In-situ warming does not change soil priming effect induced by glucose addition in a temperate forest

Abstract

Priming effect (PE) on soil organic carbon (SOC) decomposition caused by the addition of organic carbon (C) is an important ecological process in regulating soil C cycle. Additionally, most priming studies are confined to laboratory trials, while the assessment of soil PE under field conditions with variable weather conditions is scarce. This study assessed the direct effects of glucose addition and in-situ warming on the extent of PE under field conditions in a temperate forest. We evaluated soil PE using ¹³C-glucose labelling, a simple and novel technique, based on the Keeling plot method. Glucose addition significantly enhanced native SOC decomposition and induced strong PE. However, the effect of in-situ warming on the extent of PE was not significant. This study confirms the importance of PE in regulating SOC turnover under field conditions.