Global environmental change and sustainability science increasingly recognize the need to address the consequences of changes taking place in the structure and function of the biosphere. These changes raise questions such as: Who and what are vulnerable to the multiple environmental changes underway, and where? Research demonstrates that vulnerability is registered not by exposure to hazards (perturbations and stresses) alone but also resides in the sensitivity and resilience of the system experiencing such hazards. This recognition requires revisions and enlargements in the basic design of vulnerability assessments, including the capacity to treat coupled human-environment systems and those linkages within and without the systems that affect their vulnerability. A vulnerability framework for the assessment of coupled human-environment systems is presented.

The Lower Mekong River basin (LMB) has experienced droughts in recent decades, causing detrimental economic losses and food security conundrums. This study quantified the impact of climate change on drought, and rainfed rice production in the LMB. The Soil and Water Assessment Tool (SWAT) and AquaCrop models were used to evaluate long-term drought indices and rainfed rice yields under historical and future climate conditions (1954-2099) with four climate models and two emission scenarios (RCP 4.5 and RCP8.5) from the Coupled Model Intercomparison Project Phase 5 (CMIP5). We found that rice yield might increase (24-43%) due to the elevated levels of atmospheric CO concentration (+ 34.3 to + 121.9%) and increases in precipitation. Contrastingly, considerable decreases in rice yield up to 1.5 ton/ha in the Vietnam Central High Plain (VCHP) region could be expected resulting from reduced precipitation by about 34% during drought years. To avert any major food crisis, an expansion of irrigation areas could be required to compensate for the expected reduction in rice yields. We conclude that a framework combining hydrology and crop models to assess climate change impacts on food production is key to develop adaptation strategies in the future.

The fluxes of energy, water, and carbon from terrestrial ecosystems influence the atmosphere. Land-atmosphere feedbacks can intensify extreme climate events like severe droughts and heatwaves because low soil moisture decreases both evaporation and plant transpiration and increases local temperature. Here, we combine data from a network of temperate and boreal eddy covariance towers, satellite data, plant trait datasets, and a mechanistic vegetation model to diagnose the controls of soil moisture feedbacks to drought. We find that climate and plant functional traits, particularly those related to maximum leaf gas exchange rate and water transport through the plant hydraulic continuum, jointly affect drought intensification. Our results reveal that plant physiological traits directly affect drought intensification and indicate that inclusion of plant hydraulic transport mechanisms in models may be critical for accurately simulating land-atmosphere feedbacks and climate extremes under climate change.Copyright © 2019 the Author(s). Published by PNAS.

生态脆弱性评价是了解区域生态状况的重要途径,科学评估生态脆弱性等级及变化对区域生态保护与建设,实现区域可持续发展具有重要意义。研究利用SRP模型构建新疆生态脆弱性评价指标体系,结合空间主成分分析方法构建生态脆弱性指数评价模型,分析新疆生态脆弱性时空演变特征。结果表明：（1） 2000—2018年,新疆生态敏感性整体为中度敏感,呈现东南高西北低,主要受景观破碎度和土壤侵蚀程度影响;生态恢复力受植被覆盖度影响较大,整体呈西北高、东南低,变化幅度小,恢复力较弱;生态压力大致呈南、北部的山区和中部绿洲区、山区高、东南低,主要影响因子是人均GDP、农业依赖度和人口密度。（2） 2000—2018年新疆生态脆弱性整体处于中度脆弱到重度脆弱。南、北部植被覆盖度低的地区生态脆弱等级较高,中部高海拔林草丰富地区生态脆弱性等级相对较低;2000—2018年新疆生态脆弱性综合指数呈现先增长后降低趋势。（3） 生态脆弱性主要驱动力方面,人为活动因子的农业依赖度、人口密度、土地垦殖率,自然环境因子的生境质量指数、景观破碎度、景观恢复力指数和年均降水量7个指标是新疆2000—2018年生态脆弱性变化的主要单因子;生境质量指数、景观恢复力指数、景观破碎度指数、植被覆盖率的变化与区域人类活动的相互作用是促使新疆生态脆弱性的主要驱动力。

Ecological vulnerability assessment is an important way to understand regional ecological conditions. There are great significance for regional ecological protection and construction. This study establishes ecological vulnerability evaluation index system based on the SRP model, analyze the spatial and temporal distribution characteristics and driving forces of ecological vulnerability in Xinjiang from 2000 to 2018. The main conclusions are as follows: (1) From 2000 to 2018, the ecological sensitivity index was generally at moderate sensitivity, showing high in the southeast and low in the northwest, and it was greatly affected by landscape fragmentation and soil erosion. The ecological resilience index was mainly affected by vegetation coverage, high in northwest and low in southeast, and it was relatively stable, mainly low-recovery states. The ecological stress index was mainly influenced by per capita GDP, agricultural dependence, and population density. It was high in the northern, southern mountainous areas and central Oasis and mountainous, and low in the southeast. (2) Ecological vulnerability was overall moderate to severely fragile level from 2000 to 2018 in Xinjiang. In north and south of Xinjiang, there are low vegetation coverage, low rainfall, and high aridity, so higher ecological fragility was observed. In contrast, the high-altitude areas dominated by woodlands and grasslands in central area are rich in biodiversity, and so ecological vulnerability was relatively low. Overall, the comprehensive index of ecological vulnerability showed an initial increasing trend, followed by a decrease. (3) Drivers of ecological vulnerability in Xinjiang, agricultural dependence, population density, and land reclamation rate of anthropogenic factors and habitat quality index, landscape fragmentation, landscape resilience index, and annual average precipitation of natural environmental factors are mainly single factors. The interaction of these factors, including habitat quality index, landscape resilience index, landscape fragmentation index, vegetation coverage, and regional human activities are the main driving forces.

Wetland landscape patterns of shallow riverconnected lakes exhibit distinct seasonal dynamics under natural hydrological regime. To elucidate the impacts of landscape pattern changes on bird diversity, we investigated the distribution of bird species and abundance in Anhui Anqing Caizi Lake National Wetland Park during the high (August-October 2019) and low (November 2019-January 2020) water seasons. The characteristics of landscape elements were analyzed using the landscape pattern index method based on remote sensing image data, and the relationship between bird diversity and landscape elements was studied. The results showed that there were 11 orders, 31 families, and 61 species of birds in the park. Among all the recorded species, three species were under the national Class Ⅰ key protection, six species were under the national Class Ⅱ key protection, and 15 species were under the key protection of Anhui Province. During the highwater season, birds were mainly distributed in the rational utilization zone and were predominantly forest birds. During the lowwater season, birds were concentrated in an ecological conservation zone and were primarily Anseriformes, with a maximum number of 10974 individuals. Species richness and bird diversity index were higher in the highwater season than in the low-water season, whereas the abundance of water birds was higher in the low-water season than in the highwater season. Bird diversity index was significantly higher in rational utilization zone than that in other functional zones, with a decreased diversity index monthly. The results of canonical correspondence analysis showed that landscape diversity index, uniformity index, fragmentation, mudflat area, and grassland area were the main factors influencing bird diversity in the wetland park.

Global vegetation over the past 18,000 years has been transformed first by the climate changes that accompanied the last deglaciation and again by increasing human pressures; however, the magnitude and patterns of rates of vegetation change are poorly understood globally. Using a compilation of 1181 fossil pollen sequences and newly developed statistical methods, we detect a worldwide acceleration in the rates of vegetation compositional change beginning between 4.6 and 2.9 thousand years ago that is globally unprecedented over the past 18,000 years in both magnitude and extent. Late Holocene rates of change equal or exceed the deglacial rates for all continents, which suggests that the scale of human effects on terrestrial ecosystems exceeds even the climate-driven transformations of the last deglaciation. The acceleration of biodiversity change demonstrated in ecological datasets from the past century began millennia ago.Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Human Footprint, the pressure imposed on the eco-environment by changing ecological processes and natural landscapes, is raising worldwide concerns on biodiversity and ecological conservation. Due to the lack of spatiotemporally consistent datasets of Human Footprint over a long temporal span, many relevant studies on this topic have been limited. Here, we mapped the annual dynamics of the global Human Footprint from 2000 to 2018 using eight variables that reflect different aspects of human pressures. The accuracy assessment revealed a good agreement between our mapped results and the previously developed datasets in different years. We found more than two million km of wilderness (i.e., regions with Human Footprint values below one) were lost over the past two decades. The biome dominated by mangroves experienced the most significant loss (i.e., above 5%) of wilderness, likely attributed to intensified human activities in coastal areas. The derived annual and spatiotemporally consistent global Human Footprint can be a fundamental dataset for many relevant studies about human activities and natural resources.© 2022. The Author(s).

植被覆盖度(FVC)作为表征植被生长状况与生态系统变化的定量指标,其时空变化趋势及驱动力是全球及区域生态环境的重要研究内容。本研究基于GEE云计算平台,应用像元二分模型对黑龙江省1990—2020年FVC进行估测,并通过Mann-Kendall突变检验、Sen趋势分析、Mann-Kendall显著性检验、相关性分析及结构方程模型,分析FVC的时空变化趋势及驱动力。结果表明: 基于像元二分模型法计算研究区FVC具有较高精度(R²>0.7、均方根误差<0.1、相对均方根误差<14%)。1990—2020年,黑龙江省年均FVC为0.79,呈波动上升趋势(0.72～0.85),年均增长0.4%,市级行政区年均FVC也呈不同程度的增长。黑龙江省以极高FVC类型为主,其面积占比逐渐增加。FVC呈增加趋势的面积占比为67.4%,呈减小趋势的面积占比为26.2%,其余保持不变。人为活动因子对年均FVC的相关性高于生长季月平均气象因子对年均FVC的相关性。人为活动因子是黑龙江省FVC变化的主要驱动因子,其次为土地利用类型,而生长季月平均气象因子对FVC变化的总影响为负。本研究结果可为黑龙江省长时间植被覆盖监测与驱动力分析提供技术支撑,也为生态环境的恢复与保护、相关土地利用政策的制定提供了依据。

在多源数据的支撑下，基于敏感性-恢复力-压力模型构建评估指标体系，分析生态恢复工程实施前后（1997年和2021年）陕北黄土高原不同行政区、不同生态功能区和不同坡度的生态脆弱性时空分异规律及驱动机制。结果表明：（1） 陕北黄土高原生态脆弱性明显改善，生态脆弱性指数均值从41.74下降至32.96，减幅21.0%;生态脆弱性等级也整体下降，已由中脆弱和低脆弱性占主导转化为低脆弱性占主导的格局。生态脆弱性存在明显地带性分布特征，从南到北生态脆弱性等级逐步提高。（2） 1997—2021年，51.2%的区域生态脆弱性有所改善，以中脆弱改善到低脆弱为主;4.6%的区域生态脆弱性有所增加，以一般脆弱增加至低脆弱、低脆弱增加至中脆弱为主。铜川市、延安市和榆林市辖区内生态脆弱性指数和等级均在下降，其中铜川市生态脆弱性最低，榆林市最高。3个生态功能区生态脆弱性指数和等级均在显著下降，降幅表现为：退耕还林区>风沙区>黄桥林区。（3） 符合退耕条件的区域，高等级脆弱性大幅转化为低等级脆弱性，生态脆弱性得到明显改善，工程取得了较为显著的成效。（4） 剖析驱动机制可以发现，人为因素和自然因素的驱动力各占83.1%和16.9%，说明生态恢复工程是区域生态脆弱性显著改善的主要驱动力。研究结果可为该区域生态恢复工程成效评估和生态可持续性修复提供科学的参考数据。

Studying spatiotemporal changes in ecological vulnerability in the Loess Plateau region of northern Shaanxi before and after the implementation of an ecological restoration project helps to understand the impact of the project implementation on regional ecological vulnerability and provides a scientific reference for the sustainable restoration of regional ecology. This study aims to provide a scientific foundation for the sustainable restoration of the ecology in this region by leveraging multisource data and an evaluation index system built around the sensitivity-resilience-stress model. The analysis encompasses the spatiotemporal variation of ecological vulnerability in different administrative regions, diverse ecological function areas, and varying slopes in the region before and after the implementation of the project (1997 and 2021) is analyzed with the driving mechanism. The results show the following key insights: (1) The ecological vulnerability in the Loess Plateau, China, was improved substantially. The mean regional ecological vulnerability index decreases from 41.74 to 32.96, a decrease of 21.0%. This shift transforms from medium and low vulnerability to a predominantly low vulnerability pattern. (2) Ecological vulnerability in the study area exhibits a zonal distribution, and the ecological vulnerability in the south is better than that in the north. From 1997 to 2021, 51.2% of the regional ecological vulnerability in the study area was improved, mainly from medium to low vulnerability, accounting for 75.3% of the total area improved, predominantly concentrated in farmland to forest and sandstorm areas. The second notable improvement involves the shift from low to general vulnerability, accounting for 16.9% of the improved areas, mainly within the Huangqiao forest area. Conversely, 4.6% of the regional ecological vulnerability increases in the study area, with general vulnerability rising to low and low vulnerability rising to medium, accounting for 52.9% and 45.6% of the increased area of ecological vulnerability, respectively. These increases are scattered in the sandstorm areas and Huangqiao forest areas. Among the administrative units, Tongchuan City is the lowest ecologically fragile, while Yulin City is the highest, with the most vulnerable areas concentrated in Yulin City. However, the ecological vulnerability index and grade declined in the three municipal districts. Similarly, the ecological vulnerability index and grade of the three ecofunctional areas considerably decreased, with the largest decrease in the area of returning farmland to forest, followed by the wind-sand areas, and finally, the Huangqiao forest area. (3) In designated cropland-to-forest conversion zones, high-grade vulnerability largely transforms into low-grade vulnerability, leading to noticeable regional ecological improvement. (4) Analysis of the driving mechanism reveals that the driving forces of human and natural factors account for 83.1% and 16.9%, respectively. This result shows that ecological restoration projects are the main driving force for the profound improvement of regional ecological vulnerability.

基于暴露度-敏感性-适应力生态脆弱性概念模型构建评价指标体系，利用投影寻踪模型和遗传算法确定指标权重，计算了河湟地区生态脆弱性指数，采用时空扫描探究生态脆弱性空间聚集特征及时空变化规律，借助地理探测器研究生态脆弱性的影响因素。结果表明：2000—2020年河湟地区生态脆弱性以轻度脆弱与中度脆弱为主，空间分布存在明显的地域差异。生态脆弱性存在明显的时间聚集性与局部的空间聚集特征，高值集聚与低值集聚共存，空间集聚主要分布于甘肃省境内。2000—2020年生态脆弱度整体呈降低趋势，53.36%的土地生态脆弱性有所降低。对生态脆弱性影响最大的因子是植被覆盖度，其次是沙漠化指数、植被净初级生产力、干旱指数、生境质量指数、海拔等。

An evaluation index system was constructed based on a concept model for exposure sensitivity adaptation ecological vulnerability. A projection pursuit model and genetic algorithm were used to determine the index weight, and the ecological vulnerability index was calculated for the Hehuang region. Spatio-temporal scanning was used to explore the spatial aggregation characteristics and spatio-temporal change laws for ecological vulnerability. The factors influencing ecological vulnerability were explored with the aid of geographical detectors. From 2000 to 2020, the ecological vulnerability of the Hehuang region was found to predominately be light and medium, with obvious regional differences in the spatial distribution. Ecological vulnerability has obvious characteristics for time and local spatial aggregation. High value aggregation and low value aggregation can coexist, and spatial aggregation is mainly distributed in Gansu Province. From 2000 to 2020, the ecological vulnerability of 53.36% of the land decreased. The most influential factor on ecological vulnerability is vegetation coverage, followed by desertification index, net primary productivity of vegetation, drought index, habitat quality index, and altitude.

生境质量是衡量生态系统服务功能及其健康程度的重要指标，准确预测生境质量的演变对于推动区域生态环境的高质量发展至关重要。耦合系统动力学-斑块生成土地利用模拟（SD-PLUS）模型与生态系统服务和权衡的综合评估（InVEST）模型，预测了2035年不同气候情景下（SSP1-2.6、SSP2-4.5、SSP3-7.0、SSP5-8.5）伊犁河谷土地利用/覆被格局变化，并评估了其生境质量时空演变特征。结果表明：（1） 1980—2020年，伊犁河谷土地利用类型呈现“4增2减”的变化趋势。2035年4种气候情景下，伊犁河谷林草地面积降幅较大，建设用地扩张趋势较为明显，挤占了城郊优质耕地资源。（2） 伊犁河谷生境质量等级与土地利用/覆被类型密切相关。生境高值及较高值区主要分布在地形崎岖的林草地覆被区，低值及较低值区主要分布在人类活动集聚区及南北天山未利用地覆被区。（3） 1980—2020年，伊犁河谷生境质量呈现下降趋势。生境质量退化区主要分布在伊犁河-巩乃斯河流域以及特克斯河流域附近。（4） 2035年4种气候情景下，伊犁河谷生境指数持续走低。生境指数均值排序为：SSP1-2.6>SSP2-4.5>SSP3-7.0>SSP5-8.5。伊宁市、边境口岸、农牧业基地等区域生境质量存在退化风险。研究结果可为伊犁河谷地区生态修复政策的制定提供参考依据，为干旱区半干旱区生境质量预测提供新思路。

Habitat quality is critical for ecosystem service function and overall health. Accurate prediction of its evolution is essential for fostering high-quality regional ecosystem development. This study employed the system dynamic patch-generating land use simulation (SD-PLUS) model and the integrated valuation of ecosystem services and trade-offs (InVEST) model to forecast land pattern changes, and evaluate the spatial-temporal evolution of habitat quality in the Ili River Valley under diverse 2035 climate scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5). The findings are as follows: (1) From 1980 to 2020, Ili River Valley land use exhibited a “four increase and two decrease” trend. In 2035, under the four climate scenarios, forest and grassland areas in the Ili River Valley will decrease, with a noticeable trend of construction land expansion, leading to the displacement of high-quality arable land in the suburbs. (2) Habitat quality in the Ili River Valley correlates closely with land use/cover type. High- and higher-value habitat areas are primarily scattered in rugged forest and grassland cover areas. Low- and lower-value areas are mainly concentrated in areas with concentrated human activities and unused land cover areas in the north and south Tianshan Mountains. (3) From 1980 to 2020, the habitat quality in the Ili River Valley exhibited a declining trend, particularly in areas near the Ili-Kunes River and Tekes River Basins. (4) The habitat index of the Ili River Valley is projected to decrease under the four climate scenarios in 2035, with the mean value following the order: SSP1-2.6>SSP2-4.5>SSP3-7.0>SSP5-8.5. Notably, habitat quality in Yining City, border ports, and agricultural and livestock bases is at risk of degradation. In conclusion, the results of this study provide valuable insights for developing ecological restoration policies in the Ili River Valley region and offer innovative ideas for predicting habitat quality in arid and semi-arid areas.