Data Entry: Please note that the research database will be replaced by UNIverse by the end of October 2023. Please enter your data into the system https://universe-intern.unibas.ch. Thanks
Relative stability of soil carbon revealed by shifts in delta N-15 and C:N ratio
Journal
Biogeosciences
Volume
5
Number
1
Pages / Article-Number
123-128
Abstract
Life on earth drives a continuous exchange of carbon between soils and the atmosphere. Some forms of soil carbon, or organic matter, are more stable and have a longer residence time in soil than others. Relative differences in stability have often been derived from shifts in delta C-13 (which is bound to a vegetation change from C3 to C4 type) or through C-14-dating (which is bound to small sample numbers because of high measurement costs). Here, we propose a new concept based on the increase in delta N-15 and the decrease in C:N ratio with increasing stability. We tested the concept on grasslands at different elevations in the Swiss Alps. Depending on elevation and soil depth, it predicted mineral-associated organic carbon to be 3 to 73 times more stable than particulate organic carbon. Analysis of C-14-ages generally endorsed these predictions.