13 research outputs found
Assessing the effects of forest-to-bog restoration in the hyporheic zone at known Atlantic salmon (Salmo salar) spawning sites
In the UK, large areas of blanket bogs were afforested with non-native conifers between the 1960s and the 1980s. Following recognition of the detrimental effects of such practice on biodiversity and carbon stocks, large-scale restoration trials started in the late 1990s and are further supported by recent changes in policy. The removal of forestry from peatlands is likely to be a widespread land-use change in the coming decades and could affect adjacent freshwater systems. This study aimed to investigate whether forestry removal with drain blocking affected nearby spawning sites used by Atlantic salmon (Salmo salar). We analysed the chemistry of hyporheic (beneath and just above the streambed) and surface water, and measured sediment deposition upstream of, within and downstream of a forestry block in the north of Scotland, during and after restoration management operations. We found no immediate effect of management except on potassium and zinc concentrations, which increased after restoration. The general lack of effect is attributed to catchment properties, including the small proportion of catchment (< 5 %) affected by management, and to dilution effects related to heavy precipitation during the intervention phase. We suggest that longer-term monitoring should be implemented as the sizes of areas undergoing restoration management increases
Net ecosystem exchange from two formerly afforested peatlands undergoing restoration in the Flow Country of northern Scotland
Northern peatlands are important in the global carbon (C) cycle as they help regulate local, regional and global C budgets through high atmospheric carbon dioxide (CO2) uptake and low net CO2 losses to the atmosphere. Since the 1900s (but particularly the 1950s) land-use change has affected many peatland areas, driven in part by attempts to improve their commercial value. During this period, many peatlands in the UK were drained and planted with non-native conifer plantations. Efforts are now underway to restore the ecosystem functioning of these peatlands to those characteristic of pristine peatlands, in particular C flux dynamics. A lack of ecosystem level measurements means that the timescales of restoration and the degree to which they are successful remains poorly determined. In this research, we present the first year-round study of net ecosystem CO2 exchange (NEE) from peatlands undergoing restoration from forestry. Annual NEE was measured from two sites between March 2014 and June 2015, where restoration commenced 10 years and 16 years prior to the start of this study, and the results were then compared to existing measurements from a near-pristine peatland. Existing NEE data (expressed as CO2-C) from the near-pristine peatland indicated a C sink of 114 g m-2 yr-1, and our estimates suggest that the older restored site (16 years) was also a NEE sink (71 g m-2 yr-1). In contrast, the younger site (10 years) was a NEE source (80 g m-2 yr-1). We critically assess the confidence of these measurements and also present these data in relation to other northern hemisphere peatlands to better understand the timeframe in which a peatland site can turn from a C source to a C sink after restoration
Orbital Observations of Dust Lofted by Daytime Convective Turbulence
Over the past several decades, orbital observations of lofted dust have revealed the importance of mineral aerosols as a climate forcing mechanism on both Earth and Mars. Increasingly detailed and diverse data sets have provided an ever-improving understanding of dust sources, transport pathways, and sinks on both planets, but the role of dust in modulating atmospheric processes is complex and not always well understood. We present a review of orbital observations of entrained dust on Earth and Mars, particularly that produced by the dust-laden structures produced by daytime convective turbulence called “dust devils”. On Earth, dust devils are thought to contribute only a small fraction of the atmospheric dust budget; accordingly, there are not yet any published accounts of their occurrence from orbit. In contrast, dust devils on Mars are thought to account for several tens of percent of the planet’s atmospheric dust budget; the literature regarding martian dust devils is quite rich. Because terrestrial dust devils may temporarily contribute significantly to local dust loading and lowered air quality, we suggest that martian dust devil studies may inform future studies of convectively-lofted dust on Earth
The dynamic morphology of the wood anemone, Anemone nemorosa L. in an ancient coppice wood
SIGLEAvailable from British Library Document Supply Centre- DSC:DX177296 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
A community and population perspective of the possible role of grazing in determining the ground flora of ancient woodlands
A sample survey of the distribution of the string sedge Carex chordorrhiza on the Insh Marshes, Badenoch & Strathspey
SIGLEAvailable from British Library Document Supply Centre- DSC:8313.903(7) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Experimental investigation of the response of the string sedge Carex chordorrhiza to changes in water depth in summer
SIGLEGBUnited Kingdo
CLARA conceptual design report
This report describes the conceptual design of a proposed free electron laser test facility called CLARA that will be a major upgrade to the existing VELA accelerator test facility at Daresbury Laboratory in the UK. CLARA will be able to test a number of new free electron laser schemes that have been proposed but require a proof of principle experiment to confirm that they perform as predicted. The primary focus of CLARA will be on ultra short photon pulse generation which will take free electron lasers into a whole new regime, enabling a new area of photon science to emerge
Composição de gastrópodes terrestres em duas áreas do Centro de Estudos Ambientais e Desenvolvimento Sustentado (CEADS), Vila Dois Rios, Ilha Grande, Rio de Janeiro, Brasil: um estudo-piloto Composition of terrestrial gastropods in two areas of the Center to Environmental Studies and Sustainable Development (CEADS), Vila Dois Rios, Ilha Grande, Angra dos Reis, Rio de Janeiro, Brazil: a preliminary study
<abstract language="eng">A survey of the Ilha Grande land snails was carried out in order to compare the diversity and similarity among two regions of secondary Atlantic Rain Forest. The diversity was estimated using the richness and the equitatibility; the alpha diversity was calculated using the Simpson index (γ). The Sörensen and Jaccard indexes were used to calculate the similarity. A quantitative survey of two 600 m² area, one in each studied region, recorded 336 individuals snails distributed in 23 species and 13 families. The region with more altered secondary forest showed higher richness (17) and diversity (γ = 3,6) than the region more preserved (richness = 14; γ = 2,78), but, the same equitatibility (0,20). The similarity was medium by Jaccard index (IJ = 0,52) and low by Sorensen index (IS = 0,15). These differences could be explained by the dominance of Subulinidae (four species and 117 specimens) in the more altered region and Systrophiidae in the more preserved (four species and 97 specimens)