第六届青年地学论坛

1699 / 2019-08-27 11:03:48

Mycorrhiza and its potential contribution to soil carbon sequestration in subtropical forests

4、生态与可持续发展 > 专题2：生物地球化学循环与全球变化

Arbuscular mycorrhiza (AM) is the dominate symbiosis in subtropical forests. We found glomalin-related soil protein (GRSP), the byproduct of AM fungi, is an easily measurable indictor to investigate microbial involved soil carbon dynamics. Our results showed that the mean content of total GRSP (T-GRSP) is 394.71±108.90 g m-2 in the top 10 cm soil, which accounted for 3.2-4.7% of soil organic carbon (SOC). T-GRSP has high aromatic (20.6-30.0%) and alkyl (27.7-38.3%) carbon than SOC (aromatic (2.3-8.7%) and (22.7-35.3%)) in subtropical forests, indicating that T-GRSP promotes the accumulation of recalcitrant component of SOC. Elevated CO2 concentration significantly increased GRSP by 35.02%. Nitrogen addition increased GRSP by 1.72%-48.49%. However, the marginal increase of GRSP was observed because of the interaction between elevated CO2 and N addition offset their independent effects. Warming also increased GRSP concentration with distinct seasonal dynamics. Our current knowledge on GRSP indicated that it could be an indicator of microbial regulator on soil carbon dynamics in subtropical forests, especially in light of environmental changes already occurred and would be accelerated under anthropogenic activities.