Phosphorus supply affects long-term carbon accumulation in mid-latitude ombrotrophic peatlands

Ombrotrophic peatlands are a globally important carbon store and depend on atmospheric nutrient deposition to balance ecosystem productivity and microbial decomposition. Human activities have increased atmospheric nutrient fluxes, but the impacts of variability in phosphorus supply on carbon sequestration in ombrotrophic peatlands are unclear. Here, we synthesise phosphorus, nitrogen and carbon stoichiometric data in the surface and deeper layers of mid-latitude Sphagnum-dominated peatlands across Europe, North America and Chile. We find that long-term elevated phosphorus deposition and accumulation strongly correlate with increased organic matter decomposition and lower carbon accumulation in the catotelm. This contrasts with literature that finds short-term increases in phosphorus supply stimulates rapid carbon accumulation, suggesting phosphorus deposition imposes a threshold effect on net ecosystem productivity and carbon burial. We suggest phosphorus supply is an important, but overlooked, factor governing long-term carbon storage in ombrotrophic peatlands, raising the prospect that post-industrial phosphorus deposition may degrade this carbon sink

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Infrared spectral data of peat and ash from Cruz do Bocelo mire, northwestern Spain

The data are included in two csv files: - Cruz_do_Bocelo_IR_peat_data.csv: Wavenumbers (WN) and standardized absorbances for peat samples (pB01 to pB69). - Cruz_do_Bocelo_IR_ash_data.csv: Wavenumbers (WN) and standardized absorbances for ash samples (aB01 to aB70).-- Data values are separated by semicolon.-- The core was sliced into 2 cm slices, which are numbered from the top ( sample 1: 0 – ⁠2 cm) to the bottom (sample 70, 138 – ⁠140 cm). Samples codes start with "p" for peat and "a" for ash, followed by "B" (i.e., Bocelo) and the number in the sequence (01 to 70).The dataset contains standardized absorbance values of spectra for peat and ash samples, collected in the mid infrared (wavenumber 4000 – ⁠400 cm⁻¹) region using Fourier transform infrared spectroscopy - Attenuated total reflectance (FTIR-ATR). The spectra enable the characterization of the molecular and mineral composition of peat and ash, and how they vary with depth. It also helps in establishing the chronology of changes in the mineral composition of the deposited dust and understanding the factors controlling these changes. The samples were obtained from a core collected in 2007 at Cruz do Bocelo mire (NW Spain) and cover the last 2800 years.These data were obtained with funding by the grant Grupos de Referencia Competitiva (ED431C 2021/32) of Xunta de Galicia. L.L.M was supported by the Madrid Talent Attraction Program (Programa de Atracción de Talento de la Comunidad de Madrid, modalidad 1, 2019-T1/AMB-12782).Peer reviewe

Investigating the Mineral Composition of Peat by Combining FTIR-ATR and Multivariate Analysis

This article belongs to the Section Crystallography and Physical Chemistry of Minerals & Nanominerals.The mineral content of peat has received little attention until the last few decades, when peat cores have been increasingly used to study past dust deposition. Paleodust deposition is commonly reconstructed through elemental datasets, which are used to infer deposition rates, storminess patterns, mineral composition, source identification, and fertilization effects. To date, only a few studies have directly analyzed the mineralogy (by XRD and SEM) and particle size of peat mineral matter, and the conducted studies have usually been constrained by the need to remove a large amount of organic matter, which risks altering the mineral component. One alternative is to use quick, nondestructive techniques, such as FTIR-ATR, that require little sample preparation. In this study, we analyzed by FTIR-ATR both the bulk peat and ash fractions of a sequence taken in a minerogenic mire that covered a wide inorganic matter content range (6%–57%). Aided by principal component analysis on transposed IR spectral data, we were able to identify the main minerals in bulk peat and ash, quartz, mica (likely muscovite), K feldspar (likely microcline), and plagioclase (likely anorthite), which are consistent with the local geology of the mire catchment. Changes in mineral composition during the last ca. 2800 years were coeval with previously reconstructed environmental changes using the same core. Our results suggest that FTIR-ATR has great potential to investigate peat mineral matter and the processes that drive its compositional change.This research was funded by the grant Grupos de Referencia Competitiva (ED431C 2021/32) of Xunta de Galicia. L.L.M was supported by the Madrid Talent Attraction Program (Programa de Atracción de Talento de la Comunidad de Madrid, modalidad 1, 2019-T1/AMB-12782)

Postglacial vegetation data obtained using macrofossil analysis on a peat sequence reaching ~10 000 years BP in Store Mosse bog, south-central Sweden

Peatland vegetation from an ombrotrophic bog (Store Mosse bog) located in south-central Sweden. The data include an Age & Peat Properties Dataset (peat bulk density analysis, peat accumulation rates (peat-AR), and an age model based on 16 radiocarbon dates) and a Plant Macrofossil Analysis Dataset, on a 678 cm long peat sequence which was collected in November 2018 (using a Russian corer) and reaches almost 10000 cal years BP in basal age. The plant macrofossil analysis includes 119 samples; 5 cubic cm of fresh peat per sample was gently cleaned using a 120 µm mesh sieve under running water (no pre-analysis treatment was required). The samples were analysed using a stereomicroscope (magnification ranging X10-40) for plant coverage percentages using a petri dish with a 10 x 10 mm grid as scale, and species identification was made using a high-power light microscope (based on stem and branch leaves for Sphagnum species)

Peat properties (radiocarbon dating, bulk density analysis, and peat accumulation rates) obtained from a peat sequence reaching ~10 000 years BP in Store Mosse bog, south-central Sweden

Peat properties from an ombrotrophic bog (Store Mosse bog) located in south-central Sweden. The data include peat bulk density analysis, peat accumulation rates (peat-AR), and an age model based on 16 radiocarbon dates, on a 678 cm long peat sequence which was collected in November 2018 (using a Russian corer) and reaches almost 10000 cal years BP in basal age. The peat sequence is based on 9 consecutive peat cores (of 1 m each) obtained from two alternating holes in the southern part of Store Mosse bog. The peat cores were subsampled into 1 cm slices and then stored in a cold room before analysis. The bulk density analysis was made at a 1 cm resolution by taking a cube of peat (roughly 1 cubic cm) from each subsampled slice to be freeze-dried, then weighed and measured (using a caliper) to calculate its density - these values were then used to align the cores to obtain one composite peat sequence with a depth of 678 cm. The age model was created using R_Bacon which utilizes the IntCa13.14C calibration curve, based on 16 radiocarbon age dates of hand-picked plant macrofossil remains. Using the bulk density data and the ages from the age model, the peat accumulation rates (peat-AR) were calculated at 1 cm resolution by dividing the total mass (g/m²) by time between each sample, presented as g/m²/a

Storm chasing: Tracking Holocene storminess in southern Sweden using mineral proxies from inland and coastal peat bogs

Severe extratropical winter storms are a recurrent feature of the European climate and cause widespread socioeconomic losses. Due to insufficient long-term data, it remains unclear whether storminess has shown a notable response to changes in external forcing over the past millennia, which impacts our ability to project future storminess in a changing climate. Reconstructing past storm variability is essential to improving our understanding of storms on these longer, missing timescales. Peat sequences from coastal ombrotrophic bogs are increasingly used for this purpose, where greater quantities of coarser grained beach sand are deposited by strong winds during storm events. Moving inland however, storm intensity decreases, as does sand availability, muting potential paleostorm signals in bogs. We circumvent these issues by taking the innovative approach of using mid-infrared (MIR) spectral data, supported by elemental information, from the inorganic fraction of Store Mosse Dune South (SMDS), a 5000-year-old sequence from a large peatland located in southern Sweden. We infer past changes in mineral composition and thereby, the grain size of the deposited material. The record is dominated by quartz, whose coarse nature was confirmed through analyses of potential local source sediments. This was supported by further mineralogical and elemental proxies of atmospheric input. Comparison of SMDS with within-bog and regionally relevant records showed that there is a difference in proxy and site response to what should be similar timing in shifts in storminess over the ∼100 km transect considered. We suggest the construction of regional storm stacks, built here by applying changepoint modelling to four transect sites jointly. This modelling approach has the effect of reinforcing signals in common while reducing the influence of random noise. The resulting Southern Sweden-Storm Stack dates stormier periods to 4495–4290, 3880–3790, 2885–2855, 2300–2005, 1175–1065 and 715-425 cal yr BP. By comparing with a newly constructed Western Scotland-Storm Stack and proximal dune records, we argue that regional storm stacks allow us to better compare past storminess over wider areas, gauge storm track movements and by extension, increase our understanding of the drivers of storminess on centennial to millennial timescale

Peat properties, elemental variations, age model and FTIR-ATR analyses for peat ash and local source sediments for the Store Mosse Dune South record

Reconstructing past storm variability is essential to improving our understanding of storminess in a future changing climate. Peat sequences from coastal ombrotrophic bogs are increasingly used for this purpose, where greater quantities of coarser grained beach sand are deposited by strong winds during storm events. Moving inland however, storm intensity decreases, as does sand availability, muting potential paleostorm signals in bogs. We circumvent these issues by taking the innovative approach of using mid-infrared (MIR) spectral data, supported by elemental information, from the inorganic fraction of Store Mosse Dune South (SMDS, 57°16'37.70N, 13°55'30.86E), a 5000-year-old sequence from a large peatland located in southern Sweden. We infer past changes in mineral composition and thereby, the grain size of the deposited material. The record is dominated by quartz, whose coarse nature was confirmed through analyses of potential local source sediments. This was supported by further mineralogical and elemental proxies of atmospheric mineral inputs. Comparison of SMDS with within-bog and regionally relevant records showed that there is a difference in proxy and site response to what should be similar timing in shifts in storminess over the ~100 km transect considered. We suggest the construction of regional storm stacks, built here by applying changepoint modelling to four of the transect sites jointly. This modelling approach has the effect of reinforcing signals in common while reducing the influence of random noise. The resulting Southern Sweden-Storm Stack dates stormier periods to 4495-4290, 3880-3790, 2885-2855, 2300-2005, 1175-1065 and 715-425 cal yr BP