PT Journal AU Joseph, J Külls, C Arend, M Schaub, M Hagedorn, F Gessler, A Weiler, M TI Application of a laser-based spectrometer for continuous in situ measurements of stable isotopes of soil CO 2 in calcareous and acidic soils SO Soil PY 2019 BP 49 EP 62 VL 5 IS 1 ER