Anthropocene最新文献

This study aimed to assess the potential impact of global climate change on the highland areas of Kastamonu, a significant province in Turkey known for its numerous and varied highlands. The investigation focused on 59 selected highland locations within the region. Using the De Martonne climate classification, projections were made for four future periods (2040, 2060, 2080, and 2100) under two scenarios: SSPs 245 and SSPs 585. The outcomes of the study indicate that the highlands under scrutiny are susceptible to substantial effects from global climate change. Notably, these climatic alterations are expected to become evident within the next two decades, predominantly manifesting as a shift towards arid climate classifications. These shifts are anticipated to have a profound impact on the composition and diversity of species in the highland ecosystems. Based on the findings, it is advisable to consider interventions for the most climate-sensitive highland areas, such as facilitating the migration of species adapted to the new climate conditions and implementing initiatives to enhance species diversity. These efforts could help mitigate the potential loss of species and populations resulting from climate change.

The lipid content of a high mountain lake (Lake Isoba) allowed the reconstruction of the paleoenvironmental changes and anthropic influence in Northern Spain during the last 550 years. Fatty acids (FAs) and n-alkan-2-ones indicate little degradation of OM. Three units were delimited. During Unit A (ca. 1460–1780 CE) high carbon preference index values, predominance of high-molecular-weight saturated FAs, and good correspondence between the predominant n-alkane and saturated FA chains indicate higher OM input and evidence of minimal degradation, linked to the cold and dry Little Ice Age, that favoured the OM input derived mainly from land plants, and the reduced bacterial activity. In Unit B (ca. 1780–2006 CE) the n-alkane and saturated FA profiles showed a remarkable mismatch suggestive of preferential microbial synthesis of long chain saturated FAs from primary OM and/or bacterial activity (predominance of low-molecular-weight saturated FAs but with a bimodal distribution), in coincidence with a decrease in OM input, which could be linked to the global warming that started in the second half of the 19th century. Although OM continued deriving mainly from terrigenous plants, aquatic macrophytes increased their contribution to the OM indicating the amelioration of environmental conditions. Evidence of considerable phytoplankton productivity and microbial activity was significant in Unit C (ca. 2006–2018 CE) coinciding with the highest concentrations of n-alkanes and saturated FAs, linked to warmer and drier conditions, and to greater anthropogenic influence. In addition, organic sulfur and gammacerane indicates loss of oligotrophy, and the record of faecal stanols, particularly that of 24-ethylcoprostanol, strongly evidences notable and rising water pollution associated with increasing cattle ranching in the lake catchment during the past 10–15 years.

The Mediterranean Basin is an environmental change hotspot that, relative to other regions of the world, is forecasted to experience a significant shift in biodiversity due to multiple factors such as climate change and agricultural intensification. Within this framework, the Eastern Mediterranean region is projected to face a temperature rise of ∼3.5–7 °C by 2070–2099 which will result in severe heat stress and freshwater scarcity, along with increased human impacts due to pronounced demographic growth. To assess the impact of environmental and human pressures on plant diversity, we studied the evolution of this major constituent of biodiversity in the Eastern Mediterranean over 8000 years. Our analysis demonstrates that plant diversity has been impacted by long-term (e.g. multi-millennial scale) changes in temperature, precipitation and anthropogenic activities. We identified a tipping point for each of these drivers, showing that Eastern Mediterranean plant diversity has already exceeded its tipping point for precipitation (threshold: 376 ± 17 mm for winter), while it has already attained its critical threshold for temperature (threshold: 1.33 ± 0.5 °C) and anthropogenic activities (threshold: −1.05 ± 0.4 - low to medium pressures). This suggests that the region’s vegetation will probably progressively give way to species that are better suited and more resilient to the changing environmental conditions.

Agricultural development has transformed the vegetation cover of many landscapes around the world, thereby altering water and sediment fluxes to river systems. Past work in the upper midwestern United States, particularly in areas of moderate relief, has shown that increases in water and sediment fluxes associated with agricultural development have dramatically altered river dynamics. Less is known about how agriculture has affected river dynamics, particularly rates of lateral migration, in relatively low relief landscapes of the Midwest shaped by glaciation during the Wisconsin Episode. This research examines rates of lateral migration of a channel bend along a lowland meandering river in Illinois, USA before and after agricultural development. The rate of lateral migration prior to agricultural development is estimated through dating of carbonaceous material within lateral-accretion deposits underlying distinct meander scrolls. The rate of lateral migration after agricultural development is determined from analysis of changes in river-channel position determined from survey records, aerial imagery, and digital elevation data. Average rates of migration before and after agricultural development are similar, suggesting that agricultural development has not substantially affected rates of lateral migration of the river. Some accelerated movement occurred locally following agricultural development, but this movement cannot be definitively tied to landscape transformation. Possible factors responsible for the lack of sensitivity of the river system to agricultural development include high resistance of the cohesive, tree-lined riverbanks to erosion and the low bankfull stream power per unit area of the modern river. From a management perspective, the study highlights the importance of bank vegetation in maintaining channel stability in low-relief agricultural landscapes.

Road deicing salts have impacted the hydrogeochemistry of lakes throughout the snow-belt region of the globe. This paper advances our understanding of the historical change in salt concentrations in, and sources to, the Finger Lakes of western and central New York state, and compares the results to other lakes across the globe. Surface water samples from Honeoye, Canandaigua, Keuka, Seneca, Cayuga, Owasco, Skaneateles and Otisco lakes were analyzed for chloride (Cl) concentrations, and augmented with published and unpublished decade, and for the first time, century-scale Cl data for these lakes and Hemlock Lake. A mass-balance model estimated the Cl flux required to match the measured Cl concentrations in each lake. Cl concentration and flux trends defined two groups of lakes. Group 1: A mid-1900′s peak in Cl concentrations was detected in Seneca and Cayuga lakes, that resulted from a short but significant spike of Cl, most likely from salt mine wastes during pre-Environmental Protection Agency times. Group 2: Hemlock, Honeoye, Canandaigua, Keuka, Owasco, Skaneateles and Otisco lakes, revealed smaller yet increasing concentrations and fluxes over time that were interpreted to reflect increasing use of road deicing salts in their watersheds and supported by correlations to their state and federal road lengths, percentage of impervious surfaces, water residence times in each watershed and the production of road salt in the US, but not to their trophic status, nor their percentage of agricultural land. Estimated Cl inputs from municipal wastewater treatment facilities, individual septic systems and the atmosphere (precipitation) were also insignificant in the Finger Lakes region. These results help clarify the processes responsible for increasing Chloride concentrations in lakes globally.

Soil and water bioengineering (SWBE) is a nature-based solution (NBS) that can be used to stabilize riverbanks with living vegetation. Aside to protecting property and people, SWBE provides benefits for human well-being and biodiversity. Its use remains modest in cities, where the presumed benefits are important in a context of biodiversity crisis and warming. Negative public perceptions have been identified as one barrier to the dissemination of NBS. This article studies how environmental expertise influences perceptions and values associated with SWBE, and how the possible differences in perceptions and values induced by knowledge contribute to hindering or promoting the dissemination of these solutions. We carried out an original interdisciplinary study based on a sociological survey and ecological field measurements to characterize: (1) the perceived value that actors associate with several riverbanks equipped with different protection structures (green, hybrid, or gray) according to their level of expertise in the aquatic environment; (2) the interactions between these perceived values and the ecological values measured by restoration ecologists; and (3) the perceived benefits and drawbacks of SBWE techniques. Our results show that the ecological and social benefits provided by NBS are recognized by all, whatever their level of knowledge. Despite this consensus, we observed different hierarchies of value associated with bank protection structures among the surveyed actors, depending on their level of environmental expertise (some prioritising ecological values, others relational values), and these could hinder the dissemination of NBS. The most tangible obstacle to the dissemination of NBS in urban areas relates to the risk perceptions of lay people, who experience a higher sense of vulnerability than they do with traditional gray solutions.

The United States (U.S.) coastal plain is subject to rising sea levels, land subsidence, more severe coastal storms, and more intense droughts. These changes lead to inputs of marine salts into freshwater-dependent coastal systems, creating saltwater intrusion. The penetration of salinity into the coastal interior is exacerbated by groundwater extraction and the high density of agricultural canals and ditches throughout much of the rural U.S. landscape. Together saltwater intrusion and sea level rise (SWISLR) create substantial changes to the social-ecological systems situated along the coastal plain. Many scholars and practitioners are engaged in studying and managing SWISLR impacts on social, economic, and ecological systems. However, most efforts are localized and disconnected, despite a widespread desire to understand this common threat. In addition to variable rates of sea level rise across the U.S. outer coastal plain, differences in geomorphic setting, water resources infrastructure and management, and climate extremes are resulting in different patterns of saltwater intrusion. Understanding both the absolute magnitude of this rapid environmental change, and the causes and consequences for its spatial and temporal variation presents an opportunity to build new mechanistic models to link directional climate change to temporally and spatially dynamic socio-environmental impacts. The diverse trajectories of change offer rich opportunities to test and refine modern theories of ecosystem state change in systems with exceptionally strong socioecological feedbacks.

Records of environmental changes at regional or continental scales in less-developed regions may aid clarification of the onset of the Anthropocene. A sediment core was collected from Bosten Lake in Xinjiang Province, northwestern China, to investigate historical variations of combustion indicators of black carbon (BC), char and soot and to reflect human influences over the past 150 years. Results show that a rapid increase in soot fluxes (over 1.5 times on average) happened after 1950, consistent with the Great Acceleration period as well as establishment of the People's Republic of China, following a rapidly developing economy. Soot flux peaked around the 1960, coincident with wasteland reclamation in Xinjiang Province, decreasing after the year 2000 owing to environmental protection requirements such as desulfurization. Average char/soot ratios before and after 1950 were 0.56 and 0.37, respectively, such low ratios suggest a predominant contribution of soot from long-range transport, while the industrialization in China since the 1950 s may have caused further reduction in the ratios. Sedimentary soot deposition flux in less-developed areas thus recorded key anthropogenic activities occurring in China and supports the onset of the Anthropocene in the mid-20th century, as proposed by the Anthropocene Working Group.

Vertical distributions of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in a sediment core from Lake Issyk-Kul are powerful tools for reconstructing historical anthropogenic activities over the past 350 years. Four periods were identified according to the variations in these environmental proxies. Period Ⅰ (1670s–1800s) corresponds to a phase of limited anthropogenic activity reflected by the lowest ΣPAH₁₆ concentrations, mainly from biomass combustion and petrogenic processes. Along with pronounced deforestation due to wildfires documented in the pollen record, a similar decrease in PAHs suggests that PAHs were most likely generated by natural sources around Lake Issyk-Kul during this period. Period Ⅱ (1800s–1930s) reflects increasing agricultural activities with fluctuations in various PAH concentrations. Anthropogenic biomass-derived PAH inputs from agricultural activities gradually replaced natural inputs to Lake Issyk-Kul, coinciding with several historical events. However, natural factors still mainly controlled changing lake levels before the 1930s. Period Ⅲ (1930s–1970s) corresponds to rapid development of agricultural activities, inferred by slight increases in ΣPAH₁₆ concentrations dominated by coal-derived PAHs and a considerable increase in ΣOCP₁₈ concentrations. Concentrated agricultural activities around Lake Issyk-Kul significantly influenced environmental changes in grain size and water level in the lake. Period Ⅳ (post-1970 s) corresponds to intensive industrial and urban activities, including a 10-year economic depression (1990s–2000s), characterized by the highest ΣPAH₁₆ concentrations mainly from petroleum combustion followed by a sharp drop after the 1990s as the dissolution of the Soviet Union. Industrialization and urbanization in study area have changed the trophic state of Lake Issyk-Kul, particularly in recent years. Climate change has also induced “lateral remobilization” of contaminants, increasing pollution levels in this mountain lake.

There is currently great interest in increasing the total land area in ‘conservation’ by the year 2030 to stabilize biodiversity and reduce net carbon emissions to combat climate change; however, there remains a lack of clarity on what actually constitutes ‘conservation.’ Land placed into permanent protection from resource utilization falls under the category of land preservation (e.g. National Parks) where land ‘conservation’ can include resource utilization to meet human resource needs. Land ‘preservation’ is an effective means of protecting habitat, but isolation of preserved parcels can limit their effectiveness. The trade-off between land preservation and conservation requires that we consider land use strategies in a global context and as complementary of one another. Most assessments for increasing land conservation are based on vegetative and wildlife inventory, where far fewer assessments are based on soils or belowground accounting. Herein, we present a soil based perspective that could be useful in evaluating the capacity for different land management strategies to meet broader conservation goals, including 30 by 30 and provide a focus on forest management to demonstrate our approach. Our soils-based assessment of different land-use practices suggests that land management practices that cause minimal soil disturbance, generate minimal bare soil, and exhibit a dominance of native species would be effective at achieving meaningful land conservation benefits while continuing to meet human resource needs. Incentivizing conservation oriented land management practices could dramatically accelerate our ability to achieve large scale conservation objectives such as 30 by 30.