78 research outputs found

    Drivers of soil organic carbon from temperate to alpine forests: a model-based analysis of the Swiss forest soil inventory with Yasso20

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    Predicting soil organic carbon (SOC) stocks and their dynamics in forest ecosystems is crucial for assessing forest C balance, but the relative importance of key controls – litter inputs, climate, and soil properties – remains uncertain. Here, we linked SOC stocks at 556 old-growth Swiss forest sites from 350 to 2000 m a.s.l. to a comprehensive set of environmental variables, encompassing climate (mean annual precipitation, MAP: 700–2100 mm, mean annual temperature, MAT: 0–12 °C), soil properties, and forest types. In addition, we compared measured SOC stocks with stocks simulated by the Yasso20 model, which is widely used for reporting SOC stock changes. Since Yasso20 is driven solely by litter inputs and climate, deviations between modeled and measured stocks can reveal the significance of additional factors such as organo-mineral interactions that we hypothesized to be crucial for SOC stocks. Total SOC stocks exhibited distinct regional patterns, with the highest values in the Southern Alps, where soils are rich in Fe and Al oxides and receive high MAP. On average, total SOC stocks simulated by Yasso20 aligned well with measured SOC stocks (13.7 vs. 13.2 kg C m−2). However, the model did not capture regional SOC variability, underestimating SOC stocks by up to 7 kg C m−2 in the Southern Alps. The underestimation was primarily explained by soil mineral properties, with their influence depending on soil pH. In soils with pH ≤ 5, exchangeable Fe had the strongest effect on Yasso20 deviations from measured stocks, while in soils with pH &gt; 5, exchangeable Ca had the strongest effect on model deviations. Beyond Fe and Ca, MAP emerged as an important driver of total SOC stocks, with SOC stocks increasing with MAP. At higher elevations, this coincided with low MAT and a high share of conifers. While Yasso20 accounted for MAT, Yasso20 underestimated SOC stocks for MAP &gt; 1400 mm. Overall, our results indicate that mineral-driven SOC stabilization and climate are the primary drivers of Yasso20 deviations from measured SOC stocks. Incorporating mineral-driven soil organic matter stabilization and coupling to a soil water model can improve the modeling of SOC stocks. However, further studies are needed to verify how C stabilization mechanisms and soil moisture can be included in model-based estimates of SOC stock changes, which is the primary application of Yasso in greenhouse gas inventories.</p

    Validation of the Swiss methane emission inventory by atmospheric observations and inverse modelling

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    Atmospheric inverse modelling has the potential to provide observation-based estimates of greenhouse gas emissions at the country scale, thereby allowing for an independent validation of national emission inventories. Here, we present a regional-scale inverse modelling study to quantify the emissions of methane (CH4_{4}) from Switzerland, making use of the newly established CarboCount-CH measurement network and a high-resolution Lagrangian transport model. In our reference inversion, prior emissions were taken from the “bottom-up” Swiss Greenhouse Gas Inventory (SGHGI) as published by the Swiss Federal Office for the Environment in 2014 for the year 2012. Overall we estimate national CH4_{4} emissions to be 196 ± 18 Ggyr1^{-1} for the year 2013 (1σ uncertainty). This result is in close agreement with the recently revised SGHGI estimate of 206 ± 33 Ggyr1^{-1} as reported in 2015 for the year 2012. Results from sensitivity inversions using alternative prior emissions, uncertainty covariance settings, large-scale background mole fractions, two different inverse algorithms (Bayesian and extended Kalman filter), and two different transport models confirm the robustness and independent character of our estimate. According to the latest SGHGI estimate the main CH4_{4} source categories in Switzerland are agriculture (78 %), waste handling (15 %) and natural gas distribution and combustion (6 %). The spatial distribution and seasonal variability of our posterior emissions suggest an overestimation of agricultural CH4_{4} emissions by 10 to 20% in the most recent SGHGI, which is likely due to an overestimation of emissions from manure handling. Urban areas do not appear as emission hotspots in our posterior results, suggesting that leakages from natural gas distribution are only a minor source of CH4_{4} in Switzerland. This is consistent with rather low emissions of 8.4 Ggyr1^{-1} reported by the SGHGI but inconsistent with the much higher value of 32 Ggyr1^{-1} implied by the EDGARv4.2 inventory for this sector. Increased CH4_{4} emissions (up to 30% compared to the prior) were deduced for the northeastern parts of Switzerland. This feature was common to most sensitivity inversions, which is a strong indicator that it is a real feature and not an artefact of the transport model and the inversion system. However, it was not possible to assign an unambiguous source process to the region. The observations of the CarboCount-CH network provided invaluable and independent information for the validation of the national bottom-up inventory. Similar systems need to be sustained to provide independent monitoring of future climate agreements

    Costs and benefits of orthographic inconsistency in reading:evidence from a cross-linguistic comparison

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    We compared reading acquisition in English and Italian children up to late primary school analyzing RTs and errors as a function of various psycholinguistic variables and changes due to experience. Our results show that reading becomes progressively more reliant on larger processing units with age, but that this is modulated by consistency of the language. In English, an inconsistent orthography, reliance on larger units occurs earlier on and it is demonstrated by faster RTs, a stronger effect of lexical variables and lack of length effect (by fifth grade). However, not all English children are able to master this mode of processing yielding larger inter-individual variability. In Italian, a consistent orthography, reliance on larger units occurs later and it is less pronounced. This is demonstrated by larger length effects which remain significant even in older children and by larger effects of a global factor (related to speed of orthographic decoding) explaining changes of performance across ages. Our results show the importance of considering not only overall performance, but inter-individual variability and variability between conditions when interpreting cross-linguistic differences

    [Certificate of Voter Registration for John Patterson Osterhout]

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    Certificate of voter registration for John Patterson Osterhout in Austin county. Chief Justice of Austin county, C. B. Oney, testified that John fulfilled the oath of amnesty and John Campbell, county clerk, attested to the registration

    High-Speed Cryogenic Alternator Development. Volume 1

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    Evolution of water quality around the Island of Borneo during the last 8-years

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    AbstractWater quality around the Island of Borneo is important for the coral reefs in Borneo's proximity. Sediment input into freshwater and marine ecosystems is a result of natural processes. However, mining, deforestation, poor agricultural practices can greatly increase sediment input into aquatic systems. According to time series analysis of the coastal waters around Borneo, water quality has worsened in the last 8 years. This short study analyzes and illustrates the particular year-to-year changes in the relevant waters using MERIS data from 2003-2010, as well as for the entire 8-year period. Changes in the statistical characteristics of the water surface variables, yellow substance (colored dissolved organic matter) and total suspended matter, in Borneo's coastal waters can be seen. The intra-annual variables derived include minimum, maximum, standard deviation and average. The interesting inter-annual variables investigated are slopes of the mentioned water quality characteristics over a period of 8 years around Borneo, which changed since 2003 and decreases for most of the Island of Bro. According to this study, further land development on the island of Borneo will further decrease water quality around Borneo and worsen conditions for coral reefs and other coastal ecosystems. This study also illustrates the utility and prowess of the open source programs BEAM, GRASS and R

    Development of a Miniature Gas-Bearing Cryogenic Turbo Refrigerator

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