Open AccessInterannual variations of soil organic carbon fractions in unmanaged volcanic soils (Canary Islands, Spain)
Author(s) -
ArmasHerrera Cecilia María,
Mora Juan Luis,
Arbelo Carmen Dolores,
RodríguezRodríguez Antonio
Publication year - 2012
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.355
Subject(s) - soil water , humus , biogeochemical cycle , environmental science , soil carbon , ecosystem , environmental chemistry , total organic carbon , organic matter , soil organic matter , plant litter , litter , biomass (ecology) , soil science , agronomy , chemistry , ecology , biology
The stability over time of the organic C stocked in soils under undisturbed ecosystems is poorly studied, despite being suitable for detecting changes related to climate fluctuations and global warming. Volcanic soils often show high organic C contents due to the stabilization of organic matter by short‐range ordered minerals or Al‐humus complexes. We investigated the dynamics of different organic C fractions in volcanic soils of protected natural ecosystems of the C anary I slands ( S pain) to evaluate the stability of their C pools. The study was carried out in 10 plots, including both undisturbed and formerly disturbed ecosystems, over two annual periods. C inputs to (litterfall) and outputs from (respiration) the soil, root C stocks (0–30 cm), soil organic C ( SOC ) fractions belonging to C pools with different degrees of biogeochemical stability –total oxidisable C ( TOC ), microbial biomass C ( MBC ), water soluble C ( WSC ), hot‐water extractable C ( HWC ), humic C ( HSC ), – and total soil N ( TN ) (at 0–15 and 15–30 cm) were measured seasonally.A statistically significant interannual increase in CO 2 emissions and a decrease in the SOC , mainly at the expense of the most labile organic forms, were observed, while the root C stocks and litterfall inputs remained relatively constant over the study period. The observed changes may reflect an initial increase in SOC resulting from low soil respiration rates due to drought during the first year of study. The soils of nearly mature ecosystems were more apparently affected by C losses, while those undergoing the process of active natural regeneration exhibited disguised C loss because of the C sequestration trend that is characteristic of progressive ecological succession.