Co-located ecological data for exploring top- and subsoil carbon dynamics across grassland-woodland contrasts

Soil organic carbon (SOC) is a soil health indicator and understanding dynamics changing SOC stocks will help achieving net zero goals. Here we present four datasets featuring 11,750 data points covering co-located aboveground and below-ground metrics for exploring ecosystem SOC dynamics. Five sites across England with an established land use contrast, grassland and woodland next to each other, were rigorously sampled for aboveground (n = 109), surface (n = 33 soil water release curves), topsoil, and subsoil metrics. Commonly measured soil metrics were analysed in five soil increments for 0-1 metre (n = 4550). Less commonly measured soil metrics which were assumed to change across the soil profile were measured on a subset of samples only (n = 3762). Additionally, we developed a simple method for soil organic matter fractionation using density fractionation which is part of the less common metrics. Finally, soil metrics which may impact SOC dynamics, but with less confidence as to their importance across the soil profile were only measured on topsoil (~5-15 cm = mineral soil) and subsoil (below 50 cm) samples (n = 2567).

Climate and atmospheric deposition effects on forest water-use efficiency and nitrogen availability across Britain

Rising atmospheric CO2 (ca) has been shown to increase forest carbon uptake. Yet, whether the ca-fertilization effect on forests is modulated by changes in sulphur (Sdep) and nitrogen (Ndep) deposition and how Ndep affects ecosystem N availability remains unclear. We explored spatial and temporal (over 30-years) changes in tree-ring δ13C-derived intrinsic water-use efficiency (iWUE), δ18O and δ15N for four species in twelve forests across climate and atmospheric deposition gradients in Britain. The increase in iWUE was not uniform across sites and species-specific underlying physiological mechanisms reflected the interactions between climate and atmospheric drivers (oak and Scots pine), but also an age effect (Sitka spruce). Most species showed no significant trends for tree-ring δ15N, suggesting no changes in N availability. Increase in iWUE was mostly associated with increase in temperature and decrease in moisture conditions across the South-North gradient and over 30-years. However, when excluding Sitka spruce (to account for age or stand development effects), variations in iWUE were significantly associated with changes in ca and Sdep. Our data suggest that overall climate had the prevailing effect on changes in iWUE across the investigated sites. Whereas, detection of Ndep, Sdep and ca signals was partially confounded by structural changes during stand development.

Meta-analysis of multidecadal biodiversity trends in Europe

Local biodiversity trends over time are likely to be decoupled from global trends, as local processes may compensate or counteract global change. We analyze 161 long-term biological time series (15-91 years) collected across Europe, using a comprehensive dataset comprising ~6,200 marine, freshwater and terrestrial taxa. We test whether (i) local long-term biodiversity trends are consistent among biogeoregions, realms and taxonomic groups, and (ii) changes in biodiversity correlate with regional climate and local conditions. Our results reveal that local trends of abundance, richness and diversity differ among biogeoregions, realms and taxonomic groups, demonstrating that biodiversity changes at local scale are often complex and cannot be easily generalized. However, we find increases in richness and abundance with increasing temperature and naturalness as well as a clear spatial pattern in changes in community composition (i.e. temporal taxonomic turnover) in most biogeoregions of Northern and Eastern Europe.

Environment and host as large-scale controls of ectomycorrhizal fungi

Explaining the large-scale diversity of soil organisms that drive biogeochemical processes-and their responses to environmental change-is critical. However, identifying consistent drivers of belowground diversity and abundance for some soil organisms at large spatial scales remains problematic. Here we investigate a major guild, the ectomycorrhizal fungi, across European forests at a spatial scale and resolution that is-to our knowledge-unprecedented, to explore key biotic and abiotic predictors of ectomycorrhizal diversity and to identify dominant responses and thresholds for change across complex environmental gradients. We show the effect of 38 host, environment, climate and geographical variables on ectomycorrhizal diversity, and define thresholds of community change for key variables. We quantify host specificity and reveal plasticity in functional traits involved in soil foraging across gradients. We conclude that environmental and host factors explain most of the variation in ectomycorrhizal diversity, that the environmental thresholds used as major ecosystem assessment tools need adjustment and that the importance of belowground specificity and plasticity has previously been underappreciated.

Tree mineral nutrition is deteriorating in Europe

The response of forest ecosystems to increased atmospheric CO2 is constrained by nutrient availability. It is thus crucial to account for nutrient limitation when studying the forest response to climate change. The objectives of this study were to describe the nutritional status of the main European tree species, to identify growth-limiting nutrients and to assess changes in tree nutrition during the past two decades. We analysed the foliar nutrition data collected during 1992-2009 on the intensive forest monitoring plots of the ICP Forests programme. Of the 22 significant temporal trends that were observed in foliar nutrient concentrations, 20 were decreasing and two were increasing. Some of these trends were alarming, among which the foliar P concentration in F. sylvatica, Q. Petraea and P. sylvestris that significantly deteriorated during 1992-2009. In Q. Petraea and P. sylvestris, the decrease in foliar P concentration was more pronounced on plots with low foliar P status, meaning that trees with latent P deficiency could become deficient in the near future. Increased tree productivity, possibly resulting from high N deposition and from the global increase in atmospheric CO2, has led to higher nutrient demand by trees. As the soil nutrient supply was not always sufficient to meet the demands of faster growing trees, this could partly explain the deterioration of tree mineral nutrition. The results suggest that when evaluating forest carbon storage capacity and when planning to reduce CO2 emissions by increasing use of wood biomass for bioenergy, it is crucial that nutrient limitations for forest growth are considered.

Atmospheric deposition of phosphorus to land and freshwater

We compiled published and newly-obtained data on the directly-measured atmospheric deposition of total phosphorus (TP), filtered total phosphorus (FTP), and inorganic phosphorus (PO4-P) to open land, lakes, and marine coasts. The resulting global data base includes data for c. 250 sites, covering the period 1954 to 2012. Most (82%) of the measurement locations are in Europe and North America, with 44 in Africa, Asia, Oceania, and South-Central America. The deposition rates are log-normally distributed, and for the whole data set the geometric mean deposition rates are 0.027, 0.019 and 0.14 g m(-2) a(-1) for TP, FTP and PO4-P respectively. At smaller scales there is little systematic spatial variation, except for high deposition rates at some sites in Germany, likely due to local agricultural sources. In cases for which PO4-P was determined as well as one of the other forms of P, strong parallels between logarithmic values were found. Based on the directly-measured deposition rates to land, and published estimates of P deposition to the oceans, we estimate a total annual transfer of P to and from the atmosphere of 3.7 Tg. However, much of the phosphorus in larger particles (principally primary biological aerosol particles) is probably redeposited near to its origin, so that long-range transport, important for tropical forests, large areas of peatland and the oceans, mainly involves fine dust from deserts and soils, as described by the simulations of Mahowald et al. (Global Biogeochemical Cycles 22, GB4026, 2008). We suggest that local release to the atmosphere and subsequent deposition bring about a pseudo-diffusive redistribution of P in the landscape, with P-poor ecosystems, for example ombrotrophic peatlands and oligotrophic lakes, gaining at the expense of P-rich ones. Simple calculations suggest that atmospheric transport could bring about significant local redistribution of P among terrestrial ecosystems. Although most atmospherically transported P is natural in origin, local transfers from fertilised farmland to P-poor ecosystems may be significant, and this requires further research.

Chemical fluxes in time through forest ecosystems in the UK - soil response to pollution recovery

Long term trend analysis of bulk precipitation, throughfall and soil solution elemental fluxes from 12 years monitoring at 10 ICP Level II forest sites in the UK reveal coherent national chemical trends indicating recovery from sulphur deposition and acidification. Soil solution pH increased and sulphate and aluminium decreased at most sites. Trends in nitrogen were variable and dependant on its form. Dissolved organic nitrogen increased in bulk precipitation, throughfall and soil solution at most sites. Nitrate in soil solution declined at sites receiving high nitrogen deposition. Increase in soil dissolved organic carbon was detected - a response to pollution recovery, changes in soil temperature and/or increased microbial activity. An increase of sodium and chloride was evident - a possible result of more frequent storm events at exposed sites. The intensive and integrated nature of monitoring enables the relationships between climate/pollutant exposure and chemical/biological response in forestry to be explored.

The value of blood lactate measurements in ICU: an evaluation of the role in the management of patients on haemofiltration

In response to clinical demand some point-of-care analysers now provide blood lactate measurements, but recently concern has been expressed about the value and interpretation of these measurements. We undertook this study to evaluate blood lactate measurements in patients with acute renal failure undergoing haemofiltration (HF) with lactate replacement fluid. At baseline, 27 patients had base deficits of >5 mmol/l and 14 (52%) had blood lactates of >3.5 mmol/l. Lactate 'tolerance' was monitored by peak changes in these parameters during the procedure. There was a worsening of base deficit in only three of the patients in whom lactate rises exceeded 10 mmol/l with one survivor. Twelve patients with rises of blood lactate greater than 5 mmol/l improved their base deficit (+1 to +17) with eight (67%) survivors. Of the remaining 12 patients with improved base deficit (+2 to +20), 10 (83%) survived. Lactate tolerance was compromised in patients with co-incidental liver disease, those on inotropic support, and in patients with initial blood lactate measurements of >10 mmol/l and large base deficits. The data suggest that blood lactate and simultaneous acid-base response measurements during HF help to assign correct buffer replacement and should be performed on all patients.

The Value of Blood Lactate Measurements in ICU: An Evaluation of the Role in the Management of Patients on Haemofiltration

In response to clinical demand some point-of-care analysers now provide blood lactate measurements in critical care. Recent literature has raised concerns about the value and interpretation of these measurements. Two particular concerns relate to over-interpretation of lactate rises as equating tissue hypoxia and also the failure to recognise the contribution from inotropic support. We undertook this study to evaluate blood lactate measurements in intensive care unit (ICU) patients in the assessment of response to, and requirements for, haemofiltration (HF) with lactate replacement fluid and to evaluate influences from hepatic failure and from inotropic supportive therapy. Haemofiltration is a convenient renal replacement therapy widely used in intensive care management as an alternative to haemodialysis. Mainly used for the treatment of acute renal failure the process involves removal by filtration of fluid, electrolytes, metabolites and other substances and simultaneous replacement of essential fluid and electrolytes as well as a buffer, usually in the form of lactate (sodium salt). There is controversy about whether lactate replacement may be harmful to the patient and, if so, when it would be appropriate to use a lactate-free fluid at greater expense. Serial blood lactate with simultaneous blood gas measurements were recorded in 27 patients requiring HF for acute renal failure. At baseline all patients had base deficits of >5mmol/L and 14 (52%) had blood lactates of >3.5mmol/L. Lactate 'tolerance' was monitored by peak changes in these parameters during the procedure. There was a worsening of base deficit in only three of the patients in whom lactate rises exceeded 10 mmol/L at some stage during HF with one survivor. A further twelve patients with rises of blood lactate greater than 5 mmol/L improved their base deficit (+1 to +17) with 8 (67%) survivors. Of the remaining twelve patients with improved base deficit (+2 to +20), 10(83%) survived. The influence on 'lactate tolerance' in patients with co-incidental liver disease and those on inotropic support was studied. In these groups lactate tolerance was compromised, particularly those on adrenaline support. Patients with initial blood lactate measurements of >10mmol/l and large base deficits were also lactate intolerant. The data suggest that rises in blood lactate during HF signal harm if accompanied by inadequate improvement in base deficit. Blood lactate and simultaneous acid-base response measurements during HF help to assign correct buffer replacement and should be performed on all patients.

Diclofenac vs oxybuprocaine eyedrops for analgesia in paediatric strabismus surgery

Forty children undergoing strabismus surgery as day patients were randomly allocated to receive oxybuprocaine 0.4% eyedrops or 0.1% diclofenac eyedrops for perioperative analgesia. A non-invasive anaesthetic technique using the reinforced laryngeal mask airway was used. The study demonstrated that both topical analgesics provided good to excellent analgesia and the anaesthetic technique was associated with a relatively low incidence of nausea and vomiting. Complications were limited to two children who were admitted with persistent postoperative nausea and vomiting.