Climate change has exacerbated the frequency and severity of droughts worldwide. Evaluating the response of gross primary productivity (GPP) to drought is thus beneficial to improving our understanding of the impact of drought on the carbon cycle balance. Although many studies have investigated the relationship between vegetation productivity and dry/wet conditions, the capability of different drought indices of assessing the influence of water deficit is not well understood. Moreover, few studies consider the effects of drought on vegetation with a focus on periods of drought. Here, we investigated the spatial-temporal patterns of GPP, the standardized precipitation evapotranspiration index (SPEI), and the vapor pressure deficit (VPD) in China from 2001 to 2020 and examined the relationship between GPP and water deficit/drought for different vegetation types. The results revealed that SPEI and GPP were positively correlated over approximately 70.7% of the total area, and VPD was negatively correlated with GPP over about 66.2% of the domain. Furthermore, vegetation productivity was more negatively affected by water deficit in summer and autumn. During periods of drought, the greatest negative impact was on deciduous forests and croplands, and woody savannas were the least impacted. This research provides a scientific reference for developing mitigation and adaptation measures to lessen the impact of drought disasters under a changing climate.

Due to the complex coupling between phenology and climatic factors, the influence mechanism of climate, especially preseason temperature and preseason precipitation, on vegetation phenology is still unclear. In the present study, we explored the long-term trends of phenological parameters of different vegetation types in China north of 30°N from 1982 to 2014 and their comprehensive responses to preseason temperature and precipitation. Simultaneously, annual double-season phenological stages were considered. Results show that the satellite-based phenological data were corresponding with the ground-based phenological data. Our analyses confirmed that the preseason temperature has a strong controlling effect on vegetation phenology. The start date of the growing season (SOS) had a significant advanced trend for 13.5% of the study area, and the end date of the growing season (EOS) showed a significant delayed trend for 23.1% of the study area. The impact of preseason precipitation on EOS was overall stronger than that on SOS, and different vegetation types had different responses. Compared with other vegetation types, SOS and EOS of crops were greatly affected by human activities while the preseason precipitation had less impact. This study will help us to make a scientific decision to tackle global climate change and regulate ecological engineering.

Increased drought frequency in Australia is a pressing concern for scholars. In 2018, a severe drought in eastern Australia was recorded by the Emergency Events Database (EM-DAT). To investigate the main causes and impacts of this drought across southeastern Australia, this work presents an overview of the drought mechanism and depicts its evolutionary process. The Standardized Precipitation Evapotranspiration Index (SPEI) from the Global Drought Monitor was used to identify the drought event and characterize its spatiotemporal distribution. The Normalized Difference Vegetation Index (NDVI) and the sun-induced chlorophyll fluorescence (SIF) were used to investigate the drought impacts on vegetation growth. In addition, the effects of drought response measures on Sustainable Development Goals (SDGs) were analyzed. Our results showed that the exceptional drought occurred across southeastern Australia from April to December, and it was most severe in July, owing to an extreme lack of precipitation and increase in temperature. Moreover, we identified profound and long-lasting impacts of the drought on NDVI and SIF levels, especially for cropland. Furthermore, we also found that SIF was superior to NDVI in detecting drought impacts. This study advised on how to formulate timely and effective drought-response measures and supports sustainable socioeconomic development in Australia.

Cities worldwide are expanding greenspaces, including parks, urban forests, and grasslands. However, population exposure to tree and nontree vegetation is less well understood. Here, we use multiple satellite-derived datasets on vegetation, climate, and socioeconomic factors to examine the variations of urban tree and nontree vegetation cover, drivers of changes, and the impacts on global urban population exposure between 2000 to 2020. We find that approximately 90% of cities experienced an ascending trend in tree cover, and 49% of cities showed growth in nontree vegetation (p < 0.05). The increase in urban tree cover is most evident in high-latitude areas, such as Eastern Russia and Northern Europe. Human exposure to urban tree vegetation considerably declined in the Global South, widening the disparity between the North and South. Our study underscores persistent inequalities in human exposure to green space in cities and calls for evidence-based strategies that reduce increasing disparities.

While significant progress has been achieved in researching water erosion, our understanding of global patterns and the magnitude of wind soil erosion remains limited. Here, we present a comprehensive assessment using the revised wind erosion equation (RWEQ) of the global rates and long‐term trends (1982–2019) of wind erosion using a spatially explicit (0.05° × 0.05°) quantitative model. On average, in this study global wind erosion caused 312.5 Pg yr⁻¹ of soil loss, with a decreasing trend of 1.04 ± 0.48 Pg yr⁻¹ (p < 0.05) during 1982–2019. Excluding stable regions, approximately 36% of the modeled areas exhibit a significant decrease in wind erosion, accounting for 3.13 ± 0.18 Pg yr⁻¹, while only 9% experience a notable increase, amounting for 1.83 ± 0.16 Pg yr⁻¹. The decrease of wind erosion primarily occurs in the southern hemispheres. Notably, wind erosion decreases considerably in grassland and cropland, while it remains unchanged in dryland. Although grassland and cropland account for only 11% and 1.8% of the total erosion, they contribute to 68% and 17% of the total erosion reduction, respectively. This study highlights global wind stilling and vegetation greening as important factors contributing to the decline in wind erosion and offers valuable insights into the intricate relationship between climate change and terrestrial ecosystems, including carbon sequestration and agricultural productivity.

Satellite-estimated solar-induced chlorophyll fluorescence (SIF) is proven to be an effective indicator for dynamic drought monitoring, while the capability of SIF to assess the variability of dryland vegetation under water and heat stress remains challenging. This study presents an analysis of the responses of dryland vegetation to the worst extreme drought over the past two decades in Australia, using multi-source spaceborne SIF derived from the Global Ozone Monitoring Experiment-2 (GOME-2) and TROPOspheric Monitoring Instrument (TROPOMI). Vegetation functioning was substantially constrained by this extreme event, especially in the interior of Australia, in which there was hardly seasonal growth detected by neither satellite-based observations nor tower-based flux measurements. At a 16-day interval, both SIF and enhanced vegetation index (EVI) can timely capture the reduction at the onset of drought over dryland ecosystems. The results demonstrate that satellite-observed SIF has the potential for characterizing and monitoring the spatiotemporal dynamics of drought over water-limited ecosystems, despite coarse spatial resolution coupled with high-retrieval noise as compared with EVI. Furthermore, our study highlights that SIF retrieved from TROPOMI featuring substantially enhanced spatiotemporal resolution has the promising capability for accurately tracking the drought-induced variation of heterogeneous dryland vegetation.