Anthropocene最新文献

Coral reefs are extremely productive ecosystems, but widespread changes to benthic community structure resulting from anthropogenic impacts are likely to impact the transfer of organic matter between trophic levels, altering trophodynamics and functional diversity. We used stable isotope analysis to investigate differences in resource availability, niche width and trophic diversity of seven coral reef fish species representing key functional feeding groups on a sponge-dominated reef and an adjacent, coral-dominated reef. Four out of seven fish species had wider isotopic niches at the sponge-dominated reef compared to the coral-dominated reef, including the obligate corallivore. The proximity of the isotopic niche of the obligate corallivore to the isotopic niche of the detritivore suggests that the obligate corallivore supplemented its diet with detritus at the sponge-dominated reef. Fish sampled at the sponge-dominated reef had a significantly lower mean trophic position, used a lower range of resources (based on δ¹³C range) and obtained more carbon from benthic production than at the coral-dominated reef. Trophic diversity was lower and functional redundancy higher at the sponge-dominated reef, suggesting that fish on the sponge reef had more similar diets to each other than at the coral-dominated site. Observed differences in trophic structure between the two sites are likely due to fewer organic matter pathways supporting secondary production at the sponge-dominated reef, suggesting that transitions sponge-dominated systems will reduce community stability by eroding the potential for niche partitioning and species co-existence.

Worldwide, rivers are extensively fragmented by anthropogenic structures, reducing longitudinal connectivity, inhibiting migration and leading to severe declines in many fish populations, especially for diadromous species. However, few studies have determined the effects of annual differences in hydrology on catchment penetration past barriers to spawning habitats. We investigated the upstream spawning migration of 120 (n = 61 & 59) acoustic tagged river lamprey (Lampetra fluviatilis) across two contrasting (dry and wet) years in the River Yorkshire Ouse, England. Overall, significantly more lamprey reached spawning habitat (76% vs 39%) and penetrated significantly further upstream (median [km] from release, 53.9 vs 16.8) in the wet year than the dry year. Passage at weirs was almost exclusively during elevated river levels, which directly and collectively influenced catchment-wide distribution, especially in the dry year. Indeed, higher proportions entered two upper tributaries in the wet year (9.8% vs 27.1% and 9.8% vs 30.5%), due to increased passage efficiencies at the two main river weirs (60.5–87.5% and 54.5–83.8%), and reached assumed spawning locations 66.5% and 10.9% quicker. By contrast, there was no difference in numbers of lamprey entering, or time taken to arrive at assumed spawning location, in the two lower river tributaries between years. Our study supports the landscape-scale paradigm for ecosystem restoration because of the observed catchment-level effects of hydrology and barrier distribution on fish migration. Connectivity restoration for migratory fish should be implemented at a catchment scale, with planning incorporating spatial information regarding accessibility to key habitats to reap the largest gains.

Crop response characteristics to different timescales of precipitation deficit may represent crop system resilience to drought characteristics. In this study, we assess the crop yield response of major crops to meteorological drought estimated by a standardized precipitation index with multiple timescales (1–12 months) during 1981–2016 all over the globe. We estimate that about one- to two-thirds of global harvested areas of maize, rice, soybean, and wheat, were significantly affected by various drought timescales. Soybean and wheat might respond to more prolonged droughts, while rice and maize responded to short-medium drought time scales. Using multiple machine learning models, we reveal that set of determinants could explain most variations of crop response to drought timescale with average accuracies between 45.7% and 56.0% (across models and crop types). Moreover, this study suggests that crops in warmer and higher water availability (precipitation minus potential evapotranspiration) might respond significantly to more short-term drought. The other factors (i.e., socioeconomic, fertilizer, soil, topography, production, irrigation) shows a complex and weaker effect on defining crop vulnerability to the various drought characteristics. This study attempts to fill the gaps in understanding global crop resistance to different drought characteristics. The future challenge in understanding the multifaceted effect of physical and socioeconomic factors on global crop vulnerability to drought may remain and should be addressed in further studies.

Early farmers used at least two types of agrarian amendments that could raise pH and base saturation levels to allow the cultivation of cereals: marling and plant ash. Ash can be input in many different ways: felling and burning in place, transferring plant material from wastelands and spreading the ash, charring sod or peat blocks, burning stubble after harvest. Marling includes all the practices of amending limestone, from marl to chalky limestone composed of 99% CaCO₃. In order to understand the evolution of these agricultural practices, it is important to identify which of the two techniques was used to amend cereal crops in the past. In order to test the potential of δ^44/40Ca-δ^88/86Sr-⁸⁷Sr/⁸⁶Sr multiple isotope approach for archaeological samples, we first applied the technique to currently grown crops, amended either with marl or with ash from freshly-cut and burned trees. We found that this approach makes it possible to discriminate cereal grains amended either by marling (less radiogenic Sr) or with tree ash (more radiogenic Sr). We also identified a positive correlation between stable Ca and Sr isotope values, suggesting that the Ca and Sr came from similar sources and had undergone similar mass-dependent isotopic fractionation mechanisms. Consequently, we later on mainly focused on stable and radiogenic Sr isotopes. Stable Sr isotope fractionation was also observed between different locations, different organs of a given cereal species and between different cereal types, but also within the same cereal species or the number of grains studied for a given locality, pointing to biological fractionation combined with source variation.

Legacy pollution research has established that over the past 3000 years, mining and metallurgical activities have resulted in widespread deposition of lead (Pb) pollution. However, there is still a limited understanding of how humans have impacted the long-term cycling of Pb in the environment. We present a 4,000-year lake sediment Pb isotope record from Laguna Roya, northwestern Iberia, that identifies and quantifies the predominant sources of atmospheric Pb pollution. For the first time, Pb isotopic compositions of ancient slag samples dated (∼600 BCE–200 CE) from a mining district in the southwest of the Iberian Peninsula are compared to Pb isotope ratios of Pb pollution deposited contemporaneously in lake sediments. In addition, literature Pb isotope ratios of ores from mining regions throughout Iberia are compared with those of leaded gasoline and coal to identify additional sources of anthropogenic Pb. Deposition of atmospheric Pb pollution begins after 950 BCE, and until 1750 CE, the Pb isotopic composition most resembles the southwestern slag deposits, containing a mixture of Pb ores from southeast Iberia (up to 36%) and southwest Iberia (∼74%). Between 1750 and 1960 CE, Pb pollution is attributed to Pb mining in southcentral Iberia. After 1960 CE, the dominant Pb pollution source (∼85%) is again metal refining in southwestern Iberia, and only ∼15% is from leaded gasoline. Provenance and reconstruction of the temporal and spatial distribution of legacy Pb pollution further our understanding of how humans have affected the biogeochemical cycle of this toxic element in the environment over time.

This paper investigates the locations of past watermills in terms of their hydrological and geomorphological conditions. In our analysis, the natural landscape was treated as a resource of factors favouring or hindering the location of a specific mill and the possibility of their persistence as technological and economic conditions became increasingly unfavourable throughout history. An answer was provided to the question of which areas were environmentally preferable for the location of a plant using the energy of flowing water and in which types of landscape - enclaves of the cultural mill landscape were preserved for the longest time. The Maximum Entropy Method (MaxEnt) was used to determine the spatial probability distribution of the mill reservoir locations based on the delimitation of natural landscape types. Ten per cent of the study area shows a high occurrence probability for mill location (>0.9). The spatial distribution of MaxEnt outcomes shows that landscapes prone to mill location mainly concentrate on the edge of morainic plateaus and in the tunnel valleys. The research results allow us to understand the evolution of the cultural landscape in the lowland area, especially the role of mill settlements in colonising of forest areas and river valleys.

The original meaning of the Critical Zone (CZ) was spatial and pointed to one physical referent: the terrestrial surface of the entire Earth. As usage increased among researchers in the geosciences, social sciences, and humanities, new meanings led to the concept pointing to different places and ideas. Emerging trends have expanded the CZ further: CZs are mapped in computational spacetime and on distant planets and asteroids. The polysemous character of the CZ can be confounding for a field-based science, but Earth scientists and technologists have collaborated to collect and harmonize Big Data sets into a sizable library of CZ research in a short time (around 20 years). In this review, we map the semantic range of the CZ and explore how CZ science has remained coherent even as researchers diversified the concept by developing distinguishable but loosely overlapping meanings. We organize extant meanings into three tiers: (1) Earth’s spatial interface of the geochemical and biological; (2) scientific knowledge of geophysical functionality of the CZ, as represented in an ever-growing library of data or by a single feature as proxy (e.g. soil); (3) a planetary home vulnerable to human disruption. In a time of immense human influence on the CZ, we underscore the latent meaning of planetary home, which marshals motivations of care and protection. These three tiers—the ontological, epistemic, and anthropocenic—build on each other to make the CZ a uniquely valuable concept for navigating the socio-ecological challenges of the Anthropocene.

An ideal form of smart city planning would focus on the availability of urban amenities that can meet the basic needs of a resident’s material life, civil connections, and humanistic spirit. Previous studies have concentrated on analyzing the spatial distribution of urban services, with less attention on their contribution as local urban amenities. In this study, we propose a spatial dynamic modeling approach based on urban amenities using social media data from Google Place API to provide locational information on potential resident interactions. We use a representative region in Europe (Stockholm County, SE) to simulate and project urban development in the region until 2050. Our circular conceptual framework of spatial information and feedback supports decision-makers in testing possible urban planning scenarios that align with the vision of a smart city. Simulation results reveal the interplay between human-land interactions on a specific spatial-temporal scale, and we analyze scenario outcomes in relation to commercial and residential land uses. Overall, our study provides a new perspective on human-social behavior-driven urban development, through a smart, spatial dynamic model as a planning support system that can enhance realism, and ultimately help realize planned development objectives in the region.

Large parts of the East European forest-steppe are covered by agricultural and pastoral landscapes with decreasing proportions of semi-natural meadow steppes and fragments of semi-natural woodland. Although numerous palynological records indicate that a total deforestation occurred in the last 500 years, the details of the transformation from natural vegetation into an agrarian landscape are still lacking as well as an evaluation of the political role in this process. This study focuses on the vegetation and fire history at the northern edge of the forest-steppe in the Kursk region (Russia) and aim to reconstruct the transformation process in its historical context. New pollen, non-pollen palynomorphs and charcoal records with decennial to centennial resolution obtained from the Seim River region enable a comprehensive reconstruction of the local and regional landscape history over the last 1100 years. The palynological records provide unique insights into the heterogeneous vegetation cover of microregions and evidence spatial asynchronous deforestation and crop field creation. The findings highlight a crucial role of political systems on the formation of agro-pastoral landscapes with small remaining forest patches of today. The heterogeneity of the natural vegetation distribution before major deforestation as well as the duration of human impact should be considered in ecosystem restoration projects.

With climate change, the COVID-19 pandemic, and ongoing conflicts, food systems and the diets they produce are facing increasing fragility. In a turbulent, hot world, threatened resiliency and sustainability of food systems could make it all the more complicated to nourish a population of 9.7 billion by 2050. Climate change is having adverse impacts across food systems with more frequent and intense extreme events that will challenge food production, storage, and transport, potentially imperiling the global population’s ability to access and afford healthy diets. Inadequate diets will contribute further to detrimental human and planetary health impacts. At the same time, the way food is grown, processed, packaged, and transported is having adverse impacts on the environment and finite natural resources further accelerating climate change, tropical deforestation, and biodiversity loss. This state-of-the-science iterative review covers three areas. The paper's first section presents how climate change is connected to food systems and how dietary trends and foods consumed worldwide impact human health, climate change, and environmental degradation. The second area articulates how food systems affect global dietary trends and the macro forces shaping food systems and diets. The last section highlights how specific food policies and actions related to dietary transitions can contribute to climate adaptation and mitigation responses and, at the same time, improve human and planetary health. While there is significant urgency in acting, it is also critical to move beyond the political inertia and bridge the separatism of food systems and climate change agendas that currently exists among governments and private sector actors. The window is closing and closing fast.