Temperature sensitivity of carbon decomposition in soil aggregates along a climatic gradient

Abstract

© 2016, Sociedad Chilena de la Ciencia del Suelo. All rights reserved.Global warming affects the carbon (C) pools in terrestrial ecosystems, accelerating biological processes that feed back into the phenomenon of climate change. Globally, grassland ecosystems accumulate large quantities of organic C into soils and are considered a corner stone for global warming mitigation. The aim of this study was to evaluate the temperature sensitivity of C decomposition in different soil aggregate fractions in grassland ecosystems across a north-south latitudinal gradient in Chile. Soil samples were collected from Mediterranean semi-arid (MSA; 32°31’ to 34°19’ south latitude), temperate semi-oceanic (TSO; 35°36’ to 36°27’ south latitude), temperate oceanic (TO; 40°36’ to 43°03’ south latitude) and subpolar semi-oceanic (SPSO; 43°57’ to 47°40’ south latitude) climate zones, and water-stable macroaggregates (250-2,000 µm) and free microaggregates (50-250 µm) were isolated. Two experiments were perfor