Sorption, desorption and mineralisation of the herbicides glyphosate and MCPA in samples from two Danish soil and subsurface profiles

The vertical distribution of the sorption, desorption and mineralisation of glyphosate and MCPA was examined in samples from two contrasting soil and subsurface profiles, obtained from a sandy agricultural site and a non-agricultural clay rich site. The highest mineralisation of [14C-methylen]glyphosate, with 9.3-14.7% degraded to 14CO2 within 3 months was found in the deepest sample from the clay site. In the deeper parts of the sandy profile high sorption and low desorption of glyphosate coincided with no or minor mineralisation indicating a limited glyphosate bioavailability. MCPA was readily mineralised except in the deepest samples from both sites. The highest MCPA mineralisation was detected just below the surface layers with 72% or 44% degraded to 14CO2 at the sandy or the clay sites, respectively. MCPA sorped to a minor extent in all samples and no indications of sorption-controlled mineralisation was revealed. None of the herbicides were mineralised under anoxic conditions.     

Deltas,freshwater discharge,and waves along the Young Sound,NE Greenland

A wide range of delta morphologies occurs along the fringes of the Young Sound in Northeast Greenland due to spatial heterogeneity of delta regimes. In general, the delta regime is related to catchment and basin characteristics (geology, topography, drainage pattern, sediment availability, and bathymetry), fluvial discharges and associated sediment load, and processes by waves and currents. Main factors steering the Arctic fluvial discharges into the Young Sound are the snow and ice melt and precipitation in the catchment, and extreme events like glacier lake outburst floods (GLOFs). Waves are subordinate and only rework fringes of the delta plain forming sandy bars if the exposure and fetch are optimal. Spatial gradients and variability in driving forces (snow and precipitation) and catchment characteristics (amount of glacier coverage, sediment characteristics) as well as the strong and local influence of GLOFs in a specific catchment impede a simple upscaling of sediment fluxes from individual catchments toward a total sediment flux into the Young Sound.     

Effects of wildfire on runoff generating processes in northern Mongolia

Regional Environmental Change - Seasonal runoff generation in a headwater (~100 km2) of the mountainous Sugnugr Basin, situated within the discontinuous permafrost zone of...     

Response of the grasshopper <Emphasis Type="Italic">Myrmeleotettix maculatus</Emphasis> (Orthoptera: Acrididae) to invasion by the exotic moss <Emphasis Type="Italic">Campylopus introflexus</Emphasis> in acidic coastal dunes

In Europe, acidic coastal dunes are threatened by the invasion of the exotic moss Campylopus introflexus. While the effect of the moss encroachment on the vegetation is well analysed, knowledge of possible impact on arthropods is lacking. Thus, an experiment was conducted in acidic coastal dunes on the Baltic island of Hiddensee, Germany. Myrmeleotettix maculatus, a common Orthoptera species of open and dry habitats, was sampled by pitfall trapping in eleven plots invaded by C. introflexus and in eleven native, non-invaded plots rich in lichens. Overall, 826 individuals of M. maculatus were captured (266 nymphs, 560 adults). Mean number of adults was significantly higher in native plots. This maybe explained by a higher proportion of grasses (food supply), a higher availability of shelter (from predators, weather), or more favourable microclimate conditions in native plots and a higher mortality rate in invaded plots. However, mean number of both young and old nymphs did not differ significantly between both types. This could imply that invaded areas at least serve as favourable oviposition sites and larval habitats. The observed negative effect of the moss invasion on M. maculatus remains to be studied on other arthropods.     

Carbon capture and storage deployment rates: needs and feasibility

Carbon capture and storage (CCS) may become a key technology to limit human-induced global warming, but many uncertainties prevail, including the necessary technological development, costs, legal ramifications, and siting. As such, an important question is the scale of carbon dioxide abatement we require from CCS to meet future climate targets, and whether they appear reasonable. For a number of energy technology and efficiency improvement scenarios, we use a simple climate model to assess the necessary contribution from CCS to ‘fill the gap’ between scenarios’ carbon dioxide emissions levels and the levels needed to meet alternative climate targets. The need for CCS depends on early or delayed action to curb emissions and the characteristics of the assumed energy scenario. To meet a 2.5°C target a large contribution and fast deployment rates for CCS are required. The required deployment rates are much faster than those seen in the deployment of renewable energy technologies as well as nuclear power the last decades, and may not be feasible. This indicates that more contributions are needed from other low-carbon energy technologies and improved energy efficiency, or substitution of coal for gas in the first half of the century. In addition the limited availability of coal and gas by end of the century and resulting limited scope for CCS implies that meeting the 2.5°C target would require significant contributions from one or more of the following options: CCS linked to oil use, biomass energy based CCS (BECCS), and CCS linked to industrial processes.     

瑞典沿岸水域濒临消失的大叶藻(Zostera Marina,L.)

在瑞典斯卡格拉克海峡沿岸,大叶藻(Zostera marina)是一种生长在浅水软海底上的优势显花植物.大叶藻场是许多甲壳动物和鱼类,不管是洄游种或是稳定种的重要群落生境.在20世纪80年代期间,作为海岸带管理的基础,对瑞典西海岸有大叶藻生长的沿岸浅水区的资源进行了调查.在这次研究中我们再次考察了斯卡格拉克海峡200km沿岸的5个沿海地区中的2000hm2大叶藻场.资源调查的方法(水下测量镜)与80年代的一样,但通过使用全球定位系统(GPS)增加了绘图的精确度.这次研究的结果表明,在10～15年的时间里,大叶藻的区域延伸面积减少了58%,且地区变化很大.大叶藻的减少主要限于大叶藻场的浅水部分.本文探讨了原因和生态后果.