Chamber series and space-scale analysis of CO2 gas-exchange in grassland vegetation: A novel approach
Czobel, Sz.(Szent Istvan Univ., Goedoelloe (Hungary). Dept. of Botany and Plant Physiology) | Foti, Sz.(Szent Istvan Univ., Goedoelloe (Hungary). Dept. of Botany and Plant Physiology) | Balogh, J.(Szent Istvan Univ., Goedoelloe (Hungary). Plant Ecological Research Group of Hungarian Academy of Sciences) | Nagy, Z.(Szent Istvan Univ., Goedoelloe (Hungary). Dept. of Botany and Plant Physiology) | Bartha, S.(Hungarian Academy of Sciences, Vacratot (Hungary). Inst. of Ecology and Botany) | Tuba, Z.(Szent Istvan Univ., Goedoelloe (Hungary). Dept. of Botany and Plant Physiology)
A new type of CO2 and H2O gas exchange chamber was developed and tested. Ground areas of six chambers (0.044-4.531 square m) constituted a logarithmic series with doubling diameters from 7.5 to 240.0 cm. We demonstrate one of the first results for stand net ecosystem CO2 exchange (NEE) rates and temporal variability for two characteristic Central European grassland types: loess and sand. Our chamber-series measurement was performed in a perennial ruderal weed association. The measured mean NEE rates and their ranges in these grasslands were similar to values reported in other studies on temperate grasslands. The variability of CO2-assimilation of this weed vegetation showed clear spatial scale-dependence. We found the lowest variability of the vegetation photosynthesis at the small-middle scales. The results of spatial variability suggest the 0.2832 square m patch size is the characteristic unit of the investigated weed association.
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