would be able to provide us predictive and quantitative responses to human activities, leading to viable suggestions to policymakers. In this paper, we propose a multi-layer model for the global ecological network, where a number of local networks are connected via long-range interactions associated with migrant species, which can be induced by human activities or natural migration of wildlife, and each local network is generated by a trophic-level-based stochastic model. Predator–prey dynamics is described by a networked Lotka–Volterra model that accounts for the self-suppression effects on basal species, and the negative feedback loops. Impacts of human activities are modeled by investigating the quantitative changes of biodiversity under certain protecting strategies. We reveal that the global ecological network is organized in a clustered small-world manner, with in-degree distribution more heterogeneous than out-degree distribution. Protecting endangered species, popular preys and predicted-to-be-extinct species is more effective than randomly selected species or influential predators. Protecting after entering the fast extinction stage is more effective than at the beginning for some high trophic level species.

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