The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.Peer reviewe

Reading tea leaves worldwide: decoupled drivers of initial litter decomposition mass‐loss rate and stabilization

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large‐scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass‐loss rates and stabilization factors of plant‐derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy‐to‐degrade components accumulate during early‐stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass‐loss rates and stabilization, notably in colder locations. Using TBI improved mass‐loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early‐stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models

Predicting behavioural intentions towards medication safety among student and new graduate nurses across four countries

Aims and objectives: To identify final-year undergraduate students and new graduate nurses’ behavioural intentions towards medication safety across four countries. Background: Medication errors are a common and avoidable occurrence, being costly for not only patients but also for health systems and society. Design: A multi-site cross-sectional study. Methods: A self-administered survey was distributed to students and new graduate nurses in South Africa, India, Turkey and Australia. Descriptive statistics were calculated for all survey items. Multiple linear regressions were performed to predict behavioural intentions using the three Theory of Planned Behaviour constructs: attitudes, behavioural control and subjective norms. This study adheres to the STROBE guidelines. Results: Data were analysed for 432 students and 576 new graduate nurses. Across all countries, new graduate nurses reported significantly higher scores on all the TPB variables compared with student nurses. Attitudes towards medication management were found significantly and positively related to intention to practice safe medication management for both student and new graduate nurses. Total perceived behavioural control was significantly and negatively related to intention to practice safe medication management for students. Conclusion: Student and new graduate nurses showed favourable attitude, subjective norm, perceived behaviour control and intention in practising medication safety. However, differences in countries require further exploration on the factors influencing attitudes towards medication safety among student nurses and new nurse graduates. Relevance to clinical practice: Understanding student and new graduate nurses’ medication administration practices is important to inform strategies aimed at improving patient safety. The findings of this study highlight the need for an internationally coordinated approach to ensure safe medication administration by student and new graduate nurses

Simulating the net ecosystem CO2 exchange and its components over winter wheat cultivation sites across a large climate gradient in Europe using the ORCHIDEE-STICS generic model

International audienceOver the last decade, efforts have been carried on to develop and evaluate versions of global terrestrial ecosystem models (GTEM) in which crop specificities are represented. The goal of this study is to evaluate the ability of the ORCHIDEE-STICS (Organising Carbon and Hydrology In Dynamic EcosystEms—Simulateur mulTIdisciplinaire pour les Cultures Standard) GTEM in simulating the observed seasonal variations and annual budgets of net ecosystem exchange (NEE), gross primary production (GPP) and total ecosystem respiration (TER) fluxes over seven wheat sites spanning a large climate gradient in Europe. Overall, the seasonal variations of GPP are well represented by the model, with 5 sites out of 7 exhibiting a correlation coefficient (R) value higher than 0.9 and a normalized standard deviation (NSTD) between 0.8 and 1.2. In comparison, the model performances for catching the seasonal variations of TER are lower, especially in terms of NSTD. Regarding the annual budgets, mean simulated deviations averaged over all sites do not exceed 10% and 15% of the observed annual mean budget, for GPP and TER, respectively. For NEE, the model capacity at estimating annual budgets is low, its mean deviation corresponding to ∼35% of the observed mean value. This clearly shows that more accurate model estimates of GPP and especially TER are required for estimating NEE annual budgets. In this respect, past land-use and land-management changes are probably the most crucial processes to add, for getting soil carbon disequilibrium and more accurate NEE annual budgets. From a sensitivity analysis of the modelled fluxes to three management practices (plant variety, sowing date and fertilization intensity), we found that the fertilization is the most sensitive practice impacting the model performances of any flux, both in terms of seasonal variations and annual budgets

Effects of species selection and management on forest canopy albedo

International audienceForest management is considered to be one of the key instruments available to mitigate climate change as it can lead to increased sequestration of atmospheric carbon dioxide. However, the changes in canopy albedo may neutralise or offset the climate benefits of carbon sequestration. Although there is an emerging body of literature linking canopy albedo to management, understanding is still fragmented. We make use of a generally applicable approach: we combine a stand-level forest gap model with a canopy radiation transfer model and satellite-derived model parameters to quantify the effects of forest management on canopy albedo for different forest species and management strategies. We find that the most intensive management measures lead to largest albedo change. The choice of species in combination with thinning dominates the variation in canopy albedo. In addition, the canopy albedo of forest stands changes with the latitude, i.e. forest stands with similar structure have different albedo depending on the latitude. The structural changes associated with forest management can be described by change in LAI in combination with crown volume. However, not only the removal of trees but also the type of understorey affects the canopy albedo. The lower the canopy cover, the larger the background albedo contributes to the canopy albedo. In summary, forest albedo is strongly altered by humans

Variability in carbon exchange of European croplands

The estimated net ecosystem exchange (NEE) of CO2 based on measurements at 17 flux sites in Europe for 45 cropping periods showed an average loss of -38 gC m-2 per cropping period. The cropping period is defined as the period after sowing or planting until harvest. The variability taken as the standard deviation of these cropping periods was 251 gC m-2. These numbers do not include lateral inputs such as the carbon content of applied manure, nor the carbon exchange out of the cropping period. Both are expected to have a major effect on the C budget of high energy summer crops such as maize. NEE and gross primary production (GPP) can be estimated by crop net primary production based on inventories of biomass at these sites, independent of species and regions. NEE can also be estimated by the product of photosynthetic capacity and the number of days with the average air temperature >5 °C. Yield measured at these sites or reported at the NUTS2 level dataset of EUROSTAT is a relatively poor predictor of NEE. To investigate the difference in the variability in CO2 emissions of different crops at the same location and to compare this variation with the variation of the same crop at different locations and with the inter-annual variation the measured dataset at the flux sites was extended with simulated data. These simulations show that the variability in carbon exchange is determined by: firstly the choice of crop and the location and to a lesser extent by the yearly differences in climate