Anthropocene最新文献

The Earth has lost approximately half of its large mammal species (≥45 kg, one-third of species ≥9 kg) over the past 120,000 years, resulting in depauperate megafauna communities worldwide. Despite substantial interest and debate for over a century, the reasons for these exceptionally high extinction rates and major transformation of the biosphere remain contested. The predominant explanations are climate change, hunting by modern humans (Homo sapiens), or a combination of both. To evaluate the evidence for each hypothesis, statistical models were constructed to test the predictive power of prehistoric human and hominin presence and migration on megafauna extinction severity and on extinction bias toward larger species. Models with anthropic predictors were compared to models that considered late-Quaternary (120–0 kya) climate change and it was found that models including human factors outperformed all purely climatic models. These results thus support an overriding impact of Homo sapiens on megafauna extinctions. Given the disproportionate impact of large-bodied animals on vegetation structure, plant dispersal, nutrient cycling and co-dependent biota, this simplification and downsizing of mammal faunas worldwide represents the first planetary-scale, human-driven transformation of the environment.

Studying the legacies of past human-environment interactions is essential for understanding current landscape and biodiversity patterns. Human influences on past terrestrial and aquatic vegetation are reconstructed based on palynological analysis conducted on a sediment core from Lago di Vedana (Province of Belluno, Northern Italy). This study represents the first pollen record from the Dolomitic lowlands with varying anthropogenic influences throughout the last 700 years. The radiocarbon-dated pollen record begins ca. A.D. 1300 with semi-open forest and moderate human impact, possibly due to activities of the nearby hospice of San Gottardo. Human impact increased with the foundation of the Vedana Charterhouse in the immediate catchment of the lake in A.D. 1457. Activities of the monks involved extensive forest clearing, cultivation of Cannabis/Humulus and possibly hemp retting. In the 19th century the composition of cultivated species changed following the transformation of the Charterhouse into a farm. The 20th century is characterized by expansion of forest taxa and a distinct decline of human influences, probably due to a rural exodus and abandonment of agricultural activities. Vegetation development at Lago di Vedana is consistent with general trends in the Italian Alps and reveals local cultivation practices. The results illustrate the close intertwinement of climatic trends and local human influences, modulated by regional socio-cultural developments during the last millennium.

Understanding the factors underlying bird invasions is crucial for their management. Here, the invasion processes of Mexico by the European Starling (Sturnus vulgaris) and the Eurasian Collared-Dove (Streptopelia decaocto) are analyzed. A 30 × 30 km grid-cell map with the presence/absence of both species was generated using citizen-science data to describe their invasion patterns in time and space from their first records until 2016. Binomial Generalized Linear Models were used to determine the invasion probabilities of both species. Geographic Information was used to determine the climatic variables that better explain their presence (abiotic factors) and the number of phylogenetically closely-related species (biotic factors). A bioclimatic model was used to test if the role that climatic variables play to determine the invasion success of birds at the global scale holds at regional scales. This model related the invasion probabilities of each species with biotic and abiotic factors. The main findings are: (1) Both species have expanded from established populations in the US, and new introductions by bird-trade. (2) European Starlings invaded the country slower than Eurasian Collared-Doves. (3) European Starlings invaded areas with dry and temperate climates, while Eurasian Collared-Doves invaded most of the country, being positively affected by temperature and precipitation. (4) Invasion probabilities of both species were not constrained by phylogenetically closely-related species richness. This study indicates that for exotic invasive birds that exploit agricultural areas, biotic factors do not provide invasion resistance of megadiverse countries such as Mexico.

The land system faces many pressures from the provision of biomass resources and space to the economy. The need to understand land use and cover changes and its drivers is of high importance. This work presents an innovative approach by applying a transdisciplinary approach combining the methods of spatial analysis Land Cover Flows with the methods from the concept of socio-economic metabolism, Material and Energy Flow Accounting, Human Appropriation of Net Primary Production (HANPP) and Final Energy Return on Investment (FEROI). Our main aim is to identify the main land use changes and land cover flows, link them to the underlying socio-economic processes and interpret them in a historical context. Our results show that the overall land use intensity is growing although the positive trends of growing grasslands and forests started after the collapse of communism. The growing intensity of agricultural production with increasing suburbanisation reversed these trends. Until the 2000s the HANPP decreased but at the end of the period increased from 55 % in 2012 to 70 % in 2018. Volumes of the extraction of agricultural biomass are growing while the area of agricultural land has decreased. FEROI grew and stabilised to around 1.0 in the last period (2012–2018) comparable to the value found in the year 2001. The suburbanisation rates peaked after the year 2000 at 250 m²/km²/yr.

The impact from humans on soils, particularly in terms of intensive agriculture, has been most noticeable in the last 200 years. Intensive agricultural activities have caused soil organic carbon (SOC) to decline in many parts of the world. However, there is a dearth of approaches that can spatially estimate the change of SOC due to human influence. Here, we used the concept of Pedogenon to stratify the landscape into soil classes called Pedogenons. Within each Pedogenon, we sampled representative soils under native vegetation and soils under intensive human management. We surveyed the lower Namoi Valley area, NSW, Australia (1700 km²), comprising 13 Pedogenons (soil classes) and analysed SOC on 99 soil cores. Using Digital Soil Mapping techniques, the SOC data were used for mapping SOC every 10 cm down to 1 m using environmental covariates. Sampling points under native vegetation were used to map SOC under the native state, and all data were used for mapping SOC current state. By comparing the SOC maps at two states (native and current), we assessed SOC change. The results show that the SOC loss in irrigated cropping areas was the largest, with surface SOC content decreased by 38%, followed by non-irrigated cropping (30% loss), and pasture (19% loss). All cropping areas show a decrease in SOC stock content at least 5 t C ha⁻¹. SOC loss was greatest in the surface soils and decreased exponentially with depth. We further demonstrate that each Pedogenon can be used to define SOC sequestration potential. Understanding SOC change can provide information on areas under SOC loss threat and require immediate remediation.

Cropland expansion is effected by physiogeographic and sociocultural factors, which vary across region and over time, but have not been adequately represented in large-scale anthropogenic land cover change scenarios. Taking preindustrial cropland expansion in France, Germany, and Italy as a case study, this study first adopted a productivity-based estimation of cropland per capita, which converted crop yield to cropland demand per capita through negative correlations under different crop rotations, to improve the accuracy of national cropland areas. Then, a new allocation algorithm was proposed to allocate national cropland areas into 5′× 5′ grids. The algorithm combines land suitability, which characterizes regional differentiation of potential productivity indicated by physiogeographic factors (climate, topography, soil, etc.) that dominate cultivation, and cultivation preference, which quantifies sociocultural impacts by kernel density estimation based on city information (i.e., location, size, accessibility). The cropland cover scenario here shows similar phases but different modes of cropland expansion in these countries: (1) National cropland areas increased 1.73–2.46 times during the 11th–13th centuries, manifested by the expanding cultivated ranges in France and Germany and the increasing cultivation intensity in Italy. (2) National cropland fractions decreased by 9.16–19.98 percentage points in the 14th century, accompanied by widespread reductions in cultivation intensity. (3) Cropland gradually recovered toward its peak in 1300 AD during the 15th–18th centuries, achieved by general and remarkable increases in cultivation intensity. Compared to representative global datasets, this study is more consistent with cultivation-related descriptions in the literature, especially with respect to the cropland expansion in newly cultivated regions and on marginal lands.

Phosphorus (P) is an essential nutrient, which at excessive concentrations can cause eutrophication of aquatic ecosystems. In freshwater wetlands, water quality deteriorates under these conditions, often succumbing to algal or duckweed dominance, over the biodiversity of other aquatic vegetation. Freshwater sediment may act as an internal source of legacy bound P that can induce production of algal and duckweed blooms beyond what may be expected from external loading of P alone. This study assesses the mobility, bioavailability, and origin of phosphorus in wetland ditch systems at the designated site of special scientific interest, West Sedgemoor. Based upon associations with different P species, using principal component analysis, a clear distinction was observed between sites outside and within the West Sedgemoor Nature Reserve (managed by the Royal Society of the Protection of Birds). Sites outside the nature reserve, typically wet and damp grassland used for arable use and grazing, were generally correlated to higher percentages (median 58.5 %) of non-apatite inorganic P (associated with iron and aluminium minerology) and higher total P levels (average 1277 mg/kg), associated with algal and duckweed blooms, in comparison to areas within the nature reserve (median non-apatite inorganic P; 49.9 %) (average total phosphorus; 936.9 mg/kg).

Stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope analysis was conducted on modern and archaeological polar bear bone collagen from the Canadian Arctic Archipelago to investigate potential changes in polar bear foraging ecology over four-millennia. Polar bear δ¹³C values showed a significant decline in the modern samples relative to all archaeological time-bins, indicating a disruption in the sources of production that support the food web, occurring after the Industrial Revolution. The trophic structure, indicated through δ¹⁵N, remained unaltered throughout all time periods. The lower δ¹³C observed in the modern samples indicates a change in the relative importance of pelagic (supported by open-water phytoplankton) over sympagic (supported by sea ice-associated algae) primary production. The consistency in polar bear δ¹³C through the late Holocene includes climatic shifts such as the Medieval Warm Period (MWP, A.D. 950–1250) and the early stages of the Little Ice Age (LIA, A.D. 1300–1850). These findings suggest that polar bears inhabit a food web that is more pelagic and less sympagic today than it was through the Late Holocene. We suggest that modern, anthropogenic warming has already affected food web structure in the Canadian Arctic Archipelago when modern data are contextualized with a deep time perspective.

Transformative rather than incremental adaptation will be necessary to keep pace with rapidly changing social-ecological systems characteristic of the Anthropocene. Alongside mounting urgency for transformative adaptation, there is also growing recognition that it is no longer possible to achieve sustainable transformation without also addressing security and equity concerns. Thus, dimensions of security, equity, and sustainability (SES) are increasingly intersected in transformation research and practice. However, interpretations of SES dimensions and their intersections vary widely across disciplines, policy sectors, and problem domains, and knowledge of SES intersections is fragmented. To navigate this vast body of knowledge, a conceptual framework is presented that: 1) integrates a set of guiding critical questions for defining and assessing different framings for each SES dimension; 2) identifies modes of theorizing SES intersections; and 3) relates the previous two elements to leverage points targeted, either theoretically or in practice, for transformative change. Nine prominent integrated concepts and associated case studies were identified that explicitly addressed intersections among all SES dimensions. Integrated concepts addressed a diversity of leverage points, but only two mixed epistemological and methodological approaches sufficiently to provide explanatory insight into SES intersections while also supporting science-based change-making. Potential risks of ambiguity around SES framings and needs for addressing SES intersections in future transformation research are highlighted. Optimistically, transformation scholarship has moved beyond simply stating the importance of SES dimensions to focusing on the causal interactions among SES dimensions, which is leading to compelling new blends of explanatory and action-oriented paradigms to pursue transformation.

Water footprint accounting can evaluate the real occupancy of water resources by combining the consumption of blue water and green water. In this study, we calculated agricultural water footprint (AWF) including six patterns of crops water footprint (CWF) and three patterns of animal products water footprint (APWF) from 2000 to 2020 in Gansu Province, China, then the spatiotemporal matching pattern and its heterogeneity of AWF and socioeconomic factors were identified at the ecological functional zone level. The results show that: (1) The AWF showed a rising trend, increasing by 40%. (2) The spatial difference of AWF was obvious, the main contributor to the CWF changed from wheat to maize, and the main contributors to the APWF were always pork and beef. At the ecological zones level, the central and eastern Loess Plateau and Hexi inland areas together accounted for 60% of the total AWF of Gansu Province. (3) The center of gravity of AWF was always located in Lanzhou, the provincial capital, but tended to gradually move to the northwest. (4) The spatiotemporal matching degree between AWF and population and GDP was relatively good, but it was highly unbalanced between blue water footprint (BWF) and planting area. Considering both water-saving potential and feasibility, we suggest that Gansu Province should carry out sustainable agricultural management from three aspects, that is, optimizing the planting structure, emphasizing water conservation in animal husbandry, and improving the spatial matching degree between AWF and socioeconomic factors.