Evaluating the use of in-situ turbidity measurements to quantify fluvial sediment and phosphorus concentrations and fluxes in agricultural streams.

Accurate quantification of suspended sediments (SS) and particulate phosphorus (PP) concentrations and loads is complex due to episodic delivery associated with storms and management activities often missed by infrequent sampling. Surrogate measurements such as turbidity can improve understanding of pollutant behaviour, providing calibrations can be made cost-effectively and with quantified uncertainties. Here, we compared fortnightly and storm intensive water quality sampling with semi-continuous turbidity monitoring calibrated against spot samples as three potential methods for determining SS and PP concentrations and loads in an agricultural catchment over two-years.

Evaluation of spot and passive sampling for monitoring, flux estimation and risk assessment of pesticides within the constraints of a typical regulatory monitoring scheme.

In many agricultural catchments of Europe and North America, pesticides occur at generally low concentrations with significant temporal variation. This poses several challenges for both monitoring and understanding ecological risks/impacts of these chemicals. This study aimed to compare the performance of passive and spot sampling strategies given the constraints of typical regulatory monitoring.

Characterizing Pb mobilization from upland soils to streams using (206)Pb/(207)Pb isotopic ratios.

Anthropogenically deposited lead (Pb) binds efficiently to soil organic matter, which can be mobilized through hydrologically mediated mechanisms, with implications for ecological and potable quality of receiving waters. Lead isotopic ((206)Pb/(207)Pb) ratios change down peat profiles as a consequence of long-term temporal variation in depositional sources, each with distinctive isotopic signatures. This study characterizes differential Pb transport mechanisms from deposition to streams at two small catchments with contrasting soil types in upland Wales, U.

Is the composition of dissolved organic carbon changing in upland acidic streams?

The quantity and composition of dissolved organic carbon (DOC) exported from upland soils to surface waters is a key link in the global carbon cycle and economically important for treating potable waters. The relationship between ultraviolet (UV) absorbance and DOC concentrations can be used to infer changes in the proportion of hydrophobic (aromatic, recalcitrant) carbon and hence biodegradability of DOC. This study describes a significant change in the relationship between UV absorbance and DOC over 22 years at two upland moorland catchments in Scotland, UK.

Carbon losses from soil and its consequences for land-use management.

This paper reviews our current knowledge and understanding of carbon processes in the terrestrial ecosystem with a view to reducing soil carbon losses by optimising land-use and land management. Processes that influence the fate of carbon (in both terms of quantity and quality) are important in determining soil fertility, quality and health as well as consequences for future environmental change scenarios. We need to understand the processes that determine soil carbon losses and the fate of the carbon once lost from the soil in order to provide sustainable solutions for mitigating these carbon losses as part of land management "best practice" and balancing national carbon budgets.

Identification of environmental factors limiting plant uptake of metaldehyde seed treatments under field conditions.

Slugs are serious pests of oilseed rape (canola) and wheat with most damage occurring just after sowing and seedling emergence. As an alternative to the use of bait pellets, molluscicidal seed treatments have been shown to protect seeds and seedlings from slug damage in laboratory and semi-field experiments. However, protection offered to plants in field trials was diminished and shortlived in comparison with laboratory experiments.

An ecotoxicity assessment of contaminated forest soils from the Kola Peninsula.

Point source copper and nickel contamination emanating from smelters of the Kola Peninsula, NW Russia, has been observed since the mid-1960s. Previous studies have concentrated on the spatial distribution of heavy metals and their effects on forest ecology and indigenous mammals and birds. Soil is perceived as the major repository for the metal pollutants but there is a need to link the soil concentration of pollutants on the Kola Peninsula with biological parameters.