Communications Earth & Environment最新文献

In tropical montane forests, the Earth's largest biodiversity hotspots, there is increasing evidence that climate warming is resulting in montane species being displaced by their lowland counterparts. However, the drivers of these changes are poorly understood. Across a large elevation gradient in the Colombian Andes, we established three experimental plantations of 15 dominant tree species including both naturally occurring montane and lowland species and measured their survival and growth. Here we show that 55% of the studied montane species maintained growth at their survival's hottest temperature with the remaining 45% being intolerant to such levels of warming, declining their growth, while lowland species benefited strongly from the warmest temperatures. Our findings suggest that the direct negative effects of warming and increased competition of montane species with lowland species are promoting increased homogeneity in community composition, resulting in reduced biodiversity.

Plastic pollution in the world's oceans threatens ecosystems and biodiversity. The connected nature of the marine environment suggests that coordinated actions by countries sharing an ocean border may provide more effective pollution control than unilateral actions by any one country. However, countries often fail to cooperate, even when joint economic benefits would be higher under cooperation. Here we present a modelling framework to determine the potential economic benefits of cooperative marine plastic pollution management. The framework integrates an estimated plastic transfer matrix from a particle tracking model with game theory to derive the economic benefits of international cooperation for 16 countries bordering the North Atlantic Ocean. Subject to modelling uncertainties, a fully cooperative agreement yields aggregate annual net benefits of around $36 billion and a 64% reduction in emissions. The net benefits of cooperation persist over alternative scenarios and considering the impact of uncertainties but vary in magnitude and distribution.

Fossils preserving soft tissues and lightly biomineralized structures are essential for the reconstruction of past ecosystems and their evolution. Understanding fossilization processes, including decay and mineralisation, is crucial for accurately interpreting ancient morphologies. Here we investigate the decay of marine and freshwater shrimps deposited on the surface of three different clay beds. In experimental set ups containing kaolinite, cryogenic scanning electron microscopy shows a black film comprised of newly formed anhedral and cryptocrystalline aluminosilicates on marine shrimp cuticles, which stabilise the overall morphology. This is the first experimental evidence for the replication of arthropod lightly biomineralized structures in aluminosilicates shortly after death, while carcasses are not buried by sediments. The preservation of morphology through aluminosilicates could result in carcasses persisting on the seafloor for weeks without losing much external anatomical information. In this context, instantaneous burial capturing animals alive may not be a prerequisite for exceptional preservation as usually thought.

Atmospheric amines, derivatives of ammonia, play a unique yet not fully understood role in air quality, climate and public health. Sub-5 parts per trillion Volume (pptV, <10^-12 in volume) mixing ratios of amines facilitate the physical and/or chemical transformation of aerosols in the atmosphere, enhancing aerosol formation and growth rates, aerosol hygroscopicity, and the activation of cloud condensation nuclei. This serves as the initial step for cloud droplet formation and, consequently, influences cloud properties and the hydrological cycle. Ambient observations demonstrate more than a thousand-fold particle formation rates in the presence of amines as compared to ammonia. Yet, the challenges related to detecting minute levels of amines, the paucity of ambient amine measurements, and the limited process-based understanding of airborne aerosol production have resulted in amines being underrepresented in global climate models. Therefore, advanced techniques with extremely low detection limits and highly spatially and temporally resolved ambient amine measurements globally in diverse environments are essential.

Turbidity currents carve Earth's deepest canyons, form Earth's largest sediment deposits, and break seabed telecommunications cables. Directly measuring turbidity currents is notoriously challenging due to their destructive impact on instruments within their path. This is especially the case for canyon-flushing flows that can travel >1000 km at >5 m/s, whose dynamics are poorly understood. We deployed ocean-bottom seismometers safely outside turbidity currents, and used emitted seismic signals to remotely monitor canyon-flushing events. By analyzing seismic power variations with distance and signal polarization, we distinguish signals generated by turbulence and sediment transport and document the evolving internal speed and structure of flows. Flow-fronts have dense near-bed layers comprising multiple surges with 5-to-30-minute durations, continuing for many hours. Fastest surges occur 30-60 minutes behind the flow-front, providing momentum that sustains flow-fronts for >1000 km. Our results highlight surging within dense near-bed layers as a key driver of turbidity currents' long-distance runout.

Arctic food systems blend Traditional Ecological Knowledge with modern, often energy-intensive influences, triggered by colonization. Food systems' future depends on alignment of tradition with innovation, facilitation of resilience and a heritage-driven interaction with the global economy - at a pace determined by local communities.

Agriculture and food systems are major sources of plastic pollution but they are also vulnerable to their diverse lifecycle impacts. However, this problem is not well-recognized in global policy and scientific discourse, agendas, and monitoring of food systems. The United Nations-led Global Plastics Treaty, which has been under negotiation since 2022, is a critical opportunity to address pollution across the entire plastics lifecycle for more sustainable and resilient food systems. Here, we offer aspirational indicators for future monitoring of food systems' plastics related to (1) plastic polymers and chemicals, (2) land use, (3) trade and waste, and (4) environmental and human health. We call for interdisciplinary research collaborations to continue improving and harmonising the evidence base necessary to track and trace plastics and plastic chemicals in food systems. We also highlight the need for collaboration across disciplines and sectors to tackle this urgent challenge for biodiversity, climate change, food security and nutrition, health and human rights at a whole systems level.

Questions about when early members of the genus Homo adapted to extreme environments like deserts and rainforests have traditionally focused on Homo sapiens. Here, we present multidisciplinary evidence from Engaji Nanyori in Tanzania's Oldupai Gorge, revealing that Homo erectus thrived in hyperarid landscapes one million years ago. Using biogeochemical analyses, precise chronometric dating, palaeoclimate simulations, biome modeling, fire history reconstructions, palaeobotanical studies, faunal assemblages, and archeological evidence, we reconstruct an environment dominated by semidesert shrubland. Despite these challenges, Homo erectus repeatedly occupied fluvial landscapes, leveraging water sources and ecological focal points to mitigate risk. These findings suggest archaic humans possessed an ecological flexibility previously attributed only to later hominins. This adaptability likely facilitated the expansion of Homo erectus into the arid regions of Africa and Eurasia, redefining their role as ecological generalists thriving in some of the most challenging landscapes of the Middle Pleistocene.

The Last Ice Area-located to the north of Greenland and the northern Canadian Arctic Archipelago-is expected to persist as the central Arctic Ocean becomes seasonally ice-free within a few decades. Projections of the Last Ice Area, however, have come from relatively low resolution Global Climate Models that do not resolve sea ice export through the waterways of the Canadian Arctic Archipelago and Nares Strait. Here we revisit Last Ice Area projections using high-resolution numerical simulations from the Community Earth System Model, which resolves these narrow waterways. Under a high-end forcing scenario, the sea ice of the Last Ice Area thins and becomes more mobile, resulting in a large export southward. Under this potentially worst-case scenario, sea ice of the Last Ice Area could disappear a little more than one decade after the central Arctic Ocean has reached seasonally ice-free conditions. This loss would have profound impacts on ice-obligate species.

Permafrost thaw poses diverse risks to Arctic environments and livelihoods. Understanding the effects of permafrost thaw is vital for informed policymaking and adaptation efforts. Here, we present the consolidated findings of a risk analysis spanning four study regions: Longyearbyen (Svalbard, Norway), the Avannaata municipality (Greenland), the Beaufort Sea region and the Mackenzie River Delta (Canada) and the Bulunskiy District of the Sakha Republic (Russia). Local stakeholders' and scientists' perceptions shaped our understanding of the risks as dynamic, socionatural phenomena involving physical processes, key hazards, and societal consequences. Through an inter- and transdisciplinary risk analysis based on multidirectional knowledge exchanges and thematic network analysis, we identified five key hazards of permafrost thaw. These include infrastructure failure, disruption of mobility and supplies, decreased water quality, challenges for food security, and exposure to diseases and contaminants. The study's novelty resides in the comparative approach spanning different disciplines, environmental and societal contexts, and the transdisciplinary synthesis considering various risk perceptions.