Changes In Spatial Patterns Research Articles

Comparing the Atmospheric Responses to Reduced Arctic Sea Ice, a Warmer Ocean, and Increased CO2 and Their Contributions to Projected Change at 2°C Global Warming

Abstract We consider the combined and individual influences of Arctic sea ice loss, sea surface temperature (SST) warming, and the direct radiative effect of increased CO2 on the Northern Hemispheric climate. The surface climate (e.g., temperature and precipitation) and atmospheric circulation responses (e.g., sea level pressure and wind) to these drivers are quantified using simulations from the Polar Amplification Model Intercomparison Project (for sea ice loss and SST warming) and the Cloud Feedback Model Intercomparison Project (for increased CO2). We verify the linear additivity of the PAMIP-derived winter responses to sea ice loss and SST change. The responses to SST change are of greater magnitude than that due to sea ice loss or due to CO2 direct radiative forcing in most seasons and regions, excluding the Arctic. Notably, however, sea ice loss is at least as important as SST change for the winter atmospheric circulation response over the North Atlantic and Siberia. The dynamical responses to sea ice loss and SST change oppose each other in many regions in winter, while the responses to SST and CO2 direct radiative forcing are often opposing in summer. Such opposing responses are less evident for the thermodynamical response. The sum of all three responses reproduces well the spatial patterns of change at 2°C global warming in winter and autumn in phase 6 of the Coupled Model Intercomparison Project projections but overestimates their magnitude.

Developing an early warning land degradation indicator based on geostatistical analysis of Ecosystem Functional Types dynamics

Identifying and quantifying ecosystem degradation and recovery is of critical importance for ecosystem health, biodiversity, food security and the livelihoods of local communities. Remote sensing datasets and techniques, particularly land cover maps, provide crucial data for capturing spatial and temporal changes, supporting informed decision-making and targeted interventions. However, these maps often emphasize structural rather than functional attributes and, also due to their thematic and temporal resolution, may not detect early degradation signs. This study evaluates the effectiveness of Ecosystem Functional Attributes (EFAs) and Ecosystem Functional Types (EFTs) as early warning indicators of ecosystem degradation. Using Sentinel-2 derived Normalized Difference Vegetation Index (NDVI) data from 2016 to 2022, we conducted qualitative and quantitative EFA/EFT analysis on two fragile protected areas, Moyowosi Game Reserve (Kigoma region, Tanzania) and the Sheikh Jamal Inani National Park (Cox’s Bazar district, Bangladesh). Firstly, EFA analysis characterized vegetation productivity and seasonality, revealing temporal trends and spatial patterns of change. Secondly, EFTs served as indicators of change levels. Our findings showed significant insights into productivity shifts due to human activities and climate anomalies, identifying specific temporal events and turning points. Variogram-based geostatistical analysis highlighted changes in vegetation diversity’s spatial distribution. Integrating EFA/EFT analysis with geostatistical methods proved effective for early detection of land degradation, surpassing traditional land cover change analysis. Hence, the presented approach forms a robust framework for an early warning system, aimed at monitoring and evaluating environmentally fragile areas and aiding decision-makers in mitigating environmental degradation and promoting sustainable land management.

Transitions between Chinese dynasties influenced by spatial-patterned precipitation

Past studies have often associated the transitions of Chinese dynasties with nationwide climate change, overlooking significant spatial heterogeneity in precipitation anomalies across China. Historical changes in spatial precipitation patterns in response to Asian monsoon variability and their societal impact have not been fully explored. In this study, we present a new extended annual laminated speleothem record from central China covering the last 2000 years. By integrating paleoclimatic data from northern and southern China, we reconstructed the history of spatial precipitation patterns dominated by tripole and dipole patterns over the Common Era. Our analysis revealed that although the relationship between the monsoon and precipitation patterns was non-stationary, the positive phases of both patterns occurred more frequently during periods of monsoon weakening on multidecadal to multicentennial timescales. Moreover, the phase and intensity of these precipitation patterns varied across different intervals during the Chinese dynasties. Notably, transitions of unified dynasties often coincide with the simultaneous occurrence of the positive phases of both patterns on multidecadal timescales. This phase configuration of the patterns aligns with prolonged droughts in Eastern China, coinciding with historical records of reduced grain harvests and economic decline. Our findings highlight that historical changes in spatial configuration, rather than the nationwide synchronicity of precipitation anomalies, play a crucial role in Chinese dynastic transitions.

Trend Analysis and Spatial Behaviour of the Fire Weather Index in the Mediterranean Iberian Peninsula, 1971–2022

ABSTRACTThe Fire Weather Index (FWI) is a widely used metric to estimate the wildfire risk based on climatological variables. As anthropogenic climate change is expected to increase wildfire risk by affecting the climate of the Mediterranean Iberian Peninsula, we assess the expected increase in wildfire risk during the past decades. For this purpose, we employ a dataset containing daily FWI values in a 0.25° × 0.25° grid for each day of a 52‐year period, between 1971 and 2022, and perform a trend analysis at a statistically significant level. We evaluate the relation between FWI and spatial (altitude, latitude, and distance to the sea) variables to look for significant correlations. An analysis is performed at the geographic level by focusing on changes in concrete, relatively homogenous zones (subregions) to broadly study spatial patterns of change. The most relevant results are (1) the FWI shows an increasing trend across the study area (0.01 confidence level); (2) the FWI is determined by temperature variations on a multiyear scale, but annually by more volatile precipitation patterns; (3) the FWI does not uniformly behave across either space or time, and is subject to different variations in different zones; (4) summer and winter are the seasons with the most significant increase, and autumn is the only not significant season; (5) very high or extreme risks are increasingly prevalent across the territory, increasing wildfire risk and (6) the FWI more rapidly rises in areas further north, at a longer distance to the sea and at higher altitudes, with the Iberian System being the most affected region. The increase in wildfire risk requires putting in place more preventive measures. Our study results coincide with climatological trend studies on the region and bridge a knowledge gap as regards the historical climatology of the FWI.

Long-Term Spatiotemporal Trends in Precipitation, Temperature, and Evapotranspiration Across Arid Asia and Africa

This study examines trends in precipitation (PRE), maximum temperature (TMAX), minimum temperature (TMIN), and potential evapotranspiration (PET) using the Modified Mann-Kendall test and Sen’s slope estimator between 1901 and 2022 in the arid lands of Central Asia, West Asia and North Africa. The results reveal complex spatial and temporal climate change patterns across the study area. Annual PRE shows a slight negative trend (Z = −0.881, p = 0.378), with significant decreases from 1951–2000 (Z = −3.329, p = 0.001). The temperatures exhibit strong warming trends (TMIN: Z = 9.591, p < 0.001; TMAX: Z = 8.405, p < 0.001). PET increased significantly (Z = 6.041, p < 0.001), with acceleration in recent decades. Spatially, precipitation decreased by 10% in maximum annual values, while PET increased by 10–15% in many areas. Temperature increases of 2–3 °C were observed, with TMAX rising from 36–39 °C to 39–42 °C in some MENA regions. Seasonal analysis shows winter precipitation decreasing significantly in recent years (Z = −1.974, p = 0.048), while summer PET shows the strongest increasing trend (Z = 5.647, p < 0.001). Spatial analysis revealed clear latitudinal gradients in temperature and PET, with higher values in southern regions. PRE patterns were more complex, with coastal and mountainous areas receiving more precipitation. The combination of rising temperatures, increasing PET, and variable PRE trends suggest an overall intensification of aridity in many parts of the region. This analysis provides crucial insights into the climate variability of these water-scarce areas, emphasizing the need for targeted adaptation strategies in water resource management, agriculture, and ecosystem conservation.

Spatiotemporal Relationship Between Land Subsidence and Ecological Environmental Quality in Shenfu Mining Area, Loess Plateau, China

The exploitation of coal resources has caused problems such as ground deformation, affecting the ecological environment. Spatiotemporal varying characteristics between land subsidence and ecological environmental quality (EEQ) are an important research hotspot. Using the SBAS-InSAR method, 64 Sentinel-1 images were utilized to monitor land subsidence in the Shenfu mining area, one of China’s largest coal source regions. And the remote sensing ecological index (RSEI) was used to monitor and evaluate EEQ of the Shenfu mining area. Global and local spatial autocorrelation methods were used to assess the spatial aggregation degree and change patterns over time. Spatial Econometric Models were employed to explore the impacts of land subsidence on EEQ. The results showed the following: (1) The average RSEI values in the Shenfu mining area were 0.531, 0.488, and 0.523 in 2016, 2018, and 2020, respectively; there was a slight downward trend in EEQ. The permanent scatter (PS) point deformation rate ranged from −353.40 mm/year to +246.24 mm/year, with average deformation rates of 0.1642, 0.2181, and 0.2490 mm/year, respectively. (2) There was a significant correlation and spatial agglomeration effect between land surface subsidence and EEQ. Low–high, high–low, and low–low clusters were the main types of relationships, indicating that land subsidence primarily has a negative spatial impact on the ecological environment. (3) The relationship between land subsidence and EEQ varied spatially in the Shenfu mining area at 500 × 500 grid units. This research can provide scientific guidance for disaster prevention and sustainable development in mining areas by considering long-term differences in ecological environmental quality and its correlation with land subsidence.

A 28-time-point cropland area change dataset in Northeast China from 1000 to 2020

Abstract. Based on historical documents, population data, published results, remote sensing data products, statistical data, and survey data, this study reconstructed the cropland area and the spatial pattern changes at 28 time points from 1000 to 2020 in Northeast China. The period from 1000 to 1600 corresponds to historical provincial-level administrative districts, while the period from 1700 to 2020 corresponds to modern county-level administrative districts. The main findings are as follows: (1) the cropland in Northeast China exhibited phase changes of expansion–reduction–expansion over the past millennium. (2) The cropland area in Northeast China increased from 0.55×104 km2 in 1000 to 37.90×104 km2 in 2020, and the average cropland fraction increased from 0.37 % to 26.27 %; (3) from 1000 to 1200, the cropland area exhibited an increasing trend, which peaked in 1200. The scope of land reclamation was comparable to modern times, but the overall cropland fraction remained low. The cropland area significantly decreased between 1300 and 1600, with the main land reclamation area being reduced southward into Liaoning province. From 1700 to 1850, the cropland area increased slowly and the agricultural reclamation gradually expanded northward. After 1850, there was almost exponential growth, with the cropland area continuously expanding to the whole study area, and this growth trend persists until 2020; (4) the dataset of changes in the cropland of administrative districts in Northeast China, reconstructed based on multiple data sources and improved historical cropland reconstruction methods, significantly enhances time resolution and reliability. Additionally, the dataset shows relatively better credibility assessment results, which can provide a refined database for historical land use and land cover change (LUCC) dataset reconstruction, carbon emission estimation, climate data construction, etc. The dataset can be downloaded from https://doi.org/10.6084/m9.figshare.25450468.v2 (Jia et al., 2024).

Linking land use and precipitation changes to water quality changes in Lake Victoria using earth observation data

Due to the continued increase in land use changes and changing climatic patterns in the Lake Victoria basin, understanding the impacts of these changes on the water quality of Lake Victoria is imperative for safeguarding the integrity of the freshwater ecosystem. Thus, we analyzed spatial and temporal patterns of land cover, precipitation, and water quality changes in the Lake Victoria basin between 2000 and 2022 using global satellite products. Focusing on chlorophyll-a (Chl-a) and turbidity (TUR) in Lake Victoria, we used statistical metrics (correlation coefficient, trend analysis, change budget, and intensity analysis) to understand the relationship between land use and precipitation changes in the basin with changes in Chl-a and TUR at two major pollution hotspots on the lake, i.e., Winam Gulf and Inner Murchison Bay (IMB). Results show that the Chl-a and TUR concentrations in the Winam gulf increase with increases in precipitation. Through increases in precipitation, the erosion risks are increased and transport of nutrients from land to the lake system, promoting algal growth and turbidity. In the IMB, Chl-a and TUR concentrations decrease with an increase in precipitation, possibly due to dilution, but peak during moderate rainfall. Interestingly, changes in land use and land cover (LULC) at 5-year intervals showed no substantial correlation with water quality changes at selected hotspots even though a broader LULC change analysis over the past two decades indicated a notable 300% increase in built-up areas across the Lake Victoria basin. These findings underscore the dominant influence of precipitation changes over LULC changes on the water quality of Lake Victoria for the selected hotspot areas.

Spatio-temporal dynamics and recovery of commuting activities via bike-sharing around COVID-19: A case study of New York

The COVID-19 has led to significant changes in urban travel behaviors, with commuting being one of the most affected travel modes. Commuting cycling by bike-sharing systems (BSS) is regarded as a new transportation mode that is low-carbon and low-cost. However, its dynamic changes and spatiotemporal characteristics in different periods of COVID-19 still lack exploration. Therefore, this study adopts machine learning methods to identify commuter bike-sharing activities and develops a combined analysis method to analyze commuting cycling data via temporal, spatial, and spatiotemporal aggregation. Finally, we select the bike-sharing data in New York City from periods before, during, and after COVID-19 to conduct experiments. It has been found that commuting cycling experienced a “decrease-rebound” trend at the macroscopic level under the pandemic impact. However, at the micro level, urban mobility driven by this travel mode failed to fully recover, as evidenced by significant changes in spatial and temporal mobility patterns. The findings shall not only help traffic operators and managers discover the BSS commuting patterns but also reveal the pandemic impact on the travel behavior of urban residents, promoting the development of intelligent services for urban emergency management and traffic management.

Main spatial-temporal regularities of the state of the chemical composition of groundwater of the oligocene aquifer in the Shaim oil and gas bearing area

The constantly growing need for fresh water in the Shaim oil and gas region necessitates the exploration of new areas and the development of measures to improve the operation of water intakes. To predict the quality of groundwater, which is an operational parameter of the aquifer aquifer, it is needed up-to-date information on the chemical composition of ground-water. The aim of this study to identify main spatial-temporal regularities of the state of the chemical composition of groundwater of the oligocene aquifer in the Shaim oil and gas bearing area, compared to average values from adjacent areas. Research methods include the systematization of laboratory data on water samples, analysis of groundwater chemistry, and mapping of the main spatial-temporal patterns in component concentration changes. The average values of chemical composition indicators in the studied area are similar to those of neighbouring areas, with some indicators exceeding drinking water standards. Similarities are observed in the variability of the chemical composition, spatial patterns of changes in most chemical indicators, and the presence of areas with extreme values. Current data on the chemical composition of the oligocene aquifer ground-water, including key characteristics and spatial-temporal trends presented in distribution maps, can be used in designing groundwater intakes and forecasting long-term groundwater quality.

Low-degree gravity field coefficients based on inverse GNSS method: insights into hydrological and ice mass change studies

The relative displacements of stations from a global network of Global Navigation Satellite System (GNSS) sites provide information on global mass transport. In this study, we use 19 years of global GNSS station displacements from the 3rd International GNSS Service reprocessing campaign to estimate the coefficients of the spherical harmonics of the Earth’s gravity field up to degree and order 8 using the inverse GNSS method based on elastic loading theory. The results indicate that the C30 coefficient can be derived based on GNSS station displacements as an alternative to solutions provided by Satellite Laser Ranging (SLR) and Gravity Recovery and Climate Experiment (GRACE). GNSS may support GRACE solutions that face the problems of deriving C30, which has fundamental meaning in estimating ice mass changes in polar regions. The recovery of Antarctic ice sheet mass change from January 2007 to December 2020 based on coefficients replaced by GNSS estimates results in a linear trend of − 152 ± 4 Gt/year, in comparison to − 149 ± 2 Gt/year for the replacement based on SLR from GRACE Technical Note #14. The results indicate that the spatial and seasonal patterns of terrestrial water storage changes derived from GNSS are consistent with those estimated using GRACE/GRACE Follow-On and SLR at a few-millimeter level in the Amazon and Brahmaputra River basin regions.

Analysis on Ecological Network Pattern Changes in the Pearl River Delta Forest Urban Agglomeration from 2000 to 2020

The advancement of urbanization has led to a decline in the ecological function and environmental quality of cities, seriously reducing the services and sustainable development capacity of urban ecosystems. The construction of the National Forest Urban Agglomeration of China is conducive to alleviating the ecological and environmental problems brought about by rapid urbanization and promoting sustainable urban development. A time series analysis of ecological network changes can quickly and effectively explore the development and changes of ecological spatial patterns over time. Identifying ecological protection and restoration areas in urban agglomerations is an important way to promote ecosystem restoration and optimize ecological networks. This paper takes the Pearl River Delta forest urban agglomeration as the research area, uses multi-source remote sensing data from 2000 to 2020 (every 5 years), identifies ecological sources based on the morphological spatial pattern analysis (MSPA) method, generates ecological corridors based on the minimum cumulative resistance (MCR) model, constructs a time series ecological network pattern in the Pearl River Delta region, and analyzes the evolution process of the ecological network pattern over time. The results indicate that over time, the core green area in the ecological network pattern of the Pearl River Delta first decreased and then increased, and the complexity of ecological corridors first decreased and then increased. The main reason is that the urbanization process in the early 21st century led to severe ecological fragmentation. Under the promotion of the national forest urban agglomeration construction, the ecological network pattern of the Pearl River Delta was restored in 2015 and 2020. The time series analysis of the ecological network pattern in the Pearl River Delta region of this research confirms the effectiveness of the construction of forest urban agglomerations, providing a scientific reference for the identification of ecological networks and optimization of spatial patterns in forest urban agglomerations.

El Niño-like tropical pacific ocean cooling pattern during the last glacial maximum

Many state-of-the-art climate models are unable to reproduce the observed 20th century surface warming pattern in the tropical Pacific Ocean, casting doubt on the robustness of future projections. Here, we examine past changes in the tropical Pacific upper ocean spatial pattern using paleoclimate reconstructions from proxies and simulations from a multi-model ensemble. The proxy results demonstrate that during the Last Glacial Maximum, when atmospheric carbon dioxide concentrations were lower than present, temperatures in the western tropical Pacific Ocean decreased more than in the east, leading to an El Niño-like cooling pattern. This result contrasts with the zonally uniform cooling pattern observed in model simulations, highlighting the common issue of models overestimating the sensitivity of eastern tropical Pacific sea surface temperatures to greenhouse forcing. Our proxy results imply that the western Pacific may warm more than the east in response to future climate change, producing a La Niña-like surface warming pattern.

Study of the patterns of ice lake variation and the factors influencing these changes in the western Nyingchi area

Abstract The current ice lake dataset in the western region of Nyingchi requires further improvement. Due to the intricate distribution of ice lakes and imprecise boundary delineation, research tends to overlook small-scale ice lakes in this area. Moreover, most related studies have focused solely on variations in ice lake areas within key regions, such as the Himalayas, with little attention given to changes occurring in southeastern Tibet. The frequency of ice and snow disasters in the study area has been steadily increasing over the years. Therefore, this study utilizes Landsat satellite images and employs visual interpretation methods to generate more precise and comprehensive maps depicting the distribution of ice lakes in the western region of Nyingchi Province for the years 1994, 2010, 2018, and 2022. Additionally, changes in scale and spatial patterns of different types of ice lakes were investigated. Between 1994 and 2022, the ice lake area in the study area significantly increased by 22.5%, reaching a total of 35.8 ± 3.0 km2. This expansion was primarily driven by glacier-fed lakes, which experienced a remarkable growth rate of 30.8%. In contrast, the non-glacier-fed lakes experienced an increase by only 15.6%. Notably, ice lakes at higher elevations exhibited a peak in expansion, with those above 5143.0 m experiencing the most substantial growth rate of 44.8%. The long-term expansion rate of ice lakes is investigated through the measurement of changes in their boundaries, with the aim to understand the factors contributing to their growth. These findings indicate the rapid expansion of the ice lake near the glacier, with an annual growth rate of 1.3% per annum. Specifically, the glacial-fed section exhibited an expansion rate of 1.1% per annum, while the nonglacial-fed section experienced a growth rate of 0.6% per annum. The seasonal variability in marine glaciers is the primary factor influencing the expansion of ice lakes in this region, with temperature and precipitation serving as the principal driving forces impacting the transformation of these lakes. The data provided by the research results will facilitate a comprehensive understanding of the dynamics and mechanisms governing the ice lake in western Nyingchi, thereby contributing to an enhanced scientific comprehension of potential disaster risks associated with this ice lake.

Spatial and historical patterns of sedimentary organic matter sources and environmental changes in the Ross Sea, Antarctic: implication from bulk and n-alkane proxies

Organic carbon (OC) burial in the Antarctic marginal seas is essential for regulating global climate, particularly due to its association with ice shelf retreat. Here, we analyzed total OC (TOC), total nitrogen (TN), radiocarbon isotope, n-alkanes and relative indicators in surface and core sediments from the Ross Sea, West Antarctica. Our aim was to investigate spatial and historical changes in OC sources, and to explore the influencing factors and implications for ice shelf retreat since the last glacial maximum (LGM). Our results revealed distinct spatial patterns of OC sources as indicated by n-alkane indicators in surface sediments. In the Western Ross Sea, n-alkanes predominantly originated from phytoplankton and bacteria, as evidenced by their unimodal distribution, low carbon preference index (CPI) of short-chain n-alkanes (CPIL = 1.41 ± 0.30), and low terrestrial/aquatic ratio (TAR = 0.22 ± 0.14). In the Southwest Ross Sea, n-alkanes were derived from marine algae and terrestrial bryophytes, indicated by bimodal distribution, low ratio of low/high molecular-weight n-alkanes (L/H = 0.62 ± 0.21), low CPI of long-chain n-alkanes (CPIH = 1.18 ± 0.16), and high TAR (1.26 ± 0.66). In contrast, the Eastern Ross Sea exhibited n-alkanes that were a combination of phytoplankton and dust from Antarctic soils and/or leaf waxes from mid-latitude higher plant, as suggested by both unimodal and bimodal distributions, high L/H (1.60 ± 0.58) and CPIH (2.04 ± 0.28), and medium TAR (0.61 ± 0.30). Geologically, during the LGM (27.3 – 21.0 ka before present (BP)), there was an increased supply of terrestrial OC (TOC/TN = 13.63 ± 1.29, bimodal distribution of n-alkanes with main carbon peaks at nC17/nC19 and nC27). From 21.0 to 8.2 ka BP, as glaciers retreated and temperatures rose, the proportion of marine n-alkanes significantly increased (TOC/TN = 9.09 ± 1.82, bimodal distribution of n-alkanes with main carbon peaks at nC18/nC19 and nC25). From 8.2 ka BP to the present, as the ice shelf continued to retreat to its current position, the marine contribution became dominant (TOC/TN = 8.18 ± 0.51, unimodal distribution of n-alkanes with main carbon peak at nC17/nC18/nC19, and low TAR (0.41 ± 0.32)). This research has significant implications for understanding the variations in Antarctic OC sources and their climatic impacts in the context of accelerated glacier melting.

The Sensitivity of the Spatial Pattern of Sea Level Changes to the Depth of Antarctic Meltwater Fluxes

AbstractRegional patterns of sea level rise are affected by a range of factors including glacial melting, which has occurred in recent decades and is projected to increase in the future, perhaps dramatically. Previous modeling studies have typically included fluxes from melting glacial ice only as a surface forcing of the ocean or as an offline addition to the sea surface height fields produced by climate models. However, observational estimates suggest that the majority of the meltwater from the Antarctic Ice Sheet actually enters the ocean at depth through ice shelf basal melt. Here we use simulations with an ocean general circulation model in an idealized configuration. The results show that the simulated global sea level change pattern is sensitive to the depth at which Antarctic meltwater enters the ocean. Further analysis suggests that the response is dictated primarily by the steric response to the depth of the meltwater flux.

Distinct latitudinal patterns of shifting spring phenology across the Appalachian Trail Corridor.

Warming associated with climate change will advance the onset of spring phenology for many forest plants across the Eastern United States. Understory forbs and spring ephemerals that fix a disproportionate amount of carbon during early spring may be negatively affected by earlier canopy closure; however, information on the spatial patterns of phenological change for these communities is still lacking. To assess the potential for changes in spring phenological windows, we synthesized observations from the Appalachian Mountain Club's (AMCs) Mountain Watch (MW) project, the National Phenology Network (NPN), and AMC's iNaturalist projects between 2004 and 2022 (n = 118,250) across the length of the Appalachian Trail (AT) Corridor (34° N-46° N latitude). We used hierarchical Bayesian modeling to examine the sensitivity of spring flowering and leaf-out for 11 understory species and 14 canopy tree species to mean spring temperature (April-June). We conducted analyses across the AT Corridor, partitioned by regions of 4° latitude (south, mid-Atlantic, and north). Spring phenologies for both understory plants and canopy trees advanced with warming (~6 and ~3 days/°C, respectively). However, the sensitivity of each group varied by latitude, with the phenology of trees and understory plants advancing to a greater degree in the mid-Atlantic region (~10 days/°C) than in the southern or northern regions (~5 days/°C). While we find evidence that phenological windows remain stable in the southern and mid-Atlantic portions of the AT, we observed an expansion of the spring phenological window in the north where there was greater understory forb temperature sensitivity compared with trees (~2.7 days/°C). Our analyses indicate the differential sensitivity of forest plant phenology to potential warming across a large latitudinal gradient in the Eastern United States. Further, evidence for a temperature-driven expansion of the spring phenological window suggests a potential beneficial effect for understory plants in the northern AT, although phenological mismatch with potential pollinators and increased vulnerability to late winter frosts are possible. Using extensive citizen-science datasets allows us to synthesize regional- and continental-scale data to explore spatial and temporal trends in spring phenology related to warming. Such data can help to standardize approaches in phenological research and its application to forest climate resiliency.

Spatial pattern and landscape change prediction of blowouts in sandy grassland

Blowouts are a common type of wind-eroded landform found in sandy and desertified areas. They also represent a major degradative surface process affecting grassland ecosystems. Blowouts exacerbate changes in surface morphology through their effects on other surface phenomena including vegetation. In this paper, Xilingol League sandy grassland blowouts are taken as the research object, and the U.S. Keyhole satellite data and China’s Gaofen-1 satellite data are used as the data source, and the blowouts are extracted based on the 3 S technology for a total of six periods of high-resolution remote sensing image data in the study area from 1962 to 2023. The Landscape Pattern Index method and Fuzzy Land Use Simulation (FLUS) modelling applied to changes over the last six decades provided spatial evolution parameters for predicting future blowout distributions. Results showed that blowouts affecting the Xilingol grassland area increased by 16.81% over the past 60 years. The patch density (PD) increased by 0.9 per hectare. The mean proximity index (PROX_MN) and mean Euclidean nearest neighbour distance (ENN_MN) showed a tendency to decrease and then increase indicating initial expansion and then merging of adjacent blowouts to create the present landscape. The FLUS model used ten factors to predict changes in blowout distributions from 2023 to 2033. Factors included digital elevation model (DEM), slope, aspect, normalized difference vegetation index (NDVI), mean annual temperature, mean annual precipitation, population density, real GDP, distance to water, and distance to impervious surfaces. It was found that grassland area decreased by 6217.12 hm2 and blowout area decreased by 102.91 hm2. Results of this study can expand understanding of blowout morphodynamics in ecologically sensitive areas.

Galvanin is an electric-field sensor for directed cell migration.

Directed cell migration is critical for the rapid response of immune cells, such as neutrophils, following tissue injury or infection. Endogenous electric fields, generated by the disruption of the transepithelial potential across the skin, help to guide the movement of immune and skin cells toward the wound site. However, the mechanisms by which cells sense these physical cues remain largely unknown. Through a CRISPR-based screen, we identified Galvanin, a previously uncharacterized single-pass transmembrane protein that is required for human neutrophils to change their direction of migration in response to an applied electric field. Our results indicate that Galvanin rapidly relocalizes to the anodal side of a cell on exposure to an electric field, and that the net charge on its extracellular domain is necessary and sufficient to drive this relocalization. The spatial pattern of neutrophil protrusion and retraction changes immediately upon Galvanin relocalization, suggesting that it acts as a direct sensor of the electric field that then transduces spatial information about a cell's electrical environment to the migratory apparatus. The apparent mechanism of cell steering by sensor relocalization represents a new paradigm for directed cell migration.

Urban Sprawl and Imbalance between Supply and Demand of Ecosystem Services: Evidence from China’s Yangtze River Delta Urban Agglomerations

The contradiction between ecological resource protection and urban sprawl in urban agglomeration areas is becoming more and more prominent, facing a serious imbalance between the supply and demand of ecosystem services. To analyze the impact of urban agglomeration expansion on regional ecosystem services, based on multi-source data, an assessment model of supply and demand of ecosystem services for water conservation, carbon sequestration, soil conservation and crop production was constructed. With the help of value transformation model and spatial analysis method, this paper explores the risk of ecosystem service supply and demand imbalance faced by the Yangtze River Delta urban agglomeration in the process of expansion. This study found that the supply capacity of ecosystem services in the YRDUA has continued to decline at the spatial pixel scale; ecosystem service value deficits are a common problem in the YRDUA, with cities around Taihu Lake, such as Shanghai and Suzhou, being the most serious; the value surplus areas are concentrated in the southern cities, such as Xuancheng and Chizhou, but the balance between the supply of and demand for ecosystem services in these cities is also facing a challenge as the cities are expanding. This study analyzed the spatial pattern changes in the Yangtze River Delta region in the context of urban sprawl from the perspective of ecosystem service supply and demand, which helps to clarify the changing ecosystem service dynamics of the region and guide the formulation of urban planning policies and to achieve a balance between ecological supply and demand as well as sustainable development.