title: Belowground carbon allocation by trees drives seasonal patterns of extracellular enzyme activities by altering microbial community composition in a beech forest soil.
abstract: *Plant seasonal cycles alter carbon (C) and nitrogen (N) availability for soil microbes, which may affect microbial community composition and thus feed back on microbial decomposition of soil organic material and plant N availability. The temporal dynamics of these plant-soil interactions are, however, unclear. *Here, we experimentally manipulated the C and N availability in a beech forest through N fertilization or tree girdling and conducted a detailed analysis of the seasonal pattern of microbial community composition and decomposition processes over 2 yr. *We found a strong relationship between microbial community composition and enzyme activities over the seasonal course. Phenoloxidase and peroxidase activities were highest during late summer, whereas cellulase and protease peaked in late autumn. Girdling, and thus loss of mycorrhiza, resulted in an increase in soil organic matter-degrading enzymes and a decrease in cellulase and protease activity. *Temporal changes in enzyme activities suggest a switch of the main substrate for decomposition between summer (soil organic matter) and autumn (plant litter). Our results indicate that ectomycorrhizal fungi are possibly involved in autumn cellulase and protease activity. Our study shows that, through belowground C allocation, trees significantly alter soil microbial communities, which may affect seasonal patterns of decomposition processes.
authors.affiliation: University of Vienna, Department of Chemical Ecology and Ecosystem Research, Vienna, Austria. christina.kaiser@univie.ac.at
authors.forename: Christina
authors.initials: C
authors.lastname: Kaiser
authors.forename: Marianne
authors.initials: M
authors.lastname: Koranda
authors.forename: Barbara
authors.initials: B
authors.lastname: Kitzler
authors.forename: Lucia
authors.initials: L
authors.lastname: Fuchslueger
authors.forename: Jörg
authors.initials: J
authors.lastname: Schnecker
authors.forename: Peter
authors.initials: P
authors.lastname: Schweiger
authors.forename: Frank
authors.initials: F
authors.lastname: Rasche
authors.forename: Sophie
authors.initials: S
authors.lastname: Zechmeister-Boltenstern
authors.forename: Angela
authors.initials: A
authors.lastname: Sessitsch
authors.forename: Andreas
authors.initials: A
authors.lastname: Richter
mesh_terms: D001419:Bacteria / Q000201:enzymology / Q000254:growth & development*; D015415:Biomarkers / Q000378:metabolism; D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D002980:Climate; D005110:Extracellular Space / Q000201:enzymology*; D029964:Fagus / Q000378:metabolism* / Q000382:microbiology; D038821:Mycorrhizae / Q000201:enzymology / Q000254:growth & development*; D009584:Nitrogen / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D012044:Regression Analysis; D012621:Seasons; D012987:Soil; D012988:Soil Microbiology; D012995:Solubility; D013696:Temperature; D014197:Trees / Q000378:metabolism / Q000382:microbiology
chemical_list: D015415:Biomarkers; D010743:Phospholipids; D012987:Soil; D002244:Carbon; D009584:Nitrogen