Temporal variation of Q10 values in response to changes in soil physiochemical properties caused by fairy rings

Abstract

The temperature sensitivity (Q10 values) of soil respiration (Rs) has been a source of much debate given the potential feedbacks between soil carbon pools and global warming. Many studies have been conducted to investigate monthly variations in Q10 values. However, few studies have focused on the underlying causes of the variations, and it no clear how seasonal variation in soil physicochemical properties could affect Q10. The fairy rings (FRs) caused by basidiomycete fungi can change soil physiochemical properties. Therefore, we collected a series of soils over five months (June–October) from three zones impacted by FRs: outside (OUT), on (ON) and inside (IN) the rings to explore the relationship between soil physicochemical properties and Q10 values. We observed significantly higher plant biomass, plant nitrogen content and soil available phosphorus (P) in the ON zone than the OUT and IN zones (p < 0.05). Soil total carbon, nitrogen and water content decreased significantly from the OUT zone to the IN zone. In contrast, soil pH increased significantly from the OUT zone to the IN zone. The Q10 values increased significantly as months passed, different zones followed the order IN > OUT > ON (p < 0.05), and the response of Rs to the zones and progression through the months was the opposite to that of Q10 values. Our study suggest that soil available P and water content were two dominant factors influencing temporal patterns in Q10, and that soil pH was closely related to Rs, which can also affect Q10 indirectly.