Anthropocene最新文献

The current paper is a space-time analysis of agricultural land transitions in the Romanian Plain, which has been significantly impacted during the past century by the fundamental structural and functional transformations. Five maps, derived from historical cartographic materials and the recent CORINE Land Cover databases, were spatially analysed using a transition matrix procedure. The aim was to identify and measure the magnitude of the main land use/cover change flows related to agricultural lands. Furthermore, several underlying factors of the spatial and functional transformations have been discussed so as to understand the evolution of the historical agricultural lands over time. The results show that the most significant changes occurred between 1912 and 1970, when 38 % of the Romanian Plain’s surface underwent transformations, with notable regional differences. The analysis of the change flows in relation to the underlying factors was instrumental in explaining the land processes, an approach that can be used to understand future landscape transformations.

Our study contributes to the ongoing dialogue on the impact of climate and habitat changes on migratory bird species, particularly focusing on how these effects vary based on species’ habitat preferences. We used citizen science data for 22 African-Eurasian migratory bird species and categorized them into five groups based on habitat preferences, following the classification methodology of Atkinson et al. (2014). Using ensemble species distribution modeling (SDM), we projected changes in potentially suitable habitats across Africa from 2040 to 2100 under contrasting climate and land use scenarios. Our results indicate a differential impact of climate and land use changes on habitat suitability, with species preferring habitats with shrubs and trees being the most vulnerable. Conversely, other group species, such as open country-grassland and farmland birds could experience a significant increase in suitable habitat. We anticipate a profound change in habitat suitability, with the western part of South Africa becoming unsuitable for most species, while an increase in suitable habitat is expected in the Sahel. Bioclimatic rather than land use variables emerged as the primary drivers of these changes. The extent of change in habitat suitability will be strongly influenced by the Shared Socio-economic Pathways followed by human societies.

The spread of invasive alien species is identified as one of the most important threats to freshwater ecosystems as they can modify their trophic structure, biomass and flows. The lower Saône River is one of the most biologically productive waterways in France. It has been in strong interaction with a wide range of human activities such as fisheries for at least three millennia. To implement an ecosystem based approach, an Ecopath static trophic model was used for the first time in this river to quantify the role of three invasive or expanding species over two contrasted periods (1988–1993 and 1994–2005). The parameters used in the model integrate on the one hand catch data from fishers (professional, amateur fishing gear users, and anglers), and on the other hand the available literature data on species biomass, diet and the expert assessments of scientists and managers. Species such as the filtering Asian clam Corbicula fluminea may explain the triggering of the ecosystem shift towards a functioning where summer phytoplankton blooms are rarer. In the high trophic levels, the great cormorant Phalacrocorax carbo appears to have low trophic impact while the development of a large population of European catfish Silurus glanis has a strong effect, maintaining important trophic flows in the ecosystem in substitution for the decrease in angling landings.

As Arctic sea ice has rapidly declined, the navigational potential of the Arctic routes has greatly increased. Based on sea ice output from the First Institute Of Oceanography-Earth System Model version 2.1 (FIO-ESM v2.1) and the Arctic Transport Accessibility Model, this study investigates the future navigability of the Arctic routes for open-water ships (OW) without icebreaking capabilities and ships with different icebreaking capabilities, namely Polar Class 7 (PC7), Polar Class 6 (PC6), and Polar Class 3 (PC3). The results show that the simulations of FIO-ESM v2.1 adequately reproduce the changes in the navigability of the four types of ships in Arctic shipping routes over the past 40 years. The navigable area for the four ship types is projected to continue to expand in the future. Under the high emission scenario (Shared Socioeconomic Pathways 5–8.5, SSP585), the four ship types are projected to achieve full Arctic navigability in summer (September) by the end of the 21st century, and PC6 and PC3 ships are projected to achieve full Arctic navigability in winter (March). Under the high emission scenario, year-round navigability in the Northwest Passage is projected for PC3 and PC6 ships, and in the Northeast Passage is projected for all four types of ships. The impact of emission scenario on the navigability of the Arctic shipping routes varies with different ship types: the largest impact is for OW ships, followed by PC6 and PC7 ships, and the smallest impact is for PC3 ships. The impact of scenario is also larger in winter than in summer.