Bruns-Strenge, S/ Lange, OL 1991: Photosynthetische Primärproduktion der Flechte Cladonia portentosa an einem Dünenstandort auf der Nordseeinsel Baltrum. I. Freilandmessungen von Microklima, Wassergehalt und CO2-Gaswechsel [Photosynthetic primary production of the lichen Cladonia portentosa in a dune habitat at the Island Baltrum in the North Sea. I. Field measurements of microclimate, water relations and CO2-exchange]. - Flora185: 73-97. [RLL List # / Rec.# 2574] Keywords: CO2 EXCHANGE/ PHOTOSYNTHESIS/ PRIMARY PRODUCTION/ SAND DUNES
Abstract: 23 fig. 1 tab. ["In its natural habitat of stabilized dunes on the island Baltrum (North Sea), microclimatic conditins for Cladonia portentosa were recorded (air and thallus temperature, rel. humidity, photosynthetically active radiation). In parallel, water content of the lichen (WG, % of dry weight) was determined. With respect to lichen hydration, the 56 diurnal courses of measurements, which were spread over several seasons could be grouped into 5 different types: (1) WG continuously low; (2) nocturnal moistening (e.g. by dew fall) and high WG at sunrise; (3) days with fog and high WG throughout; (4) days with rain and long lasting high WG; (5) lichens covered by snow. In addition, during 24 days in the summer and in the winter, diurnal courses of CO2 exchange of the lichen were followed together with the WG and the microclimatic conditions. These days could be separated according to the above types. This provides an overview for the performance in production ecology of the lichen."]