Assessment of Biological and Environmental Phenology at a Landscape Level from 30 Years of Fixed-Date Repeat Photography in Northern Sweden

A 30-year series (1978–2007) of photographic records were analysed to determine changes in lake ice cover, local (low elevation) and montane (high elevation) snow cover and phenological stages of mountain birch (Betula pubescens ssp. czerepanovii) at the Abisko Scientific Research Station, Sweden. In most cases, the photographic-derived data showed no significant difference in phenophase score from manually observed field records from the same period, demonstrating the accuracy and potential of using weekly repeat photography as a quicker, cheaper and more adaptable tool to remotely study phenology in both biological and physical systems. Overall, increases in ambient temperatures coupled with decreases in winter ice and snow cover, and earlier occurrence of birch foliage, signal a reduction in the length of winter, a shift towards earlier springs and an increase in the length of available growing season in the Swedish sub-arctic.     

The Anthropocene: From Global Change to Planetary Stewardship

Over the past century, the total material wealth of humanity has been enhanced. However, in the twenty-first century, we face scarcity in critical resources, the degradation of ecosystem services, and the erosion of the planet's capability to absorb our wastes. Equity issues remain stubbornly difficult to solve. This situation is novel in its speed, its global scale and its threat to the resilience of the Earth System. The advent of the Anthropence, the time interval in which human activities now rival global geophysical processes, suggests that we need to fundamentally alter our relationship with the planet we inhabit. Many approaches could be adopted, ranging from geoengineering solutions that purposefully manipulate parts of the Earth System to becoming active stewards of our own life support system. The Anthropocene is a reminder that the Holocene, during which complex human societies have developed, has been a stable, accommodating environment and is the only state of the Earth System that we know for sure can support contemporary society. The need to achieve effective planetary stewardship is urgent. As we go further into the Anthropocene, we risk driving the Earth System onto a trajectory toward more hostile states from which we cannot easily return.     

A novel method to determine buffer strip effectiveness on deep soils

Unfertilized buffer strips (BS) generally improve surface water quality. High buffer strip effectiveness (BSE) has been reported for sloping shallow aquifers, but experimental data for plain landscapes with deeply permeable soils is lacking. We tested a novel method to determine BSE on a 20-m-deep, permeable sandy soil. Discharge from soil to ditch was temporarily collected in an in-stream reservoir to measure its quantity and quality, both for a BS and a reference (REF) treatment. Treatments were replicated once for the first, and three times for the next three leaching seasons. No significant BSE was obtained for nitrogen and phosphorus species in the reservoirs. Additionally, water samples were taken from the upper groundwater below the treatments. The effect of BS for nitrate was much bigger in upper groundwater than in the reservoirs that also collected groundwater from greater depths that were not influenced by the treatments. We conclude that measuring changes in upper groundwater to assess BSE is only valid under specific hydrogeological conditions. We propose an alternative experimental set-up for future research, including extra measurements before installing the BS and REF treatments to deal with spatial and temporal variability. The use of such data as covariates will increase the power of statistical tests by decreasing between-reservoir variability.     

Use of reactive materials to bind phosphorus

Phosphorus (P) losses from agricultural soils have caused surface water quality impairment in many regions of the world, including The Netherlands. Due to the large amounts of P accumulated in Dutch soils, the generic fertilizer and manure policy will not be sufficient to reach in time the surface water quality standards of the European Water Framework Directive. Additional measures must be considered to further reduce P enrichment of surface waters. One option is to immobilize P in soils or manure or to trap P when it moves through the landscape by using reactive materials with a large capacity to retain P. We characterized and tested two byproducts of the process of purification of deep groundwater for drinking water that could be used as reactive materials: iron sludge and iron-coated sand. Both materials contain low amounts of inorganic contaminants, which also have a low (bio)availability, and bound a large amount of P. We could describe sorption of P to the iron sludge in batch experiments well with the kinetic Freundlich equation (Q = × t (m) × C(n)). Kinetics had a large influence on P sorption in batch and column experiments and should be taken into account when iron-containing materials are tested for their capability to immobilize or trap P. A negative aspect of the iron sludge is its low hydraulic conductivity; even when mixed with pure sand to a mixture containing 20% sludge, the conductivity was very low, and only 10% sludge may be needed before application is possible in filters or barriers for removing P from groundwater. Due to its much higher hydraulic conductivity, iron-coated sand has greater potential for use under field conditions. Immobilizing P could be an option for using iron sludge as a reactive material.     

Persistence of the fluoroquinolone antibiotic difloxacin in soil and lacking effects on nitrogen turnover

The environmental risks caused by the use of fluoroquinolone antibiotics in human therapeutics and animal husbandry are associated with their persistence and (bio)accessibility in soil. To assess these aspects, we administered difloxacin to pigs and applied the contaminated manure to soil. We then evaluated the dissipation and sequestration of difloxacin in soil in the absence and presence of plants within a laboratory trial, a mesocosm trial, and a field trial. A sequential extraction yielded antibiotic fractions of differing binding strength. We also assessed the antibiotic's effects on nitrogen turnover in soil (potential nitrification and denitrification). Difloxacin was hardly (bio)accessible and was very persistent under all conditions studied (dissipation half-life in bulk soil, >217 d), rapidly forming nonextractable residues. Although varying environmental conditions did not affect persistence, dissipation was accelerated in soil surrounding plant roots. Effects on nitrogen turnover were limited due to the compound's strong binding and small (bio)accessibility despite its persistence.     

Controls on Coarse Wood Decay in Temperate Tree Species: Birth of the LOGLIFE Experiment

Dead wood provides a huge terrestrial carbon stock and a habitat to wide-ranging organisms during its decay. Our brief review highlights that, in order to understand environmental change impacts on these functions, we need to quantify the contributions of different interacting biotic and abiotic drivers to wood decomposition. LOGLIFE is a new long-term ‘common-garden’ experiment to disentangle the effects of species’ wood traits and site-related environmental drivers on wood decomposition dynamics and its associated diversity of microbial and invertebrate communities. This experiment is firmly rooted in pioneering experiments under the directorship of Terry Callaghan at Abisko Research Station, Sweden. LOGLIFE features two contrasting forest sites in the Netherlands, each hosting a similar set of coarse logs and branches of 10 tree species. LOGLIFE welcomes other researchers to test further questions concerning coarse wood decay that will also help to optimise forest management in view of carbon sequestration and biodiversity conservation.     

Differentiation of nitrous oxide emission factors for agricultural soils

Nitrous oxide (N₂O) direct soil emissions from agriculture are often estimated using the default IPCC emission factor (EF) of 1%. However, a large variation in EFs exists due to differences in environment, crops and management. We developed an approach to determine N₂O EFs that depend on N-input sources and environmental factors. The starting point of the method was a monitoring study in which an EF of 1% was found. The conditions of this experiment were set as the reference from which the effects of 16 sources of N input, three soil types, two land-use types and annual precipitation on the N₂O EF were estimated. The derived EF inference scheme performed on average better than the default IPCC EF. The use of differentiated EFs, including different regional conditions, allows accounting for the effects of more mitigation measures and offers European countries a possibility to use a Tier 2 approach.     

Multi-decadal changes in tundra environments and ecosystems: synthesis of the International Polar Year-Back to the Future project (IPY-BTF)

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in subarctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies.     

Distribution, speciation and availability of antimony (Sb) in soils and terrestrial plants from an active Sb mining area

Here, we present one of the first studies investigating the mobility, solubility and the speciation-dependent in-situ bioaccumulation of antimony (Sb) in an active Sb mining area (Xikuangshan, China). Total Sb concentrations in soils are high (527-11,798 mg kg⁻¹), and all soils, including those taken from a paddy field and a vegetable garden, show a high bioavailable Sb fraction (6.3-748 mg kg⁻¹), dominated by Sb(V). Elevated concentrations in native plant species (109-4029 mg kg⁻¹) underpin this. Both chemical equilibrium studies and XANES data suggest the presence of Ca[Sb(OH)₆]₂, controlling Sb solubility. A very close relationship was found between the citric acid extractable Sb in plants and water or sulfate extractable Sb in soil, indicating that citric acid extractable Sb content in plants may be a better predictor for bioavailable Sb in soil than total acid digestible Sb plant content.     

Survey of patterns,levels, and trends of perfluorinated compounds in aquatic organisms and bird eggs from representative German ecosystems

Purpose  

Samples from the German Environmental Specimen Bank (ESB) covering particularly the years 1994–1996, 2000–2002, and 2006–2009 were analyzed for perfluorinated compounds (PFC; mainly C4–C13 carboxylic and sulfonic acids) to gain an overview on current PFC levels and patterns in marine, limnetic, and terrestrial biota; to assess their concentrations in different trophic levels; and to investigate whether risk management measures for PFC are successful.