Das Projekt "Biogene VOC-Emissionen und Photochemie in den borealen Regionen Europas (BIPHOREP)" wird vom Umweltbundesamt gefördert und von Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung, Fraunhofer-Institut für Atmosphärische Umweltforschung durchgeführt. Objectives: Quantification of emission rates of C5 to C10 hydrocarbons from typical Boreal tree species. - Measurements of environmental and plant physiological parameters possibly controlling the source strength of VOC from vegetation. - Development of a chemical mechanism for the degradation of biogenic volatile organic compounds (BVOC) emitted by plants in the boreal regions of Europe. - Intercomparison of canopy emission rates calculated by enclosure techniques and/or Gradient-/REA-technique. - Parameterisation of C5 to C10 hydrocarbon emission rates from typical Boreal ecosystems on the basis of key environmental and plant physiological parameters. - Application and test of new chemical mechanisms using measurements from the BIPHOREP field campaigns. Main Results Obtained: Pallas Field Experiment: In July/August 1996 3 boreal tree species: (1) Norway spruce (Picea abies L. (Karst.) ssp. obovata) (2) Scots pine (Pinus sylvestris L.), and (3) Downy birch (Betula pubescens Ehrh.) were investigated with respect to VOC emission pattern and the influence of environmental and plant physiological parameters on the source strength of VOC. The following plant physiological parameters were calculated: net photosynthesis A, leaf conductance for water vapour gH20 , transpiration E, and CO2 mixing ratio inside the leaf ci. The following environmental parameters were recorded: photosynthetic active radiation PAR, leaf temperature Tleaf, CO2 mixing ratio outside the leaf ce, leaf to air water vapour pressure deficit DW. In total 22 diurnal cycles during different weather situations typical for the boreal summer were recorded. On warm and sunny days leaf temperatures of up to 35 Grad C and PAR values of up to 1400 MikroE were observed. During that time the sum of monoterpenes emitted by a Norway spruce twig mounted to 300 pmol m-2 total leaf area s-1. Main isoprenoid compounds in the VOC emission pattern were (alpha-pinene, beta-pinene/sabinene and isoprene. Maximum values of the single compounds reached ca. 100 pmol m-2 s-1. Other Monoterpenes such as myrcene, (3-carene, limonene and two unidentified substances were emitted in significant lower amounts by spruce twigs. The sum of monoterpene emission rates for pine twigs were comparable to those of spruce twigs under similar weather conditions. However, only traces of isoprene were emitted by pine twigs (lower 40 pmol m-2 s-1). Birch is a very low emitter of isoprenoids with emission rates lower 20 pmol m-2 s-1. In general the emission rates are correlated to temperature and light. A control of the emission through stomatal movement or a correlation to net photosynthesis is not obvious.
Das Projekt "Biosedimentary systems in Arctic environments: Polar coralline algae" wird vom Umweltbundesamt gefördert und von Natur-Museum und Forschungsinstitut Senckenberg, Abteilung für Meeresforschung durchgeführt. Im Jahr 2006 wurden während der MSM 02/03 Expedition die nördlichsten Vorkommen coralliner Rotalgen bei 80 Grad 30 nördlicher Breite vor Nordaustlandet entdeckt. Dieses Gebiet, sowie verschiedene andere um Spitzbergen, wurden mit dem bemannten Tauchboot Jago intensiv dokumentiert und beprobt. Coralline Algen scheinen in polaren Gewässern viel weiter verbreitet zu sein als bisher angenommen und repräsentieren somit eine einzigartige polare Karbonatfabrik. Es soll die artliche Zusammensetzung und Funktionalität dieser polaren Corallinaceen analysiert werden sowie ihre Eignung als historische Klimarekorder. Ferner sollen die Karbonatproduktionsraten quantifiziert und mit denen weiterer borealer Vorkommen verglichen werden.