Pattern of cooling benefits from ecospaces during urbanization: A case study of the Yangtze River Economic Belt

Urban ecological spaces are effective thermoregulators under global warming. However, the cooling efficiency of urban ecological spaces during the urbanization has not been studied comprehensively. Here, we investigate the spatio-temporal dynamics of Urban Cold Island (UCI) intensity in 11 typical cities of the Yangtze River Economic Belt (YREB). We determined the impact of ecological landscape trends on these dynamics by using GlobalLand and MODIS 8 d mean land surface temperature (LST) data for three periods (2000, 2010, and 2020), and the landscape pattern index and diversity index. We found that in the past 20 years, the built-up area has increased by sixfold; 62.53 % and 37.47 % of YREB were warming or cooling, with 71.22 % of the daytime cooling and 93 % of the nighttime warming. The average UCI intensity of YREB has increased from 0.518 to 0.847 and is negatively correlated with LST with a decreasing slope. As the UCI intensity of green spaces increased, that of blue spaces decreased. Surface area and landscape pattern are the key determinants of UCI intensity in blue and green spaces, respectively, especially the landscape shape index (LSI). Therefore, maintaining ecological spaces, enriching the structural integrity of green spaces, and improving blue space connectivity can help cities at different development levels cope with heat stress during regional urbanization.

Assessing the influence of simulated environmental gradients on the spatial heterogeneity of landscape patterns in the Tibetan Plateau

Landscape patterns are pivotal in the realms of land use planning and ecological development, yet there remains a dearth of comprehensive research pertaining to the prediction of changes in landscape pattern characteristics. Within this study, we adopt the PLUS-CA-Markov and Fragstats models to forecast landscape patterns on the Tibetan Plateau spanning the period from 2030 to 2050. Through qualitative and quantitative analyses, we explore the spatiotemporal characteristics of landscape pattern changes between 2000 and 2050, concurrently identifying correlations among landscape pattern indices. Moreover, acknowledging the distinctive environmental gradients encompassing the plateau, notably elevation, slope, temperature, and precipitation, we investigate their implications on landscape pattern changes. Our findings indicate that: (1) Grassland degradation exhibited the utmost severity between 2000 and 2020, primarily attributed to overgrazing and climate-induced glacial melt. In contrast, cropland, forest, and water showcased divergent trends from 2020 to 2050 when compared to the preceding two decades, indicative of the efficacy of climate change control measures. (2) The distribution of landscape patterns on the Tibetan Plateau exhibited a considerable level of instability, marked by a decline in aggregation, reduced diversity and complexity, and amplified ecological connectivity between 2000 and 2020, signifying a partial amelioration in ecological quality. Between 2020 and 2050, landscape aggregation decreased alongside landscape fragmentation and the number of connectivity paths, signifying a discernible degradation of the plateau's ecosystem. (3) The most significant trade-off relationship was observed between landscape division index and largest patch index, while the synergistic relationship between landscape shape index and mean shape index was more pronounced. (4) Landscape aggregation, division, and largest patch index demonstrated non-linear quadratic trends in relation to elevation and temperature. Landscape shape index and patch density exhibited irregular non-linear effects. Largest patch index was predominantly influenced by slope, whereas division index was most affected by precipitation.

Effects of landscape pattern on water quality at multi-spatial scales in Wuding River Basin, China

Urbanization and agricultural land use have led to water quality deterioration. Studies have been conducted on the relationship between landscape patterns and river water quality; however, the Wuding River Basin (WDRB), which is a complex ecosystem structure, is facing resource problems in river basins. Thus, the multi-scale effects of landscape patterns on river water quality in the WDRB must be quantified. This study explored the spatial and seasonal effects of land use distribution on river water quality. Using the data of 22 samples and land use images from the WDRB for 2022, we quantitatively described the correlation between river water quality and land use at spatial and seasonal scales. Stepwise multiple linear regression (SMLR) and redundancy analyses (RDA) were used to quantitatively screen and compare the relationships between land use structure, landscape patterns, and water quality at different spatial scales. The results showed that the sub-watershed scale is the best spatial scale model that explains the relationship between land use and water quality. With the gradual narrowing of the spatial scale range, cultivated land, grassland, and construction land had strong water quality interpretation abilities. The influence of land use type on water quality parameter variables was more distinct in rainy season than in the dry season. Therefore, in the layout of watershed management, reasonably adjusting the proportion relationship of vegetation and artificial building land in the sub-basin scale and basin scope can realize the effective control of water quality optimization.

The relative impacts of vegetation, topography and weather on landscape patterns of burn severity in subtropical forests of southern China

Understanding the landscape patterns of burn severity is vital for managing fire-prone ecosystems. Relatively limited research has been done about fire and burn severity patterns in subtropical forests. Here, we derived the pre-fire forest type data from a global land-cover product at 30 m resolution based on time-series Landsat imageries. Using Landsat 8 OLI remote sensing imagery and field-based composite burn index (CBI), this study spatially mapped the burn severity of 27 forest fires in the subtropical forest ecosystems in southern China from 2017 to 2021. The landscape pattern of patches with different burn severity was quantified using landscape indices. In addition, factors influencing the patterns of burn severity across the landscape were determined using the Geodetector model. Burn severity of patches varied significantly over space. High burn severity was common in forest patches with low fragmentation, low patch density, and regular shape. In contrast, moderate and low burn severity was prevalent in patches with smaller patch size, high patch density, and complex shapes. Extensively burned forest patches were located at higher elevations, while more fragmented patches were located in gently sloping areas. Topographic factors were the most significant factors influencing variances in burn severity across the forest patches, followed by weather conditions. Compared to low elevation areas, vegetation types at the high elevation areas (dominated by Masson pine) are more singular, with higher fuel loads, thus resulting in a more regularly-shaped distribution of highly severe burning patches. A detailed understanding of burn severity patterns and driving factors in a landscape can help develop sustainable forest management and restoration strategies. Practically, fire managers should conduct mechanical fuel treatments or thinning of forests at high-elevation areas to reduce the potential of severe fire behavior and the continuity of fire spread.

Impacts of landscape pattern on plants diversity and richness of 20 restored wetlands in Chaohu Lakeside of China

The recovery of wetland function and biodiversity conservation aroused considerable interest in the past decades. Although many advances have been achieved in revealing disturbing factors on plants diversity, the knowledge of biodiversity manipulation, landscape configuration and ecosystem process in restored wetlands remains incomplete. To address this issue, the landscape of 20 restored wetlands' vegetation was classified into five vegetation formations including: upland plants, wet grassland, emergent plants, floating plants and submerged plants. Meanwhile, the configuration of landscape, plants' function traits and the structure of plants communities of each wetland were analyzed. A total of 142 herbaceous plants were identified from 399 samples of 20 lakeside wetlands. The top five predominant species were Typha orientalis, Alternanthera philoxeroides, Phragmites australis, Echinochloa caudata, and Erigeron canadensis. The highest of diversity index was observed in upland plants with Shannon-Wiener index (H) of 0.92 while higher richness of plants was obtained in wet grassland with species of 88. In dry year, the immigration of upland xerophyte and obligated aquatic species to facultative area increased the biodiversity of the ecotone. Meanwhile, this change may also aggravate the diffusion risk of exotic invasive species Erigeron canadensis. Additionally, the results indicated that number and evenness of landscape outweighed Shannon diversity index (SHDI) of wetlands in shaping the richness and diversity of wetland plants. Whereas, the high value of maximum proportion of landscape (Pmax) have reduced the landscape evenness and species richness. A suggested Pmax of <0.5 was benefit for the stability and biodiversity of restored wetlands.

Spatial-temporal heterogeneity in the influence of landscape patterns on trade-offs/synergies among ecosystem services: a case study of the Loess Plateau of northern Shaanxi

Exploring the role of landscape patterns in the trade-offs/synergies among ecosystem services (ESs) is helpful for understanding ES generation and transmission processes and is of great significance for multiple ES management. However, few studies have addressed the potential spatial-temporal heterogeneity in the influence of landscape patterns on trade-offs/synergies among ESs. This study assessed the landscape patterns and five typical ESs (water retention (WR), food supply (FS), habitat quality (HQ), soil retention (SR), and landscape aesthetics (LA)) on the Loess Plateau of northern Shaanxi and used the revised trade-off/synergy degree indicator to measure trade-offs/synergies among ESs. The multiscale geographically weighted regression (MGWR) model was constructed to determine the spatial-temporal heterogeneity in the influence of landscape patterns on the trade-offs/synergies. The results showed that (1) from 2000 to 2010, the increase in cultivated land and the decrease in forestland and grassland increased landscape diversity and decreased landscape heterogeneity and fragmentation. During 2010-2020, the change range decreased, the spatial distribution was homogeneous, and the landscape diversity and fragmentation in the northwestern area increased significantly. (2) The supply of the five ESs continued to increase from 2000 to 2020. During 2000-2010, FS-SR, FS-LA and SR-LA were dominated by synergies. From 2010 to 2020, the proportion of trade-off units in all relationships increased, and HQ-FS, HQ-SR and HQ-LA were dominated by trade-offs. (3) Landscape patterns had complex impacts on trade-offs/synergies, and the same landscape variable could have the opposite impact on specific trade-offs/synergies in different periods and areas. The results of this study will inform managers in developing regional sustainable ecosystem management strategies and advocating for more research to address ecological issues from a spatial-temporal perspective.

Analyzing the impacts of topographic factors and land cover characteristics on waterlogging events in urban functional zones

Rapid urbanization and climate changes result in frequent occurrence of urban waterlogging disasters, which cause serious economic damage and pose a threat to residents' safety. Understanding the spatial characteristic and the key influencing factors of urban waterlogging has significant implications for mitigating waterlogging. In this study, the officially issued representative waterlogging points were obtained, as well as the topographic factors and land cover characteristics were selected to compare their impacts on the waterlogging event density in a highly urbanized area at urban functional zone (UFZ) scale, and to quantify the contributions of the key influencing factors on urban waterlogging events. Results showed the average density of urban waterlogging events in the study area is 9.2 points/km2, and 38.4 % of the waterlogging events are distributed in REZ. The distribution of waterlogging points in the study area revealed a significant multi-core and multilevel spatial aggregation pattern, and 12.1 % of the study area was high-density waterlogging area. In the total UFZs, the correlation coefficients of topographic indices with waterlogging density were relatively weaker than the other land cover characteristic metrics. The impervious surface ratio had significant contributions in all UFZ types. The larger ratio of impervious surface significantly increased the density of waterlogging events. The increase in the ratio of green space can effectively decrease the density of urban waterlogging. In the total UFZs, the top 3 key influencing factors of urban waterlogging were PR (35.9 %), COHESION (32.5 %) and DIVISION (11.8 %). The higher connectivity of landscape patches in REZ, INZ and COZ, as well as the increase of landscape dispersion or diversity in REZ, EGZ, INZ and GSZ can effectively reduce the occurrence of urban waterlogging. This study provides a better understanding of the formation mechanism of urban waterlogging disasters and potential implications for prioritized waterlogging mitigation strategies.

Influence of landscape patterns on nitrate and particulate organic nitrogen inputs to urban stormwater runoff

This study investigated the effect of the landscape pattern of permeable/impermeable patches on NO3--N and particulate organic nitrogen (PON) concentrations during stormwater runoff transport and their source contributions. Six landscape pattern indices, namely, mean proximity index (MPI), largest patch index (LPI), mean shape index (MSI), landscape shape index (LSI), connect index (CONNECT), and splitting index (SPLIT), were selected to reflect the fragmentation, complexity, and connectivity of permeable patches in urban catchments. The results show that lower fragmentation, higher complexity, and greater connectivity can reduce NO3--N concentrations in road runoff and drainage flow (i.e., the flow in the stormwater drainage network), as well as PON concentrations in road runoff. Further, the above landscape pattern is effective for mitigating the contributions of NO3--N and PON from road runoff. Low impact development (LID) can be incorporated with the landscape pattern of permeable/impermeable patches to mitigate nitrogen pollution in urban stormwater at the catchment scale by optimizing the spatial arrangement.

Regional proximity effects of landscape pattern evolution: Evidence from 325 county-level areas in the middle reaches of the Yangtze River, China

Unravelling the evolution of landscape patterns is essential to understand regional socio-ecological processes and to solve conflicts between environment protection and human development. However, the role of landscape transition in regional landscape pattern evolution remains unclear. Taking 325 county-level areas in the middle reaches of the Yangtze River (MRYR) as an example, this study explored the spatiotemporal associations between landscape quantity and pattern from the 1970s to 2020. Employing the methods of landscape metrics and trend and correlation analysis, associations between landscape transition and landscape pattern were found. The main results were as follows: (1) From the 1970s to 2020, urban land nearly doubled from 0.93 to 1.89 million km2. Arable land and forest showed the largest quantity reductions of 0.88 million km2 and 0.28 million km2, respectively. Other landscapes showed both decreasing and increasing trends with a spatial overlap among counties. (2) Transition in landscape quantity drives the change in landscape patches, thus affecting the landscape pattern in counties. The percentage of landscape area at the class level (CPLAND) showed relative changes in the quantities of landscape categories in each observation year, but their extreme outliers presented larger changes. (3) Diverse correlation coefficients in terms of magnitude and direction suggested that the transition from natural landscape to human-influenced landscape and the reverse processes occurred. Aggregation and diversity metrics showed spatial interaction with similar distances and the perimeter-area fractal dimension (PAFRAC) showed spatial autocorrelation at local scale. Optimal bandwidths among arable land, forest, and urban land (129.2 km) revealed direct spatial interactions and causal relationships, as did waters and unused land (66.7 km). The findings explained the evolution of landscape patterns and highlighted key areas where various landscape changes occurred, and can provide scientific support for policy-making in regional landscape transition governance.

Dynamic landscapes and the influence of human activities in the Yellow River Delta wetland region

The Yellow River Delta (YRD) wetland is one of the largest and youngest wetland ecosystems in the world. It plays an important role in regulating climate and maintaining ecological balance in the region. This study analyzes the spatiotemporal changes in land use, wetland migration, and landscape pattern from 2013 to 2022 using Landsat-8 and Sentinel-1 data in YRD. Then wetland landscape changes and the impact of human activities are determined by analyzing correlation between landscape and socio-economic indicators including nighttime light centroid, total light intensity, cultivated land area and centroid, building area and centroid, economic and population. The results show that the total wetland area increased 1426 km2 during this decade. However, the wetland landscape pattern tended to be fragmented from 2013 to 2022, with wetlands of different types interlacing and connectivity decreasing, and distribution becoming more concentrated. Different types of human activities had influences on different aspects of wetland landscape, with the expansion of cultivated land mainly compressing the core area of wetlands from the edge, the expansion of buildings mainly disrupting wetland connectivity, and socio-economic indicators such as total light intensity and the centroid mainly causing wetland fragmentation. The results show the changes of the YRD wetland and provide an explanation of how human activities effect the change of its landscape, which provides available data to achieve sustainable development goals 6.6 and may give an access to measure the change of wetland using human-activity data, which could help to adject behaviors to protect wetlands.

Impacts of landscape pattern evolution on typical ecosystem services in Ganjiang River Basin, China

Understanding the response mechanism of ecosystem services (ES) to landscape patterns is important in regional landscape planning and sustainable development. In this study, the landscape index and InVEST model were used to quantitatively analyze the spatio-temporal evolution of landscape patterns and ES in the Ganjiang River Basin of China from 1990 to 2020. Furthermore, the bivariate Moran's I method and spatial error model were used to test the spatial correlation between landscape index and ES. The results showed that (1) cropland decreased and construction land increased, and the overall landscape tended to be fragmented, the patch shape complicated, and landscape diversity increased from 1990 to 2020. Water conservation (WC) and soil conservation (SC) capacity increased by 10.56 mm and 16.24 t hm-2 a-1, respectively, whereas carbon storage (CS) decreased by 1.22 t hm-2 a-1. (2) The responses of different typical ES to landscape patterns were different in the landscape index and response degree. Typical ES negatively responded to Shannon's diversity index and patch density. WC was sensitive to the Splitting Index, whereas SC and CS were more responsive to the average patch area. (3) The overall purpose of territorial spatial planning within a basin should be to reduce the fragmentation and heterogeneity of the landscape. According to four local aggregation patterns of landscape index and ES, corresponding measures can be taken according to local conditions in different regions. These results can provide a quantitative basis for landscape management and ecological construction in the Ganjiang River Basin and scientific guidance for the Yangtze River conservation strategy.

Irreversible community difference between bacterioplankton generalists and specialists in response to lake dredging

Understanding response of bacterioplankton community responsible for maintaining ecological functions of aquatic ecosystems to environmental disturbance is an important subject. However, it remains largely unclear how bacterioplankton generalists and specialists respond to dredging disturbance. Illumina MiSeq sequencing and statistical analyses were used to evaluate landscape patterns, evolutionary potentials, environmental adaptability, and community assembly processes of generalists and specialists in response to dredging in eutrophic Lake Nanhu. The Proteobacteria and Actinobacteria dominated bacterioplankton communities of generalists and specialists, and abundances of Proteobacteria decreased and Actinobacteria increased after dredging. The generalists displayed higher phylogenetic distance, richness difference, speciation rate, extinction rate, and diversification rate as well as stronger environmental adaptation than that of specialists. In contrast, the specialists rather than generalists showed higher community diversity, taxonomic distance, and species replacement as well as closer phylogenetic clustering. Stochastic processes dominated community assemblies of generalists and specialists, and stochasticity exhibited a larger effect on community assembly of generalists rather than specialists. Our results emphasized that lake dredging could change landscape patterns of bacterioplankton generalists and specialists, whereas the short-term dredging conducted within one year was unable to reverse community difference between generalists and specialists. Our findings extend our understanding of how bacterioplankton generalists and specialists responding to dredging disturbance, and these findings might in turn call on long-term dredging for better ecological restoration of eutrophic lakes.

Influence of human activities and climate change on wetland landscape pattern-A review

Wetlands (rivers, lakes, swamps, etc.) are biodiversity hotspots, providing habitats for biota on the earth. In recent years, wetlands have been significantly affected by human activities and climate change, and wetland ecosystems have become one of the most threatened ecosystems in the world. There have been many studies on the impact of human activities and climate change on wetland landscapes, but there is still a lack of relevant reviews. This article summarizes the research on the impact of global human activities and climate change on wetland landscape patterns (vegetation distribution, etc.) from 1996 to 2021. Human activities such as dam construction, urbanization, and grazing will significantly affect the wetland landscape. Generally, dam construction and urbanization are generally believed to harm wetland vegetation, but appropriate human behaviors such as tillage benefit wetland plants' growth on reclaimed land. Prescribed fires in non-inundation periods are one of the ways to increase the vegetation coverage and diversity of wetlands. In addition, some ecological restoration projects have a positive impact on wetland vegetation (quantity, richness, etc.). Under climatic conditions, extreme floods and droughts are likely to change the wetland landscape pattern, and excessively high and low water levels will restrict plants. At the same time, the invasion of alien vegetation will inhibit the growth of native vegetation in the wetland. In an environment of global warming, rising temperatures may be a "double-edged sword" for alpine and higher latitude wetland plants. This review will help researchers better understand the impact of human activities and climate change on wetland landscape patterns and suggests avenues for future studies.

Urbanization and agriculture intensification jointly enlarge the spatial inequality of river water quality

Rivers are severely polluted by multiple anthropogenic stressors. An unevenly distributed landscape pattern can aggravate the deterioration of water quality in rivers. Identifying the impacts of landscape patterns on the spatial characteristics of water quality is helpful for river management and water sustainability. Herein we quantified the nationwide water quality degradation in China's rivers and analyzed its responses to spatial patterns of anthropogenic landscapes. The results showed that the spatial patterns of river water quality degradation had a strong spatial inequality and worsened severely in eastern and northern China. The spatial aggregation of agricultural/urban landscape and the water quality degradation exhibits high consistency. Our findings suggested that river water quality would further deteriorate from high spatial aggregation of cities and agricultures, which reminded us that the dispersion of anthropogenic landscape patterns might effectively alleviate water quality pressures.

Habitat selection of wintering cranes in typical wetlands in the middle and lower reaches of the Yangtze River over the past 20 years, China

The wetlands in the middle and lower reaches of the Yangtze River are the main overwintering and perching places for cranes. To examine the habitat selection mechanism of cranes in this area, two natural wetland reserves, Shengjin Lake and Poyang Lake, which are the main habitats of typical cranes, were selected as the study area. Using 20 years of Landsat satellite image data (between 1999 and 2019), the vegetation cover index was calculated from a pixel dichotomy model, and the landscape pattern index was obtained through Fragstats. The entropy method was adopted to determine the weight of the landscape index, and then, the habitat suitability index was calculated. Combined with the number of typical crane populations in the reserve, the selection mechanism of overwintering habitat of cranes was revealed. On the change of land-use type, the crane habitat of Shengjin Lake transferred more to non-crane habitat, and other land types increased, resulting in the decrease of crane habitat area. However, the change of crane habitat in Poyang Lake Reserve was small, so it can accommodate more cranes to overwintering here. In terms of vegetation coverage, most of the vegetation cover areas of Shengjin Lake were woodland near or far from the lake, but the woodland was not the habitat of cranes. Most of the vegetation-covered areas of Poyang Lake are grassland near the lake, which provide rest and foraging places for cranes. In the landscape pattern, the number of landscape patches in Shengjin Lake was large, the degree of landscape fragmentation was higher than that in Poyang Lake, the landscape complexity was higher, and the landscape diversity was simpler. This is not conducive to the maintenance of crane habitat, but also reduces the attractiveness of overwintering cranes, while the landscape suitability of crane habitat in Poyang Lake was higher than that in Shengjin Lake, and cranes were more likely to choose Poyang Lake as their overwintering habitat.

Evaluation of river longitudinal connectivity based on landscape pattern and its application in the middle and lower reaches of the Yellow River, China

River connectivity plays an essential role in maintaining the health and stability of river basin ecosystems. It is of great significance to protect river ecosystems to clarify the effect of water conservancy project construction and operation on river hydrological connectivity. The longitudinal connectivity is affected by the landscape patterns of river, such as the convergence and dispersion of the mid-channel bars and the river areas. This study aims to analyze the impacts of construction and regulation of Xiaolangdi Dam on the connectivity of the middle and lower reaches of the Yellow River from the perspective of landscape pattern. An improved longitudinal river connectivity evaluation method was proposed by accounting for the influence of the landscape pattern represented by mid-channel bars based on barrier coefficient method, and then was applied to analyze the connectivity pre- and post-dam construction. The results show that the amplitude and frequency of the oscillation of the river were greatly reduced and tended to be stable. The aggregation degree of mid-channel bars was reduced, and the distribution of mid-channel bars was more dispersed. The river longitudinal connectivity before and after the construction of the Xiaolangdi Dam were 1.35 and 1.50 respectively, indicating an increased river longitudinal connectivity. Overall, there are differences in connectivity before and after Xiaolangdi Dam construction, and connectivity fluctuates after dam construction. Because of the dam regulation of water and sediment, the river connectivity during the flood season increased significantly, and was greater than that before and after the flood season. The longitudinal connectivity evaluation method established in this study is accurate and efficient, and provides an intuitive and reliable new method for quantitatively analyzing the changing laws and characteristics of river connectivity.

Study on land use and landscape pattern change in the Huaihe River Ecological and economic zone from 2000 to 2020

Exploring the relationship between land use change and landscape patterns can provide a basis for regional ecological management. In this paper, based on remote sensing images of the Huaihe River Ecological and Economic Zone for the years 2000, 2005, 2010, 2015 and 2020, the spatial and temporal evolution patterns of land use in the region were quantitatively described by using the methods of land use shift matrix and landscape pattern analysis. The relationship between land use change and landscape pattern was analyzed with the Grey Relation Analysis (GRA) model. The results show that: (1) the land use of the Huaihe River Ecological and Economic Zone has changed significantly in the past 20 years, with the conversion of arable land into construction and forest lands, in addition to the growth of water areas and a decline in the areas of arable land, grassland and unused land. (2) The landscape pattern fragmentation of each type of land in the study area from 2000 to 2020 fluctuated and decreased, and the landscape connectivity and landscape diversity increased significantly. (3) The GRA model shows that construction, arable and forest lands played the most significant role in the change of landscape pattern of the Huaihe River Ecological and Economic Zone. Countermeasures are proposed to better coordinate and optimize the relationship between spatial development and landscape pattern for the Huaihe River ecological and economic Zone.

Habitat quality assessment of wintering migratory birds in Poyang Lake National Nature Reserve based on InVEST model

Poyang Lake National Nature Reserve (PLNNR) is an important resting place for wintering migratory birds on the East Asian-Australasian Flyway (EAAF). In recent years, due to human activities and climate change, the area of wetlands has shown a downward trend, and the number and habitat of wintering migratory birds have been threatened. It is urgent to evaluate the habitat quality of wintering migratory birds in PLNNR. Therefore, the InVEST model and landscape index were used to evaluate the habitat quality of wintering migratory birds, and the grey correlation theory was used to reveal the response of typical wintering migratory bird population to habitat quality. The results showed that the habitat quality of the PLNNR was still at a high level, but showed a downward trend, with the average index of habitat quality decreasing from 0.872 to 0.817. The area of the highest quality habitat decreased by 3394.92 hm², the area of the lowest, low, and medium quality habitats increased by 3112.11 hm², and the area of the high quality habitat remained stable. The lowest, low, and medium quality habitat expanded from the middle to the south of the PLNNR mainly because of the expansion of construction land and cultivated land. The area with deterioration in habitat quality was 10,477.53 hm², mainly concentrated in the center and south of the PLNNR. The area with restoration in habitat quality was 6148.26 hm², mainly concentrated in the Bang Lake and Dacha Lake. The area with no change in habitat quality remained stable. The fragmentation degree and shape complexity of highest and high quality habitats increased, dominance degree and connectivity decreased, and the landscape pattern of habitat quality showed a downward trend. Typical wintering migratory birds have a strong correlation with highest, high, and low habitat quality, and there is a downward trend with the deterioration of habitat quality. Finally, this paper puts forward constructive suggestions on the degradation of habitat quality caused by land-use change.

Influences of landscape pattern on water quality at multiple scales in an agricultural basin of western China

Determining the associations between landscape pattern and river water quality and quantifying the abrupt change points of landscape metrics are vital to optimize landscape planning and improve basin water quality. This study took an agricultural basin in western China as a case study. River water quality of 61 sub-basin outlets were monitored during wet and dry seasons from 2020 to 2021. Landscape metrics were extracted at 100 m, 300 m, 500 m riparian buffer and sub-basin scales, respectively. Relationships between water quality and landscape pattern at multiple scales were explored by using redundancy analysis (RDA). Results showed that urban-related landscape metrics served as the primary contributor to degrade water quality during both seasons, followed by cropland-related metrics, which might be attributed to the increase of urban land and reduction of agricultural chemical fertilizer use. Landscape metrics could better explain the water quality variations during wet season than dry season. The explanatory abilities of landscape metrics to overall water quality appeared little difference among spatial scales during wet season, whereas landscape metrics within 100 m riparian buffer had much larger explanatory rate than other spatial scales during dry season. Results of abrupt change point analysis revealed that the abrupt change interval values (ACIVs) of percentage of urban land (PLAND_urban) and the largest patch index of urban land (LPI_urban) differed among COD, TN, and TP. The recommended threshold values of PLAND_urban and LPI_urban for COD, TN, and TP management were smaller than 11.0%, 2.5%, and 1.0%, respectively. When the PLAND_urban or LPI_urban exceeded 19.0%, the TN, TP, and COD pollution would all significantly accelerate. Therefore, a limit value of 19% of PLAND_urban and LPI_urban, respectively is put forward. From dry season to wet season, the ACIVs of PLAND_urban and LPI_urban for COD concentration increased, whereas they decreased for TN and TP concentrations. Our results can provide scientific insights into sustainable landscape planning and effective water quality protection in agricultural basins.

Spatial transformation of changes in global cultivated land

The spatial transformation of cultivated land is an important element in the study of land use transformation. Analyzing the characteristics and direction of the global spatial transformation of cultivated land is of great significance in clarifying the spatial extent and quality of global cultivated land and ensuring global food security. In this context, this paper uses the global spatial data of cultivated land from 1992 to 2015 to analyze the characteristics of global cultivated land spatial transformation from the perspectives of cultivated land quantity, cultivated land landscape pattern, and cultivated land management pattern, applying the Mann-Kendall trend tests, trend analysis, landscape pattern index measures, and global rural per capita cultivated indicators. The global cultivated land area increased, followed by a decrease, during the study period; there were three distinct phases of change, with the years 1995 and 2005 as turning points. During the first phase, the global cultivated land area increased at an average annual rate of 0.19 %, in the second phase, the increase rate was 0.30 %, and in the third phase, the increase rate was -0.003 %. Based on the trend of cultivated land change during the study period, the areas with a dramatic change in cultivated land area were classified into six typical hotspot areas, involving the increase and decrease of area change in 10 different countries. The two countries with the largest increases in cultivated land area are Sweden and Brazil (24.82 % and 24.43 %, respectively), whereas Ukraine's cultivated land area decreased throughout the study period.

Research on the interaction of "tourism development-land use-landscape pattern" since the 1990s in a small karst basin, China

The rapid rise of tourism in the karst regions has promoted the development of the local economy by relying on the unique landforms and landscapes. However, tourism development is often accompanied by land use changes and has an impact on the ecological environment. Exploring the coupling relationship between "tourism development-land use-landscape pattern" is very important for ecologically fragile karst areas. Taking the Yulong River Basin as an example, this research applied 3S technology, spatial analysis based on POIs, and regression analysis to the following: (1) identifying the process and effects of land use change, (2) determining the spatial pattern of tourism land and its correlation with land use change, (3) determining the characteristics and impacts of landscape pattern evolution. As the results suggested: (1) The significant expansion of construction land occupies a large amount of farmland, there is a balanced relationship between farmland and forest land for mutual conversion. (2) The aggregation of tourist land is affected by the trend of tourist behavior and the distribution of scenic spots. There is a significant moderate positive correlation between tourism land and construction land. (3) With the land use change, landscape heterogeneity has improved, but landscape fragmentation is serious and landscape connectivity is reduced. This research provides new evidences for the effect of the rapid development of tourism on land use change and ecological environment and as a reference to future orderly and moderate land development and ecological sustainability in karst regions.

Ecosystem services, landscape pattern, and landscape ecological risk zoning in China

Ecosystem services represent a bridge between natural ecosystems and human well-being and are closely associated with landscape ecological risk (LER). Delimiting reasonable LER areas is important for ecosystem protection, and it is essential to link ecosystem services to LER zoning. However, only a few studies have achieved this, and the zoning accuracy of LER remains poorly understood. Therefore, in this study, we evaluated the ecosystem service value (ESV) and LER index using the equivalent value method and landscape pattern index via the remote sensing of land use data at the county level in China in 2000-2015. We applied bivariate spatial autocorrelation as well as the grey correlation analysis model to analyse the ESV-LER spatial relationships and developed a general framework to improve the accuracy of LER zoning. We found that the average ESV increased from $761.42 thousand/km² in 2000 to $766.16 thousand/km² in 2015, while the LER index continuously decreased in China. We also discerned a significant negative correlation between ESV and LER (p < 0.001), whereas approximately 750 counties in China exhibited high ESV and low LER indices during the study period. The final LER zoning revealed that the high-LER areas in China were mainly located in the plain areas, and the proportion of counties with high LER levels increased from 17.97% in 2000 to 26.56% in 2015. Overall, our results have important implications for ecological security, future landscape planning and design, and ecologically sustainable development in China.

Managing landscape patterns at the riparian zone and sub-basin scale is equally important for water quality protection

Widespread attention has been given to understanding the effect of the landscape pattern on river water quality. However, which spatial scale (riparian zone versus sub-basin) has the greater impact on water quality has long been controversial, since the key metrics that affect water quality varied with spatial scale. Thus, quantifying the spatial scale effects of key landscape metrics on water quality is critical to clarifying which scale of landscape pattern is more conducive to water quality conservation. Here, we adopted variation partitioning analysis (VPA) and random forest models to quantify the landscape pattern impact on water quality at northern Erhai Lake during the 2019 rainy season (early, mid, and late), and comprehensively analyze the key landscape metrics on different scales. The results revealed that the riparian zone and sub-basin scale landscape patterns explained similar water quality variations (difference only 0.9%) in the mid (August) and late rainy season (October), but exhibited a large difference (24.1%) during the early rainy season (June). Furthermore, rivers were primarily stressed by nitrogen pollution. Maintaining the Grassland_ED > 27.99 m/ha, Grassland_LPI > 4.19%, Farmland_LSI < 3.2 in the riparian zone, and Construction_ED < 1.69 m/ha, Construction_LSI < 2.46, Farmland_PLADJ < 89.0% at the sub-basin scale could significantly reduce the TN concentration in the stream. Meanwhile, managing of these metrics can effectively prevent rapid increases of TN in rivers. Moreover, due to the low phosphorus concentration in the rivers, none of the landscape metrics significantly explained the variation in TP. This study explored the spatial scale effect of landscape patterns on water quality and revealed the driving factors of nutrient variation. This study will provide a scientific basis for aquatic environmental management in plateau watersheds.

Spatio-temporal evolution of landscape patterns in an oasis city

Studying the spatial-temporal evolution of oasis urban landscape patterns can provide a unique reference for future sustainable development. This study aimed to characterize the spatio-temporal evolution of landscape patterns in the past 20 years. The remote sensing and spatial analysis techniques included land transfer matrix, orientation evolution combined with landscape index, natural driving factor, and mass center migration model. The results showed that (1) two decades of urbanization brought prominent LULC changes. An increase of 464.8 km² in the building area denoted the dominant change. (2) Changes in building, bare land, and green space occurred mainly in the northwest orientation. The patch Aggregation Index (AI) increased continually during building expansion. Meanwhile, the Landscape Division Index (DIVISION) experienced a progressive and complementary decline. (3) Increase in building land was associated with topography (DEM) and vegetation cover (NDVI). A lower elevation induced a larger building increment. Around NDVI average value for bare land (0.137) and farmland (0.477), building land had the largest expansion, verifying its principal land sources. (4) The center of gravity of building land overall migrated towards the north, and green space and bare land towards the south due to building encroachment. The findings could inform future sustainable urban development.

Integrating source apportionment and landscape patterns to capture nutrient variability across a typical urbanized watershed

Effective integrated watershed management requires models that can characterize the sources and transport processes of pollutants at the watershed with multiple landscape patterns. However, few studies have investigated the influence of landscape spatial configuration on pollutant transport processes. In this study, the SPARROW_TN and SPARROW_TP models were constructed by combining direct pollution source data and landscape pattern data to investigate the source composition and nutrient transport processes and to reveal the influence of landscape patterns on nutrient transport in the urbanized Beiyun River Watershed. The introduction of landscape metrics significantly improved the simulation results of both models, with R² increasing from 0.89 to 0.85 to 0.93 and 0.91, respectively. Spatial variations existed in TN and TP loads and yields, as well as the source compositions. Pollution hotspots were effectively identified. Source apportionment showed that for the entire watershed, TN came from atmospheric nitrogen deposition (35.25%), untreated sewage (28.23%), agricultural sources (22.60%), and treated sewage (13.92%). In comparison, TP came from untreated sewage (44.94%), agricultural sources (40.22%), and treated sewage (11.51%). In addition, the largest patch index of grassland correlated positively with both TN and TP, whereas the largest shape index of buildup land and interspersion and juxtaposition index of forest were negatively correlated with TN and TP, respectively. The results of this study will provide insight into effective nutrient control measures that consider spatially varying nutrient sources and associated nutrient transport processes.

The dynamic relationships between landscape structure and ecosystem services: An empirical analysis from the Wuhan metropolitan area, China

Environmental managers have been striving to optimize landscape structure to achieve a sustained supply of ecosystem services (ESs). However, we still lack a full understanding of the relationships between landscape structure and ESs due to the absence of thorough investigations on the variability of these relationships in space and time. To fill this critical gap, we assessed landscape structure alongside four important ESs (agricultural production (AP), carbon sequestration (CS), soil conservation (SC), and water retention (WR)) in the Wuhan metropolitan area (WMA), and then analyzed the spatiotemporal impacts of landscape structure on ESs from 2000 to 2020 using Geographically and Temporally Weighted Regression. The results show only AP maintained a stable growth trend over the past two decades, while the other ESs fluctuated considerably with a noticeable decline in SC and WR. The importance of landscape structure in influencing ESs varies by time and place, depending on the local landscape composition and configuration. In general, landscape composition has a stronger and less temporally stable impact on ESs compared to configuration. Furthermore, increases in landscape diversity, as measured through Shannon's diversity index, and the percentage of woodlands were found to contribute to the simultaneous benefits of multiple ESs, but in most cases the effects of landscape structure on different ESs were different or even opposite, suggesting that trade-offs are critical in landscape management. The findings highlight the complex response of ESs to dramatically changing landscapes in the WMA and can guide decision-makers in precise spatial arrangement and temporal adjustments to improve current landscape management.

Landscape dynamics and human disturbance processes in wetlands in a mining city: a case study in Huaibei, China

Wetlands are fragile ecosystems that are sensitive to human activities. In mining cities with high groundwater tables, underground mining, urbanization, and land reclamation cause severe disturbance to wetland landscape patterns, which poses a serious threat to the integrity and sustainability of the regional wetland ecosystems. This paper extracted the dynamic patterns of wetlands in Huaibei, China, from the Landsat TM/ETM remote sensing images with a time duration of 30 years from 1991 to 2021. The land-use transfer matrix and the landscape metrics were used to analyze the dynamic evolution of the wetland landscape patterns in this typical mining city. Afterwards, the human disturbance changes in the wetlands during the past 30 years were analyzed by the human disturbance transformation index (HTI). The correlation between the HTI and the changes in the landscape metrics were analyzed to reflect the influences of different human disturbance mechanisms on the evolution of the wetland landscape patterns. The results indicated that the wetland areas gradually increased with rising human disturbance levels from 1991 to 2021. However, the wetland landscape patterns showed a trend of declining landscape connectivity and fragmentation. The human disturbance levels to the wetlands were found significantly increased from 1991 to 2005 and from 2010 to 2015, and declined from 2005 to 2010 and from 2015 to 2021. The correlation between the HTI and landscape metrics indicates that current ecological restoration planning has limitations in improving the wetland landscape patterns. In the future, it is necessary to formulate systematic wetland landscape patterns restoration planning that covers the overall area according to the evolutionary trend of wetlands.

Estimating the pollutant loss rate based on the concentration process and landscape unit interactions: a case study of the Dianchi Lake Basin, Yunnan Province, China

The landscape analysis model establishes a quantitative relationship between landscape patterns and pollution processes. The spatial heterogeneity within and between landscapes affects the pollutant transmission process and originates from the superposition effect of terrestrial geographical and morphological characteristics. This study aimed to develop a new method to estimate the pollutant loss rate. From the perspective of the flow process of pollutants entering a water body, the interaction between each landscape unit and adjacent unit during pollutant migration was simulated along the pollutant migration flow path. The role of pollutants affected by external forces in the process of migration could be divided into "promoting" and "hindering." Four indices were proposed to simulate the pollutant loads entering the lake. The linear coefficients between the load of the pollutants chemical oxygen demand (COD_Cr), ammoniacal nitrogen (NH₃-N), total nitrogen (TN), and total phosphorus (TP) entering the lake and the pollutant load emission weighted by the upstream and downstream confluence ratio index were 0.930, 0.835, 0.925, and 0.795, respectively, and the non-linear variance explanation coefficients were 87.70%, 87.50%, 87.60%, and 84.70%, respectively. When the surface resistance was integrated into the index as a parameter, the linear and nonlinear correlation coefficients were significantly improved. The linear coefficients were 0.952, 0.897, 0.919, and 0.939, respectively, and the non-linear variance explanations were 99.00%, 97.30%, 95.10%, and 97.30%, respectively. The spatial distribution of landscape surface resistance reflects the spatial movement trend of pollutants from different sources. The indices characterizing the promoting and hindering effects could be integrated to calculate the loss rate of pollutant load entering the lake from landscape units at different locations in the basin space.

Multi-spatial scale effects of multidimensional landscape pattern on stream water nitrogen pollution in a subtropical agricultural watershed

Multidimensional (coupled land use, soil properties, and topography) landscape effects on stream water nitrogen (N) are complex and scale-dependent. However, studies that identify critical buffer zones that explain large variations in riverine N, and estimate specific thresholds of multidimensional landscape patterns at the class level, result in a sudden changes in riverine N pollution, are still limited. Here, a new multidimensional landscape metric that combined land use, soil properties, and topography effects was applied to various riparian buffer zones and sub-watershed scales, and their relationships to riverine N levels were investigated. We used stream water ammonium-N, nitrate-N, and total-N concentrations datasets, from 2010 to 2017, in the nine subtropical sub-watersheds in China. The results of model selection and model averaging in ordinary least squares regressions, indicated that the riparian buffer zone with widths of 400 m, had more pronounced influence on water NH₄-N and TN levels than at other scales. Within the 400 m buffer zone, the key landscape metrics for NH₄-N, NO₃-N and TN concentrations in stream water were different, and explained up to 43.35%-76.55% (adjusted R²) of the total variation in river N levels. When ENN_MN_Class17 below 39-56 m, PD_Class8 above 4.63-6.55 n/km², PLAND_Class27 above 23-29%, and CONTIG_MN_Class42 below 0.35-0.37% within the 400 m buffer zone, riverine NH₄-N and TN would be abruptly increased. This study provided practical ideas for regulation regarding landscape management linked to watershed structure, and identified reference thresholds for multidimensional landscape metrics, which should help reduce riverine N pollution in subtropical China.

Effects of multi-scale landscape pattern changes on seasonal water quality: a case study of the Tumen River Basin in China

Landscape patterns affect river water quality by influencing hydrological processes. However, with changes in spatial scale and season, landscape factors may have different effects on water pollution. Therefore, quantitative analysis of the scale effect of each landscape index was carried out to determine the mutation point of river water quality and its index relationship, which is of great significance to landscape planning and water quality protection. Based on the water quality monitoring data of 19 sampling points in the Tumen River Basin, we used redundant methods to quantify the spatial scale effects and seasonal dependencies of various landscape indicators on river water quality, then determined the mutation point of the water quality along the landscape-scale gradient. The results showed that different types of landscape indicators have different effects on river water quality, and the spatial-scale effect of landscape composition affects a river's water quality, while landscape configuration indicators had the highest sensitivity. The landscape characteristics of river straps better explained the overall water quality, a phenomenon that is more obvious in the wet season than the dry season. We identified a key landscape indicator of urban area proportion (Urban%) and a contagion index (CONTAG) as the river strap scale. An Urban% < 30% and a CONTAG > 70% suggest effective landscape planning parameters that effectively protect water quality. The results indicated that, to protect water quality, landscape regulation should follow scale-adaptability measures and consider landscape thresholds, which cause abrupt changes in water quality.

Attribution of vegetation coverage change to climate change and human activities based on the geographic detectors in the Yellow River Basin, China

Quantitatively, analyzing the driving mechanism of vegetation coverage change is of important significance for regional ecological environment evaluation and protection. Based on time series NDVI data and meteorological data of the Yellow River Basin (Inner Mongolia Section), the trend and significance of climate factors and vegetation coverage in the YRB (IMS) and four sub-regions (the Hetao Irrigation district, the Ten Tributaries region, the Hunhe river basin, and the Dahei river basin) from 2000 to 2018 were ascertained. We used geographic detectors to quantitatively analyze the effects of detection factors on vegetation coverage change. The results indicated that the spatial pattern of vegetation variation and climate change had obvious spatial heterogeneity. During 2000-2018, the regions with vegetation improvement (72.87%) were much greater than that with degradation (26.55%) in the YRB (IMS). Annual precipitation change (4.55%) was a key driving factor to the vegetation coverage change in the YRB (IMS). Among the four sub-regions, the land use conversion type demonstrated the largest explanatory power, but the q values of the four sub-regions were different from each other. The results of the interaction showed that land use change and annual precipitation change were the major driving factors that influenced regional vegetation coverage change. This study has an important reference value for improving the basin's ecological environment.

Research on the spatiotemporal coupling relationships between land use/land cover compositions or patterns and the surface urban heat island effect

Urbanization leads to changes in landscape configuration and land use/land cover (LULC) patterns, and these changes are important factors affecting the surface urban heat island (SUHI) effect. However, from the perspective of spatiotemporal changes, quantitative analytical results regarding the impacts of the LULC composition, configuration, and pattern in inland plateau lakeside cities on the SUHI effect, and the responsive relationships among these factors remain unclear. By combining satellite remote sensing data with analytical methods, such as urban-rural gradients, spatial statistics, and landscape pattern indices, the impacts of LULC changes on the SUHI effect in Kunming, China, are revealed. The results show the following. (1) The explosive growth in impervious surfaces (ISs) caused by urbanization, leading to changes in the LULC composition, configuration and pattern, is the main reason for the deterioration of the SUHI effect. Over the past 30 years, Kunming's ISs have increased by 304.58 km², SUHI has expanded by 764.26 km², and the regional average land surface temperature (LST) has increased by 1 °C. (2) This study also found that a large area of bare ground is another important reason for the sharp rise in LST, explaining why bare land (BL) has the highest average LST (28.72 °C). (3) The pattern of LULC can well explain the spatial distribution characteristics of SUHIs. The normalized difference built-up index (NDBI), normalized difference bareness index (NDBaI), and LST have the same change curve along the urban-rural gradient, while the normalized difference vegetation index (NDVI), modified normalized difference water index (MNDWI), and LST have opposite trends. (4) ISs and water body (WB) are the main types of warming and cooling, respectively, but the warming effect of ISs is greater than the cooling effect of WB. From the average value of the correlation coefficient with LST, NDBI (0.84) > MNDWI (-0.63). (5) Kunming's remote sensing index values do not have simple linear relationships with the LST. NDBaI, NDBI, and LST show significant exponential relationships, and NDVI, MNDWI, and LST show significant quadratic polynomial relationships. (6) The dominant landscape type determines the correlation between the landscape shape index (LSI) and the LST of green spaces (GSs). (7) Adopting a simple and regular landscape layout can effectively reduce the SUHI effect. These research results could provide a scientific decision-making basis for the spatial urban planning and ecological construction of Kunming and could have practical significance for guiding the green, healthy, and sustainable development of the city.

Study on the threshold relationship between landscape pattern and water quality considering spatial scale effect-a case study of Dianchi Lake Basin in China

It is of great significance to analyze the threshold relationship between landscape pattern and water quality for watershed water environment treatment. However, previous studies did not consider the influence of spatial scale on threshold. Therefore, this study proposed the idea of the relationship between landscape pattern and water quality threshold considering the spatial scale effect to solve the above problems. Firstly, the percentage of landscape composition area under 9 spatial scales (riparian buffer zone and sub-basin) of 20 rivers entering the lake in Dianchi Lake Basin was extracted to identify the optimal spatial scale of landscape pattern and water quality by redundant analysis (RDA). Then, a variety of nonlinear regression models such as power regression, exponential regression, quadratic regression, and segmented regression are used to quantitatively detect the thresholds of landscape pattern and water quality. The results show that (1) the spatial scale has a significant influence on the threshold relationship between landscape pattern and water quality, and the total interpretation rate of landscape pattern on water quality is the largest at the buffer scale of 1100 m riparian zone, which is an effective buffer for river governance. (2) Different spatial scales have different effects on the threshold relationship between landscape pattern and water quality. In the nonlinear regression model of landscape pattern and water quality in the buffer zone of 1100 m riparian zone, the significance and R² of the equation are better than those of the sub-basin. (3) From the nonlinear relationship between landscape pattern and water quality, it is found that the landscape threshold can be quantitatively identified when the water quality changes abruptly or reaches the I ~ V water quality standard. Among them, the type-1 landscape threshold at the water quality mutation point can be used as the long-term goal of water quality protection in Dianchi Lake Basin, and the type-2 landscape threshold can be used as the short-term goal of water quality adjustment. The research results can provide a scientific basis for the governance of water environment and the rational planning of landscape pattern in Dianchi Lake Basin, and have practical significance for guiding the sustainable development of cities.

The impacts of landscape patterns spatio-temporal changes on land surface temperature from a multi-scale perspective: A case study of the Yangtze River Delta

Unordered and speedy urbanization is the foremost cause of land surface temperature (LST) rise in an urban area. Understanding the effects of landscape changes on LST is crucial for the urban sustainable development. In this study, we retrieved the LSTs of 26 cities in the Yangtze River Delta Urban Agglomeration with the Landsat images during the summer time (from June to August) of 2000 and 2019. From a multi-scale perspective, i.e. grids of 10 km and 20 km, county and city level, the partial correlation analysis, geographically weighted correlation analysis and local bivariate Moran's I were conducted to explore the influence of the landscape pattern changes of the built-ups on LST change. Our results have shown that, the scale change impacts the relationships between the landscape metric changes of built-ups and the LST change. As the scale upscales, the correlation between different landscape metric changes of built-ups and the LST change continues to increase. Among them, the area-related metrics (percentage and largest patch index) have the most significant impact on LST change, showing a positive correlation. Moreover, there are obvious spatial autocorrelation and spatial spillover effects between the landscape metric changes of built-ups and the LST change. These findings are helpful for understanding regional ecology as well as land use/land cover planning to minimize the negative environmental impacts of urbanization.

Analysis of the spatial distribution and influencing factors of China national forest villages

China national forest villages are the agents to promote rural greening and beautification, as well as further implementation of the rural revitalization strategy. It is of great significance to study their spatial distribution characteristics and influencing factors. Therefore, taking 7586 China national forest villages as examples, the methods of nearest neighbor index, Tyson polygon, cold and hot spot analysis, and nuclear density index are used to study the spatial distribution characteristics of China national forest villages and their influencing factors. The results show that (1) since the nearest neighbor index is less than 1, and the Tyson polygon area variation coefficient is much greater than 64%, it is comprehensively determined that the distribution of China national forest villages belongs to agglomerated distribution. (2) The spatial clustering is characterized by "hot in the south and cold in the north." The hot spots are dominated by southern regions such as Sichuan, Hubei, and Jiangsu, and the cold spots are dominated by northern regions such as Heilongjiang, Jilin and Xinjiang. (3) The distribution characteristics of nuclear density have a strong correlation with the distribution characteristics of forest vegetation and urban agglomerations. Most high-density areas are located within the forest vegetation coverage. The first batch forms the Yangtze River Delta and Central Plains urban agglomerations high-density areas, and the second batch forms the Yangtze River Delta and Central Plains high-density areas. (4) Elevation, aspect, river, forest resources endowment, traffic, economic development level, and population size are important factors affecting the distribution of China national forest villages, and their distribution presents the characteristics of "low altitude, positive direction, near water, rich forest resources, convenient transportation, developed economy, and dense population." The research can provide reference for the evaluation and construction of China national forest villages and the implementation of village beautification and rural revitalization strategies in the future.

Linking landscape structure and vegetation productivity with nut consumption by the Cantabrian brown bear during hyperphagia

In bears, reproduction is dependent on the body reserves accumulated during hyperphagia. The Cantabrian brown bear mainly feeds on nuts during the hyperphagia period. Understanding how landscape heterogeneity and vegetation productivity in human-dominated landscapes influence the feeding habits of bears may therefore be important for disentangling species-habitat relationships of conservation interest. We determined the spatial patterns of nut consumption by brown bears during the hyperphagia period in relation to landscape structure, characteristics of fruit-producing patches and vegetation productivity. For this purpose, we constructed foraging models based on nut consumption data (obtained by scat analysis), by combining vegetation productivity data, topographical variables and landscape metrics to identify nut foraging patterns during this critical period for bears. The average wooded area of patches where scats were collected and where the nuts that the bears had consumed were produced was larger than that of the corresponding patches where nuts were not produced. For scats collected outside of nut-producing patches, the distance between the scats and the patches was greatest for chestnut-producing patches. Elevation, Gross Primary Production (GPP) and the Aggregation Index (AI) were good predictors of acorn consumption in the models. Good model fits were not obtained for data on chestnut consumption in bears. The findings confirm that brown bears feeding on nuts show a preference for relatively large, highly aggregated patches with a high degree of diversity in the landscape pattern, which may help the bears to remain undetected. The nut prediction model highlights areas of particular importance for brown bears during hyperphagia. The human presence associated with sweet chestnut forest stands or orchards may make bears feel more vulnerable when feeding.

Increasing fragmentation and squeezing of coastal wetlands: Status, drivers, and sustainable protection from the perspective of remote sensing

Coastal wetlands are of great ecological and economic value but face significant degradation and losses because of human activities. Nevertheless, the changes in spatiotemporal landscape patterns, which have occurred as a result of coastal wetland losses, have not been well documented under the rapid urbanization in coastal zones. In this study, an algorithm based on periodic tidal inundations and full time-series indices was developed to map the detailed status and trends in the coastal wetlands in Fujian Province from 1994 to 2018 by using more than archived 5000 Landsat images. The results showed that in 2018, there were 1136.56 km² of coastal wetlands along the coast of Fujian with an overall accuracy of 95.63%, which were mainly distributed in estuaries and bays. These coastal wetlands consisted of tidal flats, low marshes, and high marshes with proportions of 84.91%, 13.05%, and 2.04%, respectively. An unprecedented loss of coastal wetlands has occurred in Fujian Province, with an annual rate of 15.44 km²/a from 1994 to 2018. Many coastal wetlands were reclaimed, dredged, and converted into inland areas for aquaculture ponds, ports, and built-up areas in different urbanization periods, which has led to a great loss of coastal spaces with an area of 476.87 km². The interplay between the loss of coastal wetlands and seaward urbanization will lead to severe fragmentation and squeezing effects in the coastal zone and will weaken the coastal protection from marine disasters that is provided by coastal wetlands. Therefore, we conceived two conceptional frameworks for sustainable coastal protection based on the current situations of the coastal communities to provide a trade-off between economic development and the protection of coastal developing countries in the world.

Influence of management on vegetation restoration in coal waste dump after reclamation in semi-arid mining areas: examining ShengLi coalfield in Inner Mongolia, China

Conservation management usually carried out for a period of time to maintain the vegetation restoration of coal waste dumps after reclamation. However, the natural restoration of vegetation is faced with great challenges in semi-arid mining areas without management, due to the fragile ecological environment. Therefore, it is necessary to determine a reasonable management plan so that vegetation restoration can reach a stable state although the abandonment of the management. The objective was to explore the difference of vegetation restoration under different management modes in a typical semi-arid mining area. Two reclaimed coal waste dumps under different management measures, the north waste dump (ND) and the south waste dump (SD), were examined in the ShengLi coalfield in Inner Mongolia, China. The normalized difference vegetation index (NDVI) dataset based on Landsat series imagery was obtained using the Google Earth Engine (GEE) platform, and the landscape metrics were also calculated based on different vegetation coverage. The results proved that 3 years of management was not enough to stabilize vegetation restoration. A serious vegetation degradation occurred at the ND after the management stopped, with 40.1% of the pixels recorded a significant decrease (ρ = 0.05). The vegetation coverage became fragmented, and there was a tendency of succession to lower coverage. On the contrary, the vegetation restoration of SD was better under continuous management, and no significant degradation trend was observed. Furthermore, the results indicated that rainfall is the main influencing factor on vegetation restoration in semi-arid mining areas. The coal waste dump was more susceptible to weather change in natural restoration. By contrast, continuous management measures will resist such climate disturbances, even in dry years. This research will provide support for the formulation of the reclamation management plan of coal waste dumps in semi-arid mining areas.

Risk assessment of non-point source pollution based on landscape pattern in the Hanjiang River basin, China

Non-point source (NPS) pollution has become a vital contaminant source affecting the water environment because of its wide distribution, hydrodynamic complexity, and difficulty in prevention and control. In this study, the identification and evaluation of NPS pollution risk based on landscape pattern were carried out in the Hanjiang River basin above Ankang hydrological section, Shaanxi province, China. Landscape distribution information was obtained through land use data, analyzing the contribution of "source-sink" landscape to NPS pollution through the location-weighted landscape contrast index. Using the NPS pollution risk index to identify and evaluate the regional NPS pollution risk considering the slope, cost distance, soil erosion, and precipitation erosion affect migration of pollutants. The results showed that (i) the pollution risk was generally high in the whole watershed, and the sub-watersheds dominated by "source" landscapes account for 74.61% of the whole basin; (ii) the high-risk areas were distributed in the central, eastern, and western regions of the river basin; the extremely high-risk areas accounted for 12.7% of the whole watershed; and the southern and northern regions were dominated by forestland and grassland with little pollution risk; (iii) "source" landscapes were mostly distributed in areas close to the river course, which had a great impact on environment, and the landscape pattern units near the water body needed to be further adjusted to reduce the influence of NPS pollution.

Landscape and microhabitat features determine small mammal abundance in forest patches in agricultural landscapes

Intensification of agricultural landscapes represent a major threat for biodiversity conservation also affecting several ecosystem services. The natural and semi-natural remnants, available in the agricultural matrix, represent important sites for small mammals and rodents, which are fundamental for sustaining various ecosystem functions and trophic chains. We studied the populations of two small mammals (Apodemus agrarius, A. sylvaticus) to evaluate the effects of landscape and habitat features on species abundance along a gradient of agricultural landscape intensification. The study was performed in Friuli Venezia Giulia (north-eastern Italy) during 19 months, in 19 wood remnants. Species abundance was determined using Capture-Mark-Recapture (CMR) techniques. In the same plots, main ecological parameters of the habitat (at microhabitat and patch scale) and landscape were considered. Abundance of A. agrarius increased in landscapes with high extent of permanent crops (i.e., orchards and poplar plantations) and low content of undecomposed litter in the wood understory. Instead, A. sylvaticus, a more generalist species, showed an opposite, albeit less strong, relationship with the same variables. Both species were not affected by any landscape structural feature (e.g., patch shape, isolation). Our findings showed that microhabitat features and landscape composition rather than wood and landscape structure affect populations’ abundance and species interaction. The opposite response of the two study species was probably because of their specific ecological requirements. In this light, conservation management of agricultural landscapes should consider the ecological needs of species at both landscape and habitat levels, by rebalancing composition patterns in the context of ecological intensification, and promoting a sustainable forest patch management.

Sources, transformations of suspended particulate organic matter and their linkage with landscape patterns in the urbanized Beiyun river Watershed of Beijing, China

This study explored the sources, transformations of suspended particulate organic matter (POM), and the influence of landscape patterns on POM within the Beiyun River Watershed by applying the stable carbon and nitrogen isotope technique combined with multiple statistical analyses. The POM variables showed great spatial fluctuations under different urban development gradients. Analysis of multiple isotopes revealed that assimilation of phytoplankton might exist in the rainy season, while nitrification occurs in the dry season. SIAR modeling results indicated that the sewage debris and phytoplankton were the main sources of POM in both seasons, accounting for 52.58% and 38.39% in the rainy season, 33.17% and 31.95% in the dry season, respectively. Spatiotemporal variations of POM sources existed in the study watershed, probably due to urbanization and human disturbance. The multiple linear stepwise regression and redundant analysis results indicated that landscape metrics reflecting contagion and fragmentation at the class level correlated well with the POM variables over seasons. Interspersion and juxtaposition indices of grassland and water were negatively related to POM variables in the rainy season, whereas the landscape division index of buildup land showed negative correlations with POM parameters in the dry season. Increasing the adjacency of grassland and water to other land uses, while reducing the aggregation of buildup lands would be an efficient way for urban river water quality improvement.

Interactive effects of natural and anthropogenic factors on heterogenetic accumulations of heavy metals in surface soils through geodetector analysis

The rapid socioeconomic development has led to severe pollution of urban soils by heavy metals. It is vital to identify and quantify the factors that affect trace-element pollution for better preventing and managing soil pollution. In this study, we collected 179 surface soil samples from Zhangzhou City in a coastal area of south China to determine the concentration of seven heavy metals (As, Cr, Cu, Hg, Ni, Pb, and Zn) and used the Nemerow Pollution Index (P_n) to estimate the level of heavy metal pollution in soils. Eighteen environmental factors, including six natural factors (e.g. soil properties, surface topography) and twelve anthropogenic factors (e.g. industry, road network, land use types and landscape pattern), were evaluated with the geodetector statistical method. The results indicate that the heavy metal contamination of soils in Zhangzhou City was highly heterogeneous. We found that the primary influencing factors for heavy metal concentrations were soil organic matter content, agriculture activities, and landscape pattern. Furthermore, the nonlinear relationship between the primary factors and their interaction factors enhanced soil contamination by the heavy metals. Among the anthropogenic factors, landscape pattern enhanced P_n the most when interacting with natural factor. In addition, the buffer zone should be considered when evaluating the effects of factors such as land use and landscape pattern, because the interactions between landscape pattern and slope aspect produce a maximum effect, accounting for 31.0% of the P_n value on the scale of 800 m. Based on this analysis, we identified the key factors of heavy metal pollution in the soils of Zhangzhou City and proposed strategic procedures for effective soil pollution prevention and treatment in the future.

Optimal control of nonpoint source pollution in the Bahe River Basin, Northwest China, based on the SWAT model

This study conducts in the Bahe River Basin, an agricultural basin in Northwest China. We use the Soil and Water Assessment Tool (SWAT) model to identify the spatial distribution characteristics of non-point source (NPS) pollution and determine the critical source areas (CSA). Then the relationship between landscape pattern and NPS pollution is analyzed by spearman correlation analysis and redundancy analysis (RDA). On this basis, we set up eight landscape management practices in the CSA and evaluate their reduction effects on NPS pollution loads. The results show that the spatial distribution of nitrogen and phosphorus loss intensity has a certain correlation with rainfall and runoff, and the correlation between phosphorus loss intensity and sediment loss intensity is more significant. The NPS pollution load is closely related to the landscape pattern of the river basin, and is affected by the fragmentation, aggregation and complexity of the landscape. Farmland, forest land, and grassland are the main landscape components of the river basin. Farmland is the main source of NPS pollution, whereas forest land and grassland can effectively inhibit the output of NPS pollution, and the reduction effect of forest land is significantly better than that of grassland. The largest patch index (LPI), landscape shape index (LSI), patch density (PD) are the main landscape factors that affect the output of NPS pollution load. Among all the scenarios, the reduction effect of returning farmland to forest land in slopes above 15° is the best, and the reduction rates of total nitrogen (TN) and total phosphorus (TP) loads have reached about 25%. This study provides some reference for the management of NPS pollution in the Bahe River Basin and other similar basins.

Class and landscape level habitat fragmentation analysis in the Bale mountains national park, southeastern Ethiopia

The changes of natural habitat structure and function due to human interference is hastening worldwide, and it is compulsory to preserve biological resources in a protected system. This study aims to measure the landscape ecological structure and the extent of habitat fragmentation in the Bale mountains national park. The land use/land cover change was determined by interpreting the 1985, 1995, 2005 and 2017 Landsat images with ArcGIS 10.3, and the selected landscape structural metrics was analyzed using FRAGSTATS 4.2.1. All land cover classes showed a declining trend, except the farmland, and grassland depicted the highest area reduction. From 1985 to 2017 grassland, Erica, forestland, and afro-alpine were decreased by 9.36 %, 0.26 %, 0.06 %, and 0.01 %, respectively. Whereas, farmland was increased by 43.67 %. The study area was characterized as progressively fragmented since it was signified by the escalated value of patch number (40.22 %), area-weighted mean shape index (18.84 %), and edge density (22.27 %) and a declined value of mean patch size (28.68 %) and core area (10.60 %) over the study period. Considering this result, there was a high loss in area available for core dependent species, particularly for Mountain nyala in the grasslands and woodlands, Ethiopian wolf in afro-alpine regions, and Bale monkey in the bamboo forest. Both forestland and grassland need a conservation priority since these habitats were the most fragmented and habitat lost area.

Using urban landscape pattern to understand and evaluate infectious disease risk

COVID-19 case numbers in 161 sub-districts of Wuhan were investigated based on landscape epidemiology, and their landscape metrics were calculated based on land use/land cover (LULC). Initially, a mediation model verified a partially mediated population role in the relationship between landscape pattern and infection number. Adjusted incidence rate (AIR) and community safety index (CSI), two indicators for infection risk in sub-districts, were 25.82∼63.56 ‱ and 3.00∼15.87 respectively, and central urban sub-districts were at higher infection risk. Geographically weighted regression (GWR) performed better than OLS regression with AICc differences of 7.951∼181.261. The adjusted R² in GWR models of class-level index and infection risk were 0.697 to 0.817, while for the landscape-level index they were 0.668 to 0.835. Secondly, 16 key landscape metrics were identified based on GWR, and then a prediction model for infection risk in sub-districts and communities was developed. Using principal component analysis (PCA), development intensity, landscape level, and urban blue-green space were considered to be principal components affecting disease infection risk, explaining 73.1 % of the total variance. Cropland (PLAND and LSI), urban land (NP, LPI, and LSI) and unused land (NP) represent development intensity, greatly affecting infection risk in urban areas. Landscape level CONTAG, DIVISION, SHDI, and SHEI represent mobility and connectivity, having a profound impact on infection risk in both urban and suburban areas. Water (PLAND, NP, LPI, and LSI) and woodland (NP, and LSI) represent urban blue-green spaces, and were particularly important for infection risk in suburban areas. Based on urban landscape pattern, we proposed a framework to understand and evaluate infection risk. These findings provide a basis for risk evaluation and policy-making of urban infectious disease, which is significant for community management and urban planning for infectious disease worldwide.

Analyzing the influence of land use/land cover change on landscape pattern and ecosystem services in the Poyang Lake Region, China

The Poyang Lake Region (PLR) is well known for its ecological and economic importance. This paper first analyzed the changes in land use/land cover (LULC), followed by changes in landscape patterns and ecosystem services by landscape metrics and equivalent coefficients table method. Then, the influence of LULC change on landscape pattern and ecosystem services in both historical period (from 1990 to 2015) and future period (2030) was explored. The results showed that the area of construction land was 607.9 km² in 1990 and 972.5 km² in 2015. The increased construction land mainly converted from cultivated land. For the entire PLR, a higher use degree of LULC and a trend of fragmentation existed in recent years. The total ecosystem service values (ESVs) decreased by ¥2.44 × 10⁹ from 1990 to 2015, mainly because of shrinkage of cultivated land and sharp increase in construction land. It was predicted that the areas of construction land and waterbody would increase by 34.6% and 2.2% compared with those in 2015. These changes would lead to more regular in patch shape, longer in patch edge, less connectivity of patches, and an increase of ¥6.2 × 10⁸ ESVs in 2030.

Ecosystem service potential, flow, demand and their spatial associations: a comparison of the nutrient retention service between a human- and a nature-dominated watershed

Nutrient regulation is an important ecosystem regulating service in watersheds. However, systematic investigations of the spatial associations between the potential, flow, and demand of the nutrient regulation service are still lacking. Therefore, we performed a case study comparing the total phosphorus (TP) retention in the Dianchi Lake (DL) watershed (human-dominated) with that in the Lower Reach of the Zi River (LRZR) watershed (nature-dominated). We used four indicators-TP retention potential, TP retention, TP load, and TP export-to represent the potential, flow, demand, and flow-demand budget of the TP retention service, respectively. We estimated the TP retention and export using the InVEST tool, mapped the four TP indicators and calculated their correlations, and estimated the contributions of different ecosystem types and terrain ranges to TP retention and export. We determined the following: (1) the incongruity between the spatial distribution of the TP retention potential and the other three TP indicators was smaller in the LRZR watershed than in the DL watershed; (2) the TP retention potentials generally increased-while the other three TP indicators decreased-with increases in the elevation gradient in the DL watershed and the slope gradients in both study areas; and (3) paddy fields exhibited the highest TP retention intensity and residential areas exhibited the highest TP export intensity among the major ecosystem types in both study areas. Moreover, the TP retention intensities of dryland crops and residential areas in the DL watershed were much higher than they were in the LRZR watershed. Our findings imply that the flow of the nutrient retention service is influenced more by the service demand than by the service potential and that it is influenced by both landscape composition and pattern. Because of the limitations and uncertainties in the modeling outputs, our results should be carefully used in other studies or in decision-making.

Study on the gradient change of the landscape pattern in the Three Gorges Reservoir area by coupling the optimal grain size method and multidirectional gradient transect method

Human disturbance in the landscape lead to dramatic changes in the spatial structure of landscape patterns. This paper takes the Chongqing Three Gorges Reservoir area of China as case study to carry out gradient change analysis of the landscape pattern. Firstly, the coupled inflection point analysis, information loss method, and principal component analysis are used to determine the optimal grain size in a landscape gradient analysis. Secondly, the multidirectional gradient transect method is selected to analyze the law of landscape gradient change and the change of the landscape index. Finally, we analyzed various landscapes at the type level and obtained the distributions of the landscape types. The research highlights the gradient characteristics and landscape structure responses of typical transects of landscape subdivision types. The main results are as follows: (1) The optimal grain size of gradient analysis is 50 m. The patch density, patch shape complexity, and land use abundance of transects from the head to the tail of the reservoir increase. (2) At the landscape level, low mountain areas are more strongly blocked, and landscape connectivity reaches a minimum. At the type level, the landscape shape in the urban-rural interface zone is more complex. (3) Various landscape types are regularly ordered and form the gradient of "urban-agricultural-natural."

Surface temperature variations and their relationships with land cover in the Pearl River Delta

The characteristics of land use/land cover (LULC) types may affect the thermal environment of urban zones. In this study, the urban zones of the Pearl River Delta (PRD) were examined to explore the spatiotemporal variations in land surface temperature (LST) from 2001 to 2017, as well as the relationships between LST and various influencing factors. Landscape pattern analysis was undertaken to explore the correlation between patch metrics and LST with resolutions from 100 m to 1 km. The results showed that (1) the high-temperature zones were mainly distributed on built-up land; the area of LST hot spots increased from 16% (2001) to 23% (2017). (2) The mean LST of each LULC type was calculated, indicating that the temperature of forestland was more than 5 °C lower than that of built-up land. (3) The landscape patterns of different land use types exhibited various effects on LST in terms of magnitude and importance. Considering the significance of the landscape indexes, it is necessary to avoid a large-scale layout of a single built-up land type when planning an urban environment. It is thus recommended that multiple contiguous forestlands be planned to mitigate urban heat island (UHI) effects. Furthermore, the landscape patterns and structure of different LULC types have various effects on LST and need to be explored in fine detail. This study helped reveal the impact of different LULC types on LST and provides urban planners in the PRD with optional schemes for mitigating the impacts of urbanization on the UHI.

Identifying dominant factors of waterlogging events in metropolitan coastal cities: The case study of Guangzhou, China

Urban waterlogging disasters are affected by environmental conditions and human activities. Previous studies had explored the effect of land-use type on waterlogging in relatively small watersheds. Few, however, have comprehensively revealed the relative contributions of the environmental and anthropogenic factors to urban waterlogging concerning different scales of analysis. Indeed what is less known, are the dominant factors and the appropriate scale of analysis. To overcome this limitation, a novel method that integrates the stepwise regression model with hierarchical partitioning analysis is presented. The purpose is to investigate the complex mechanism of urban waterlogging by identifying the relative contribution of each environmental and anthropogenic factor and the stability linking waterlogging to influencing factors at multiple scales of analysis (i.e. 1 km, 2 km, 3 km, 4 km, and 5 km). We consider waterlogging events in the central urban districts of Guangzhou (PR China) from 2009 to 2015 as a case study. The results show that the spatial distribution of waterlogging events in the central urban area presents a strong agglomeration pattern. The waterlogging hot spots are mainly concentrated in the historical area of Guangzhou. Under all analysis scales, we find that the percent cover of urban green spaces (44.74%), percent cover of residential area (41.03%), and slope.std (36.85%) both have a dominant contribution to urban waterlogging, which suggests the importance of land cover composition in determining urban waterlogging. However, the relative contribution and dominant factors of waterlogging varied across different analysis scales, presenting a strong scale effect. Under a small analysis scale (1 km), the topography factors (slope.std and relative elevation) are confirmed as the dominant variables; however, with the increase of analysis scale, the influence of land cover composition (greenspace, residence area, grassland) and land cover spatial configuration (LPI, AI, Cohesion index) on waterlogging magnitude is greater than other factors. This finding provides additional insights that the urban waterlogging can be alleviated by balancing the relative composition of land cover features as well as by optimizing their spatial configuration. Since the optimal statistical scale for urban waterlogging studies only worked for specific influencing factors, the appropriate analysis scale for urban waterlogging study should be determined by the characteristics of study areas. This study has the capability to extend our scientific understanding of the complex mechanisms of waterlogging in the highly urbanized coastal city, providing useful support for the prevention and management of urban waterlogging.