Open, Grass- and Forb-Dominated (OGFD) ecosystems, including tundra, tropical grasslands and savanna, provide habitat for both wild and domesticated large ungulate herbivores. These ecosystems exist across a wide temperature gradient from the Arctic regions to the Equator, but are confined to a narrow set of moisture conditions that range from arid deserts to forest-dominated systems. Primary productivity in OGFD ecosystems appears extremely sensitive to environmental change. We compared global trends in the annual maximum and mean values of the Normalized Difference Vegetation Index (NDVI) and identified the key bioclimatic indices that controlled OGFD productivity changes in various regions for the period from 1982 to 2011. We found significantly increased or decreased annual maximum NDVI values of 36.3% and 4.6% for OGFD ecosystems, respectively. Trends in the annual mean NDVI are similar for most OGFD ecosystems and show greater area decreases and smaller area increases than trends in the annual maximum NDVI in global OGFD ecosystems during the study period. Ecosystems in which the productivity significantly increased were distributed mainly in the Arctic, mid-eastern South America, central Africa, central Eurasia and Oceania, while those with decreasing trends in productivity were mainly on the Mongolian Plateau. Temperature increases tended to improve productivity in colder OGFD ecosystems; and precipitation is positively correlated with productivity changes in grassland and savannas, but negatively correlated with changes in the Arctic tundra. Simple bioclimatic indices explain 42% to 55% of productivity changes in OGFD systems worldwide, and the main climatic predictors of productivity differed significantly between regions. In light of future climate change, the findings of this study will help support management of global OGFD ecosystems.

Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) are a widely applied tool in provenance applications in archaeology, paleoecology, forensics, and food science. Bedrock Sr is naturally and anthropogenically transferred to other reservoirs on the Earth’s surface through interactions with the hydrosphere, atmosphere, and biosphere. We attempt to reassess the contribution of the spatial distribution of bioavailable strontium isotopes using the geographic detector model (GDM). Our study reveals that the watershed factor explains 50.35% of the spatial variation of bioavailable Sr isotopes, while the climate, terrain, geology, and soil explain 14.41%, 4.94%, 4.63%, and 4.70% of the spatial variation of bioavailable Sr isotopes. The factors influencing the spatial variation of bioavailable Sr isotopes in China were ranked as follows: basin > climate > terrain > geology > soil type. The nonlinear enhancements of the interactions between the watershed and geology explained 59.90% of the spatial variation in bioavailable Sr isotopes, indicating that natural processes still control the bioavailability of strontium isotopes in China. Based on the synthesized river-water isotopic data, the large-scale bioavailable Sr isoscape discussed herein can be useful for migratory studies in China. The enrichment of strontium isotope data to refine Sr isotopes, as well as the search for better data on possible controlling factors, will make the analysis more comprehensive and provide a solid foundation for explaining strontium isotope migration.

To assess the environmental risks of carbon capture and storage (CCS) due to underground CO₂ leakage, many studies have examined the impact on plant growth; however, the effect of leaked CO₂ on root morphology remains poorly understood. This study simulated the effects of CO₂ leakage from CCS on maize (Zea mays L.) root systems through pot experiments—one control treatment (no added CO₂) and two elevated soil CO₂ treatments (1000 g m⁻² d⁻¹ and 2000 g m⁻² d⁻¹). Compared with the control, root length, root surface area, and root volume were reduced by 44.73%, 34.14%, and 19.16%, respectively, in response to CO₂ treatments with a flux of 2000 g m⁻² d⁻¹. Meanwhile, the fine root length in CO₂ treatments with a flux of 1000 g m⁻² d⁻¹ and 2000 g m⁻² d⁻¹ were reduced by 29.44% and 45.88%, respectively, whereas no obvious difference in regard to coarse roots was found. Understanding changes in plant root morphology in this experiment, especially the decrease in the fine root length, are essential for explaining plant responses to CO₂ leakage from CCS.