综合性期刊最新文献

Anthropogenic global change presents a growing threat to insect pollinators. Yet, long-term, continental-scale assessments of their population trends remain limited. Here, we leveraged a curated database of over four million occurrence records, covering 88% of extant bee and hoverfly species in Europe, to assess persistence, richness, and occupancy trends over the past century. Species persistence at the European level was relatively high, with modern records available for 87% of bee and 89% of hoverfly species. Regional richness changes were modest, with declines in the Atlantic and Continental regions for both pollinator groups. Recent increases were observed in the Alpine region for bees, but species richness remained largely stable elsewhere. At the species level, however, a more concerning picture emerged: Most bee species and about half of hoverfly species declined in occupancy. Species traits explained little variation in these trends, although there was a weak tendency for cold-adapted bees to show steeper declines than warm-adapted ones. Genera showing some of the steepest declines include parasitic or dietary specialists, though neither of these traits significantly predicted occupancy trends. Overall, we highlight clear warning signs of species population declines, but with potential recovery opportunities if we take urgent actions to reverse those trends.

Rapid electricity demand growth, grid connection delays, and supply chain constraints create a serious risk of supply shortages and rising electricity costs in the next few years. This paper studies the strategy of adding colocated renewables and storage at existing power plants to take advantage of spare grid capacity. Using satellite imagery, we assess solar and wind potential near 3,890 U.S. fossil and renewable plants. By 2030, we find that existing fossil plants could host up to 597 GW of economically viable solar and wind without exceeding the existing interconnection capacity of each site. Existing renewable plants could host an additional 260 GW of firm capacity-comprising storage paired with added solar and wind capacity. These additions could accelerate clean energy deployment and enhance reliability and affordability, but realizing this potential is contingent upon regulatory reforms and coordinating the operational constraints of colocated resources.

Urban heat island (UHI) intensifies heat-related risks and environmental degradation in cities worldwide, yet existing mitigation strategies have largely overlooked how the spatial scale of homogeneous functional building clusters influences local climate. This scale may matter because buildings with similar functions often share similar morphology, activity schedules, and anthropogenic heat-release patterns, allowing their spatial contiguity to shape ventilation and heat accumulation. Here, we introduce the Urban Homogeneous Scale (UHS)-an indicator that measures the spatial scale of contiguous, functionally similar building clusters-and analyze 233,844 observations across 101 global cities to assess its potential for mitigating surface UHI. We find that larger UHS is associated with lower surface UHI: every 100-meter increase in UHS corresponds to 4.5% decrease in daytime UHI. This daytime cooling effect is particularly more pronounced in inland, humid, and high-income regions. In low-income regions, larger building area and higher building volume more strongly weaken UHS cooling capacity than in wealthier regions, revealing a socioeconomic inequality in UHS's mitigation benefits. Our findings identify the spatial scale of building clusters as a essential dimension of urban form associated with urban heat burden, and suggest that considering UHS alongside targeted controls on built environmental characteristics may inform future heat-mitigation planning.

Marine heatwaves are increasingly recognized for their capacity to generate ecological surprises, yet the pathways that propagate these unexpected responses are often poorly understood. Here, we document an unanticipated ecological response 7 y after a Bering Sea marine heatwave, in which formerly rare snow crab (Chionoecetes opilio) × Tanner crab (C. bairdi) hybrid abundance increased 13.4-fold, and the proportion of commercial-sized hybrid males increased 13.1-fold, relative to historical averages. Using causal modeling, we show that the hybrid crab surge was mediated by a heatwave-induced collapse of snow crab rather than direct thermal effects on hybrid survival or increased spatial overlap between mature snow and Tanner crab. Our results reveal an indirect cascading pathway through which an extreme climate event triggered unexpected ecological consequences and unforeseen challenges for fisheries management in the Bering Sea. The dramatic increase in abundance of harvestable hybrid crab, coupled with their exclusion from existing management frameworks, highlights the vulnerability of inflexible management systems to unanticipated ecosystem responses.

Ocean ecosystems have played a crucial role in people's lives around the world for millennia. However, questions persist about when, why, and how people first began removing biomass from offshore habitats and established fisheries in distant, oceanic environments. We explore the antiquity and evolution of tuna (Thunnini) and billfish (Istiophoridae/Xiphiidae) fisheries, two groups of fishes that occur around the world, are economically significant, and are ecologically important open ocean apex predators. The earliest archaeological evidence of fishing for tuna occurs ~44,000 years ago and billfish at ~10,000 years ago, with early fisheries for some tuna species appearing around the world by 3,000 to 1,000 years ago. Most early fisheries are in areas where tunas and billfishes could be accessed relatively close to shore (e.g., submarine canyons) and/or where these fishes may come inshore seasonally or during warm ocean events. Early tuna and billfish fisheries were often linked to ceremony/ritual, alongside advances in maritime technologies. With few exceptions, sustained and intensive commercial exploitation of pelagic predators in offshore and oceanic habitats is a late development in the human past, occurring primarily during the last 200 y. Our findings document a long-term continuum of human interactions with global marine ecosystems spanning thousands of years, including significant differences between the timing and pathways by which people became dominant ecological drivers in nearshore compared to offshore/oceanic ecosystems.

Transboundary aquifers (TBAs) underlie 35% of global groundwater-irrigated cropland, yet few are covered by formal cooperative arrangements. Whether this limited cooperation is consequential depends in part on where groundwater is used within shared aquifers, because pumping far from international borders may generate little cross-border impact. Combining [Formula: see text]116,000 well observations with global irrigation data across all 426 known TBAs, we assess how groundwater use and depletion differ from comparable domestic systems and how they are distributed relative to international borders. While we find no evidence of greater average depletion in TBAs, depletion is more strongly concentrated toward international borders in shared aquifers and varies substantially across systems. Irrigation is also more intensive and concentrated toward borders in shared aquifers, although much of this pattern is attenuated after accounting for border rivers. Groundwater-supplied irrigation remains more border-proximate after accounting for these rivers. A dyad-level typology distinguishes shared systems according to where groundwater demand is concentrated, linking their potential for cross-border interaction to different management options. These findings suggest that transboundary groundwater governance should be organized around the geography of groundwater use and potential cross-border interactions rather than treating shared aquifers as uniform governance units.

Terrestrial megafauna (animals >1,000 kg) have substantial impacts on ecosystems while alive; yet, we know little about the impacts of these ecosystem engineers after they die. Like whale carcasses in the ocean, terrestrial megacarcasses may leave ecological legacies via the nutrient pulses they create on the landscape. Here, we investigated the impact of elephant megacarcasses on savanna ecosystems in Kruger National Park, South Africa. To determine how elephant carcasses affect below- and aboveground biodiversity and ecosystem processes, we collected soil and plant samples from 40 carcass sites (pairing "on carcass" and "off carcass" samples) ranging from 8 d to 7.7 y postmortem. We found that elephant carcasses released enormous pools of nutrients into savanna soils, increasing ammonium by 31×, nitrate by 7×, and phosphorus by 3× on average. These extreme ammonium concentrations were negatively correlated with the biodiversity of bacteria and plants, which were both suppressed at elephant carcass sites. Despite these decreases in biodiversity, ecosystem processes were strongly elevated at elephant carcass sites, with soil microbial respiration elevated for 1 to 2 y and herbivore grazing >3× higher for 7+ y postmortem. These results demonstrate that elephant megacarcasses generate coldspots of biodiversity but hotspots of ecosystem processes, unveiling a cryptic ecological function of megaherbivores that is extreme in both magnitude and duration relative to carcasses of smaller animals. As humans drive terrestrial megafauna toward extinction, we risk losing not only their ecosystem engineering abilities while they are alive but also the ecological legacies their carcasses create after death.