TY  - JOUR
AU  - Thieme, Lisa
AU  - Graeber, Daniel
AU  - Hofmann, Diana
AU  - Bischoff, Sebastian
AU  - Schwarz, Martin T.
AU  - Steffen, Bernhard
AU  - Meyer, Ulf-Niklas
AU  - Kaupenjohann, Martin
AU  - Wilcke, Wolfgang
AU  - Michalzik, Beate
AU  - Siemens, Jan
TI  - Dissolved organic matter characteristics of deciduous and coniferous forests with variable management: different at the source, aligned in the soil
JO  - Biogeosciences
VL  - 16
IS  - 7
SN  - 1726-4189
CY  - Katlenburg-Lindau [u.a.]
PB  - Copernicus
M1  - FZJ-2019-03024
SP  - 1411 - 1432
PY  - 2019
AB  - Dissolved  organic  matter  (DOM)  is  part  of  thebiogeochemical cycles of carbon and nutrients, carries pol-lutants  and  drives  soil  formation.  The  DOM  concentrationand  properties  along  the  water  flow  path  through  forestecosystems  depend  on  its  sampling  location  and  transfor-mation processes. To improve our understanding of the ef-fects  of  forest  management,  especially  tree  species  selec-tion and management intensity, on DOM concentrations andproperties  of  samples  from  different  ecosystem  fluxes,  westudied throughfall, stemflow, litter leachate and mineral soilsolution  at  26  forest  sites  in  the  three  regions  of  the  Ger-man  Biodiversity  Exploratories.  We  covered  forest  standswith  three  management  categories  (coniferous,  deciduousage class and unmanaged beech forests). In water samplesfrom these forests, we monitored DOC concentrations over 4years and characterized the quality of DOM with UV-vis ab-sorption, fluorescence spectroscopy combined with parallelfactor  analysis  (PARAFAC)  and  Fourier  transform  ion  cy-clotron  resonance  mass  spectrometry  (FT-ICR-MS).  Addi-tionally, we performed incubation-based biodegradation as-says.  Multivariate  statistics  revealed  strong  significant  ef-fects  of  ecosystem  fluxes  and  smaller  effects  of  main  treespecies  on  DOM  quality.  Coniferous  forests  differed  fromdeciduous  forests  by  showing  larger  DOC  concentrations,more lignin- and protein-like molecules, and fewer tannin-like molecules in throughfall, stemflow, and litter leachate.Cluster  analysis  of  FT-ICR-MS  data  indicated  that  DOMcompositions, which varied in aboveground samples depend-ing  on  tree  species,  become  aligned  in  mineral  soil.  Thisalignment of DOM composition along the water flow pathin mineral soil is likely caused by microbial production andconsumption  of  DOM  in  combination  with  its  interactionwith the solid phase, producing a characteristic pattern of or-ganic compounds in forest mineral soils. We found similarlypronounced effects of ecosystem fluxes on the biodegradabil-ity of DOM, but surprisingly no differences between deciduous  and  coniferous  forests.  Forest  management  intensity,mainly  determined  by  biomass  extraction,  contribution  ofspecies, which are not site-adapted, and deadwood mass, didnot  influence  DOC  concentrations,  DOM  composition  andproperties significantly.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000463512200002
DO  - DOI:10.5194/bg-16-1411-2019
UR  - https://juser.fz-juelich.de/record/862823
ER  -