Enhance Landscape Connectivity Research Articles

Ecological Network Construction in High-Density Water Network Areas Based on a Three-Dimensional Perspective: The Case of Foshan City

The acceleration of urbanization has resulted in varying degrees of impact on the stability and health of high-density urban ecosystems. Building urban ecological networks is crucial for safeguarding biodiversity and sustaining ecosystem vitality. In this study, the city of Foshan was selected as the study area, which is a prime representative of a high-density water network city. Additionally, a morphological spatial pattern analysis was employed to identify the ecological source. We built an ecological resistance surface using geographic, natural, and behavioral elements, adjusting it based on the density of the water network and the building height. Following this, the circuit theoretical model was utilized to create an ecological network by identifying ecological corridors. There were three key findings. First, the ecological network consisted of 30 ecological source sites and 53 ecological corridors, and 103 ecological “pinch points” and 193 ecological barrier points were identified. Second, the ecological sources were predominantly situated in the southwestern and northern parts of Foshan City. Meanwhile, the suburbs of Foshan City contained the primary ecological barrier points, mainly stemming from new construction sites, while the key ecological “pinch points” were concentrated at river junctions. The third outcome was the recommendations to (a) boost the connectivity of the ecological network in the suburbs, (b) improve the connection of the water network in urban areas, and (c) focus on enhancing landscape connectivity. The objective was to develop approaches for optimizing urban ecological networks, leading to better connectivity and improved ecological network quality.

Incorporating barriers restoration and stepping stones establishment to enhance the connectivity of watershed ecological security patterns

Enhancing the connectivity of watershed ecological security patterns (ESPs) is increasingly emphasized for preserving ecological processes. Yet the importance of small-scale conservation and restoration was ignored and few studies have quantitatively compared the contribution of barriers restoration and stepping stones establishment to landscape connectivity. In this study, taking Dongting Lake Basin as an example, a watershed ESP was constructed based on the minimum cumulative resistance model and optimized through graded barriers restoration and different stepping stones establishment. Then the enhancement effects of landscape connectivity were compared to identify the most cost-effective optimization scheme. The results showed that the average of six schemes only protected and repaired less than 1% of the total area, which could enhance corridor connectivity by about 12% and 16% for average corridor length and corridor cumulative resistance respectively. For the optimal ESP, establishing natural patches near the midpoint of longer corridors as stepping stones, increased the probability of connectivity by 21.05%, and reduced the average corridor length and corridor cumulative resistance of corridor connectivity by 17.99% and 15.48% respectively. It also increased network circuitry index of network connectivity from 0.541 to 0.570, compared with the original ESP, indicating the possibility of successful ecological flow increased effectively. It can be concluded that the connectivity enhancement of stepping stones approach was better than barriers restoration approach. This study highlights the importance of small-scale barriers restoration and stepping stones establishment in enhancing landscape connectivity.

Direct and indirect effects of linear non-cultivated habitats on epigaeic macroarthropod assemblages

Non-cultivated habitats are indispensable ecological spaces within agricultural landscapes that support biodiversity and associated ecosystem services on farmland, thereby contributing to sustainable agriculture. The abundance of taxonomic groups within these habitats serves as a reliable indicator of the diversity levels in epigaeic macroarthropod communities, while the functional groups offer insights into the trophic dynamics of macroarthropods. In recent decades, the impact of non-cultivated habitats on biodiversity within agricultural contexts has received increasing attention. However, few studies have focused on the pathways and factors that influence epigaeic macroarthropod assemblages in different non-cultivated habitats. In this study, Changtu County, a typical agricultural county in the Northeastern Black Soil Region of China, was selected as the study area. The functional and taxonomic groups of epigaeic macroarthropod abundance in different non-cultivated habitats were compared. The structural equation model (SEM) was used to evaluate the direct and indirect effects of non-cultivated habitat type, soil nutrients and vegetation structure reflecting major differences in non-cultivated habitat types on epigaeic macroarthropod assemblages. Our results showed that: (1) linear semi-natural non-cultivated habitats around fields can effectively enhance landscape connectivity. Among these habitats, woodlands (WL), grasslands (GL), and ditches (CD) with high herbaceous vegetation density are usually more favorable for biodiversity conservation in agricultural ecosystems. (2) While dirt roads (DR) and paved roads (PR) may affect the mobility and foraging ability of epigaeic macroarthropods, improving herbaceous vegetation structures along road margins (e.g., planting flowering plants, establishing vegetation buffer zones) can effectively enhance field biodiversity. (3) The characteristics of herbaceous vegetation community are the most important factors affecting the functional and taxonomic groups of epigaeic macroarthropods in different non-cultivated habitats, especially the herbaceous vegetation height (PAH) and species abundance (PAB). In addition, for epigaeic macroarthropods taxonomic groups, non-cultivated habitats affect them not only directly through herbaceous vegetation, but also indirectly through soil organic carbon (SOC). Our results emphasize that in the planning of agricultural landscapes, it is feasible to achieve a harmonious synergy between ecosystem stability and agricultural production through strategic allocation and alteration of herbaceous vegetation structure and soil conditions in different types of non-cultivated habitats.

Cumulative effects on habitat networks: How greedy should we be?

Connectivity conservation and restoration are key strategies to preserve biodiversity under the pressure of habitat loss and fragmentation. Numerous quantitative approaches have been developed to help conservation practitioners take the most effective and cost-efficient actions to conserve, restore or create habitat patches or corridors that preserve or enhance landscape connectivity. This problem is often solved by ranking habitat patches (or corridors) with suboptimal algorithms that do not account for the cumulative effects that may occur in the case of simultaneous or sequential losses (or enhancements) of multiple habitat patches. Accounting for these cumulative effects is one of the current challenges for connectivity conservation. Here, we quantify these cumulative effects and explore the trade-off between solution quality and computational time when optimizing the selection of conservation/restoration actions that maximize landscape connectivity under a budget constraint; connectivity is here measured by the frequently-used Equivalent Connected Area. We compare the solutions obtained with a new optimization pipeline with solutions obtained with four simpler algorithms used in most connectivity conservation studies. Comparison is performed for four case studies covering a wide range of possible applications for conservation practitioners. We show that the simpler algorithms can provide suboptimal solutions, when conservation/restoration actions have a strong impact on least-cost paths between the habitat patches, and that optimal resolution should be considered whenever possible.

Exploring the regional differences of ecosystem health and its spatial relationships with urban forms in China.

A deeper understanding of the regional differences and driving factors behind ecosystem health (EH) is of vital for ecosystem management and restoration. Although a considerable number of studies have focused on this topic, few studies have explored the spatial relationship and scale effect between urban forms and EH from the perspective of urban scale, agglomeration and irregularity. Therefore, this study first constructed an improved evaluation framework by integrating vigor, organization, resilience and ecosystem services supply-demand ratio to measure the EH level in China at the county scale during 1995-2015, and then evaluated and compared the spatial relationships between five urban form metrics and EH based on the spatial regression model at the national, regional, urban agglomeration and city scales.The results showed thatthe level of EH in China spatially decreased from the southeast to the northwest, and displaying significant spatial agglomeration. At the national scale, the fragmentation and complexity of urban form exerted the greater negative influence on EH than urban expansion scale.At the regional scale, controlling urban expansion scale and enhancing landscape connectivity were conducive to the improving of EH in the central and eastern regions.At the urban agglomeration scale, the regularity and compactness of urban form played a key role in the sustainable development of regional and national urban agglomerations.At the city scale, large cities can improve environmental quality by limiting the size of core patches and reducing the complexity of urban shape.This paper can provide a scientific guidance for ecosystem protection and urban high-quality development.

Ecological network construction and optimization in Guangzhou from the perspective of biodiversity conservation

Rapid urbanization has resulted in fragmentation and decreased connectivity in urban landscapes, endangering regional biodiversity conservation and high-quality, sustainable development. networks (ENs) construction and optimization is a critical technique to enhance landscape connectivity effectively, promote species interaction and dispersal, and thereby hence urban biodiversity., most existing studies on ENs construction have been undertaken from the perspective of ecosystem service functions or the value of landscape structure, with regional species still being overlooked. on the distribution data of critical species in this study, the maximum entropy model (MaxEnt), wilderness mapping model, and granularity reverse method were integrated to identify ecological sources. the habitat quality (HQ) index was utilized to construct a resistance surface modified by landscape connectivity and ecological sensitivity. findings indicate that: (1) a grid scale of 1700 m is the relatively optimal minimum threshold for ecological source sites in Guangzhou; (2) 35 crucial ecological sources in Guangzhou are identified, with a total area of 1100.42 km2, mainly woodlands, distributed in mountain systems in the northern and central parts of the city; and (3) 59 ecological corridors are identified, with a total length of 817.4 km, with a relatively high density in the central part of the city. some extent, this study offers fresh ideas for constructing urban ENs from the standpoint of biodiversity conservation. contributes to the city achieving a win-win economic development and ecological protection situation.

Agricultural margins could enhance landscape connectivity for pollinating insects across the Central Valley of California, U.S.A.

One of the defining features of the Anthropocene is eroding ecosystem services, decreases in biodiversity, and overall reductions in the abundance of once-common organisms, including many insects that play innumerable roles in natural communities and agricultural systems that support human society. It is now clear that the preservation of insects cannot rely solely on the legal protection of natural areas far removed from the densest areas of human habitation. Instead, a critical challenge moving forward is to intelligently manage areas that include intensively farmed landscapes, such as the Central Valley of California. Here we attempt to meet this challenge with a tool for modeling landscape connectivity for insects (with pollinators in particular in mind) that builds on available information including lethality of pesticides and expert opinion on insect movement. Despite the massive fragmentation of the Central Valley, we find that connectivity is possible, especially utilizing the restoration or improvement of agricultural margins, which (in their summed area) exceed natural areas. Our modeling approach is flexible and can be used to address a wide range of questions regarding both changes in land cover as well as changes in pesticide application rates. Finally, we highlight key steps that could be taken moving forward and the great many knowledge gaps that could be addressed in the field to improve future iterations of our modeling approach.

Influence of land use changes on landscape connectivity for North China leopard (Panthera pardus japonensis).

North China leopard (Panthera pardus japonensis) is the most widespread subspecies of leopard and one of the rare and endangered species in China. It is currently confined to several isolated natural reserves, and little is known about its habitat network connectivity with land use changes. This study was conducted to assess the impacts of land use changes on landscape connectivity for North China leopard in the Great Taihang Region. Circuit theory‐based connectivity models and least‐cost path analyses were used to delineate pathways suitable for species movement, and evaluate the impacts of land use changes on landscape connectivity. The results revealed that there were 37 least‐cost paths in 1990 and 38 in 2020. The area of forest land increased from 57,142.74 km2 to 74,836.64 km2, with the percentage increasing from 26.61% to 34.85%. In general, the increase in forest land area promoted the landscape connectivity for North China leopard at broad spatial scales. The improvement of landscape connectivity was not always consistent with the land use changes, and there was a slightly decreasing trend on connectivity in some key movement barrier areas with high intensity of human activities. Improving landscape connectivity at broad spatial scales is as important as protecting the habitats (natural reserves) where the species lives. Our study can serve as an example of exploring the relationships between land use changes and landscape connectivity for species conservation at broad spatial scales with limited movement pattern data. This information is proved to be critical for enhancing landscape connectivity for the conservation concern of North China leopard and planning of natural reserves network.

Ecological networks and corridors development in urban areas: An example of Tabriz, Iran

Landscape fragmentation and the elimination of urban green spaces are the results of human activities which put significant pressure on urban sustainability. The planning and developing of urban ecological networks and corridors as an effective approach is a response to rapid urbanization and fragmentation of natural areas. The Tabriz metropolitan as the fourth-largest city in Iran was selected as a case study that has grown rapidly over the past few decades. This study presents a practical approach and framework for assessing and enhancing ecological connectivity of landscape. The framework was developed based on the landscape metrics, graph theory, least-cost modeling, and geographic information system tools during three different periods (1984-2000-2020). The results using the values of landscape metrics such as CA, Edge Distance, Mean Patch Size, Mean Shape Index, large patch index, NP, Landscape shape index, and COHESION indicate that the urban landscape of Tabriz has been more fragmented over the past 3 decades and has lost its connectivity. To reduce the effects of fragmentation and enhance landscape connectivity in study area, we proposed a network of ecological corridors that passes through the core ecological patches. Our results also indicate that the core patches and the least-cost created corridors are mainly located in the suburbs of Tabriz and the central part of the city cannot be suitable for ecological development. Therefore, using the above-mentioned methods could be an effective approach to develop ecological networks and improve landscape connectivity that can encourage urban planners and managers to protect and develop green networks.

Broad scale functional connectivity for Asian elephants in the Nepal-India transboundary region

The Nepal-India transboundary region hosts one of Asia's most complex large mammal assemblages, including a small (but growing) population of Asian elephants (Elephas maximus). These elephants occur in four widespread and geographically disjunct subpopulations, and some of them undergo seasonal transboundary movements. We conducted a broad-scale evaluation of the amount and quality of elephant habitat available in the region and of functional landscape connectivity between and within subpopulations using Maxent, circuit theory, and least-cost path analysis. Habitat suitability was highly influenced by abiotic geographical factors (altitude and precipitation) and less by ecological factors (habitat heterogeneity, plant productivity) and human disturbance (distance to settlements). The region had a relatively small amount of high and optimal suitability habitat (12.6% out of 93,700 km2) but all subpopulations seem to be far from carrying capacity, suggesting ample potential for further population growth. Landscape connectivity was higher between and within the west and far-west subpopulations, which should be considered a single subpopulation. The central and ea st subpopulations, however, had low to very low between-subpopulation connectivity. Conservation priorities include maintaining the current connectivity in the west subpopulation and across the border in the east, and protecting high-quality habitats in eastern Nepal. Restoring connectivity between the central and other subpopulations is possible if the number of elephants continues growing, and it should be a long-term conservation aspiration. Maintaining and enhancing landscape connectivity in this region requires transboundary cooperation and coordination between Nepali and Indian authorities. If successful, it will bring considerable benefits for the conservation of elephants and other wildlife.

Circular utilization of urban tree waste contributes to the mitigation of climate change and eutrophication

Circular utilization of urban tree waste contributes to the mitigation of climate change and eutrophication

Forecasting the influence of conservation strategies on landscape connectivity.

Maintaining and enhancing landscape connectivity reduces biodiversity declines due to habitat fragmentation. Uncertainty remains, however, about the effectiveness of conservation for enhancing connectivity for multiple species on dynamic landscapes, especially over long time horizons. We forecasted landscape connectivity from 2020 to 2100 under four common conservation land-acquisition strategies: acquiring the lowest cost land, acquiring land clustered around already established conservation areas, acquiring land with high geodiversity characteristics, and acquiring land opportunistically. We used graph theoretic metrics to quantify landscape connectivity across these four strategies, evaluating connectivity for four ecologically relevant species guilds that represent endpoints along a spectrum of vagility and habitat specificity: long- versus short-distance dispersal ability and habitat specialists versus generalists. We applied our method to central North Carolina and incorporated landscape dynamics, including forest growth, succession, disturbance, and management. Landscape connectivity improved for specialist species under all conservation strategies employed, although increases were highly variable across strategies. For generalist species, connectivity improvements were negligible. Overall, clustering the development of new protected areas around land already designated for conservation yielded the largest improvements in connectivity; increases were several orders of magnitude beyond current landscape connectivity for long- and short-distance dispersing specialist species. Conserving the lowest cost land contributed the least to connectivity. Our approach provides insight into the connectivity contributions of a suite of conservation alternatives prior to on-the-ground implementation and, therefore, can inform connectivity planning to maximize conservation benefit.

Arboreal elements of the agricultural matrix as structural connecting devices in fragmented landscapes – A case study in the Los Tuxtlas Biosphere Reserve

Agriculture is one of the main drivers of deforestation worldwide, generating highly fragmented landscapes that severely limit the mobility of forest species. Knowledge of the state of previously forested landscapes, taking into account all of its arboreal elements (including isolated trees, living fences, riparian corridors, and others) is a necessary first step to gaining a better understanding of the ecological dynamics of anthropic landscapes, and for designing conservation and management plans that enhance functional connectivity within these landscapes. We used high-resolution images (2.5 m/pixel) to identify all of the arboreal elements—from single tree crowns up to large forest fragments—for 40,000 ha of the Los Tuxtlas Biosphere Reserve. We included isolated trees, usually ignored in most inventories of fragmented landscapes, but which together with the other arboreal elements play an important role as landscape connectors and extra habitat for many species. Using a graph theory approach, we assessed landscape connectivity at six inter-patch distances across open areas (from 50 to 500 m), and propose two strategies for improving landscape connectivity: the creation of woodland islets and the widening of forested riparian corridors in the agricultural matrix. The main arboreal elements that influenced connectivity were old-growth forest fragments and widespread treed living fences, each increasing connectivity by up to 57% (depending on the threshold distance), while riparian corridors and isolated trees contributed 38% and 6%, respectively. Isolated trees in pastures substantially increased the number of effective connections at all distances (>85%). The GIS-simulated restoration proposals to establish circular woodland islets (10 m radius) in the middle of open agricultural areas increased connectivity by 26%, while widening riparian corridors by up to 10 m per riverside increased it by 11%. Increasing the number of arboreal elements within the agricultural matrix at key sites would enhance landscape connectivity considerably, benefiting the organisms that live in forest remnants in the study area without the need to stop agricultural activities.

Willingness of private landowners to participate in forest conservation in the Chaco region of Argentina

To effectively conserve forests and the ecosystem services they provide, mechanisms are needed to promote conservation on private lands that reduce forest fragmentation, secure lands with high conservation value, and enhance landscape connectivity. Incentive-based programs like payments for ecosystem services (PES) are important policy tools for attaining conservation on private lands. In 2019, we conducted 81 in-person surveys with private forestland owners, whose properties are located on the border of protected areas and in corridors connecting protected areas in Argentina's Chaco forest. We examined landowners' preferences for alternative conservation incentives, how Argentina's current PES program could be altered to increase landowner enrollment, and the amount of compensation landowners require to enroll in PES. We found that knowledge of Argentina's PES program, motivations for forest ownership, attitudes toward forest conservation policy, and property characteristics influenced landowners' preferences for conservation program design. Although indigenous communities preferred conservation easements, other private landowners were more likely to choose a PES program. Research participants preferred PES programs with shorter contract lengths or that permitted them to engage in silvopasture. The payments research participants required to engage in land uses currently authorized under Argentina's PES program exceed current PES funding. Relying solely on PES to engage landowners in conservation may result in lost opportunities to conserve forest on private lands.

Small Landscape Elements Double Connectivity in Highly Fragmented Areas of the Brazilian Atlantic Forest

The Atlantic Forest in Brazil is a biodiversity hotspot, yet its diverse ecosystems and species are becoming increasingly threatened by habitat loss and extreme habitat fragmentation. Most habitat patches of Atlantic Forest are dispersed across agricultural landscapes (e.g., grazing and cropping) in relatively small and isolated fragments (80% < 50 ha). Forest fragments < 1 ha, scattered trees in pastures, tree lines on trenches and fences, and remnant riparian forest, collectively called here Small Landscape Elements (SLEs), are very common in this context. While these SLEs make up much of the Atlantic Forests footprint, very little is known about their role or impact on the persistence and conservation of species. In this study, we investigate the role of SLEs on landscape configuration, particularly their contribution toward landscape connectivity of individual species and the genetic flow of species between larger forest fragments. We randomly selected 20 buffers of 707 hectares within a 411,670 hectare area of the Atlantic Forest that was completely covered by forest in the past located in the south of Minas Gerais State, Brazil. The forest cover randomly varied between these buffers. We used graph theory to measure landscape connectivity as the probability of connectivity for different disperser movement types between landscape knots (habitat patches). We used three estimated dispersal distances in the models: pollen disperser insect (50 m), low-mobility seed disperser bird (100 m) and high-mobility seed disperser bird (760 m). The SLEs together increased the probability of connection by roughly 50%, for all model dispersers, if compared to a theoretical baseline landscape containing no SLEs. Of all SLEs, riparian forests contribute the most toward enhancing landscape connectivity. In these highly fragmented landscapes, such as the Atlantic Forest (>70%), the position of SLEs within the landscapes was more important than their respective areas for connectivity. Although the landscapes were deeply fragmented, we showed that the presence of SLEs can increase connectivity and reduce further biodiversity loss in the Atlantic Forest.

Spatio-Temporal Dynamics of Landscape Connectivity and Ecological Network Construction in Long Yangxia Basin at the 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.

Isolated trees and small woody patches greatly contribute to connectivity in highly fragmented tropical landscapes

Decreasing landscape connectivity, due to habitat loss and agricultural expansion, is a threat for species movement and other flux-dependent ecological processes. Tree cover within the agricultural matrix provides perching sites, dispersal routes, and extra habitat for animals. Isolated trees and living fences in tropical pastures add structural complexity to actual matrices, but their role in landscape connectivity is undervalued. Our main objective was to assess the potential value of small (≤1ha) woody patches for maintaining landscape connectivity in highly fragmented landscapes using birds as focal species. We used high-resolution images and LIDAR data to classify different tree cover types. We assess the probability of connectivity for different hypothetical dispersal distances between woody patches, using a graph-theoretic approach and simulating scenarios that differed in tree cover composition. We estimated the impacts and contribution of tree cover class removals on landscape connectivity. The connectivity index increased widely among scenarios with increasing tree cover composition. The highest connectivity value was obtained in the scenario that included all arboreal elements currently present in the matrix. Small wooded patches and isolated trees contributed from 26% to 59% to overall connectivity. The presence of small (≤1ha) patches of tree cover greatly enhance landscape connectivity for animals with low vagility and behavioral limitations on crossing gaps. Isolated trees and living fences play a crucial role in increasing habitat reachability within rural landscapes and ensuring and enhancing connectivity for animals that perform daily-movements at short-distances. The spatial distribution of arboreal elements within landscapes could be optimized to increase connectivity and must be considered in conservation planning.

Road verges provide connectivity for small mammals: A case study with wood mice (Apodemus sylvaticus) in an agro-silvo pastoral system

Roads disrupt landscape connectivity for many terrestrial mammals. These infrastructures can be barriers to movement thereby threatening population persistence. Nonetheless, small mammals may use road verges as habitat or corridor, thus increasing migration across intensively managed landscapes. However, in well-preserved habitats where road verges show a similar vegetation structure to surrounding areas, their role is still unknown. Road verges would have an important role as fine-scale connectivity providers for small mammals in a well-preserved habitat depending on land management on road surroundings. We aimed to quantify the effects of road verges and paved lanes on the fine-scale landscape connectivity for the wood mouse (Apodemus sylvaticus) in a well-preserved Mediterranean woodland. Additionally, we assessed the impact on connectivity of vegetation cutting on verges and of management in surrounding areas (i.e. firebreaks, grazing, ploughing and cork stripping). We quantified connectivity using graph theory based on two years of capture-recapture data. We compared a set of connectivity metrics (derived from the probability of connectivity index) in a road area and in a virtual roadless scenario. We found that the presence of the road reduced overall fine-scale landscape connectivity, acting as a partial barrier for wood mice movement. However, verges had a key role in promoting movement on road surroundings. Vegetation cutting on verges, and land ploughing in the surrounding landscape were the only management activities compromising connectivity. Our study supports the already known role of road verges as habitat corridors for small mammals. However, it goes beyond existing knowledge by quantifying the connectivity enhancement provided by road verges and demonstrating that this role is highly relevant even in well-preserved landscapes. Therefore, our findings emphasize the critical role of road verges and suggest important management options to enhance landscape connectivity for small mammals.

Assessment of Road-Induced Landscape Fragmentation and Implications for Landscape Planning: the case of İzmir Province

Yollar, buyuk bir cevre sorunu ve biyolojik cesitlilik kaybi ile peyzaj parcalanmasinin ana nedenlerinden biri olarak kabul edilmektedir. Yapilan arastirmalar, yollarin genellikle artan peyzaj parcalanmasina yol actigini; ayrica araclarin neden oldugu kirlilik ve yol aglari etrafindaki yerlesimlerin hizla artmasi yoluyla peyzajlarin yapisi ve isleyisini de etkilediklerini ortaya koymaktadir. Bu calisma, Izmir ili merkez ilcelerinde yollarin varligi ile peyzaj parcalanmasi arasindaki iliskiyi sinif ve peyzaj duzeyinde peyzaj metriklerini kullanarak incelemektedir. Calismada, CORINE arazi ortusu haritasi (CLC2012) ve Urban Atlas2012 (Kent Atlasi2012) (UA2012) ile birlikte kullanilarak, calisma alanina iliskin detayli yol verisinin icerildigi ve icerilmedigi arazi ortusu haritalari kullanilmistir. Analizler FRAGSTATS 4.2 ve ArcGIS 10.5.1 yazilimlarinda gerceklestirilmistir. Sonuclar artan yol varliginin kent peyzajinda artan parcalanmaya sebep oldugunu gostermektedir. Ancak, yollarin neden oldugu parcalanmanin degerlendirilmesinde bazi peyzaj metriklerinin etkinliklerinin olasi kisitliliklarini goz onunde bulundurmak gerekmektedir. Diger yandan, bu calismanin sonuclari, peyzaj parcalanmasini degerlendirirken yama sayisi (NP), alan agirlikli ortalama yama alani (AREA_AM), kenar yogunlugu (ED) ve etkin ag boyutunun (MESH) peyzaj parcalanmasina iliskin daha saglikli degerler sundugunu vurgulamaktadir. Calisma, biyolojik cesitliligin desteklenmesi ve insanlarin yasam kalitesinin iyilestirilmesi bakimindan yollar ve yol aglari cevresinde firsatlar yaratmak icin peyzaj planlama uygulamalarina isik tutabilecek bazi onemli onerilerle sonlandirilmistir. Ornegin, pratik anlamda, yol aglari cevresinde yol kenari bitki ortusu ve bitkilendirilmis banketler, yol aglarinin parcalanma etkisini azaltabilir ve peyzaj baglantililigini arttirilabilir. Ayrica, bu alanlarin korunmasi ve duzenli bakimi peyzaj kalitesinin arttirilmasinda ve biyolojik cesitliligin desteklenmesinde de onemli rol oynayacaktir.

The response of spiders to less-focused non-crop habitats in the agricultural landscape along the lower reach of the Yellow River

Non-crop habitats have been suggested to impact local biodiversity significantly in agricultural landscapes. However, there have been few studies of the effects of less-focused non-crop habitats (orchard, wetland, pit and ditch) on variation of spider abundance. In this study, spiders in 30 woodlands were captured using pitfall traps in Fengqiu County, China, and the effects of local and landscape variations at different scales (50 m, 100 m, 200 m, 350 m and 500 m) on spider abundance were analysed. The most important variation that influenced spider abundance at the 500 m scale was the less-focused non-crop habitat (LNH) cover, and 10% was an appropriate proportion of LNH cover to sustain high level of spider diversity in the investigated landscape. Non-metric multidimensional scaling analyses revealed that there were significant differences in the spider composition among the high, medium and low LNH coverage. Based on indicator species analysis, different spider species were associated with landscapes with different levels of LNH cover. Lycosidae, which accounted for 48% of the total specimens, preferred woodland habitats neighbouring areas with high LNH cover. Compared with woodland habitats, LNH provided more diverse food sources and habitat to sustain more spider species in the study area. Furthermore, linear elements composed of vegetation, such as pits and ditches, may prevent agricultural intensification by enhancing landscape connectivity and providing habitats for different spiders. Our findings may provide a theoretical basis for biodiversity conservation in agro-ecosystems and top-down control of pests.