TY  - JOUR
AU  - De Feudis, M.
AU  - Cardelli, V.
AU  - Massaccesi, L.
AU  - Hofmann, D.
AU  - Berns, A. E.
AU  - Bol, R.
AU  - Cocco, S.
AU  - Corti, G.
AU  - Agnelli, A.
TI  - Altitude affects the quality of the water-extractable organic matter (WEOM) from rhizosphere and bulk soil in European beech forests
JO  - Geoderma
VL  - 302
SN  - 0016-7061
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2017-03348
SP  - 6 - 13
PY  - 2017
AB  - Water-extractable organic matter (WEOM) is the most dynamic and bioavailable fraction of the soil organicmatter pool. Although the litterfloor is considered the main source of WEOM, roots also release a great amountof labile organic compounds through rhizodeposition processes. This makes the rhizosphere, the small soilvolume in proximity to the roots, a soil compartment relatively enriched in WEOM. Since both the rhizosphereand the labile organic C pool are highly sensitive to the environmental conditions we evaluated thecharacteristics of WEOM from rhizosphere and bulk soil collected from the A horizons of European beech(Fagus sylvaticaL.) forest soils of Apennines mountains (central Italy) at two altitudes (800 and 1000 m), usingelevation as a proxy for temperature change. Specifically, we tested ifi) the rhizosphere contains higher amountsof WEOM with a greater diversity of compounds with respect to the bulk soil, andii) this effect is morepronounced at higher altitude. At both 800 m and 1000 m above sea level, the main distinction between WEOMfrom rhizosphere and bulk soil was the larger amounts of sugars in the soil close to the roots. Further, our resultsindicated an influence of altitude on rhizospheric processes as suggested by the larger concentrations of organicC and soluble phenols, and richness of tannins in the rhizosphere WEOM than in the bulk soil at 1000 m. Weattributed this influence to environmental constraints which enhanced the release of labile organics andsecondary metabolites by rhizodeposition and humification processes in the rhizosphere. As a whole, our datadraw a picture where the roots are able to affect the characteristics of WEOM and environmental constraintsenhance the differentiation between rhizosphere and bulk soil. This view confirms the influence of therhizosphere on the soil C cycle, and the importance of the rhizospheric processes when environmental conditionsbecome harsher.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000403522800002
DO  - DOI:10.1016/j.geoderma.2017.04.015
UR  - https://juser.fz-juelich.de/record/829704
ER  -