Relationship between ecosystem productivity and photosynthetically-active radiation for northern peatlands

We analyzed the relationship between net ecosystem exchange of carbon dioxide (NEE) and irradiance (as photosynthetic photon flux density or PPFD), using published and unpublished data that have been collected during midgrowing season for carbon balance studies at seven peatlands in North America and Europe. NEE measurements included both eddy-correlation tower and clear, static chamber methods, which gave very similar results. Data were analyzed by site, as aggregated data sets by peatland type (bog, poor fen, rich fen, and all fens) and as a single aggregated data set for all peatlands. In all cases, a fit with a rectangular hyperbola (NEE = α PPFD Pmax/(α PPFD + Pmax) + R) better described the NEE-PPFD relationship than did a linear fit (NEE = β PPFD + R). Poor and rich fens generally had similar NEE-PPFD relationships, while bogs had lower respiration rates (R = −2.0μmol m−2s−1 for bogs and −2.7 μmol m−2s−1 for fens) and lower NEE at moderate and high light levels (Pmax = 5.2 μmol m−2s−1 for bogs and 10.8 μmol m−2s−1 for fens). As a single class, northern peatlands had much smaller ecosystem respiration (R = −2.4 μmol m−2s−1) and NEE rates (α = 0.020 and Pmax = 9.2μmol m−2s−1) than the upland ecosystems (closed canopy forest, grassland, and cropland) summarized by Ruimy et al. [1995]. Despite this low productivity, northern peatland soil carbon pools are generally 5–50 times larger than upland ecosystems because of slow rates of decomposition caused by litter quality and anaerobic, cold soils

Dust inputs and bacteria influence dissolved organic matter in clear alpine lakes

Remote lakes are usually unaffected by direct human influence, yet they receive inputs of atmospheric pollutants, dust, and other aerosols, both inorganic and organic. In remote, alpine lakes, these atmospheric inputs may influence the pool of dissolved organic matter, a critical constituent for the biogeochemical functioning of aquatic ecosystems. Here, to assess this influence, we evaluate factors related to aerosol deposition, climate, catchment properties, and microbial constituents in a global dataset of 86 alpine and polar lakes. We show significant latitudinal trends in dissolved organic matter quantity and quality, and uncover new evidence that this geographic pattern is influenced by dust deposition, flux of incident ultraviolet radiation, and bacterial processing. Our results suggest that changes in land use and climate that result in increasing dust flux, ultraviolet radiation, and air temperature may act to shift the optical quality of dissolved organic matter in clear, alpine lakes

Integrated Ecosystem Assessment: Lake Ontario Water Management

BACKGROUND: Ecosystem management requires organizing, synthesizing, and projecting information at a large scale while simultaneously addressing public interests, dynamic ecological properties, and a continuum of physicochemical conditions. We compared the impacts of seven water level management plans for Lake Ontario on a set of environmental attributes of public relevance. METHODOLOGY AND FINDINGS: Our assessment method was developed with a set of established impact assessment tools (checklists, classifications, matrices, simulations, representative taxa, and performance relations) and the concept of archetypal geomorphic shoreline classes. We considered each environmental attribute and shoreline class in its typical and essential form and predicted how water level change would interact with defining properties. The analysis indicated that about half the shoreline of Lake Ontario is potentially sensitive to water level change with a small portion being highly sensitive. The current water management plan may be best for maintaining the environmental resources. In contrast, a natural water regime plan designed for greatest environmental benefits most often had adverse impacts, impacted most shoreline classes, and the largest portion of the lake coast. Plans that balanced multiple objectives and avoided hydrologic extremes were found to be similar relative to the environment, low on adverse impacts, and had many minor impacts across many shoreline classes. SIGNIFICANCE: The Lake Ontario ecosystem assessment provided information that can inform decisions about water management and the environment. No approach and set of methods will perfectly and unarguably accomplish integrated ecosystem assessment. For managing water levels in Lake Ontario, we found that there are no uniformly good and bad options for environmental conservation. The scientific challenge was selecting a set of tools and practices to present broad, relevant, unbiased, and accessible information to guide decision-making on a set of management options

Edition und Kommentar des Krankenjournals D22 (1821) von Samuel Hahnemann

Die Transkription von $\textit {Samuel Hahnemanns}$ (1755-1843) Krankenjournal D22 und zeitgenössische Archivmaterialien ermöglichen den Vergleich zweier unterschiedlicher Patientenkollektive des Begründers der Homöopathie während seiner Praxistätigkeit in Leipzig und Köthen im Jahre 1821. Charakteristika der $\it Hahnemannschen$ Konsultation, Fallaufnahme und Arzneimittelfindung, die therapeutische Umsetzung der Miasmentheorie als Grundlage seines Verständnisses von chronischen Krankheiten und seine Honorarpraxis werden ebenso wie die Austestung von Arzneien am Kranken zu Prüfungszwecken aufgezeigt. Plazebo und unterschiedliche Schwefelzubereitungen werden am häufigsten verordnet. $\it Hahnemanns$ Methodik der Arzneimittelprüfung und somit der Inhalt seiner Arzneimittellehren werden kritisch hinterfragt. Fehler bei den bisher bekannten Lebensdaten seiner Kinder und Beziehungen zu ranghohen Regierungsbeamten während des Umzuges von Leipzig nach Köthen sind neu gewonnene Aspekte der Biographie $\it Hahnemanns$

Strukturelle Bewertung von Straßenoberbaukonstruktionen auf Projektebene

Diese Arbeit beschäftigt sich mit der strukturellen Bewertung von Straßenoberbaukonstruktionen auf Projektebene, sowie der praktischen Anwendung der Erkenntnisse aus dem Verkehrsinfrastrukturforschungsprojekt SUB-KRIT. Hierfür werden eingangs technische Grundlagen, das VIF-Forschungsprojekt SUB-KRIT sowie die Teststrecke beschrieben. Darauf aufbauend erfolgt die praktische Anwendung des Bewertungsprozesses, aus der in weiterer Folge Erkenntnisse sowie eine Umsetzung in einer RVS Richtlinie abgeleitet werden. Durch den Einsatz von SUB-KRIT ist es möglich, eine effektive und effiziente Bewertung von Straßenoberbaukonstruktionen unter Berücksichtigung prognostizierter Lebenszykluskostenanalysen durchzuführen. Aufgrund des stufenweisen Aufbaus des Bewertungsprozesses können kostenintensive und eventuell nicht zielführende Untersuchungen und Bewertungsschritte vermieden werden. Dadurch ist es dem Anwender innerhalb der einzelnen Stufen möglich, eine wirtschaftlich günstige und bautechnisch qualitative Entscheidung hinsichtlich passender Erhaltungsmaßnahmen zu treffen.This thesis deals with the structural assessment of pavement constructions on project level as well as the practical application of the findings from the traffic infrastructure research project SUB-KRIT. Therefor the technical basics, the VIF research project SUB-KRIT as well as the street segment, which is going to be tested, are described initially. Based on this, the practical application of the assessment process takes place, from which further findings and an implementation in a RVS guideline are derived. By using the SUB-KRIT, it is possible to carry out an effective and efficient assessment of the pavement construction under the consideration of the forecasted life-cycle-cost analysis. Due to the gradual structure of the assessment process cost, intensive and eventually not effective investigations and assessment steps can be avoided. Thereby the user has the possibility to make an economically favourable and structurally qualitative decision regarding the appropriate conservation measures at the end of each individual stage.vorgelegt von: Patrick Daniel MortschWien, FH Campus Wien, Masterarb., 2019(VLID)446770

Regional adaptation strategies

This new collection of essays by leading Canadian scientists, engineers, social scientists, and humanists offers an overview and assessment of climate change and its impacts on Canada from physical, social, technological, economic, political, and ethical / religious perspectives. Interpreting and summarizing the large and complex literatures from each of these disciplines, the book offers a multidisciplinary approach to the challenges we face in Canada. Special attention is given to Canada's response to the Kyoto Protocol, as well as an assessment of the overall adequacy of Kyoto as a response to the global challenge of climate change