Changes In Landscape Structure Research Articles

Seasonal changes in ecosystem health and their spatial relationship with landscape structure in china's Loess plateau

Environmental managers have sought to optimize landscape structure to maintain regional ecosystem health (EH). However, we still lack a full understanding of the effects of changing landscape structure on EH, especially in terms of shorter time scales (e.g., monthly or seasonal scales) and spatial heterogeneity. To address this gap, this study used the vigor-organization-resilience-services (VORS) model to assess the annual and seasonal variation of EH in the Loess Plateau (LP) during 2000–2015, and then applied the geographically weighted regression (GWR) model to investigate the spatial effects of different aspects (i.e., landscape composition and configuration) of the landscape structure change on EH over time. Our results showed that the EH level in the LP from 2000 to 2015 displayed temporal non-stationarity at annual and seasonal scales, and a spatial pattern of decreasing from southeast to northwest. The effects of landscape structure on EH had obvious spatial and temporal heterogeneity, depending on the local landscape composition and configuration. In general, landscape configuration exerted a greater impact on EH than landscape composition apart from Shannon’s diversity index and percentage of forestland area, but the intensity and direction of the impact displayed higher temporally instability and therefore should receive more attention. Furthermore, regulation of the dominant patch size, landscape connectivity and forest spatial spacing is the optimal choice for regional ecosystem management. The results suggest that EH responses to changes in landscape structure in the LP vary by time and place, and that the integrating temporal variation and spatial characteristics can help decision-makers make precise spatial arrangements and temporal adjustments to keep the negative ecological impacts within reasonable limits.

Characterizing landscape fragmentation of Koitobos river sub-basin, Trans-Nzoia, Kenya

The changes in landscape structure and functioning due to unprecedented human interference are hastening across the globe and it is thus a compelling necessity to preserve and restore our ecosystems. This study aimed to characterize levels of landscape fragmentation, habitat structure, driving forces, and perceptions of the residents on the most preferred reconfiguration approaches. The land use/land cover [LULC] change was first determined by interpreting the 1973, 1986, 1995, 2002, 2014, and 2022 Landsat images using the QGIS 3.26 while the selected landscape fragmentation metrics were analyzed using FRAGSTATS 4.2. Forests, shrubs, and grasslands showed a declining trend, except for agriculture, water, and built-up areas, which depicted high increases for the study periods [1973 to 2022]. The landscape of the study area is characterized as progressively fragmenting as signified by high escalated values of patch number [374 %], edge density [7828 %] between 1986 and 2002, contagion [10.3%], and a declined value of Shannon Diversity Index [SHDI] [-17.42%], Shannon evenness index [SHEI] [-25.8 %] and connectedness [-43.3%]. Considering these results, high losses of forests and grasslands coupled with expansive farmlands and built-up areas have led to unprecedented landscape fragmentation From field surveys and oral interviews, this has not only left streams vulnerable to massive sediment loads but has also triggered annual floods which occur during wet months even though change in onset of rainfall seasons was also reported. The findings call for restoration and integrated and sustainable restoration efforts, especially for the forests, grasslands, and riparian corridors along with sustainable urban planning and community-based sensitization on watershed management.

Seed‐dispersal mode and habitat connectivity underpin variation in carbon stocking between Brazilian biomes

Abstract In tropical forests, about 60%–80% of woody plant species depend on animal–plant interactions for dispersal. The dependence on animal species for dispersal makes this interaction very fragile in the face of anthropogenic changes in land use. Disrupting seed‐dispersal processes, principally zoochoric dispersal, could significantly alter the long‐term carbon storage potential of tropical forests. An important question is how landscape structure changes tree carbon stocks in different types of tropical vegetation and how variation is mediated by the dispersal mode of animal (zoochoric) or abiotic (non‐zoochoric) seeds. We focused on tree plots at 126 sites in Brazil spanning four types of forest and savanna vegetation, and calculated carbon stored in zoochoric, non‐zoochoric, and large frugivore‐dispersed species. Our results showed that carbon stocks in zoochoric species and non‐zoochoric species differ significantly among vegetation types, with rainforests having higher stocks in zoochoric species and deciduous seasonally dry tropical forests having higher values in non‐zoochoric species. A greater area of native vegetation promotes higher proportions of carbon stocks dispersed by large frugivore species, whereas a higher mean shape index reduces this proportion. Synthesis. This study highlights that seed‐dispersal type underpins the variation in carbon stocks between vegetation types and that the maintenance of habitat of large dispersers and connectivity are key for retaining carbon stocks in zoochoric species, particularly in rainforest and cerrado sensu stricto.

Computational insights into dynamics and conformational stability of N-acetylmannosamine kinase mutations

The activity of UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE) is essential for the biosynthesis of sialic acid, which is involved in cellular processes in health and diseases. GNE contains an N-terminal epimerase domain and a C-terminal kinase domain (N-acetylmannosamine kinase, MNK). Mutations of the GNE protein led to hypoactivity of the enzyme and cause sialurea or autosomal recessive inclusion body myopathy/Nonaka myopathy. Here, we used all-atom molecular dynamics (MD) simulations to comprehend the folding, dynamics and conformational stability of MNK variants, including the wild type (WT) and three mutants (H677R, V696M and H677R/V696M). The deleterious and destabilizing nature of MNK mutants were predicted using different prediction tools. Results predicted that mutations modulate the stability, flexibility and function of MNK. The effect of mutations on the conformational stability and dynamics of MNK was next studied through the free-energy landscape (FEL), hydrogen-bonds and secondary structure changes. The FEL results show that the mutations interfere with various conformational transitions in both WT and mutants, exposing the structural underpinnings of protein destabilization and unfolding brought on by mutation. We discover that, when compared to the other two mutations, V696M and H677R/V696M, H677R has the most harmful effects. These findings have a strong correlation with published experimental studies that demonstrate how these mutations disrupt MNK activity. Hence, this computational study describes the structural details to unravel the mutant effects at the atomistic resolution and has implications for understanding the GNE's physiological and pathological role. Communicated by Ramaswamy H. Sarma

The legacy of millennial-scale land-use practices on landscape composition, diversity and slope erosion in the subalpine areas of Eastern Carpathians, Romania

We conducted multi-proxy analyses in two subalpine lakes, Lake Gropile, in the Rodna Mountains and Lake Vinderelu in the Maramureș Mountains, the Eastern Carpathians, Romania, to investigate the effect of different land-use practices on landscape composition, diversity and slope erosion. In the case of Lake Gropile, results evidenced a more extended tree and shrub cover and high fire activity between 6400 and 2800 cal yr BP, accompanied by reduced soil erosion, which appeared more strongly regulated by climatic conditions. Anthropogenic impact became evident 2800 years ago, when landscape openness, pasturing, and disturbance of soil cover increased and intensified over the last four centuries. In the case of Lake Vinderelu, intensified burning was followed by grazing around 1200–1100 cal yr BP and continued throughout the last millennium. Results also highlight the site-specific effects of land-use on vegetation composition and landscape diversity. For Lake Vinderelu, a combined effect of local burning and grazing in removing shrub cover appear to be the main drivers of changes in landscape diversity and structure. At Lake Gropile, fire was more connected to shrub cover changes while grazing to herbaceous cover diversity. Moderate to low grazing appeared to benefit both subalpine ecosystems, creating rich grassland-shrub mosaic communities, while overgrazing reduced landscape diversity and exacerbated erosion. Our findings document the millennial-scale legacy of land-use practices on the subalpine landscapes in this region. We propose that these semi-natural ecosystems hold important ecological and cultural value, and recommend their maintenance through controlled, low intensity pasturing and/or burning.

Exploring agricultural landscape change from the second half of the twentieth century onwards: combining aerial imagery with farmer perspectives.

Anthropogenic landscape change is an important driver shaping our environment. Historical landscape analysis contributes to the monitoring and understanding of these change processes. Such analyses are often focused on specific spatial scales and single research methods, thus covering only limited aspects of landscape change. Here, we aim to assess the potential of combining the analysis of historical aerial imagery and local stakeholder interviews for landscape change studies using a standardized mapping and interviewing approach. We compared six agricultural landscapes across Europe and mapped land-cover using historical aerial imagery (starting between 1930 and 1980, depending on data availability, until recent years) with an object-based image analysis and random forest classification. For local perspectives of landscape change, we conducted oral history interviews (OHIs) with (almost) retired farmers. Comparing recorded landscape changes from both approaches provided insight into advantages of combining these two methods. Object-based analysis enabled the identification of high-resolution land-cover dynamics, with scale enlargement and cropland/grassland expansion being the most commonly recurring trends across European landscapes. Perceived landscape changes identified in the OHIs included changes in farm management, landscape structure, and infrastructure. Farmers also reported drivers and personal values associated with landscape change. Combining the two historical landscape analysis tools resulted in a qualitative and quantitative understanding of changes in land-cover, land use, and land management. Comparing physical land-cover change with local farmer perspectives is key to a comprehensive understanding of landscape change. There are different ways the two methods can be combined, leading to different venues for science and policy making. The online version contains supplementary material available at 10.1007/s10980-024-01914-z.

Ecosystem Service Value Changes in Response to Land Use Dynamics in Lithuania

Changes in land cover affect ecosystems and the services they provide. The aim of this study was to assess the spatial changes in land use from 1990 to 2018 and analyze the changes in ecosystem service value (ESV) in response to the changes in landscape structure in Lithuania. Croplands provided the majority of the ESV, followed by forests, grasslands, and wetlands. The total ESV in Lithuania was USD 29 billion year−1 in 2018, and land use had a significant impact on ESV, with a total decrease of USD 438 million year−1 between 1990 and 2018. The total ESV change was mainly influenced by the decrease in provisioning (USD 426 million year−1) and regulating (USD 208 million year−1) services. The reduction in cropland area was a major factor in the loss of ESV. The increase in the value of habitat and cultural services was not large enough to offset the reduction of the ESV. The highest elasticities were in the urban municipalities, indicating a significant change in ESV due to land use change. The results of this study provide valuable insight into the potential of the sustainable management and regeneration of ecosystems.

Landscape effects of urbanisation in a post-socialist city. A case study of Wrocław (Poland)

Progressing urbanisation is contributing to the changes of vertical and horizontal landscape structure. The aim of this paper is to investigate the spatial regularities of changes in the landscape pattern that resulted from the urbanisation processes in Wrocław (Poland) between 1994 and 2020. The research area is an example of a post-socialist city characterized by fluctuating spatial processes, especially after the economic and political transformation of the year 1989. In the empirical part, authors have analysed the changes in the number of buildings and the structure of land cover using methods of spatial analysis in a GIS environment, with a particular focus on landscape metrics. The results show two main trends in landscape changes within the city boundaries, which the authors refer to as expansion and transformation. These processes were related to various driving forces and their intensity depended on analysed sub-periods and distance from the city centre. Expansion and transformation are mainly exhibited by an increase in developed area at the cost of the decline of natural and open areas (especially agricultural lands) and densification in central areas.

Assessing current use and visions for sacral complexes in a landscape: An example from Central Europe

Abstract A significant phenomenon of sacral complexes in a landscape is their cultural heritage dimension. They are part of historical landscape structures, representing a type of cultural landscape. In addition, they are often perceived as important landscape landmarks and symbols. In Slovakia (Central Europe), most such complexes are abandoned and deteriorated. In this context presented paper deals with the assessment and possible future human use of Calvary in Hliník nad Hronom (Slovakia) in order to preserve it for future generations. A central aspect of our research work presented in this contribution is to elaborate a sustainable and feasible concept for the Calvary following the integrated approach of its revitalization. Firstly, we analyzed Calvary´s historical and regional setting with the help of a thorough review of literature, historical maps, and pictures. Then we evaluated architectural, landscape, and vegetation values, as well as landscape structure changes using relevant methodologies. Based on this evaluation, much fieldwork, and social survey we were able to identify the current problems of the place connected with abandonment and use, evaluated values, socio-economic factors, and preservation policies. Subsequently, we prepared a future concept for the Calvary following the selected criteria and distinguishing features and looking at the Calvary as a result of collective work. Finally, recommendations were formulated for legal framework and spatial planning procedures in order to enforce better preservation of values of sacral complexes in the country.

Land Cover and Landscape Structural Changes Using Extreme Gradient Boosting Random Forest and Fragmentation Analysis

Land use and land cover change constitute a significant driver of land degradation worldwide, and machine-learning algorithms are providing new opportunities for effectively classifying land use and land cover changes over time. The aims of this study are threefold: Firstly, we aim to compare the accuracies of the parametric classifier Naïve Bayes with the non-parametric classifier Extreme Gradient Boosting Random Forest algorithm on the 2020 LULC dataset. Secondly, we quantify land use and land cover changes in the Cradle of Humankind from 1990 to 2020 using the Extreme Gradient Boosting Random Forest algorithm and post-classification change detection. Thirdly, the study uses landscape metrics to examine landscape structural changes occurring in the same area due to fragmentation. The classification results show that while Naïve Bayers and XGB Random Forest produce classification results of high accuracy, the XGB Random Forest Classifier produced superior results compared to the Naïve Bayers Classifier. From 1990 to 2020, bare ground/rock outcrop significantly increased by 39%, and open bush by 32%. Indigenous forests and natural grasslands lost area (26% and 12%, respectively). The results from this study indicate increasing land cover fragmentation and attest to land degradation, as shown by increases in bare ground and a reduction in indigenous forest and natural grassland. The decline in indigenous forests and natural grassland indicates the degradation of native vegetation, considered as prehistoric plant food sources. The high classification results also attest to the efficacy of the XGBRFClassifier executed in GEE. Land degradation evident in the nature reserve has long-term ecological consequences, such as loss of habitat, biodiversity decline, soil erosion, and alteration of local ecosystems, which together diminish the aesthetic value of the heritage site and negatively impact its tourism value. Consequently, it destroys crucial local economies and threatens sustainable tourism.

Assessment of wetland landscape changes based on landscape metrics and trophic state index (case study: Anzali International Wetland).

Wetlands play an important role in conserving biodiversity, the hydrosphere's equilibrium, and the maintenance of daily livelihood; therefore, the trophic process hastens the succession procedure in them, resulting in structural changes in the landscape. The study aimed to monitor and investigate the impact of the trophic procedure on landscape structural changes in Anzali Wetland, specifically domains related to vegetation canopy and water bodies, over 24 years. The TSI (trophic state index) of the Anzali Wetland, a vital habitat in the south of the Caspian Sea, was estimated by using the Carlson TSI for 1994, 2002, 2014, and 2018. Based on satellite data for these years, the structural landscape changes were also measured using metrics such as the number of patches (NumP), class area (CA), mean patch size (MPS), and mean shape index (MSI) of the measured patch using in Patch Analyst. The Spearman rank correlation coefficient was then used to calculate the correlation between the two variables of trophic index modifications and landscape metrics. Results showed that the TSI of the wetland touched 59.51 in 1994 and then reached 65.10 in 2018. Its water body area, which was 5283.90 ha in 1994, decreased to 4183.92 ha in 2018, indicating the greatest decrease in the area from 2002 to 2018. In addition, the maximum area of vegetation canopy in 2018 was 11696.31 ha. The trophic exhibited a positive correlation of 0.8 with the area of the vegetation canopy and a positive correlation of 0.4 with the NumP of the vegetation canopy. It also had an inverse correlation of -0.4 with the area and NumP of the water body. Based on the study findings, changes in the trophic level of Anzali Wetland can be regarded as a direct factor influencing the vegetation canopy and water body.

Changes in landscape structure and ecosystem services since 1850 analyzed using landscape metrics in two German municipalities

Land use has fundamentally altered landscape structure and ecosystem service provision over the last century in central Europe and worldwide. In this study, we analyzed long-term changes in landscape structures and ecosystem services in two case study areas in Germany in 1850 and 2018. First, we reconstructed land use changes using historical and current serial cadastral maps, historical documents, and digital aerial photographs. Second, we analyzed landscape structure by calculating select landscape metrics for several land-use types in both case study areas and time steps. Land use analysis for the first case study in the intensively used agricultural area of Jesewitz (Saxony) showed a significantly decreased percentage of grassland from 9.2% (in 1850) to 3.9% (in 2018) and an increase in built-up areas from 1.2% to 3.8%. For the second study area, located in the mountainous region of Ilsenburg, Harz (Saxony-Anhalt), the analysis revealed a stable forest area of 78% at both time steps. Grasslands dominated the non-forest areas and showed a significant decrease in area from 53.2% (in 1850) to 19.6% (in 2018). The settlement area increased markedly from 1.8% to 16.4%. Business and industrial areas also increased significantly from 0.9% to 10.0%. The present study shows that the risk of soil degradation caused by erosion has increased significantly since 1850. Furthermore, the risk of biodiversity loss has increased significantly owing to habitat degradation and devastation of vegetation structures. Moreover, the results showed that changes in landscape structure adversely affected the availability and quality of ecosystem services.

Long-term changes in the composition and distribution of the Hungarian bumble bee fauna (Hymenoptera, Apidae, Bombus)

One of the most important pollinator taxa is Bombus (Hymenoptera, Apidae), the genus of bumble bees, since they are important, often specialized, pollinators of many plants. As a result of climate change, warming winters and changes in landscape structure, the distribution and frequency of Bombus species is constantly changing. To develop appropriate protection strategies, it is essential to monitor them and update the occurrence and threat status of the species. The last review of the distribution of Bombus species in Hungary was completed 20 years ago. Here we present updated distribution maps based on published data from the last 20 years together with unpublished data collected in 2018–2021. Based on the new data, we examine changes in the last two decades. In the case of 9 species further studies should be carried out to confirm the presence of stable populations, while 3 species are recommended for protection by law in Hungary. Seven species showed increasing frequency, B. argillaceus and B. haematurus.

Examining the Influence of Landscape Patch Shapes on River Water Quality

River water quality can be affected by a range of factors, including both point and non-point sources of pollution. Of these factors, changes in land use and land cover are particularly significant, as they can alter the structure of the landscape and consequently impact water quality in rivers. To investigate the relationship between patch shapes, a measure of landscape structure, and river water quality at the catchment scale, this study utilized spatial data from 39 catchments in the southern basin of the Caspian Sea. This study employed stepwise multivariate regression modeling to explore how changes in landscape structure, which can be measured by landscape metrics including the shape index, the contiguity index, the fractal dimension index, the perimeter–area ratio, and the related circumscribing circle, impact water quality variables. Four regression models—linear, exponential, logarithmic, and power models—were evaluated, and the most appropriate model for each water quality variable was determined using the Akaike information criterion. To validate the models, three groups of accuracy metrics were employed, and Monte Carlo simulation was utilized to analyze the models’ behavior. This study found that landscape structure metrics could explain up to 71% and 82% of the variations in the measures of TDS and Mg, respectively, and the shape index, the contiguity index, and fractal metric were particularly significant in predicting water quality. Moreover, this study verified the accuracy of the models and revealed that changes in landscape structure, such as a decline in patch continuity and an increase in patch complexity, can impact river water quality. The findings of this study suggest optimizing landscape structure metrics in land use planning to reduce river pollution and improve water quality.

Influence of landscape structure on previous exposure to Leptospira spp. and Brucella abortus in free-living neotropical primates from southern Brazil.

The environments in which neotropical primates live have been undergoing an intense fragmentation process, constituting a major threat to the species' survival and causing resource scarcity, social isolation, and difficulty in dispersal, leaving populations increasingly vulnerable. Moreover, the proximity of wild environments to anthropized landscapes can change the dynamics of pathogens and the parasite-host-environment relationship, creating conditions that favor exposure to different pathogens. To investigate the previous exposure of free-living primates in Rio Grande do Sul State (RS), southern Brazil, to the bacterial agents Leptospira spp. and Brucella abortus, we investigated agglutinating antibodies against 23 serovars of Leptospira spp. using the microscopic agglutination test and B. abortus acidified antigen test in primate serum samples; 101 samples from primates captured between 2002 and 2016 in different forest fragments were used: 63 Alouatta caraya, 36 Alouatta guariba clamitans, and 02 Sapajus nigritus cucullatus. In addition, the forest remnants where the primates were sampled were characterized in a multiscale approach in radii ranging from 200 to 1400 m to investigate the potential relationship of previous exposure to the agent with the elements that make up the landscape structure. The serological investigation indicated the presence of antibodies for at least one of the 23 serovars of Leptospira spp. in 36.6% (37/101) of the samples analyzed, with titers ranging from 100 to 1600. The most observed serovars were Panama (17.8%), Ballum (5.9%), Butembo (5.9%), Canicola (5.9%), Hardjo (4.9%), and Tarassovi (3.9%); no samples were seropositive for Brucella abortus. Decreased forest cover and edge density were the landscape factors that had a significant relationship with Leptospira spp. exposure, indicating that habitat fragmentation may influence contact with the pathogen. The data generated in this study demonstrate the importance of understanding how changes in landscape structure affect exposure to pathogenic microorganisms of zoonotic relevance. Hence, improving epidemiological research and understanding primates' ecological role in these settings can help improve environmental surveillance and conservation strategies for primate populations in different landscapes.

Evaluation of Spatial Landscape Changes for the Period from 1998 to 2021 Caused by Extreme Flood Events in the Hornád Basin in Eastern Slovakia

Tracking changes in the structure of landscape dynamics as a result of flood activity is a complex process. This study presents a model for determining changes to landscapes caused by flood events by evaluating a specific territory in Eastern Slovakia, which has been affected by repeated large-scale flood events in the past. The area has not been subject to a comprehensive monitoring of changes in the landscape structure. Based on the observation of several sets of data, a combination of statistical methods and GIS spatial analysis tools (visualizing tools for compare categories, mapping, and modelling techniques, spatial analysis models for land use change and flood modelling) were used to identify changes in the landscape structure in the period from 1998 to 2021. The results point to the significance of the year 2010, with the precipitation totals for this year showing a level significantly higher than the rolling average and confirming the occurrence of an extreme flood event. The dynamics of landscape structure changes were evaluated based on changes in the representation of selected types of land cover classes. The results of a spatial evaluation of the Corine Land Cover demonstrate that the most-significant area changes were recorded in 2012 in the pasture class, with a decrease of 31% or approximately 96.5 ha. The identified difference in the frequency of representation of individual values of the normalized differential vegetation index confirms the loss of landscape diversity and the emergence of a more homogeneous type of landscape. An assessment of the state of pastures in the study area shows that this class has completely disappeared from the site near the watercourse.

Landscape structure is a key driver of soil protist diversity in meadows in the Swiss Alps

ContextHuman-induced changes in landscape structure are among the main causes of biodiversity loss. Despite their important contribution to biodiversity and ecosystem functioning, microbes—and particularly protists—remain spatially understudied. Soil microbiota are most often driven by local soil properties, but the influence of the surrounding landscape is rarely assessed.ObjectivesWe assessed the effect of landscape structure on soil protist alpha and beta diversity in meadows in the western Swiss Alps.MethodsWe sampled 178 plots along an elevation gradient representing a broad range of environmental conditions and land-use. We measured landscape structure around each plot at 5 successive spatial scales (i.e. neighbourhood windows of increasing radius, ranging from 100 to 2000 m around a plot). We investigated the changes of protist alpha and beta diversity as a function of landscape structure, local environmental conditions and geographic distance.ResultsLandscape structures, especially percentage of meadows, forests, or open habitats, played a key role for protist alpha and beta diversity. The importance of landscape structure was comparable to that of environmental conditions and spatial variables, and increased with the size of the neighbourhood window considered.ConclusionsOur results suggest that dispersal from neighbouring habitats is a key driver of protist alpha and beta diversity which highlight the importance of landscape-scale assembly mechanisms for microbial diversity. Landscape structure emerges as a key driver of microbial communities which has profound implications for our understanding of the consequences of land-use change on soil microbial communities and their associated functions.

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

Global change effects on Mediterranean small mammal population dynamics: Demography of Algerian mice (Mus spretus) along land use and climate gradients

Climate and land use change are key global change drivers shaping future species' distributions and abundances. Negative interactions among effects of drivers can reduce the accuracy of models aimed at predicting such distributions. Here we analyse how climate and land use affected population dynamics and demography of the Algerian mouse (Mus spretus), an open-land thermophilic Mediterranean small mammal. Change to a warmer and drier climate would facilitate the expansion of the species, whereas landscape change (forest encroachment following extensive land abandonment) would produce its retreat. We correlated abundance and demography parameters computed from captures obtained in 16 plots during a 10-years period (2008–2017; SEMICE small mammal monitoring) with climate, vegetation and land use change. Climate became warmer and dryer, and afforestation due to encroachment occurred in 81 % of plots. Expected positive effects of climate warming, derived from bioclimatic niche models, were counterbalanced by negative effects of both increasing hydric deficit and changes in vegetation and landscape structure. Abundance showed a slight but significant decline (−5 %). The species' range was more resilient to change, as shown by occupancy analyses, apparently due to strong local effects of vegetation structure on occupancy. This result highlighted that negative population trends would not necessarily produce range retractions. Simultaneously analysing both abundance trends and occupancy patterns may thus allow for deeper understanding and more accurate predictions of expected population trends in response to interacting global change drivers.

Monitoring changes in landscape structure in the Adirondack-to-Laurentians (A2L) transboundary wildlife linkage between 1992 and 2018: Identifying priority areas for conservation and restoration

Monitoring changes in landscape structure in the Adirondack-to-Laurentians (A2L) transboundary wildlife linkage between 1992 and 2018: Identifying priority areas for conservation and restoration