Spatial-temporal Changes Research Articles

Characterization of Hydrologic Sand and Dust Storm Sources in the Middle East

Due to diverse hydroclimatic conditions and human interventions, the Middle East hosts a variety of active sources of sand and dust storms (SDS). Discrimination of different types of SDS sources is the most important factor for adopting optimal mitigation measures to combat SDS. This study employed a binary mask-based modeling framework to identify Middle East SDS sources. Accordingly, using time series of remotely sensed data of land surface and atmospheric aerosol parameters, SDS sources covering an area of 1 million Km2 were identified with an overall accuracy of 82.6%. Considering the type of land use and spatial-temporal changes in water bodies, SDS sources were categorized into seven types in terms of origin. Desert sources have the largest share (>79%), whereas hydrologic sources accounted for about 8.4%. The results showed that water bodies had a declining trend after 2000. The occurrence of two severe drought periods in 2000–2001 and 2007–2012 led to a 52% decrease in water bodies and a 14–37% increase in SDS emission compared to the pre-2000 period. The latter drought period also led to a sharp decrease in groundwater resources across the region. Our results revealed that natural circumstances and drought actively contribute to the depletion of water resources that led to the formation of SDS sources in the Middle East, while the role of anthropogenic factors is predominant in the case of hydrologic SDS sources.

Modelling the Mediterranean Sea ecosystem at high spatial resolution to inform the ecosystem-based management in the region

Cumulative pressures are rapidly expanding in the Mediterranean Sea with consequences for marine biodiversity and marine resources, and the services they provide. Policy makers urge for a marine ecosystem assessment of the region in space and time. This study evaluates how the whole Mediterranean food web may have responded to historical changes in the climate, environment and fisheries, through the use of an ecosystem modelling over a long time span (decades) at high spatial resolution (8 × 8 km), to inform regional and sub-regional management. Results indicate coastal and shelf areas to be the sites with highest marine biodiversity and marine resources biomass, which decrease towards the south-eastern regions. High levels of total catches and discards are predicted to be concentrated in the Western sub-basin and the Adriatic Sea. Mean spatial–temporal changes of total and commercial biomass show increases in offshore waters of the region, while biodiversity indicators show marginal changes. Total catches and discards increase greatly in offshore waters of the Western and Eastern sub-basins. Spatial patterns and temporal mean changes of marine biodiversity, community biomasses and trophic indices, assessed in this study, aim at identifying areas and food web components that show signs of deterioration with the overall goal of assisting policy makers in designing and implementing spatial management actions for the region.

Spatial-Temporal Change and Synergy/Trade-Off Relationship of “Production–Living–Ecological” Space along the Sino-Vietnamese Border

The internal trade-off of land space is caused by the competition of land use for multiple functions, such as agricultural production, economic development and ecological protection. In response to this common problem, this study uses a positive and negative assignment method and a more refined evaluation scale to analyze the spatial and temporal variation characteristics and synergy/trade-off relationship of production–living–ecological space in the Sino-Vietnamese border area from 2000 to 2020. The results show that: (1) There was great regional diversity in the evolution characteristics of the Sino-Vietnamese border. Production space (PS) and living space (LS) presented prominent expansion, and ecological space (ES) was shrinking. (2) From 2000 to 2020, the degree of synergy between PS and LS has increased gradually. The trade-off relationship between PS and ES has shown different fluctuation intensities. The synergy/trade-off relationship between LS and ES has changed, and its trade-off intensity has continuously increased. (3) On the spatial scale, the PS and LS trade-off areas are mostly distributed in the central and western regions with higher altitudes, and the spatial pattern of the synergy zone is expanding. The synergy and trade-off relationship between PS and ES are relatively stable over time. The area of the trade-off between LS and ES has expanded gradually. In conclusion, the synergy/trade-off relationship between the PLES functions has strong consistency with regional economic and social development, which can serve as a scientific basis for the healthy and sustainable development of land space.

Assessing Spatial-Temporal Changes in Monetary Values of Urban Ecosystem Services through Remotely Sensed Data

Reckless urbanization in developing regions is leading to the deterioration of the urban environment. The ensuing impacts can place a burden on urban ecology, urban infrastructure, and residents. This scenario requires a combination of avoidance measures and a detailed assessment of the ecological sustainability of the city. While monetary assessments are certainly conceivable, in this study, the contributions of urban environmental infrastructure are weighed financially. Semi-planned (Jhang) and planned (Faisalabad) urban settlements provided the context for this survey. The study uses the Benefit Transfer Method (BTM) to assess changes in the monetary value of urban ecosystem services (UES) from remote sensing data. This finding suggests that urbanization in Pakistan is devouring productive ecological land in urban areas. The assessment shows that between 1989 and 2019, the agricultural area in Faisalabad shrank (−17.38%), and the built-up area increased (16.05%). Likewise, in Jhang City, the built-up area (4.44%) and wasteland (3.10%) swelled. However, during this period (1989–2019), the proportion of agricultural land in Jhang City decreased (−8.93%). As a result, prime areas of UES are falling back into low-return areas. It also found that provisioning ecosystem services (PES) accounted for a significant portion (68.12%) of the UES produced in Faisalabad and Jhang (69.72%), respectively. In contrast, Cultural Ecosystem Services (CES) contributed the smallest share of UES in Faisalabad (1.63%) and Jhang (1.65%). However, the remaining two services, regulatory and support services, made significant contributions. The assessment shows the role of incoherence, inconsistency, resource constraints, and neglect in compromising the urban environmental integrity of these cities. This situation requires a comprehensive assessment and coordinated effort. For this, it is feasible and useful to combine socioeconomic information with land cover data through computerized equipment.

Spatial-Temporal Changes and Influencing Factors of Ecological Protection Levels in the Middle and Lower Reaches of the Yellow River

In recent years, ecological problems in the middle and lower reaches of the Yellow River have been frequent. Therefore, exploring its core influences can advance the implementation of “Ecological Protection and High-quality Development of the Yellow River Basin”. This paper constructs an indicator system based on PSR guidelines, evaluates the ecological protection level of 55 cities in the middle and lower reaches of the Yellow River from 2009 to 2019, and uses correlation analysis with geographically and temporally weighted regression (GTWR) model to explore the spatial distribution characteristics of influencing factors, such as intensity of fertilizer application, amount of agricultural film applied, afforestation area per capita, and green technology innovation level on the ecological protection level. It is found that the overall level of ecological protection has shown a steady increase, but the spatial distribution varies widely. The ecological level increased from 0.2218 to 0.3357, showing a decreasing distribution trend from coastal to inland. Furthermore, it is found that the ecological protection level has a significant positive spatial correlation, mainly for similar clustering. The Global Moran’s I for ecological protection level is greater than 0, and the Moran scatter plot has a high number of cities distributed in the first and third quadrants. There is a heterogeneity in the spatial and temporal distribution of factors influencing the level of ecological protection. Fertilizer application, the agricultural film uses, and afforestation area per capita are mainly negatively affected, while green innovation level has a strong positive effect, and agricultural film use, afforestation area per capita, and green innovation level become the core influencing factor of different regions. Therefore, in the middle and lower reaches of the Yellow River, the ecological protection level should be improved by implementing a regional differentiated development strategy, realizing cross-regional linkages between cities and focusing on differences in core driving factors.

Spatial distribution and temporal change of vegetation restoration after the eruption of Mount St. Helens: from 1984 to 2019

Approximately ten terrestrial volcanic eruptions occur yearly, significantly impacting the surrounding area. Mount St. Helens has been one of the most popular active volcanoes in recent years. This study analysed the vegetation cover status from 1984 to 2019. Remote Sensing and GIS technology were mainly used in this study to perform detailed research on the rates and trends of vegetation change. The results show that the vegetation in the study area has continued to recover in general, but some areas are consistently devoid of vegetation growth. After analysing the spatial and temporal perspectives, the vegetation recovery rate was relatively slow in the eastern part of the study area. This vegetation recovery status may be related to factors such as volcanic eruption, deep slope, lack of seeds, and massive wildfires. The area in the north-western part of the eruption area gained rapid growth in the first ten years, which may be caused by plant measures.

Faster increase in evapotranspiration in permafrost-dominated basins in the warming Pan-Arctic

Land evapotranspiration (ET) is a key factor in the hydrological cycle and is particularly sensitive to climate change. In the past few decades, the Pan-Arctic region has witnessed a strong warming trend, causing substantial changes in ground surface conditions. However, it remains poorly understood how ET varies across such a region. Here, we investigated the spatial–temporal changes in ET over six large Pan-Arctic river basins using corrected ET estimates from GLEAM and ERA5-Land during 1981–2020. The 40-year mean annual ET in the Ob, Yenisei, Lena, Kolyma, Yukon, and Mackenzie River basins were approximately 366 mm·yr−1, 271 mm·yr−1, 228 mm·yr−1, 239 mm·yr−1, 278 mm·yr−1, and 295 mm·yr−1, respectively. Climatologically, permafrost-dominated basins tend to have lower ET than those with less permafrost. Temporally, the annual ET in permafrost-dominated basins has increased faster than that in less permafrost-developed basins over the past four decades. This increase is particularly prominent in the Kolyma River basin (completely covered by permafrost), where the significant trend in ET (7.5 mm·decade−1, p < 0.001) is the highest among the six basins. Further analyses show that intensified permafrost thawing is likely the key factor contributing to increased ET in permafrost-dominated basins, as seen from the positive relationship between the thickening in the active layer (ALT) and the change in ET. Under an amplified warming background, ET in permafrost-dominated regions is expected to continue to increase. The results reported in this study improve our understanding of the variations in ET and the associated mechanisms in the changing Arctic.

Study of spatialtemporal changes in Chinese forest eco-space and optimization strategies for enhancing carbon sequestration capacity through ecological spatial network theory

The conservation of forest ecosystems and the enhancement of carbon sequestration capacity play a crucial role in maintaining ecological balance and human development. However, with excessive deforestation, the flow of energy and information within the ecosystem has changed, which in turn has led to changes in the topological properties and carbon sequestration capacity of forest ecosystems. In order to better investigate the nature and carbon sequestration capacity of forest ecological space in mainland China during 2000–2018, we constructed a time-series Chinese forest ecological spatial network based on complex network theory and graph theory, combined with the modified minimal cumulative resistance model (MCR). By combining the net primary productivity (NPP) values obtained from the Boreal Ecosystem Productivity Simulator (BEPS) model of existing scholars, we further explored the relationship between topology and carbon sequestration capacity within forest ecosystems, and proposed strategies and suggestions for optimization. The results show that forest ecological sources and ecological corridors showed an increasing trend and resistance values decreased year by year during 2000–2018, especially in the western region, indicating that ecological restoration projects in western China have achieved certain effects. However, the stability of forest ecosystems has been decreasing year by year, and the forest carbon sequestration capacity in western China is also decreasing. Through correlation analysis, we found that carbon sequestration capacity showed highly significant positive correlation with closeness centrality, harmonic closeness centrality, clustering, and eigen centrality, and carbon sequestration capacity showed highly significant negative correlation with betweeness centrality. Through Principal Components Analysis (PCA), we suggest that consolidating small patches in the northeast, reducing the number of redundant ecological corridors, adding stepping stone patches to shorten the length of ecological corridors, and increasing ecological corridors in non-northeast areas are conducive to enhancing plant carbon sequestration capacity. This study provides theoretical support and ecological engineering recommendations for China to achieve its strategic goals of carbon neutrality and carbon peaking.

LC-MS/MS-based arachidonic acid metabolomics in acute spinal cord injury reveals the upregulation of 5-LOX and COX-2 products.

Arachidonic acid (AA) plays a critical role in inflammatory regulation and secondary injury after spinal cord injury (SCI). However, the overall AA metabolism profile in the acute phase of SCI remains elusive. Here we quantified AA metabolomics by High Performance Liquid Chromatography-Tandem Mass Spectrometry-Based Method (LC-MS/MS) using spinal cord tissue collected at 4h, 24h and 48h after contusive SCI in rats. Remarkably, Prostaglandin E2 (PGE2) and Leukotriene B4 (LTB4) were significantly increased throughout the acute SCI. Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), the key enzymes involved in the production of PGE2 and LTB4, were elevated in the lesioned spinal cord tissue, validated by both western blot and immunofluorecnce. The spatial-temporal changes of COX-2 and 5-LOX mainly occurs in neurons both in epicenter and rostral and caudal spinal cord segments after SCI. Our study sheds light on the dynamic microenvironment changes in acute SCI by characterizing the profile of AA metabolism. The COX-2 and 5-LOX may be promising therapeutic target for SCI.

Spatial-temporal changes in ecosystem services and social-ecological drivers in a typical coastal tourism city: A case study of Sanya, China

Tourism is an important economic and social activity with distinct characteristics of human-land interaction, which creates increasingly pronounced ecological and environmental challenges. The changes in four ecosystem services, including water yield (WY), carbon storage (CS), soil retention (SR) and habitat quality (HQ) in the coastal and noncoastal zones of Sanya were analysed, and the influencing factors were discussed. We found that from 2000 to 2018, the built-up land area of the coastal zone of Sanya quadrupled; CS, SR and HQ of the coastal zone were lower than those of the non-coastal zone with a clear downwards trend; and WY was higher than that of the noncoastal zone, indicating that the development of coastal tourism in Sanya damaged the surrounding ecological environment. The decline in ecosystem services in Sanya from 2010 to 2018 was smaller than that from 2000 to 2010, indicating that Sanya's ecological and environmental protection measures have been effective in recent years. The ecosystem services of Sanya were mainly affected by the natural environment, such as precipitation(P), and fractional vegetation coverage (FVC), but the impact of tourism factors, such as total tourism attraction (TA) and accommodation capacity (AC) also gradually became significant. Based on these findings, we propose to adhere to the sustainable development of coastal ecotourism, implement dynamic planning and dynamic monitoring, and strengthen the protection of coastal and its buffer zone. This study is of great significance to the scientific decision-making and comprehensive regulation of tourism-oriented cities and towns to improve ecosystem services.

Spatial-Temporal Changes and Simulation of Land Use in Metropolitan Areas: A Case of the Zhengzhou Metropolitan Area, China.

Metropolitan areas are the main spatial units sustaining development. Investigating internal factor changes in metropolitan areas are of great significance for improving the quality of development in these areas. As an emerging national central city of China, Zhengzhou has experienced rapid urban expansion and urbanization. In this study, principal component analysis and the model and Geodetector model were used to comprehensively analyze the influencing factors of land use change in Zhengzhou from 1980 to 2015. Based on the CA-Markov model, we improved the accuracy of multi-criteria evaluation of suitability factors and simulated land use change in 2015. The results show that land use conversions in the study area between 1980 and 2015 were frequent, with the areas of farmland, woodland, grassland, water, and unused land decreasing by 5.00%, 17.12%, 21.59%, 18.31%, and 94.48%, respectively, while construction land increased by 53.61%. The key influences on land use change are the urbanization and growth of residential or non-agricultural populations. In 2035, the area of farmland in the study area will decrease by 11.09% compared with that in 2015 and construction land will increase by 38.94%, while the area of other land use types will not significantly change. Zhengzhou, as the center city, forms a diamond-shaped core development area of Zhengzhou-Kaifeng-Xinxiang-Jiaozuo, while Xuchang is considered an independent sub-center uniting the surrounding cities for expansion. With its radiation power of unipolar core development for many years and the developmental momentum of Zhengzhou-Kaifeng integration, Zhengzhou city jointly drives the economic development of the surrounding cities. The protection of farmland and control of the expansion of construction land are the major challenges for the Zhengzhou metropolitan area to achieve sustainable development.

Spatio-Temporal Changes, Trade-Offs and Synergies of Major Ecosystem Services in the Three-River Headwaters Region from 2000 to 2019

The Three-River Headwaters Region (TRHR) is an important part of the ecological barrier of the Qinghai–Tibet Plateau. Understanding the TRHR’s major ecosystem service trade-offs and synergies is important for scientifically integrating and optimizing ecosystem services. We studied the spatial–temporal changes, trade-offs and synergies of the TRHR’s water retention (WR), soil retention (SR), windbreak and sand fixation (WD) and forage supply (FS) services from 2000 to 2019. The results showed that: (1) The TRHR’s WR, SR and FS services gradually decreased from east to west in space, and showed an increasing trend between years; the WD service gradually decreased from west to east in space, and showed a downward trend between years. (2) The synergistic relationship was the dominant relationship between the TRHR’s grassland regulation and provision services. Future research on ecosystem service trade-offs and synergies should consider both the type of ecosystem services and the ecosystem’s multifunctionality. (3) The improvement of the TRHR’s ecosystem services in the future needs to focus on improving the fraction vegetation coverage (FVC) through ecological engineering measures in Maduo, and other areas near the 400 mm precipitation line, and enhancing the synergy of ecosystem services. (4) The restoration of TRHR FVC needs to consider the difference in natural endowments. It is recommended to adopt near-natural restoration in the northwest of the TRHR, and avoid setting too high restoration targets. Planting high-quality pastures in the southeast of the TRHR with good water and heat conditions and rationally allocating grassland ecological and production functions are recommended measures. (5) The TRHR’s grassland should give priority to the development of the ecological functions of natural grasslands, and then give full play to its production functions. Overgrazing is strictly prohibited, so as to avoid the “over-transformation” of ecosystem regulation services to supply services.

Spatial-temporal changes of land use/cover change and habitat quality in Sanjiang plain from 1985 to 2017

Land use/Land cover (LULC) change seriously affects ecosystem services and ecosystem functions. In order to maintain ecological security and orderly social development, habitat quality assessment based on Land use/Land cover change is worth exploring. Based on multi-source land use data and Google remote sensing data from 1985 to 2017, land use transfer matrix and habitat quality index were used to study land use change, spatial-temporal evolution of habitat quality, and driving factors influencing habitat quality change in Sanjiang Plain. The results showed that Land use/Land cover changed significantly from 1985 to 2017, especially paddy land increased by 22,184.92 km2, while unutilized land decreased by 11,533.53 km2. The increase of construction land was mainly at the expense of dry land. There was a polarization in habitat quality, and the high intensity of land use utilization and development resulted in a significant decrease in habitat quality. From 1985 to 2017, the largest change in habitat quality was grassland, which decreased from 0.99 to 0.91.

Spatial–temporal variation analysis of water storage and its impacts on ecology and environment in high‐intensity coal mining areas

AbstractIn common with other important coal bases in northwestern China, the hydrology and ecology and environment of Ordos, northern Shaanxi (Shanbei), and Shanxi Provinces have much. Terrestrial water storage anomaly (TWSA), soil moisture anomaly (SMA), and groundwater storage anomaly (GWSA), are important water storage qualities that play a critical role in the distribution and growth of vegetation. In this paper, multi‐source remote sensing data were used to analyze the spatial–temporal changes and relationships of water storage, ecology and environment from 2002 to 2020. The numerical results showed the TWSA and GWSA in the study area had a declining trend and the rates were −7.512 mm yr‐1 and −8.268 mm yr‐1, respectively. On the contrary, the SMS showed an increasing trend, and the rate was 0.840 mm yr‐1. By trend variation and correlation analysis, we found GWSA is the main part in the variation of TWSA. By further analysis, it was found that the climate factors are not the major factors causing the variation of GWSA, but coal mining and artificial irrigation activities, which are especially clear in the Taihang Mountains in eastern Shanxi Province. The ecology and environment have been improving, and water storage and climate factors have played a different role in different regions. The warm climate conditions and the increased 0–40 cm of soil water have promoted the growth of vegetation and the improvement of the ecology and environment. The research results are helpful to understand the impacts of water storage on the ecology and environment in high‐intensity coal mining areas.

Spatial–Temporal Change in Paddy Field and Dryland in Different Topographic Gradients: A Case Study of China during 1990–2020

As a country with a vast area and complex terrain, the differentiation between paddy field and dryland under different topographic gradients in China is difficult. Based on a land-use grid data set with an accuracy of 1 km, this study applied the Topographic Potential Index and used land-use transition matrices and landscape analysis to compare the change in dryland and paddy field in China from 1990 to 2020 at different elevations, slopes, and slope aspects. The results indicate that paddy field and dryland were mostly distributed in areas with better photothermal conditions. However, in recent years, the paddy field and dryland on the “sunny” slope decreased. Specifically, the area of paddy field and dryland on the southeast, south, and southwest slopes decreased, while they increased on the northwest, north, and northeast slopes. From 1990 to 2020, land conversion among paddy field, dryland, and other land use was mostly concentrated in the third ladder (&lt;500 m elevation) of China. However, the changes in paddy field and dryland have now become active on the second ladder of China. Moreover, the change from other land to dryland on the second ladder accounted for nearly 50% of the country’s change from other land to dryland. Paddy fields and drylands in areas with low elevation and low slopes were reduced, whereas those with higher elevation and higher slopes increased, indicating that the arable land in mountainous areas increased. This indicates that the topographic conditions of arable land that become worse may aggravate soil erosion in the planting process. The landscape fragmentation of paddy field and dryland increased. Compared with paddy field, the dryland was more aggregated, the shape was more complex, and the land plots were more fragmented. As a result, paddy field and dryland show significant differences in their spatial–temporal pattern, landscape characteristics, and land-use changes, and these results can provide an important reference for the sustainable utilization of arable land resources.

Analysis of the Impact of Landscape Patterns on Urban Heat Islands: A Case Study of Chengdu, China.

The urbanization process, such as population growth and the expansion of roads, railways, residential areas, and industrial areas, causes severe landscape fragmentation and changes in the surface temperature balance, resulting in the heat island effect. This study used Landsat data to study the impact of landscape patterns on urban heat islands (UHIs) and temporal-spatial change characteristics. In addition, spatial correlation analysis was employed to detect the relationships between land surface temperature (LST) and landscape patterns. The results showed that the impervious surfaces landscape area increased significantly, and the Woodland landscape area increased. However, the bare land, cropland, and water body area decreased. The cohesion of cropland and woodland landscape in the suburb decreased, and there was a high degree of fragmentation. The difference between the contributions of the central city and suburbs to the whole region is narrowing, and the expansion of urban heat islands is shifting from the central city to the suburbs. The percentage of landscape index (PLAND) and the patch cohesion index (COHESION) of woodland, water body, and cropland were negatively correlated with LST. Meanwhile, the PLAND and COHESION of impervious surface and bare land were positively correlated with LST, and the splitting index (SPLIT) was the opposite of the PLAND and COHESION. The fragmentation of impervious surfaces and bare land landscapes reduces the UHI effect. Based on these results, countermeasures to mitigate the heat island effect are proposed. These measures will play an essential role in improving urban ecology and the environmental quality of human settlements.

Delimiting Ecological Space and Simulating Spatial-Temporal Changes in Its Ecosystem Service Functions Based on a Dynamic Perspective: A Case Study on Qionglai City of Sichuan Province, China

Delimiting ecological space scientifically and making reasonable predictions of the spatial-temporal trend of changes in the dominant ecosystem service functions (ESFs) are the basis of constructing an ecological protection pattern of territorial space, which has important theoretical significance and application value. At present, most research on the identification, functional partitioning and pattern reconstruction of ecological space refers to the current ESFs and their structural information, which ignores the spatial-temporal dynamic nature of the comprehensive and dominant ESFs, and does not seriously consider the change simulation in the dominant ESFs of the future ecological space. This affects the rationality of constructing an ecological space protection pattern to some extent. In this study, we propose an ecological space delimitation method based on the dynamic change characteristics of the ESFs, realize the identification of the ecological space range in Qionglai City and solve the problem of ignoring the spatial-temporal changes of ESFs in current research. On this basis, we also apply the Markov-CA model to integrate the spatial-temporal change characteristics of the dominant ESFs, successfully realize the simulation of the spatial-temporal changes in the dominant ESFs in Qionglai City's ecological space in 2025, find a suitable method for simulating ecological spatial-temporal changes and also provide a basis for constructing a reasonable ecological space protection pattern. This study finds that the comprehensive quantity of ESF and its annual rate of change in Qionglai City show obvious dynamics, which confirms the necessity of considering the dynamic characteristics of ESFs when identifying ecological space. The areas of ecological space in Qionglai city represent 98307 ha by using the ecological space identification method proposed in this study, which is consistent with the ecological spatial distribution in the local ecological civilization construction plan. This confirms the reliability of the ecological space identification method based on the dynamic characteristics of the ESFs. The results also show that the dominant ESFs in Qionglai City represented strong non-stationary characteristics during 2003–2019, which showed that we should fully consider the influence of the dynamics in the dominant ESFs on the future ESF pattern during the process of constructing the ecological spatial protection pattern. The Markov-CA model realized the simulation of spatial-temporal changes in the dominant ESFs with a high precision Kappa coefficient of above 0.95, which illustrated the feasibility of using this model to simulate the future dominant ESF spatial pattern. The simulation results showed that the dominant ESFs in Qionglai will still undergo mutual conversions during 2019–2025 due to the effect of the their non-stationary nature. The ecological space will still maintain the three dominant ESFs of primary product production, climate regulation and hydrological regulation in 2025, but their areas will change to 32793 ha, 52490 ha and 13024 ha, respectively. This study can serve as a scientific reference for the delimitation of the ecological conservation redline, ecological function regionalization and the construction of an ecological spatial protection pattern.

Quantifying the Evolution of Giant Panda Habitats in Sichuan Province under Different Scenarios

The giant panda (Ailuropoda melanoleuca) is a relic species in China and a flagship species in the field of endangered wildlife conservation. The conservation of the giant panda’s habitat has gained widespread attention for this reason. Historically, Chinese Giant Panda Nature Reserves are surrounded by communities and the resource utilization behavior of households disturbs the giant panda habitat. Changes in these communities and in Giant Panda Nature Reserves began around 2010, with the feminization and aging of the farm labor force. These changes brought different resource utilization behaviors that led to different evolutionary tendencies in giant panda habitats. This research study assesses the impact of these tendencies based on data from the fourth survey of the giant panda in the Sichuan Province and from geographic information data. The paper aims to uncover the internal mechanisms of farmers’ resource utilization behavior in terms of the changes wrought to giant panda habitats. The paper simulates the future habitat of the giant panda based on the LUCC (land use/cover change) model to identify anticipated changes in future landscape patterns and the habitat quality of giant pandas under the current scenarios. The paper analyzes the spatial-temporal change of landscape patterns through the land use transfer matrix, based on the Markov model. The results of the scenario analyses illustrate the spatial and temporal difference in habitat quality. The driving mechanism for landscape pattern change is explored using the logistic regression model. The paper simulates the variation tendency of giant panda habitats under differential labor force structures and resource utilization behavior based on the CA (cellular automata) model, with the robustness of the results verified by participatory experiment. Through four scenarios of simulated farm labor force structure and resource utilization behavior, results suggest that the quality of giant panda habitats in the future will be relatively high when workforce feminization and aging is intense and resource utilization behavior is weakened. The simulated results confirm that the current agricultural labor force structure can reduce the intensity of resource utilization behavior. In this scenario, disturbance to giant panda habitats would decrease and their quality would improve.

An evaluation of coastal sand dune flora of Cuddalore District, Tamil Nadu, India: perspectives for conservation and management

ABSTRACT Most of the sand dunes close to the Cuddalore coast of India have been destroyed due to human pressure. The remaining coastal sand dune (CSD) is under extreme threat due to unplanned development. The purpose of this study is to investigate the species diversity, plant communities in different morphological types, spatial-temporal changes in the distribution of sand dunes, and the state of their conservation. In the coastal dunes of Cuddalore, 25 perpendicular transects parallel to the coast were sampled. Following analysis, 105 vascular plants from 39 plant families and 85 genera were identified as part of the CSD flora. The least disturbed sites harbored more species than the heavily disturbed sites. Members of the Poaceae and Fabaceae families dominated the flora, and 68% of the species in the dunes were herbaceous. The sand dune cover is significantly reduced and fragmented in various parts of the study area, and negative changes have been observed at a rate of more than 100 ha per year between 2003 and 2020. A CSD conservation policy that ensures species succession in the form of a three-layered zone is proposed as a long-term sustainable option for preserving Cuddalore coastal flora biodiversity.

Vegetation photosynthesis changes and response to water constraints in the Yangtze River and Yellow River Basin, China

• Spatio-temporal pattern of annual maximum GOSIF were evaluated. • Water deficit area had an expanding trend, water surplus area had a shrinking trend. • The r GOSIF-scPDSI and r GOSIF-SPEI03 variations can be explained by atmospheric CO 2 . Satellite remotely sensed solar-induced chlorophyll fluorescence (SIF) is an effective index for detecting the ecosystem-level photosynthetic capacity, yet it remains poorly understood how vegetation photosynthesis responds to water constraints. This study determined the spatial–temporal changes and water constraints on vegetation photosynthesis based on the Self-Calibrated Palmer Drought Severity Index (scPDSI), Standardized Precipitation Evapotranspiration Index (SPEI) and global Orbiting Carbon Observatory-2 SIF (GOSIF) data in the Yangtze River and Yellow River basin between 2000 and 2018. The results showed that annual maximum GOSIF steadily increased across the whole basin ( slope = 0.0031 W m -2 μm -1 sr -1 a -1 , P < 0.001). The maximum increasing trend was found in the semi-arid region (0.0034 W m -2 μm -1 sr -1 a -1 , P < 0.001). The highest value of annual maximum GOSIF was found in the Qinling-Daba Mountains along with Hengduan Mountain. The lowest GOSIF was found in the western portions of the Loess Plateau and the source region of Yangtze River and Yellow River. Positive correlations between satellite GOSIF and water availability were particularly strong in the Loess Plateaus; in contrast, negative correlations were found in the Hengduan Mountains. The area of water deficit displayed a significant trend towards expansion ( slope = 1.539 % a -1 and 0.898 % a -1 , P < 0.05), while water surplus areas significantly shrank ( slope = 0.847 % a -1 and 0.584 % a -1 , P < 0.05) in the Yangtze River and Yellow River basin. Atmospheric CO 2 concentration and precipitation were the dominant drivers for the water deficit regions, while atmospheric CO 2 concentration and temperature were the dominant drivers for the water surplus regions. This study emphasizes the effect of water constraints on regional vegetation photosynthesis under global warming conditions and patterns of greening.