Exploring watershed ecological risk bundles based on ecosystem services: A case study of Shanxi Province, China.

Humans are having an increasingly profound impact on the environment along with the advent of the Anthropocene. Ecological risk assessment (ERA) as a method to quantify ecological problems can provide support for decision-makers, and it is one of key issues to integrate ecosystem services into ERA. In this study, an ERA framework was proposed under the loss-probability paradigm from the perspective of ecosystem services risk bundles. The results showed that initiatives aimed at ecological protection in Shanxi Province had been effective, the number of watersheds with low-risk bundles increased significantly (from 16.09% to 34.49%) and the watersheds basically overlapped with key forestation areas. However, the effects of forestation activities may no longer be as significant as they once were, as the relationship between forestation and water supply was becoming increasingly contradictory. Meanwhile, the conflict between urban expansion and natural ecosystem protection was intensifying, habitat degradation risks were gradually polarized, and the risk bundles dominated by high carbon emission and habitat degradation were increasing significantly (from 15.88% to 33.54%). Strengthening the construction of urban green space and controlling the expansion of human activities may be the next focus of ecological conservation in Shanxi Province. This study enriched the ERA framework with an ecosystem services risk bundle approach.

The first global multi-timescale daily SPEI dataset from 1982 to 2021.

Global warming accelerates water cycle, causing more droughts globally that challenge monitoring and forecasting. The Standardized Precipitation Evapotranspiration Index (SPEI) is used to assess drought characteristics and response time of natural and economic systems at various timescales. However, existing SPEI datasets have coarse spatial or temporal resolution or limited spatial extent, restricting their ability to accurately identify the start or end dates or the extent of drought at the global scale. To narrow these gaps, we developed a global daily SPEI dataset (SPEI-GD), with a 0.25° spatial resolution from 1982 to 2021 at multiple timescales (5, 30, 90, 180 and 360 days), based on the precipitation from European Center for Medium Weather Forecasting Reanalysis V5 (ERA5) dataset and the potential evapotranspiration from Singer's dataset. Compared to widely used SPEIbase dataset, the SPEI-GD can improve the spatial-temporal resolution and the accuracy of SPEI in areas where meteorological sites are lacking. The SPEI-GD significantly correlates with site-based SPEI and soil moisture. Our dataset solidly supports sub-seasonal and daily-scale global and regional drought research.

Worldwide impacts of atmospheric vapor pressure deficit on the interannual variability of terrestrial carbon sinks.

Interannual variability of the terrestrial ecosystem carbon sink is substantially regulated by various environmental variables and highly dominates the interannual variation of atmospheric carbon dioxide (CO2) concentrations. Thus, it is necessary to determine dominating factors affecting the interannual variability of the carbon sink to improve our capability of predicting future terrestrial carbon sinks. Using global datasets derived from machine-learning methods and process-based ecosystem models, this study reveals that the interannual variability of the atmospheric vapor pressure deficit (VPD) was significantly negatively correlated with net ecosystem production (NEP) and substantially impacted the interannual variability of the atmospheric CO2 growth rate (CGR). Further analyses found widespread constraints of VPD interannual variability on terrestrial gross primary production (GPP), causing VPD to impact NEP and CGR. Partial correlation analysis confirms the persistent and widespread impacts of VPD on terrestrial carbon sinks compared to other environmental variables. Current Earth system models underestimate the interannual variability in VPD and its impacts on GPP and NEP. Our results highlight the importance of VPD for terrestrial carbon sinks in assessing ecosystems' responses to future climate conditions.