Avian influenza viruses (AIV) pose a major zoonotic threat with pandemic potential. Waterbirds facilitate AIV spillovers into farm animals and humans through exposure and virus reassortment. Here, we propose waterbird activity entropy (WAE), an indicator of waterbird activity intensity based on monthly distributions of 779 species worldwide. WAE demonstrated high explanative power (AUC = 0.87 ± 0.001) for global avian influenza cases, particularly for H5N1, revealing the potential of WAE for identifying AIV exposure hotspots which cover 14% of global land area. Notably, the AIV exposure hotspots in the USA, EU, China, and India contain 52% of the globally exposed human population, 41% cattle, and 51% poultry. Despite reporting 300 Mha of hotspots area (15% globally), highlighting considerable surveillance gaps. This WAE-based framework enhances AIV risk assessment by incorporating waterbird residency time, offering critical insights for anticipating AIV emergence and improving surveillance.

Under global warming, advances in spring phenology due to the rising temperature have been widely reported. However, the physiological mechanisms underlying the warming-induced earlier spring phenology remain poorly understood. Here, using multiple long-term and large-scale phenological datasets between 1951 and 2018, we show that warmer temperatures during the previous growing season between May and September led to earlier spring phenology in the Northern Hemisphere. We also found that warming-induced increases in maximum photosynthetic rate in the previous year advanced spring phenology, with an average of 2.50 days °C ^-1 . Furthermore, we found a significant decline in the advancing effect of warming during the previous growing season on spring phenology from cold to warm periods over the past decades. Our results suggest that the observed warming-induced earlier spring phenology may be driven by increased photosynthetic carbon assimilation in the previous season, while the slowdown in the advanced spring phenology arise likely from decreased carbon assimilation when warming exceeding the optimal temperatures for photosynthesis. Our study highlights the vital role of photosynthetic carbon assimilation during growing season in spring phenology under global warming.

The timing of autumn leaf senescence is crucial for ecosystem dynamics, influencing plant productivity and nutrient cycling. Despite its importance, the influence of species diversity on senescence and its implications for predicting phenological shifts in plant communities under climate change remain poorly understood. Here we address this knowledge gap by integrating ground-sourced data from Northern China with global remote sensing data to examine grassland ecosystems. Our analysis reveals that increased species diversity in grasslands leads to earlier autumn senescence, regardless of climatic and soil attributes. This effect is largely attributed to the effect of species diversity on resource allocation, enhancing belowground biomass at the expense of aboveground resources, thereby advancing senescence. Our findings highlight the role of biodiversity in modifying resource distribution and the growing season length, offering essential insights for understanding ecosystem responses to climate change.

The timing of leaf senescence critically shapes ecosystem dynamics by regulating plant productivity and nutrient cycling. While species diversity is recognized as a key driver of ecosystem functioning, its effect on autumn senescence remains poorly understood. To address this gap, here we integrated field observations from Northern China and global remote sensing data to investigate grassland autumn senescence. Our analyses reveal that higher species diversity accelerates autumn senescence, even after controlling for climate and soil factors. Mechanistically, this relationship is mediated by resource allocation strategies: enhanced species diversity promotes the allocation of resources to belowground biomass, thereby reducing aboveground resource availability and triggering earlier senescence. Our findings highlight a negative relationship between species diversity and the timing of autumn senescence in semi-arid grasslands, which facilitates increased carbon allocation to belowground compartments and accelerates the seasonal carbon cycle, offering critical insights into global carbon flux exchange under future climate warming.

Rapid Arctic warming drives poleward shifts in bird distributions, reshaping encounter patterns between species from Eurasia and North America. However, how climate change reshapes the distributions of avian influenza virus (AIV) hosts and thereby alters cross-continental virus-sharing hotspots remains poorly understood, impeding surveillance and monitoring for AIV control and prevention. We integrated the current and projected distributions for 178 avian influenza host species, selected from 415 confirmed host species based on data availability, to quantify changes in patterns of cross-continental host encounter combinations (CHEC). We find 142 novel CHEC types emerging in the Arctic. Over 120 Mha (5%) of Arctic regions are facing significant CHEC increases by 2100, far exceeding temperate and tropical regions. Under SSP37.0, the Pacific corridor will surpass the Atlantic as the primary transcontinental pathway after 2080, with 22% higher CHEC. Large areas of eastern Siberia and Greenland were identified as priority early-warning sentinel regions for transcontinental virus transmission. Hosts with shorter generation lengths, carnivorous diets, and ground-foraging strategies are more likely to drive the Arctic CHEC increase. Our findings highlight the Arctic as an emerging interface for cross-continental AIV host encounters, with quantitative identification of spatial hotspots and key driver species, underscoring the urgent need for enhanced high-latitude surveillance of host dispersal and AIV lineage reassortment.

Pests pose escalating threats to forest ecosystem services globally, yet the patterns of forest vulnerability to these threats remain unclear. Leveraging over 7 million occurrence records of 2,038 pest species, we identify north-western Europe and eastern North America as global epicenters of forest-pest richness, dominated by insect fauna. Risk zones, where high pest richness coincides with timber production, carbon-rich forests, or diverse tree communities, cover 3.5% and 1.6% of forest globally within and outside the native ranges of pests, respectively. Forests in regions with stable temperatures and adequate precipitation support high ecosystem services but also favor pest richness, while forest fragmentation amplifies vulnerability to pests. Our findings provide a spatial blueprint for global pest management and underscore the urgent need for protecting forest health.