Thu, Aug 05, 2021:On Demand
Background/Question/Methods
Rehabilitation of agricultural landscapes with riparian systems is a transformative practice that achieves several ecosystem services, including carbon (C) storage. Yet, there is very little information on this plant community and its role in soil C storage in these critical transition zones. Plant litter plays a crucial role in soil C dynamics, via fresh C inputs and potential soil C loss through priming effects. However, the role of morphological litter traits and broad litter functional diversity in these C fluxes is not well known. In this study, we assessed C dynamics of riparian plant litter using CO2 flux and δ13C signatures. Drawing on a network of established riparian buffers within southern Ontario, Canada, we collected litter from plant communities which have significantly different community weighted functional leaf trait syndromes: a rehabilitated deciduous buffer (RDB), a mature coniferous buffer (MCB) and a grassland buffer (GRB). We employed a 95-day incubation experiment, comparing the C dynamic of soil with GRB, RDB or MCB litter mixtures and soil with no litter (control). We assessed two treatments of litter diversity: the original diversified litter mixture, a composition determined with field measurements, and single species, representing the dominant species of each plant community.
Results/Conclusions We found significantly different rates of total C-CO2 between riparian type, where total C-CO2 emissions were highest for the GRB treatment after 95 days (354.7 ± 13.3 mg C-CO2 kg-1 soil), followed by RDB (266.1 ± 12.0 mg C-CO2 kg-1 soil) and MCB (208.9 ± 18.7 mg C-CO2 kg-1 soil). Litter diversity had a significant positive impact among all riparian types, with higher total C-CO2 emissions within litter mixtures as compared to single species treatments. The impacts of litter functional trait syndromes and litter functional diversity on priming effects will also be discussed.
Results/Conclusions We found significantly different rates of total C-CO2 between riparian type, where total C-CO2 emissions were highest for the GRB treatment after 95 days (354.7 ± 13.3 mg C-CO2 kg-1 soil), followed by RDB (266.1 ± 12.0 mg C-CO2 kg-1 soil) and MCB (208.9 ± 18.7 mg C-CO2 kg-1 soil). Litter diversity had a significant positive impact among all riparian types, with higher total C-CO2 emissions within litter mixtures as compared to single species treatments. The impacts of litter functional trait syndromes and litter functional diversity on priming effects will also be discussed.