Fragmented Landscapes Research Articles

Avian seed dispersal out of the forests: A view through the lens of Pleistocene landscapes

Abstract Recent evidence supports that, prior to the impact of modern humans, the temperate zone of Europe was not dominated by a closed continuous forest, but consisted of heterogeneous landscapes with grasslands, light woodlands and forests. Until the late Pleistocene, this region held a diverse community of megaherbivores that maintained the open and semi‐open vegetation through grazing and browsing. This new baseline is congruent with the fact that many European woody species are light‐demanding and fail to regenerate in the shaded interiors of temperate forests. Notably, most of these species are dispersed by frugivorous and seed‐caching animals, mostly birds. Nowadays, avian seed dispersers play a key role for the connectivity and expansion of woodland patches in fragmented anthropogenic landscapes. Indeed, avian seed dispersal within and across the deforested matrix is the norm rather than the exception. Here, I reflect on the current patterns of avian seed dispersal in the fragmented anthropogenic landscapes of Europe from a Pleistocene perspective. The aim of this exercise is to discuss linkages between past and present landscapes, seeking an historical understanding of the high spatial complementarity of avian seed dispersal in and out of the forests. Synthesis: I conclude that the spatial patterns of avian seed dispersal in anthropogenic landscapes are congruent with an ecological and evolutionary history with open and semi‐open habitats created and maintained by megaherbivores (ecological memory). By shaping the environmental conditions for millions of years, megaherbivores would have created selective pressures on animals and plants for life in landscape mosaics with forests and open habitats (niche construction). Finally, I discuss differences in landscape patterns today and in the Pleistocene, as well as the generality of these ideas to other biogeographical regions.

Urban structures are poor stepping stones for crevice-nesting ants in fragmented landscapes

AbstractDespite the high fragmentation of its natural habitats—grasslands with limestone rocks—a previous study revealed that the ant species Temnothorax nigriceps show no evidence of genetic isolation between populations separated by kilometers of presumably unsuitable landscape. In the present study, we hypothesized that urban anthropogenic structures might allow the species to nest and maintain efficient gene flow in spite of the ongoing fragmentation. To test this, we surveyed the presence of T. nigriceps in many putatively suitable anthropized habitats—such as stone walls, ornamental devices, or urban park structures—in an urban area near a continuous source of propagules from natural habitats. We found very few occurrences of T. nigriceps in this urban area, suggesting either a low density of nests in such habitats or difficulty in detecting them in anthropized environment. We discuss the importance of surrounding vegetation and water sources for nesting, especially in anthropized environment where temperatures on mineral surfaces can exceed those in the species’ natural habitats. We conclude that T. nigriceps tend to nest in the most natural-like structures, implying that urban habitats provide poor substitute for the species’ native environment.

Protected Areas Do Not Outweigh the Species Richness or Functional Diversity and Traits of Birds in Brazil

Protected areas (PAs) are widely recognized as being essential for maintaining global biodiversity. In this study, I aimed to determine whether PAs support a greater richness of forest bird species than unprotected habitats and whether they exhibit functional diversity indices and traits comparable to those found in protected forests in the eastern Brazilian Semideciduous Atlantic Forest. I conducted bird surveys across 20 forest fragments of varying sizes (43 to 37,000 ha), 12 of which were legally designated as PAs. The results indicated that species richness was not significantly higher in PAs and that there were no significant differences in functional diversity indices and traits between unprotected and protected forests. In eastern Brazil, some forest remnants were designated as PAs merely because they were among the last remaining patches within a heavily fragmented landscape. Therefore, protected areas do not necessarily serve as accurate proxies for well-preserved habitats.

Multiscale Effects of Xylella fastidiosa on Landscape Services

The spread of Xylella fastidiosa since 2013 in the Mediterranean olive groves of the Apulia region has modified the landscape. The aims of this research are focused on the analysis of its effects on the following: (1) Landscape multifunctionality supported by olive groves in terms of landscape service provision; (2) The functional relations among the main Mediterranean land covers in terms of landscape service supply and demand. (3) The landscape fragmentation at different spatial scales. The landscape has completely changed, mainly in those land covers that, in the past, acted as stabilizing factors (croplands and olive groves), which has been replaced by grasslands in 2021. The main effects of Xylella fastidiosa were on the multifunctionality of olive grove landscape in terms of food production, water regulation, carbon sequestration, and pollination, as well as on landscape cultural value. Ecosystem service supply is mainly related to olive groves, tree covers, shrublands, and wetlands. The province of Lecce showed the highest fragmentation, as demonstrated by the number of patches, the mean patch area, and the DIVISION metric, while the province of Brindisi was the least fragmented, with a DIVISION metric similar in 2011 and in 2021. The multiscale assessment of “olive groves” fragmentation has helped in better analyzing the effect of its spatial configuration on the provision of landscape services and in identifying the right spatial scale for each landscape service provision. It is essential to analyze landscape service flow to enlarge the understanding of the ways in which their supply is maintained through a landscape regeneration policy toward the socio-economic–ecological recovery.

Latency-Aware Unified Dynamic Networks for Efficient Image Recognition.

Dynamic networks have become a pivotal area of study in deep learning due to their ability to selectively activate computing units (such as layers or channels) or dynamically allocate computation to information-rich regions. This capability significantly curtails unnecessary computations, adapting to varying inputs. Despite these advantages, the practical efficiency of dynamic models often falls short of theoretical computation. This discrepancy arises from three primary challenges: 1) a lack of a unified framework across different dynamic inference paradigms due to the fragmented research landscape; 2) an excessive focus on algorithm design at the expense of scheduling strategies, which are essential for optimizing resource utilization on hardware; and 3) the complexity of latency evaluation, since most current libraries cater to static operators. To tackle these issues, we introduce Latency-Aware Unified Dynamic Networks (LAUDNet), a general framework that integrates three fundamental dynamic paradigms-spatially-adaptive computation, layer skipping, and channel skipping-into a single unified formulation. LAUDNet not only refines algorithmic design but also enhances scheduling optimization with the aid of a latency predictor. This predictor efficiently and accurately predicts the inference latency of dynamic operators on specific hardware setups. Our empirical assessments across multiple vision tasks-image classification, object detection, and instance segmentation-confirm that LAUDNet significantly bridges the gap between theoretical and practical efficiency. For instance, LAUDNet cuts down the practical latency of its static counterpart, ResNet-101, by over 50% on hardware platforms like V100, RTX 3090, and TX2 GPUs. Additionally, LAUDNet excels in the accuracy-efficiency trade-off compared to other methods.

Evolution of landscape patterns and driving forces in rural areas of the Fuchun River Basin

At the optimal analysis granularity and extent, this study reveals the spatiotemporal evolution characteristics of landscape patterns in rural areas of the Fuchun River Basin from 1990 to 2020. It also explores the spatiotemporal differentiation of driving forces using Geodetector and Geographically Weighted Regression. The results indicate that: 1) The optimal analysis granularity for the study area is 30 m × 30 m, and the optimal analysis extent is 200 m. 2) Compared to the 1990s, the past two decades have seen an increased degree of landscape fragmentation, higher isolation, and stronger human disturbance in the study area, with significant differentiation. These changes are most pronounced in the semi-urbanized areas along the river and in the northern regions. 3) Digital Elevation Model and land cover type are the most critical driving factors. Over time, the explanatory power of most driving factors shows an overall increasing trend. 4) There is a significant spatial heterogeneity in the driving forces. The influence of the Digital Elevation Model and slope is stronger in the north and south, weaker in the central region, while the influence of temperature increases from north to south. The impact of land cover type is stronger in the central area and weaker in the periphery. This study provides a reference for the scientific use of land resources and the protection of ecological spaces in rural areas within highly urbanized regions at the basin scale.

Landscape fragmentation of built-up land significantly impact on water quality in the Yellow River Basin

Urbanization development often leads to significant changes in the extent in area and fragmentation of built-up land landscape pattern (BLLP) in river basins, which greatly impact the processes of rainfall runoff and pollutant migration. Understanding the spatial scale effects and driving mechanisms of BLLP changes on water quality in large river basins is a challenging research topic and an international frontier in the interdisciplinary fields of geography and environment. This study analyzes the spatial variations of BLLP and water quality throughout the Yellow River Basin (YRB) during the rainy seasons from 2019 to 2021 (4hours scale). Utilized the random forest model to quantitatively separates the contributions of rainfall processes to surface runoff and water pollution, revealing the scale effects and non-linear driving mechanisms of BLLP impacts on water environment changes. The results indicate that: 1) The YRB exhibits great spatial heterogeneity in terms of both BLLP and water quality, with places with lower water quality displaying bigger areas and higher degrees of BLLP fragmentation. 2) The patch density and built-up land area (PD.B and CA.B) have a major impact on changes in water quality in the YRB, with notable impacts noted in circular buffer zones with radii of 20 km and 5 km, respectively. 3) PD.B is sensitive to water quality in the YRB, explaining 39.1% to 49.5% of the variance under different rainfall conditions, and exhibits a significant non-linear relationship, with an impact threshold of 0.38 (n/100 ha). The study suggests that for large-scale regions like the YRB, the degree of BLLP fragmentation is more likely to lead to degradation of water environmental quality compared to its area. BLLP fragmentation due to higher PD.B and CA.B disrupts the original ecosystem and hydrological connectivity, resulting in poorer retention and filtration of pollutants carried by rainfall runoff, while increasing the export of other pollutants. However, once urbanization surpasses a certain threshold, the BLLP fragmentation can enhance water quality by reducing the impermeable surface connectivity, as they are no longer impacted by expanding areas. To achieve ecologically sustainable development, it is necessary to apply rational landscape management and water resource management policies that consider the dual process of how BLLP fragmentation affects the water environment.

Beyond the ‘spaghetti bowl’: assessing the role of the AfCFTA Protocol on Intellectual Property in Africa’s complex regulatory environment

Abstract For decades, international IP frameworks have been criticized for neglecting forms of IP, such as traditional knowledge, that are crucial to middle- and low-income economies but often do not conform to the global standards set by Western conceptions of IP. This oversight continues to shape IP policy development even in African countries, many of which struggle to create IP policies that align with their unique economic and developmental needs. In response to these challenges and driven by an expressed commitment to fostering and safeguarding African innovation and forms of IP, 54 African nations have recently adopted an IP Protocol to the African Continental Free Trade Agreement (AfCFTA). However, given the continent’s already fragmented IP regulatory landscape, this article questions whether the AfCFTA Protocol on IP (AfCFTA IP Protocol) can successfully foster the development of frameworks that reflect Africa’s distinctive socio-economic realities and priorities. This article evaluates the protocol in relation to previous attempts at continental IP harmonization efforts in Africa and examines the extent to which the AfCFTA IP Protocol can be deployed to achieve its stated goals of IP harmonization on the continent. While the AfCFTA IP Protocol is a positive initiative, its introduction and adoption may be somewhat premature, given the continent’s ‘spaghetti bowl’ of IP regulations.

Beyond Composting Basics: A Sustainable Development Goals—Oriented Strategic Guidance to IoT Integration for Composting in Modern Urban Ecosystems

IoT-based composting provides clear advantages over conventional urban composting in areas such as enhanced monitoring, efficiency, resource utilization, and management. Bibliometric analysis of 121 publications on IoT-based urban composting identified critical research gaps and emphasizes the necessity for a strategic framework for full implementation and execution of sustainable development goals-oriented IoT-based composting in modern cities across. Under the key theme of IoT-based urbanized composting automation, 16.5% of publications focus on urbanized composting automation but overlook the system’s scalability. The lowest mean citations of 72.7 (22.3% of publications) in intelligent composting process optimization show the lack of broader applications. A total of 28.9% of total publications focus on urban composting sustainability assessment but lack IoT integration in their scope. The composting process, pollution, environmental impact, cost, and life cycle analysis of modern city composting share 19% and 13.3%, respectively. However, both key themes lack real-time monitoring, operation, and economic feasibility for scalable models. The article highlights a fragmented landscape providing sustainable development goals-oriented strategic guidance for the full implementation and execution of IoT-based composting facilities in modern city ecosystems. The article comprehensively explains the budgetary constraints, scalability, data management, technological compatibility, privacy, security, and regulatory compliance essential for sustainable operation.

Assessing Landscape Fragmentation Dynamics with Fourier Transforms

Abstract Quantifying landscape fragmentation is crucial for understanding its impact on biodiversity. Within landscape ecology, there is an ongoing effort to create metrics that systematically characterize landscape patterns and predict their effects on various species. In this study, we utilized Fourier transforms to measure landscape fragmentation in urban and heterogeneous landscapes over periods of 24 and 12 years, respectively. Analyzing Landsat images from 1986, 1999, and 2010, we focused on the first principal component (PC1) to evaluate changes in fragmentation over time. Our analysis revealed a significant increase in fragmentation in urban areas from 1986 to 2010, with a particularly noticeable rise between 1999 and 2010. Specifically, the average Fourier spectrum decreased slightly from 16.0 to 15.9 throughout the study period, indicating increased fragmentation at both urban and landscape levels. The sensitivity analysis further showed that removing 6,000 cells from the original image caused the mean Fourier spectrum to drop from 16.0 to 15.5, demonstrating the method’s effectiveness in detecting subtle land cover changes. Our findings demonstrated that Fourier analysis effectively detects subtle landscape changes, particularly in larger study areas and over longer time intervals. However, it lacks detailed information on specific types or quantities of altered land cover. To address this limitation, integrating Fourier analysis with land cover classification datasets could enhance understanding of landscape dynamics and support more informed conservation and management decisions.

Spatiotemporal Correlation Analysis of Landscape Pattern and Habitat Quality in and Around China’s Tropical Rainforest National Park

With the establishment of the national park system in China, balancing ecological conservation within national parks and development in surrounding areas has become a critical issue. Despite its importance, studies on the scale effects of landscape fragmentation and its relationship with habitat quality (HQ) in these regions remain scarce. Therefore, this study focuses on the Hainan Tropical Rainforest National Park (HTRNP) in China and the surrounding nine cities and counties. The optimal scale for analyzing the spatiotemporal characteristics of landscape patterns, we assessed the best grain size and extent of landscape pattern indices using the regional information loss assessment model, area loss index, and semivariance function analysis. Based on this, the Fragstats and InVEST models analyzed the spatiotemporal evolution of landscape patterns and HQ from 1980 to 2020. Additionally, bivariate spatial autocorrelation theory was applied to examine the spatial correlation between the two. The results show that (1) the landscape indices in the study area vary with grain size and extent. The optimal grain size is 300 m, and the optimal extent is 2 km × 2 km. (2) Over the past 40 years, the landscape pattern of HTRNP has remained stable. In contrast, the surrounding areas exhibit notable spatial differentiation, with landscapes in coastal town centers becoming increasingly fragmented. (3) Over the past 40 years, the overall HQ in the study area has been relatively high, showing a spatial distribution pattern that decreases gradually from the center of HTRNP outward to rural areas, towns, and coastal regions. HTRNP has maintained a high and stable HQ, while the surrounding areas exhibited a decreasing trend in HQ, although the decline was relatively modest. (4) The spatial distribution of HQ aligns closely with landscape patterns, indicating a significant spatial correlation. The landscape connectivity of HTRNP remains high, with consistently superior HQ. In contrast, coastal town centers are characterized by highly fragmented landscapes and poor HQ. This study reveals the spatiotemporal dynamics of landscape patterns and HQ, along with their spatial associations. These findings provide a scientific basis for ecological conservation in national parks and the planning optimization of surrounding areas.

The Aquatic Metatron: A large‐scale experimental facility to study the combined effects of habitat fragmentation and climate change on aquatic meta‐ecosystems

Abstract Revealing the effects of multiple global change drivers on ecosystem dynamics and functioning is a crucial endeavour, which necessitates the use of appropriate tools. Here, we present the Aquatic Metatron, a unique mesocosm facility providing a large‐scale experimental resource to study the combined effects of global change components, in particular climate change and habitat fragmentation, on the ecological and evolutionary dynamics of aquatic ecosystems. The Aquatic Metatron consists of 144 mesocosms of 2 m3 each that can be connected to each other with aquatic corridors, and—for a subset of them—with aerial corridors. This enables effective control of dispersal across meta‐ecosystems. In addition, the temperature in each mesocosm is supervised and precisely controlled, either through a heating (all mesocosms) or a cooling (72 mesocosms) system. All mesocosms can be monitored automatically for abiotic and biotic factors (pH, dissolved oxygen, conductivity, turbidity and chlorophyll a) allowing for long‐term experimentation. We tested the platform by conducting three experiments involving the manipulation of various components of global change: climate warming, biodiversity loss, eutrophication and aquatic/aerial fragmentation. The technical innovations of the platform have been validated, in particular its capacity to accurately recreate multiple climatic scenarios (e.g. heatwaves, warming, cooling) and the possibility of using aerial and water corridors to simulate fragmented landscapes. The Aquatic Metatron is located in the south‐west of France (https://sete‐moulis‐cnrs.fr/fr) and is part of AnaEE France and AnaEE‐ERIC (https://www.anaee.eu/), which are large‐scale research infrastructures. The Aquatic Metatron is a research facility accessible to external researchers and projects.

Comparative Validation and Misclassification Diagnosis of 30-Meter Land Cover Datasets in China

Land cover maps with high accuracy are essential for environmental protection and climate change research. The 30-meter-resolution maps, with their better resolution and longer historical records, are extensively utilized to assess changes in land cover and their effects on carbon storage, land–atmosphere energy balance, and water cycle processes. However, current data products use different classification methods, resulting in significant classification inconsistency and triggering serious disagreements among related studies. Here, we compared four mainstream land cover products in China, namely GLC_FCS30, CLCD, Globeland30, and CNLUCC. The result shows that only 50.34% of the classification results were consistent across the four datasets. The differences between pairs of datasets ranged from 21.10% to 37.53%. Importantly, most inconsistency occurs in transitional zones among land cover types sensitive to climate change and human activities. Based on the accuracy evaluation, CLCD is the most accurate land cover product, with an overall accuracy reaching 86.98 ± 0.76%, followed by CNLUCC (81.38 ± 0.87%) and GLC_FCS30 (77.83 ± 0.80%). Globeland30 had the lowest accuracy (75.24 ± 0.91%), primarily due to misclassification between croplands and forests. Misclassification diagnoses revealed that vegetation-related spectral confusion among land cover types contributed significantly to misclassifications, followed by slope, cloud cover, and landscape fragmentation, which affected satellite observation angles, data availability, and mixed pixels. Automated classification methods using the random forest algorithm can perform better than those that depend on traditional human–machine interactive interpretation or object-based approaches. However, their classification accuracy depends more on selecting training samples and feature variables.

Ecology and life history predict avian nest success in the global tropics

Nest predation rates critically influence avian biodiversity and evolution. In the north temperate zone, increased nest failure along edges of forest fragments is hypothesized to play a major role in the disappearance of bird species from disturbed landscapes. However, we lack comprehensive syntheses from tropical latitudes, where biodiversity is highest and increasingly threatened by habitat fragmentation and disturbance. We assembled data from five decades of field studies across the global tropics (1,112 populations of 661 species) and used phylogenetic models to evaluate proposed predictors of nest success. We found significant effects of several traits, including adult body mass and nest architecture. Contrary to results from many temperate locations, anthropogenic habitat disruption did not consistently reduce nest success; in fact, raw nest success rates were lower in large tracts of primary forest than in disturbed or fragmented landscapes. Follow-up analyses within species, using a subset of 76 species for which we had estimates of nest survival in habitats with different levels of disruption, confirmed that neither disturbance nor fragmentation significantly influenced nest success. These results suggest that nest predation alone cannot explain observed declines in avian biodiversity in tropical forest fragments, raising new questions about the demographic processes that drive extinction in the tropics.

Landscape pattern evolution and ecological security assessment based on land use changes in mining cities: a case study of Heihe city

The development of mining cities has led to changes in land use and the evolution of landscape patterns. Constructing an ecological security evaluation system can reflect the ecological security status of mining city areas and provide planning references for these cities. This study, based on Heihe City’s land use data from 1980 to 2020, systematically analyzes the spatial and temporal evolution characteristics of land use, landscape patterns, and landscape ecological security levels by constructing a land use transfer matrix and calculating landscape pattern indices and landscape ecological security indices. The results show that: 1) Forest land is the main type of land use in Heihe City, accounting for over 50% of the total area. Land use changes primarily occurred between 2000–2010 and 2010–2020, with the spatial pattern characterized by overall stability and localized dramatic shifts, mainly involving the conversion of forest land to farmland and unused land. 2) From 1980 to 2020, the landscape ecological security pattern in Heihe City improved. Landscape diversity and landscape contagion increased, while landscape fragmentation, the largest patch area, and the average patch area decreased. Land use was optimized overall, but the trend of forest fragmentation became noticeable. 3) Between 1980 and 2020, the landscape ecological security level in Heihe City improved significantly. Driven by ecological restoration policies, the ecological security level in the southern region greatly improved, while the spatial pattern continued to show a trend of lower security in the south and higher security in the north. Specifically, the area proportions of low-security and relatively low-security areas increased by 6.23% and 9.55%, respectively. The spatial clustering of landscape ecological security levels is evident, with high-high value clustering mainly in the north and low-low value clustering mainly in the south. It is necessary to further promote ecological protection in the north to ensure the ecological barrier function, while strengthening ecological restoration in the south to improve ecological security levels. Additionally, continuous macro-policy regulation is needed to maintain long-term ecological security in Heihe City. The ecological security level of mining city landscapes is influenced by economic dependence, policy constraints, and environmental issues. This study can provide guidance for planning improvements in the study area and other mining cities.

Assessing the Interaction Impacts of Multi-Scenario Land Use and Landscape Pattern on Water Ecosystem Services in the Greater Bay Area by Multi-Model Coupling

Water ecosystem services (WESs) are intrinsically associated with the livelihood of urban residents and are frequently disrupted by human activities. Land use and landscape patterns are key driving factors of alterations in WESs. However, existing research primarily quantifies single-factor influences and often overlooks the interactions between these factors. This study addresses this gap by employing a multi-model coupling approach, integrating the Patch-generating Land Use Simulation (PLUS), Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, and Geographical Detector (GD) models alongside various indicators to analyse the evolution of land use, landscape patterns and WESs in the Greater Bay Area from 2000 to 2020, and to simulate spatio-temporal change patterns in different scenarios from 2030 to 2050. Additionally, this study examines the multi-factorial interactions between land use, landscape patterns, and WESs. The results indicate that (1) urbanisation steadily increased, leading to intensified landscape fragmentation, and water yield (WY) and total phosphorus (TP) consistently increased, while total nitrogen (TN) in water gradually decreased; (2) urban areas exerted the most significant impact on WY in the Greater Bay Area while Patch density (PD) had a stronger influence on WY, and Shannon’s diversity index (SHDI) had the most pronounced effect on TN and TP; (3) the interaction between any two land-use types or landscape indices exerted a greater impact on WESs compared with the impact of individual factors alone. The interaction between urban areas and cropland substantially influenced WY (q¯ = 0.634) and most strongly affected TN and TP in water (q¯ = 0.74 and 0.73, respectively). SHDI and PD had the most significant impact on WY in the economic development scenario (q¯ = 0.19) and exhibited the greatest influence on the TN and TP levels in the ecological priority scenario (q¯ = 0.12 and 0.15, respectively). Our findings can provide theoretical and technical support for the integrated scientific planning of regional water ecosystems and the development of comprehensive land use policies in the future.

Activity-based measures of landscape fragmentation

ContextLandscape fragmentation, which has demonstrated links to habitat loss, increased isolation, a loss of connectivity, and decreased biodiversity, is difficult to quantify. Traditional pattern-based approaches to measuring fragmentation use landscape metrics to quantify aspects of the composition or configuration of landscapes.ObjectiveThe objective of this study was to examine the relative improvements of an alternative activity-based approach using the cost of traversing a landscape as a proxy for fragmentation and compare it with the traditional approach.MethodsOne thousand binary landscapes varying in composition and configuration were simulated, and least-cost path analysis provided the data to calculate the activity-based metrics, which were compared with computed traditional pattern-based metrics.ResultsActivity-based fragmentation assessments were sensitive to levels of landscape fragmentation, but offered improvements over exiting pattern-based methods in that some metrics varied monotonically across the spectrum of landscape configurations and thus makes their interpretation more holistically meaningful.ConclusionsThis study provides a modular conceptual framework for assessing fragmentation using activity-based metrics that offer functional improvements over existing pattern-based approaches. While we present a focused theoretical implementation, the process to be measured and the scale of observation can be altered to suit specific user requirements, ecosystems, or species of interest.

Analysis of the Spatial-Temporal Characteristics and Driving Factors of Cultivated Land Fragmentation Under the Expansion of Urban and Rural Construction Land: A Case Study of Ezhou City

A systematic understanding of the spatial-temporal evolution patterns of cultivated land fragmentation (CLF), its driving factors, and its relationship with the expansion of urban and rural construction land is essential for identifying strategies to mitigate CLF in rapidly urbanizing regions. This study combined landscape fragmentation with ownership fragmentation, analyzing CLF through three dimensions: resource endowment, spatial concentration, and convenience of utilization, with eight selected indicators. By comparing village-level data from 2013 to 2022, we explored the key drivers of CLF and its conflicts with urban and rural construction land expansion. The findings indicate a clear spatial variation in village-level CLF in Ezhou, characterized by low fragmentation in the northwest and northeast, and high fragmentation in the southwest and central regions. This pattern is in contrast to Ezhou’s economic development, which decreased progressively from east to north and south. Over the study period, village-level CLF in Ezhou evolved from being primarily moderately and relatively severely fragmented to predominantly severely and relatively severely fragmented, with an overall declining trend and more pronounced polarization. At the same time, the CLF within the village region demonstrated notable spatial clustering features, with a rapid increase observed between 2013 and 2022. It was also discovered that CLF is driven by various factors, with the main influences being the proportion of construction land, land use intensity, and population density. Cultivated land is the main source of both urban construction land (UCL) and rural construction land (RCL), with average contribution rates of 46.47% and 62.62%, respectively. This research offers empirical evidence for rapid urbanization and serves as a critical reference for rural revitalization and coordinated urban–rural development, with potential guidance for future policy formulation and implementation.

Spatial–temporal effect of sea–land gradient on landscape pattern and ecological risk in the coastal zone: A case study of Dalian City

Abstract Coastal zones have intense human activity and are ecologically fragile. Assessing ecological risks in coastal zones is crucial to promoting ecological safety and sustainable development for coastal cities. However, the relationship between ecological risk assessment and distance from the coastline is indeterminate in current research. To solve this problem, this study constructs the sea–land gradient and reconstructs the landscape pattern index and landscape ecological risk index (ERI) considering the sea–land gradient paradigm. This study aims to analyze the spatial–temporal variation characteristics and effects of the sea–land gradient on landscape pattern and ecological risk in Dalian City from 2000 to 2015. The results show the following: (1) between 2000 and 2015, a significant effect of coastline on the coastal landscape pattern in Dalian is reducing landscape fragmentation. The extent of this influence gradually diminished along the sea–land gradient. The landscape aggregation of urban building sites near the sea was relatively high and gradually increased over the years; (2) in Dalian, the landscape ERI has decreased near the sea and increased near the inland year by year; (3) the dominant pattern of landscape ecological risk was characterized by a transition from high to low levels within the [0, 2.5] km zone, while a transition from low to high levels predominated within the [2.5, Max] km zone; and (4) the northern region in Dalian primarily goes from high to low risk in the buffer zone near the landside, whereas the southern area has this changing pattern in the buffer zone near the seaside.

Long-term contamination by non-native fish assemblages in a Neotropical floodplain.

Biological invasions are a major threat to biodiversity in species-rich regions. Therefore, it is important to understand mechanisms behind the long-term establishment of non-native fish species in aquatic environments in the Neotropical region. Here, we associated fish biomass, species richness, and the proportion of non-native species (contamination and Kempton's indices) to quantify the non-native pressure over fish biodiversity in lakes and rivers of the Parana River floodplain, seasonally, from 2000 to 2017. We divided species into native and non-native assemblages sampled in spatio-temporal gradients. Temporal trends were examined using linear regressions and generalised additive models. Fish biomass in gillnets increased for both native and non-native fish species, but their Kempton indices were inversely correlated. Extinction of native species occurred locally with biotic differentiation of non-native species in lakes, rivers, and ecosystem contamination. A constant increase in fish biomass resulted in overwhelming biodiversity of non-natives at the end of the time series evaluated. Native biotic resistance to introductions was not detected in deterministic trends. The observed patterns were consistent with previous studies showing native biotic homogenisation and extinction of species in response to biological invasions, landscape fragmentation, and riverine impoundments. Increases in abundance and species richness of non-native fish were the biodiversity drivers that resulted in non-native species outweighing native species in the Parana floodplain.