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Miehe G.,University of Marburg | Miehe S.,University of Marburg | Bach K.,University of Marburg | Nolling J.,University of Marburg | And 7 more authors.
Journal of Arid Environments | Year: 2011

Eleven plant communities of the central Tibetan ecotone (31°20'-33°00'N/89°00'-92°10'E) between the Kobresia pygmaea grazing pastures of the eastern highlands and the open short grass steppe with cushion plants (" Alpine Steppe" ) of the north-western highlands have been described on the basis of 189 plot-based floristically complete vegetation records. In parallel, remote sensing techniques distinguish four main land-use cover types. Our hypotheses are: (1) The plant communities of the central Tibetan highlands are grazing-adapted and resilient to degradation. (2) In contrast to grazing resilient plant functional types, the turf cover of the K. pygmaea pastures and the Kobresia schoenoides wetlands is degradable through desiccation, periglacial processes, soil-dwelling small mammals and livestock. Five grazing-related plant functional traits are introduced. Grazing tolerance is the prevalent functional type. Species with no specific protection against grazing make up not more than 6% of the total cover. Unpalatable plants cover up to 8%. Only the azonal K. schoenoides swamps - the indispensable winter grazing reserve - have been widely degraded and depleted by 75%, being replaced by Carex sagaensis grazing pastures. It can be foreseen that governmental policy of sedentarisation of nomads will lead to reduced grazing mobility and degradation of winter grazing reserves. © 2011 Elsevier Ltd. Source


Born W.,Carl von Ossietzky Str. 17 | Gebhardt O.,Helmholtzzentrum fur Umweltforschung UFZ | Gmeiner J.,Ludwig Maximilians University of Munich | Rueff F.,Ludwig Maximilians University of Munich
Umweltmedizin in Forschung und Praxis | Year: 2012

Background: Common ragweed (Ambrosia artemisiifolia) is increasingly dispersing within Germany. Ragweed pollen can cause important inhalative allergic diseases. The aim of the study is to estimate health costs resulting from exposure to Ambrosia pollen in Germany. Methods: The hypothesis was a linear relation between complaints and health costs and sensitization prevalence to ragweed pollen of 12% and of 50% of pollen-allergic patients. Based on interviews of 117 Ambrosiasensitized patients we calculated health costs for an extended period of seasonal complaints caused by ragweed. The Cost of Illness Method and the Contingent Valuation Method were employed for the calculation of costs. Results: Current total costs for the estimated 12 % and 50% of polinosis patients vary between 2.3 and 14.2 billion a per year. Asthma patients with hospital stays cause 1.5 to 10.8 billion a in direct costs. Indirect costs due to productivity loss vary between 827 million and 3.5 billion a. Intangible costs are also high because 64% of the patients indicate a large extent of psychological strain. The increased length of allergic symptoms due to Ambrosia allergies may increase costs by 97 to 421 a (yielding a total of 1289 to 2104 a in costs per patient per year). Conclusion: Potential costs and the high psychological strain of patients underline how indispensable concerted action of all responsible federal but also regional authorities is. Preventive management and a comprehensive monitoring of Ambrosia will help to minimise future health costs of Ambrosia. © ecomed Medizin, Verlagsgruppe Hüthig Jehle Rehm GmbH, Landsberg. Source


Hug L.A.,University of Toronto | Hug L.A.,University of California at Berkeley | Maphosa F.,Wageningen University | Leys D.,University of Manchester | And 5 more authors.
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2013

Organohalide respiration is an anaerobic bacterial respiratory process that uses halogenated hydrocarbons as terminal electron acceptors during electron transport-based energy conservation. This dechlorination process has triggered considerable interest for detoxification of anthropogenic groundwater contaminants. Organohalide-respiring bacteria have been identified from multiple bacterial phyla, and can be categorized as obligate and non-obligate organohalide respirers. The majority of the currently known organohalide- respiring bacteria carry multiple reductive dehalogenase genes. Analysis of a curated set of reductive dehalogenases reveals that sequence similarity and substrate specificity are generally not correlated, making functional prediction from sequence information difficult. In this article, an ortholo- gue-based classification system for the reductive dehalogenases is proposed to aid integration of new sequencing data and to unify terminology. © 2013 The Author(s) Published by the Royal Society. All rights reserved. Source


Lorz C.,TU Dresden | Bakker F.,CAESB | Neder K.,CAESB | Roig H.L.,University of Brasilia | And 2 more authors.
Hydrologie und Wasserbewirtschaftung | Year: 2011

Water resources in the Federal District of Brazil are subject to considerable pressure. Major stress factors are population growth and land-use changes. The project IWAS-ÁGUA DF aims at creating a scientific basis for the sustainable management of water resources in the sense of Integrated Water Resources Management (IWRM).The first step was to document the substantial changes in land uses due to urbanization and extension of croplands going along with the reduction of (semi)natural vegetation. Severe consequences of landuse change and water withdrawal are drastic decreases in base-flow discharges and negative effects on water quality. Conclusions for scientific activities in sense of the IWRM are (i) analysis of runoff generation and identification of measures to increase base-flow discharge, (ii) measures to minimize releases of pollutants and sediments, and (iii) extension of the monitoring of selected pollutants and sediments in reservoir inflows. Source


Holscher T.,Helmholtzzentrum fur Umweltforschung UFZ | Lisec J.,TU Berlin | Lisec J.,Max Planck Institute of Molecular Plant Physiology | Baani M.,TU Berlin | And 4 more authors.
Environmental Science and Technology | Year: 2010

The wide though not ubiquitous distribution of chlorobenzene-dechlorinating bacteria in anaerobic sludge from German sewage plants is demonstrated. The model substrates 1,2,3- and 1,2,4-trichlorobenzene (TCB) were dechlorinated to dichlorobenzenes (DCBs) and monochlorobenzene (MCB) via distinct pathways. For easy visualization and differentiation of the pathways, a novel plotting method was developed. While many of the cultures showed a dechlorination pattern similar to that previously found for Dehalococcoides species, removing doubly flanked rather than singly flanked chlorine substituents from TCBs, some cultures formed 1,2-DCB from 1,2,3-TCB and/or 1,3-DCB from 1,2,4-TCB. Stable cultures preferentially catalyzing the removal of singly flanked chlorines were obtained by repeated subcultivation in sediment-free synthetic medium. This dechlorination pattern is potentially of great benefit for remediation as the accumulation of persistent intermediates such as 1,3,5-TCB from highly chlorinated compounds can be avoided. In addition, the cultures dechlorinated 1,3,5-TCB, pentachlorobenzene (PeCB), and hexachlorobenzene (HCB). Nested PCR demonstrated the presence of low numbers of Dehalococcoides species. However, the observed insensitivity of the dechlorinating bacteria in our cultures to oxygen and sensitivity to vancomycin is not in accordance with the reported properties of Dehalococcoides species, suggesting that other bacteria than Dehalococcoides catalyzed the removal of singly flanked chlorines from TCB. © 2010 American Chemical Society. Source

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