Estimation of greenhouse gas emission reductions based on vegetation changes after rewetting in Drentsche Aa brook valley

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Conventional subsoil irrigation techniques do not lower carbon emissions from drained peat meadows

The focus of current water management in drained peatlands is to facilitate optimal drainage, which has led to soil subsidence and a strong increase in greenhouse gas (GHG) emissions. The Dutch land and water authorities proposed the application of subsoil irrigation (SSI) system on a large scale to potentially reduce GHG emissions, while maintaining high biomass production. Based on model results, the expectation was that SSI would reduce peat decomposition in summer by preventing groundwater tables (GWTs) from dropping below −60 cm. In 2017–2018, we evaluated the effects of SSI on GHG emissions (CO2, CH4, N2O) for four dairy farms on drained peat meadows in the Netherlands. Each farm had a treatment site with SSI installation and a control site drained only by ditches (ditch water level −60 / −90 cm, 100 m distance between ditches). The SSI system consisted of perforated pipes −70 cm from surface level with spacing of 5–6 m to improve drainage during winter–spring and irrigation in summer. GHG emissions were measured using closed chambers every 2–4 weeks for CO2, CH4 and N2O. Measured ecosystem respiration (Reco) only showed a small difference between SSI and control sites when the GWT of SSI sites were substantially higher than the control site (&gt; 20 cm difference). Over all years and locations, however, there was no significant difference found, despite the 6–18 cm higher GWT in summer and 1–20 cm lower GWT in wet conditions at SSI sites. Differences in mean annual GWT remained low (&lt; 5 cm). Direct comparison of measured N2O and CH4 fluxes between SSI and control sites did not show any significant differences. CO2 fluxes varied according to temperature and management events, while differences between control and SSI sites remained small. Therefore, there was no difference between the annual gap-filled net ecosystem exchange (NEE) of the SSI and control sites. The net ecosystem carbon balance (NECB) was on average 40 and 30 t CO2 ha−1 yr−1 in 2017 and 2018 on the SSI sites and 38 and 34 t CO2 ha−1 yr−1 in 2017 and 2018 on the control sites. This lack of SSI effect is probably because the GWT increase remains limited to deeper soil layers (60–120 cm depth), which contribute little to peat oxidation. We conclude that SSI modulates water table dynamics but fails to lower annual carbon emission. SSI seems unsuitable as a climate mitigation strategy. Future research should focus on potential effects of GWT manipulation in the uppermost organic layers (−30 cm and higher) on GHG emissions from drained peatlands.</p

Bordertexturen als transdisziplinärer Ansatz zur Untersuchung von Grenzen. Ein Werkstattbericht

Der Beitrag versteht sich als Werkstattbericht und gibt erste Einblicke in die Entwicklung eines kulturwissenschaftlich orientierten Ansatz‘ zur Untersuchung von Grenz(raum)phänomenen. Dieser versucht weitgreifender zu sein als etablierte sozialwissenschaftliche Perspektiven und fasst Grenz(raum)phänomene als auf Grenzen und Differenzen bezogene Gefüge aus unterschiedlichen Praktiken und Diskursen. Die als Bordertexturen verstandenen Gefüge werden anhand von Fallbeispielen an der U.S.-Mexikanischen Grenze, der deutsch-französischen Grenze und in Nordirland illustriert und in verschiedene Analysedimensionen aufgeschlüsselt. Dazu zählen Korporealität, Räumlichkeit und Materialität als in diesem Beitrag exemplarisch aufgezeigte heuristische Zugänge zu Bordertexturen. Der Ansatz relativiert die verbreitete territoriale Perspektive auf Grenze und erweitert das Spektrum der Analyseperspektiven und Gegenstandsbereiche in den Border Studies

Indirect excitation of ultrafast demagnetization

Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a negligible number of IR photons penetrate the aluminum layer. In comparison with an uncapped cobalt/palladium reference film, the initial demagnetization of the capped film occurs with a delayed onset and at a slower rate. Both observations are qualitatively in line with energy transport from the aluminum layer into the underlying magnetic film by the excited, hot electrons of the aluminum film. Our data thus confirm recent theoretical predictions

Retinal Not Systemic Oxidative and Inflammatory Stress Correlated with VEGF Expression in Rodent Models of Insulin Resistance and Diabetes

To correlate changes between VEGF expression with systemic and retinal oxidative stress and inflammation in rodent models of obesity induced insulin resistance and diabetes

Whole-Day Schools - Management and Education

Ganztagsschulen haben durch ihr Mehr an Zeit einen größeren Spielraum, die Schulgestaltung an den Bedürfnissen der Beteiligten zu orientieren. In einer Auseinandersetzung mit anderen Perspektiven kann es gelingen, die Ausrichtung der eigenen Schule zu diskutieren, zu festigen und zu schärfen. Pädagogische Fortbildungsveranstaltungen bieten dazu eine Möglichkeit. Der zweite bayerische Ganztagsschulkongress Ganztagsschule gestalten – ganztags Unterricht organisieren am 3. und 4. März 2010 in Forchheim bot den Teilnehmerinnen und Teilnehmern anhand vielfältiger Vorträge und Workshops ein Forum zur Diskussion mit Perspektiven aus Wissenschaft, Schulpraxis und Bildungspolitik. Die Dokumentation der Veranstaltung liegt hiermit vor.All-day schools stand out against other types of schools due to the extended availability of time and therewith a wider range of possibilities to adjust the orientation of the school to the needs of the persons involved. Schools can evolve and strengthen their orientation by a discursive examination and discussion of different approaches. A good opportunity for advancing this discussion are events in pedagogical further education. During the second Bavarian all-day school congress "Modelling All-Day School - Organizing All-Day Tuition", held on the 3rd and 4th of March 2010 in Forchheim/Germany, participants had the opportunity to attend numerous workshops and presentations as well as a panel discussion featuring experts from the fields of educational science, educational policy and teaching. The documentation of the congress is now available

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

Resonant Magnetic Scattering Studies using Synchrotron Radiation and Laser-Generated Extreme Ultraviolet Light

In this thesis magnetic domain patterns of ferromagnetic alloys are studied using resonant magnetic scattering (RMS). For this purpose synchrotron radiation in the soft X-ray range and laser-based extreme ultraviolet (XUV) light from a laboratory light source are employed. The synchrotron measurements give detailed information about the properties of magnetic domains with nanometer precision and element selectivity. These specialties allow investigations of domain patterns of complex layered systems, including FePd/CoPd bilayers or CoPd/Pd/NiFe trilayers. Time-resolved experiments with visible laser radiation are conducted to examine the laserinduced demagnetization of FePd/CoPd bilayers, pointing out the influence of intense laser pulses on the magnetic coupling of the two layers. This technique is capable of tracing the temporal evolution of the magnetization, nevertheless it cannot image nanometer-sized magnetic domains due to the limited spatial resolution. Consequently, a new approach is necessary to resolve domain patterns and ultrafast magnetization dynamics at the same time. This aim motivates the most important question addressed in this thesis: whether a tabletop XUV light source based on high-order harmonic generation (HHG) can be used for RMS experiments on magnetic domain patterns. In this context it is further shown, how intense laser exposure causes permanent and reversible modifcations of the magnetic nanostructure and the sample morphology. Finally, coherence properties of the generated XUV radiation are examined, using nonmagnetic scattering at grains and knife-edge diffraction. The results obtained reveal the advantages and limitations of HHG sources for applications which demand a high light coherence

Production in peatlands:Comparing ecosystem services of different land use options following conventional farming

Majority of Dutch peatlands are drained and used intensively as grasslands for dairy farming. This delivers high productivity but causes severe damage to ecosystem services supply. Peatland rewetting is the best way to reverse the damage, but high water levels do not fit with intensive dairy production. Paludiculture, defined as crop production under wet conditions, provides viable land use alternatives. However, performance of paludiculture is rarely compared to drainage-based agriculture. Here, we compared the performances of six land use options on peatland following a gradient of low, medium, and high water levels, including conventional and organic drainage-based dairy farming, low-input grasslands for grazing and mowing, and high-input paludiculture with reed and Sphagnum cultivation. For each land use option, we conducted environmental system analysis on model farm system defined by a literature based inventory analysis. The analysis used five ecosystem services as indicators of environmental impacts with a functional unit of 1-ha peat soil. Ecosystem services included biomass provisioning, climate, water, and nutrient regulation, and maintenance of habitat. Results showed that drainage-based dairy farming systems support high provisioning services but low regulation and maintenance services. Organic farming provides higher climate and nutrient regulation services than its conventional counterpart, but limited overall improvement due to the persistent drainage. Low-intensity grassland and paludiculture systems have high regulation and maintenance services value, but do not supply biomass provisioning comparable to the drainage-based systems. Without capitalizing the co-benefits of regulation and maintenance services, and accounting for the societal costs from ecosystem disservices including greenhouse gas emission and nitrogen pollution, it is not likely that the farmers will be incentivized to change the current farming system towards the wetter alternatives. Sustainable use of peatlands urges fundamental changes in land and water management along with the financial and policy support required.</p

Production in peatlands: Comparing ecosystem services of different land use options following conventional farming

Majority of Dutch peatlands are drained and used intensively as grasslands for dairy farming. This delivers high productivity but causes severe damage to ecosystem services supply. Peatland rewetting is the best way to reverse the damage, but high water levels do not fit with intensive dairy production. Paludiculture, defined as crop production under wet conditions, provides viable land use alternatives. However, performance of paludiculture is rarely compared to drainage-based agriculture. Here, we compared the performances of six land use options on peatland following a gradient of low, medium, and high water levels, including conventional and organic drainage-based dairy farming, low-input grasslands for grazing and mowing, and high-input paludiculture with reed and Sphagnum cultivation. For each land use option, we conducted environmental system analysis on model farm system defined by a literature based inventory analysis. The analysis used five ecosystem services as indicators of environmental impacts with a functional unit of 1-ha peat soil. Ecosystem services included biomass provisioning, climate, water, and nutrient regulation, and maintenance of habitat. Results showed that drainage-based dairy farming systems support high provisioning services but low regulation and maintenance services. Organic farming provides higher climate and nutrient regulation services than its conventional counterpart, but limited overall improvement due to the persistent drainage. Low-intensity grassland and paludiculture systems have high regulation and maintenance services value, but do not supply biomass provisioning comparable to the drainage-based systems. Without capitalizing the co-benefits of regulation and maintenance services, and accounting for the societal costs from ecosystem disservices including greenhouse gas emission and nitrogen pollution, it is not likely that the farmers will be incentivized to change the current farming system towards the wetter alternatives. Sustainable use of peatlands urges fundamental changes in land and water management along with the financial and policy support required