Forest Landscape Connectivity Research Articles

Spatiotemporal Changes in Ecological Quality and Its Response to Forest Landscape Connectivity—A Study from the Perspective of Landscape Structural and Functional Connectivity

Spatiotemporal Changes in Ecological Quality and Its Response to Forest Landscape Connectivity—A Study from the Perspective of Landscape Structural and Functional Connectivity

The Evolution of Forest Landscape Connectivity and Ecological Network Construction: A Case Study of Zhejiang’s Ecological Corridors

As main components of terrestrial ecosystems, forests play irreplaceable roles in maintaining ecological balance and protecting the basic environment for human survival and development. In this study, the dynamic changes in the forest landscape connectivity in Zhejiang province in 2000, 2010, and 2020 were detected by identifying ecological sources and evaluating connectivity indexes based on morphological spatial analysis (MSPA) and a minimum cumulative resistance (MCR) model. The results are as follows: (1) The forest area of Zhejiang increased by 64.88% from 2000 to 2020, indicating that the overall habitat quality has improved and that ecological risks have decreased, which are attributed to Zhejiang’s adherence to comprehensive environmental management. (2) Regions with low connectivity are distributed mainly in the north, where human activities are intensive. The overall pattern of high connectivity in the middle of the region and low connectivity elsewhere demonstrates the uneven distribution of forest landscape connectivity across the province. (3) The extracted ecological corridors have a mesh-like structure that is dense in the middle and slack in the north. Important corridors have disappeared over time, indicating potential issues in maintaining connectivity for species migration. (4) These results can provide optimization strategies for ecological infrastructure planning in Zhejiang province and offer a theoretical reference for the optimization of the ecological network system.

Host vegetation connectivity is decisive for the natural spread of pine wilt disease.

Pine wilt disease has caused significant economic, ecological, and social losses in China, but there is a notable lack of research on the dynamic process of its propagation and diffusion over long timescales. This study revealed the spatial and temporal spread of the natural invasion of pine wilt disease through an analysis of long time series at macroscopic scales. We analysed and verified by simulations the driving mechanisms of host and wind fields in the natural spread of pine wilt disease. The research findings indicate that from 1982 to 2019, the number of counties affected by pine wilt disease in the Yangtze River Delta region of China exhibited a pattern of 'steady increase-fluctuation-outbreak'. The host forest played a decisive role in the natural spread of the disease, while the wind field played a supporting role. The study revealed specific contributions from various factors, where host forest landscape connectivity, host forest area share, mean wind speed, and wind frequency accounted for 31.8%, 28.7%, 22.6%, and 8.8%, respectively. The interaction of increased host forest area and increased wind speed can significantly increase the risk of pine wilt disease transmission. To validate these findings, vectorial metacellular automata simulations of pine nematode transmission in the Yangtze River Delta were conducted, yielding results with an accuracy of 0.803. By quantifying the contribution of host forest connectivity to the natural spread of pine wilt disease, this research offers a scientific foundation and innovative insights for preventing and controlling its dissemination. © 2024 Society of Chemical Industry.

Establishing an Ecological Network to Enhance Forest Connectivity in South Korea’s Demilitarized Zone

This investigation delineated an ecological network within South Korea’s Demilitarized Zone (DMZ) to enhance ecosystem functionality, with a focus on forest landscape connectivity. The study employed spatial autocorrelation analysis and the minimum cumulative resistance model to identify key source patches. These patches are vital for maintaining connectivity across various topographies and land uses in the DMZ. Morphological spatial pattern analysis in the DMZ’s forest area showed a variation in forest patch types. The core class, less affected by external influences, was more prevalent in the eastern part. In contrast, the edge class, influenced by different environmental boundaries, was dominant in the western part. A 452.36 km long ecological network was constructed, serving as an essential corridor linking habitats of endangered species. This network covers a total forest area of 730.17 km2, which includes an existing forest protection area of 165.84 km2 (22.7%). The study also identified 564.33 km2 (77.3%) of previously non-designated forest regions as potential conservation areas. This aims to significantly increase forest connectivity within the DMZ. The research highlights the effectiveness of spatial planning tools in promoting ecosystem integrity in politically sensitive and restricted-access areas.

Forest landscape connectivity to prioritize afforestation in urban ecosystems: Seoul as a case study

Forest landscape connectivity is a key indicator that reflects the quality and function of the ecological environment. In urban ecosystems, analysis frameworks are needed to prioritize and optimize afforestation projects that maintain and increase forest landscape connectivity to help mitigate the increasing fragmentation of urban habitats, coordinate the relationship between urban development and urban ecosystem services, and guide decision making processes. The objective of this study is to identify forest patches that are most worth conserving and small patches that make the most significant contribution to landscape connectivity after their transformation into forest patches in a high-density city. We conducted a case study in Seoul, South Korea, where we initially quantified the landscape connectivity changes from 2001 to 2018 using the probability of connectivity (PC) and integral index of connectivity indices. Subsequently, we calculated the importance of each forest patch for four different years and ranked the potential contribution of each patch based on data from 2018 using the delta values for PC index (dPC). Our results showed that forest landscape connectivity in Seoul increased significantly from 2001 to 2018. In all four years, the ten forest patches with the highest dPC values remained nearly unchanged and were large in size; however, the individual area of each patch was not strictly related to its importance for connectivity. Based on these findings, we further examined the potential effect that the afforestation of habitat patches smaller than 20 ha would have on the overall forest landscape connectivity in Seoul. We also identified the 50 most important patches for afforestation using six land use and land cover types to provide a guide for effective afforestation efforts in Seoul. We expect that this study could enhance the effectiveness of habitat connectivity intervention while providing a realistic strategy for ecological afforestation planning in urban ecosystems.

Forest Fragmentation and Landscape Connectivity Changes in Ecuadorian Mangroves: Some Hope for the Future?

This study investigates the impact of fragmentation on Ecuador’s coastal mangrove forests. Fragmentation is identified as a primary cause of aquatic ecosystem degradation. We analyzed the relationship between habitat loss, fragmentation, and mangrove connectivity through a multitemporal approach using Global Mangrove Watch and fragmentation and connectivity metrics. The terrain was divided into 10 km2 hexagons, and six fragmentation metrics were calculated. A Getis–Ord Gi* statistical analysis was used to identified areas with the best and worst conservation status, while connectivity analyses were performed for a generic species with a 5 km dispersion. Findings revealed widespread mangrove fragmentation in Ecuador, with geographical differences between the insular region (Galapagos) and the mainland coast. Minimal loss or even expansion of mangrove forests in areas like the Galapagos Islands contrasted with severe fragmentation along the mainland coast. Transformation of forests into fisheries, mainly prawn factories, was the primary driver of change, while only a weak correlation was observed between mangrove fragmentation and conversion to agriculture, which accounts for less than 15% of all deforestation in Ecuador. Fragmentation may increase or decrease depending on the management of different deforestation drivers and should be considered in large-scale mangrove monitoring. Focusing only on mangrove deforestation rates in defining regional conservation priorities may overlook the loss of ecosystem functions and fragmentation.

基于MSPA分析的福建省生态网络构建

PDF HTML阅读 XML下载 导出引用 引用提醒 基于MSPA分析的福建省生态网络构建 DOI: 10.5846/stxb202107101863 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31971639）；福建省自然科学基金项目（2019J01406） Construction of ecological network in Fujian Province based on Morphological Spatial Pattern Analysis Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:快速城镇化进程导致森林景观破碎化、连通性下降，严重威胁区域可持续发展、生物多样性保护和生态服务能力的维持。生态网络构建是提高景观连接度，维持物种扩散过程，保护生物多样性的有效手段。以福建省为例，借助形态学空间格局分析（MSPA）探讨2000、2010和2020年的森林景观结构动态变化，并在利用组分数（NC）与整体连通性指数（IIC）确定适宜距离阈值的基础上，根据可能连通性指数（PC）筛选生态源地；从人-地关系角度选择路网分布、建设用地分布、土地覆盖类型、坡度四种评价因子构建阻力面，采用最小阻力模型（MCR）提取生态廊道形成初步生态网络，进一步计算PC指数对生态廊道进行重要性分级；最后基于图论法，利用闭合度α、线点率β、网络连接度γ对所构建的生态网络进行定量评价。结果表明：（1）近20年来福建省森林景观结构较为稳定，其中核心区占比高达76.27%，但仍存在一定程度的破碎化趋势；（2）根据NC与IIC的计算结果，以500m为合适的距离阈值计算了PC，据此识别出15处生态源地，多位于闽西及闽北地区；（3）采用MCR模型提取了105条生态廊道，其中重要生态廊道27条，分布均匀且连通四方；（4）生态廊道穿过的土地利用类型中受人类干扰小的林草地占比超过85%，耕地占比12.33%，受人类干扰强烈的建设用地及未利用土地占比不足1%；（5）识别出生态节点62个，生态网络结构指数α=0.37，β=1.69，γ=0.58，表明网络结构较为合理，连通性较好。研究结果可从整体角度出发指导福建省生态安全格局构建，以期为土地资源有限背景下，省域尺度复合种群保护工作提供科学依据。 Abstract:The rapid urbanization process has led to the fragmentation and the declining in the connectivity of forest landscapes, which seriously threatened the sustainable development of regions, including the maintenance of biodiversity and ecological service. The construction of ecological network is an effective means to improve the connectivity of landscape, maintain the spread of species, and thus protect biodiversity. Taking Fujian Province as a case, the Morphological Spatial Pattern Analysis (MSPA) was employed to explore the dynamic changes of forest landscape structure in 2000, 2010 and 2020. Then, the appropriate distance threshold of patch connectivity was determined according to the number of components (NC) and the integral index of connectivity (IIC). On this basis, the probability connectivity index (PC) was calculated to identify the ecological sources. Then, from the perspective of human-land relationship, the factors including the distance from road network, distance from construction land, land cover type, and slope, were selected to construct the comprehensive resistance surface, which reflects the degree of obstruction for the species travelling between the ecological sources (i.e., core forest patches). To this end, the minimum cumulative resistance (MCR) model was adopted to extract the preliminary ecological corridors, which was ranked and filtered subsequently by the PC values. Finally, based on the graph theory method, the quantitative evaluation of the ecological network α, β, and γ index were carried out. The results show that:(1) the forest landscape structure in Fujian Province has been relatively stable in the past 20 years, of which the core area accounted for 76.27% of the total landscape area, but it still tended to fragmentation to a certain degree; (2) According to the results of NC and IIC, the PC value was calculated with a distance threshold of 500 meters, and 15 ecological sources were identified, which were mostly in the western and northern regions of Fujian; (3) 105 ecological corridors were extracted by MCR model, of which 27 were important corridors, which were evenly distributed and extended in all directions across the study area; (4) The ecological corridors and land use were superimposed to obtain the proportion of the corridors passing through each landscape type, of which the forests and grasslands less disturbed by humans accounted for more than 85%, the cultivated land accounted for 12%, while the construction land and unused land strongly disturbed by humans accounted for less than 1%; (5) Totally, 62 ecological nodes were identified, and the ecological network structure index α, β and γ were 0.37, 1.69 and 0.58, respectively, indicating that the reasonability of the network structure and the goodness in the network connectivity. The results can shed a light on the construction of the ecological security pattern in Fujian Province from a holistic perspective, and provide a scientific basis for biodiversity conservation at the provincial scale with the limited land resources. 参考文献 相似文献 引证文献

Afforestation on agricultural land in southern Spain: an important driver to improve forest landscape connectivity

Afforestation on agricultural land in southern Spain: an important driver to improve forest landscape connectivity

Camera Trapping Reveals Spatiotemporal Partitioning Patterns and Conservation Implications for Two Sympatric Pheasant Species in the Qilian Mountains, Northwestern China.

Simple SummaryCamera-trapping technology has been widely applied to obtain survey data and enhance understanding of animal ecology. Ground-dwelling pheasants with limited distributions and weak dispersal capacity are prone to extinction due to disturbances and climate change in high-altitude mountain areas. The Qilian Mountains form a global biodiversity hotspot for endemic species and contain crucial areas for ecological and biodiversity conservation. The Blue Eared Pheasant (EP) and Blood Pheasant (BP) are indicator species of the environment and currently occur in the Qilian Mountain National Nature Reserve (QMNNR). Understanding their stable coexistence is key for making informed conservation and management actions. They have similar daily activity patterns but their monthly activity patterns are strikingly different. Both BP and EP prefer forest habitats but BP nests in more dense vegetation cover. Ninety-one percent of BP distribution falls within EP distribution in the QMNNR. Their areas of potential overlap are in the central and eastern parts of the QMNNR, but landscape connectivity is relatively poor. This study further improved the understanding of the basic knowledge of BP and EP coexistence. Conservation actions should give priority to those highly overlapping areas and strengthen forest landscape connectivity, as they provide irreplaceable habitats for threatened Galliformes.Studying the spatio-temporal niche partitioning among closely related sympatric species is essential for understanding their stable coexistence in animal communities. However, consideration of niche partitioning across multiple ecological dimensions is still poor for many sympatric pheasant species. Here, we studied temporal activity patterns and spatial distributions of the Blue Eared Pheasant (EP, Crossoptilon auritum) and Blood Pheasant (BP, Ithaginis cruentus) in the Qilian Mountains National Nature Reserve (QMNNR), Northwestern China, using 137 camera traps from August 2017 to August 2020. Kernel density estimation was applied to analyze diel activity patterns, and the Maxent model was applied to evaluate their suitable distributions and underlying habitat preferences. Eight Galliformes species were captured in 678 detection records with 485 records of EP and 106 records of BP over a total of 39,206 camera days. Their monthly activity frequencies demonstrate temporal partitioning but their diel activity patterns do not. Furthermore, 90.78% of BP distribution (2867.99 km2) overlaps with the distribution of EP (4355.86 km2) in the QMNNR. However, BP manifests a high dependence on forest habitats and shows larger Normalized Difference Vegetation Index (NDVI) values, while EP showed obvious avoidance of forest with NDVI greater than 0.75. Hence, differentiation in monthly activity patterns and partitioning in habitat preference might facilitate their coexistence in spatiotemporal dimensions. Conservation actions should give priority to highly overlapping areas in the center and east of the QMNNR and should strengthen forest landscape connectivity, as they provide irreplaceable habitats for these threatened and endemic Galliformes.

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

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.

Forest cover and connectivity have pervasive effects on the maintenance of evolutionary distinct interactions in seed dispersal networks

Seed dispersal by animals is one of the most important ecological processes in tropical forests, entailing millions of years of evolutionary adaptations of plants and frugivorous animals forming networks of interactions that, ultimately, contribute to the resilience of such forests. We analyze 29 seed dispersal networks in the threatened Atlantic Forest biodiversity hotspot, with data on the frequency of feeding visits by birds to fruiting plants to answer: 1) which are the effects of forest cover and landscape connectivity on the maintenance of phylogenetic diversity (PD) of interacting birds and plants and the evolutionary distinctiveness of the interactions (EDi) between them; and 2) how EDi and plant/bird PD affects the robustness of the interaction networks? We found that forest cover positively influences both plant and bird PD and EDi. Landscape connectivity is an important predictor of bird PD, but not plant PD, suggesting that the spatial arrangement of forest remnants is essential for guaranteeing bird movement among forest fragments. Furthermore, interaction networks of areas with higher PD and EDi had great robustness to the simulated extinction of species, which underscore the importance of larger forest blocks for conserving evolutionary information and, consequently, the health and natural resistance of seed dispersal networks against environmental change.

Multi-Scale Ecological Connectivity Dynamics Associated With Hydropower Station: A Case Study in the Lancang River Valley

Dam construction is a major threat to terrestrial ecological processes that exhibit spatial variation. As an effective indicator of species movements at large scales, the dynamics of forest landscape connectivity for the dispersal abilities of local species such as primates both upstream and downstream of the Manwan hydropower station were compared in three periods: before, during, and after dam construction (in 1974, 1988, and 2004, respectively). The equivalent connected area (ECA) index which was modified from the probability of connectivity (PC) index based on the graph theory was applied in this study. We used this method to analyze the spatial and temporal changes in the overall forest landscape connectivity due to dam construction. The results showed that forest connectivity decreased after dam construction. The forest connectivity upstream was much greater than that downstream in 1974 but was lower in 1988 and 2004. The importance of connectivity increased with increasing dispersal distance. Only 8, 12, and 18% of forest patches of small area exhibited changes in 1974, 1988, and 2004, respectively. Most of the large habitat patches (i.e., those with dECA values >50%) remained stable, and the greatest patch changes were found at a dispersal distance of 400 m in all three periods. These large forest patch changes often occurred near the boundary of the study area. The Betweenness Centrality indicator, which identifies patches as stepping stones while accounting for ecological processes and biological flows at a larger scale, indicated that some habitat patches near Manwan Dam acted as stepping stones in maintaining the forest connectivity. Furthermore, rank correlations between the forest patch area and the three dPC (intra, flux, connector) fractions indicated that the dPCflux indicator can be used to measure the prioritization of habitat patches.

Classes of protection in urban forest fragments are effectiveless in structuring butterfly assemblages: landscape and forest structure are far better predictors

Urbanization is a major cause of biodiversity loss and disconnection between people and nature. For this reason, the creation and maintenance of green areas as part of the urban landscape is a common practice in cities around the world. These green areas are generally a result of particular public policies regarding how these areas can be accessed, maintained, and how they are connected to other natural fragments in the city. In an effort to investigate aspects of the ecology of such green areas of the city of Curitiba, southern Brazil, the present study measured distinct parameters of the structure of butterfly assemblages from 19 forest fragments of distinct classes of protection, testing the influence of different policies (protection category) on butterfly assemblages. Comparatively, we also tested the predictive power of landscape variables (at distinct scales) and fragment quality (e.g. diameter at breast height, density of vegetation) using Generalized Linear Models (GLMs). Overall, 14,596 individuals belonging to 412 butterfly species were recorded, but values of species diversity and composition are very heterogeneous, indicating that the protection categories do not significantly interfere with the structure of the butterfly assemblages. More important than the protection category is the forest fragment quality and landscape connectivity. Our models showed that degraded fragments tend to present a specific butterfly composition, whereas the more urbanized landscape have poor butterfly species richness. These results reinforce the importance of implementing public policies that prioritize the conservation of the quality of forest fragments in every class of protection, as well as the conservation of forest fragments throughout the urban landscape.

Protected areas and forest fragmentation: sustainability index for prioritizing fragments for landscape restoration

ABSTRACT Tropical forests are threatened due to forest clearing and fragmentation which lead to a decrease in forest cover area and landscape connectivity, while also increasing edge effects. These impacts affect biodiversity and ecosystem service provision which are essential for humanity’s well-being. Protected areas are created to minimize these effects on biodiversity, but many of them are threatened due to forest fragmentation in the surrounding areas. Thus, forest restoration is needed to ensure the suitability of protected areas in the landscape. However, restoration planning needs to adopt an ecological landscape approach to ensure the recovery of the biodiversity and the ecological processes. This study developed a forest sustainability index (FSI) which represents the forest patch potential in facilitating landscape restoration in a protected area and its surroundings. A land-use/land-cover map was used to calculate landscape metrics at two levels: landscape and patch. Landscape metrics were subsequently selected to create the index. The tested landscape presents a great number of fragments with most of them being small in size and having irregular shapes. The focus areas for forest restoration are located close to forest fragments with higher FSI values, as these can facilitate natural restoration and guarantee the maintenance of the ecosystem processes.

Change detection of landscape connectivity arisen by forest transformation in Hazaribagh wildlife sanctuary, Jharkhand (India)

Forest land conversion is the primary driver of biodiversity decline worldwide. Hazaribagh wildlife sanctuary is a region of rich biodiversity in which forests and wildlife are deteriorating fast. The prime reasons for forest degradation and wildlife loss are the landscape connectivity weakening and forest transformation. In the present work, landscape connectivity and forest transformation relationships were analyzed in a spatio-temporal domain. The forest patches as a group of spectral abundance were extracted using the endmember retrieval technique. The connectivity analysis was performed by using a connectivity index in the extracted forest patches. Forest transformation is calculated using a post-classification change detection strategy for five types of forest cover during the four phases of the year (1992–2005, 2005–2010, 2010–2017 and 1992–2017). The forest cover was measured using a forest canopy density model using spectral indices. The landscape connectivity of 80–100% exhibit a rapid increase of 38% in 2005 from 1992 contrary to a 13% decrease in 2010 and 2017. The 23% loss of forest cover from 2005 to 2010 and a 17% loss in 2010–2017 phase of forest transformation weakened the forest connectivity. Forest cover, having a density higher than 40% was more vulnerable to degradation and landscape connectivity loss. The result shows that such declines of forest cover and landscape connectivity will reduce the genetic diversity in the forest, especially the mammalian population.

Evaluating and supporting conservation action in agricultural landscapes of the Usumacinta River Basin

There is increasing recognition that ecosystems and their services need to be managed at landscape scale and greater. The development of landscape-scale conservation strategies need to incorporate information from multiple sources. In this study, we combine various research tools to link landscape patterns with production units and systems in the Usumacinta River Basin, and inform the discussion of key questions around decision-making related to conservation action and policy in Southern Mexico. A typology based on policy-relevant farmer characteristics (land tenure, farm size, source of income, farming system) differentiated between farmers (traditional vs. cattle ranching) with different motivations that determine how management affects landscape configuration. Five main types of traditional farming systems were identified that combine different forms of land use and vary in their degree of land intensification. Major fragmentation and decrease in connectivity coincided spatially with floodplains dominated by large-scale commercial farms that specialize in livestock production. Traditional practices within large units with low-sloped high quality land were also seen to be intensive; however the presence of trees was notable throughout these units. Policies that promote livestock farming are among the principle causes motivating deforestation. Land intensification by traditional farmers decreased as the landscape became increasingly rugged. Traditional farmers are the focus of initiatives developed by the Biological Corridor project which seeks to increase forest cover and landscape connectivity. These initiatives have shown high levels of rural participation (10,010 farmers benefited from 27,778 projects involving 95,374 ha of land) and acceptance (producers carried out more than one project and several types of projects during the first eight years of work). Strong action is still required to take on the segment of large-scale ranchers. Changes in the structure of land tenure over the past decade are highlighted that could have a profound impact on conservation policies and programs.

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

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.

Effectiveness of Natura 2000 network in Romanian Alpine Biogeographical Region: an assessment based on forest landscape connectivity

Maintaining and increasing landscape connectivity, especially of forest landscapes, are some of the main concerns regarding biodiversity conservation. The connectivity of protected areas for different species represents an indicator for evaluating the effectiveness of the Natura 2000 network. Our research aims to evaluate the connectivity of forest landscapes in the Romanian Alpine Biogeographical Region (ABR) for various terrestrial species. We analysed the distribution of forest patches and Sites of Community Importance (SCI), as part of Natura 2000 network, in the Romanian ABR. We evaluated the connectivity of forest patches for terrestrial species with different dispersal distances, identifying those patches with significant contribution to maintain the forest landscape connectivity, through the graph theory approach. To quantify the importance of each node, we evaluated the dPCconnector fraction derived from the dPC index. Of the 125 SCIs in the Romanian ABR, 71 protected areas have over 1000 ha, four of them have more than 100,000 ha. The total protected surfaces cover ~35% of the Romanian ABR, and the forest surfaces, protected in SCIs, cover 26% of the total Romanian ABR. Regarding the connectivity scores, we found that the forest surfaces across the ABR are well connected (0.89 or 1 for different dispersal distances) in comparison with the Natura 2000 forest patches. The forest patches are well connected especially for the species with large dispersal distance in both cases (d = 25 km). For the species characterized by a small dispersion distance, the connectivity is lower (0.46) in the case of protected forests. Our results evidence that the connectivity objective of the forest surfaces protected through the Nature 2000 network is not totally achieved. Furthermore new protected areas are needed where the forest are still present for increasing landscape connectivity for species.

Functional analysis of landscape connectivity at the landscape, component, and patch levels: A case study of Minqing County, Fuzhou City, China

Maintaining forest landscape connectivity is one of the most effective ways to alleviate natural forest fragmentation and biodiversity loss problems. Recently, graph theory based metrics have been used as powerful tools in the assessment of landscape connectivity. However, the functional features of landscape units at different structure levels, based on which outcomes can be enriched and advice can be given for practical applications, have been overlooked. In this study, a series of graph-based connectivity indices was calculated to 1) evaluate the optimal threshold distance, 2) identify the key landscape units at the component and patch levels, and 3) classify the functional types of components and patches and analyze functional patterns at different structural levels. The relationship between patch size and patch functional performance in maintaining landscape connectivity was discussed. With a natural forest area in Minqing County of China as the study area, recommendations regarding forest conservation and connectivity enhancement were provided based on the research conclusions. This study provides a way to comprehensively analyze habitat fragmentation and functional patterns for local forest conservation.

Geographical modeling of spatial interaction between human activity and forest connectivity in an urban landscape of southeast China

Geographical detector models provide a quantitative approach for evaluating spatial correlations among ecological factors, population density and landscape connectivity. Here, we used a geographical model to assess the influence of different gradients of urbanization, human activities and various environmental factors on the connectivity of urban forest landscapes in Xiamen, China from 1996 to 2006. Our overarching hypothesis is that human activity has modified certain ecological factors in a way that has affected the connectivity of urban forest landscapes. Therefore, spatiotemporal distributions of landscape connectivity should be similar to those of ecological factors and can be represented quantitatively. Integral indices of connectivity and population density were employed to represent urban forest landscape connectivity and human activity, respectively. We then simulated the spatial relationship between forest patches and population density with Conefor 2.6 software. A geographical detector model was used to identify the dominant factors that affect urban forest landscape connectivity. The results showed that a distance of 600 m was the threshold of node importance. Mean annual temperature, mean annual precipitation, elevation, patch area, population density and dominant species had significant effects on the node importance. Mean annual temperature was more significant than population density in controlling the spatial pattern of the delta of the integral index of connectivity (dIIC). The spatial interaction between population density and various ecological factors as well as their linearly enhanced or nonlinearity enhanced urban forest landscape connectivity. In conclusion, a combination of graph theory and geographical detector models is effective for quantitatively evaluating interactive relationships among ecological factors, population density and landscape connectivity.