Anthropocene Science最新文献

Over the past two decades, the term ‘Anthropocene’ has ignited widespread academic and public interest. Since 2009, the term has been considered on stratigraphic grounds by the Anthropocene Working Group (AWG). The AWG has been championing a chronostratigraphic definition of the Anthropocene by advancing a proposal to formally recognize the unit as a post-Holocene epoch/series on the Geologic Time Scale and International Chronostratigraphic Chart. The proposal (i.e., the Anthropocene Hypothesis) has ignited debates among human, social, and natural scientists alike. One line of critique against the proposal concerns the chronostratigraphic suitability of the term ‘Anthropocene.’ This type of criticism holds that the term is inconsistent with the standard naming practices of the chronostratigraphic series; that it is inconsistent with other epochs of the Cenozoic era; that its etymology is faulty in several respects; and/or that its informal nature should be emphasized stylistically (e.g., with quotation marks or by writing the term with a lower case initial). The present contribution reviews this criticism and discusses it in the context of (chrono)stratigraphic classification and nomenclature to assess whether ‘Anthropocene’ is a suitable chronostratigraphic term. To do so, the analysis comments on and discusses guidelines, recommendations, and suggestions drafted by the International Stratigraphic Guide, which represents an international framework of reference for stratigraphic classification and nomenclature. Based on the underlying philosophy and recommendation of the Guide, there seem to be reasons to consider the ‘Anthropocene’ a suitable term in the context of chronostratigraphic nomenclature.

Ecosystems across the globe, be it terrestrial, marine or transitional in nature are under pressure due to multiple drivers of changes including anthropogenic. Restoring the vitality of degraded systems is crucial for fulfilling the UN-Sustainable Development Goals in a timely manner. It is also essential for attaining the targets of the ambitious UN-Decade on Ecosystem Restoration (UN-DER). Riparian ecosystems are one among systems undergoing drastic changes due to anthropogenic pressures. They are a heterogeneous and biodiversity rich system due to its transitional zone occurrence between terrestrial and aquatic realms, including riverbanks, floodplains and wetlands, and provide ecosystem services on both local as well as global levels. Here we review the prospects of restoring riparian ecosystems in the context of the UN-DER. Even though the momentum for restoring riparian habitats began in the 1970s, our study reveals that intensive restoration programmes across the world are sparse and more efforts are needed to restore degraded riparian systems for regaining ecosystem health and complexity. Furthermore, an in-depth analysis of various strategies deployed for restoring riparian ecosystems around the world reveals that a participatory approach and site-specific strategies are needed for better output. Also, active along with passive restoration is required for better recovery. We suggest a three-stage strategy—preassessment, restoration activities and post monitoring and maintenance. It includes the involvement of stakeholders across all stages, which also supports their livelihoods. The restoration of riparian ecosystems supports the targets of UN-DER while providing both global as well as local ecosystem services.

The Caribbean region remains susceptible to an increasing frequency of natural disasters, rising international debt, out-migration, rapid urbanization, and high imports to meet basic needs. Food and nutrition insecurity persists in these small island states, with around 67.5% of the population living in moderate or severe food insecurity. Policy adjustments required to address the targets subsumed by the second sustainable development goal (SDG2 or Zero Hunger) are still at an infant stage. This research offers rigorous and up-to-date analyzes of the current status of Caribbean food policies and practices through a scoping review and expert interviews to answer the question, “What constraints and enablers impact the ability of small island states to achieve the Zero Hunger goal?”. A scoping review is performed following the relevant population, concept, and context (PCC) methodology by the Joanna Briggs Institute (JBI). Five major challenges and barriers are identified through the scoping review: (i) island geography, (ii) governance deficiencies, and (iii) institutional constraints, compounded by (iv) collaboration barriers, and (v) externally imposed impediments (including environmental and financial shocks). To address these challenges, synergistic linkages and restrictive connections have been recognized for SDG2 localization. It was concluded that three dimensions of food security (utilization, agency, and sustainability) are mainly overlooked, necessitating special attention and action. By identifying bridging institutions and engaging various actors in supporting shared rulemaking, power, conflict management, and knowledge-sharing among local, national, and regional policy actors, a polycentric governance system is recommended as a suitable mechanism to help islands move towards food security.

In African drylands, perennial grasses preferred by grazing livestock are disappearing at an alarming rate. This has led to recurrent livestock feed shortages threatening pastoralist’s livelihoods. Combining native grass reseeding and rainwater harvesting offers a viable and innovative solution to reverse this trend. However, studies to determine how biomass yields are affected by soil moisture availability attributed to in situ rainwater harvesting in African drylands are limited. We investigated how biomass yields of three grasses native to Africa, i.e., Enteropogon macrostachyus (Bush rye grass), Cenchrus ciliaris (African foxtail grass), and Eragrostis superba (Maasai love grass), are affected by soil moisture content in a typical semi-arid landscape. Rainwater harvesting structures included trenches, micro-catchments and furrows. Additionally, rain runoff was diverted from an adjacent road used as a catchment area. Soil moisture was measured between November 2018 and August 2019 using PlantCare Mini-Logger sensors installed at 40 and 50 cm depths and 0, 1, 5 and 15 m away from the trench. Quadrat method was used to determine biomass yields in August 2019. Peaks in soil moisture were observed after rainfall events. Soil moisture content gradually decreased after the rainy season, but was higher closer to the trench. This is attributed to the prolonged rainwater retention in the trenches. Biomass yields were in the order Eragrostis superba > Cenchrus ciliaris > Enteropogon macrostachyus. Biomass production was higher near the trenches for all the studied species. Sensitivity to soil moisture demonstrated by the magnitude to yield reduction during the growing season was in the order Eragrostis superba > Cenchrus ciliaris > Enteropogon macrostachyus. These results suggest that Eragrostis superba is more sensitive to drought stress than Enteropogon macrostachyus that is adapted to a wide range of soil moisture conditions. We demonstrated that in situ rainwater harvesting structures enhanced soil moisture availability and displayed great potential for revegetating denuded natural rangelands in semi-arid African landscapes. Thus, combining rainwater harvesting and reseeding techniques can produce measurable improvements in pastoral livelihoods and should be incorporated in dryland development policies in the region. Ultimately, incorporating such innovative strategies can strengthen the effectiveness of ecological restoration in African drylands to meet the objectives of the UN Decade on Ecosystem Restoration and achieving the UN Sustainable Development Goals.

Graphical abstract

Total ocean carbon exceeds 40,000 GT either dissolved in the water column or buried in ocean sediments, and the ocean continues to sequester carbon from the atmosphere. Selective removal of predatory fish through extractive fishing alters the community structure of the ocean. This altered community results in increased biomass of more productive, low trophic level fish, higher overall fish respiration rates and lower carbon sequestration rates from fish, despite possible decreases in total fish biomass. High-pressure fishing on high trophic level fish, a globally occurring phenomenon, may result in as much as a 19% increase in respiration from fish communities overall. This increase in respiration will reduce sequestration rates and could prove highly significant in global carbon budgets. Preliminary estimates suggest a loss of sequestration equating to around 90Mt C.year⁻¹ (~ 10% of total ocean sequestration or ~ 1% of anthropogenic fossil fuel emissions per year). Ultimately, to reduce these carbon emissions, fishing needs to be carbon optimised, alongside other fisheries management outcomes, which may mean that fewer higher trophic level fish are removed. This study highlights the potential magnitude of fishing on ocean carbon dynamics and presents the key uncertainties (including understanding the effects of fishing on zoo- and phytoplankton communities) we need to urgently research to accurately quantify the effects and model future fishing practices.

Graphical Abstract

Biodiversity, soil, air, and water are the vital life-supporting systems of this planet Earth. However, the deliberate and accidental introduction of invasive alien plants (IAPs) in the Anthropocene majorly due to the global international trade perturbed the homeostasis of our biosphere. IAPs are considered as one of the major drivers of biodiversity loss and ecosystem degradation. The pervasive threats of IAPs to environmental sustainability and biosecurity are further exacerbated under the COVID-19 pandemic. The environmental disturbances resulting from IAPs can be attributed to several mechanisms/hypothesis (e.g., novel weapon (NW), enemy release (ER), and evolution of increased competitive ability (EICA), efficient reproductive attributes, and phenotypic plasticity, etc.) deployed by IAPs. Nevertheless, the interrelationship of IAPs with environmental degradation and restoration remain elusive especially in terms of ecological sustainability. Moreover, there is a dearth of studies which empirically assess the synergies of IAPs spread with other anthropogenic disturbances such as climate and land-use change. In this context, the present review is aimed to depict the impacts of IAPs on environment and also to assess their role as drivers of ecosystem degradation. The restoration prospects targeted to revitalize the associated abiotic (soil and water) and biotic environment (biodiversity) are also discussed in detail. Furthermore, the effects of IAPs on socio-economy, livelihood, and plant-soil microbe interactions are emphasized. On the other hand, the ecosystem services of IAPs such as associated bioresource co-benefits (e.g., bioenergy, phytoremediation, biopolymers, and ethnomedicines) can also be vital in sustainable management prospects. Nevertheless, IAPs-ecological restoration interrelationship needs long-term pragmatic evaluation in terms of ecological economics and ecosystem resilience. The incorporation of ‘hybrid technologies’, integrating modern scientific information (e.g., ‘biorefinery’: conversion of IAPs feedstock to produce bioenergy/biopolymers) with traditional ecological knowledge (TEK) can safeguard the environmental sustainability in the Anthropocene. Importantly, the management of IAPs in concert with circular economy principles can remarkably help achieving the target of UN Sustainable Development Goals and UN-Decade on Ecosystem Restoration.