Title Soil macroaggregate dynamics in a mountain spatial climate gradient
Author Cécillon, L.; de Mello, N.A.; de Danieli, S.; Brun, J.
Author Affil Cécillon, L., CEMAGREF Grenoble, Mountain Ecosystems Research Unit, Saint Martin d'Heres, France. Other: Norwegian University of Life Sciences, Norway; Austrian Forest Research Center, Austria; French Agency for Environment and Energy Management, France; Federal University of Technology, Brazil; CETIOM Paris-Grignon, France
Source Mountain soils under a changing climate and land use, edited by F. Hagedorn, R. Jandl and J. Mulder. Biogeochemistry (Dordrecht), 97(1), p.31-43, . Publisher: Springer, Dordrecht - Boston - Lancaster, International. ISSN: 0168- 2563
Publication Date Jan. 2010
Notes In English. 59 refs. GeoRef Acc. No: 310477
Index Terms aggregates; Alpine landscapes; climate; climatic change; freezing; freeze thaw cycles; soils; soil aggregates; soil temperature; spectra; temperature; thawing; vegetation; France--French Alps; aggregate; alpine environment; Alps; climate change; dynamics; Europe; France; French Alps; frost action; horizons; mountains; near-infrared spectra; organic compounds; physicochemical properties; terrestrial environment; Western Europe
Abstract We investigated the response of soil macroaggregate dynamics to soil temperature modification along a spatial gradient located on a forested north-facing slope in the southern French Alps, simulating long-term adjustment of soil-plant interactions to absence or occurrence of soil frost. Soil macroaggregate (›250 µm) content of Ah horizons was strongly depleted (72%) in colder plots affected by freeze-thaw events, compared to 96% in warmer and frost-free plots (p‹0.05). A visual assessment of soil macroaggregation showed that physical processes were the main drivers of soil macroaggregation in colder plots, with 66% of the 5-12.5 mm fraction and the whole 3.15-5 mm fraction. Conversely, we found a balanced contribution of biological and physical aggregation pathways in warmer plots. All identified macroaggregate types could be classified, depending on their organic matter (OM) quality, using principal component analyses of their near infrared spectra. Such spectral classifications indicated temporal changes in OM quality of macroaggregates, from formation to colonization by fine roots, suggesting ecosystem-specific ontogenic trajectories for soil macroaggregation. Further physico-chemical characterizations of soil macroaggregates and Ah horizons showed that soil organic carbon content in the Ah horizon was constant along the gradient, whereas soil erodibility was reduced in warmer soils, which prevented the occurrence of fragile macroaggregates formed by freeze- thaw events. Our study thus suggests changes in the erodibility of mountain forest soils under changing climate. Soil erodibility could be affected either positively under warmer conditions, or negatively, under increased soil frost. Copyright 2009 Springer Science+Business Media B.V.
URL http://hdl.handle.net/10.1007/s10533-009-9341-9
Publication Type journal article
Record ID 65007122