Peatland vascular plant functional types affect dissolved organic matter chemistry

• Published in: Plant and soil Vol. 407; no. 1/2; pp. 135 - 143
• Main Authors: Robroek, Bjorn J. M., Albrecht, Remy J. H., Hamard, Samuel, Pulgarin, Adrian, Bragazza, Luca, Buttler, Alexandre, Jassey, Vincent EJ
• Format: Journal Article
• Language: English
• Published: Cham Springer 01.10.2016; Springer International Publishing; Springer Nature B.V; Springer Verlag
• Subjects: Biomedical and Life Sciences; Chemistry; Dissolved organic carbon; Dissolved organic matter; Ecology; Environmental aspects; Environmental Sciences; Flowers & plants; Global Changes; Lawns; Life Sciences; Microhabitats; Peat; Peat soils; Peatlands; Plant Physiology; Plant populations; Plant Sciences; Polysaccharides; Regular Article; Soil organic matter; Soil Science & Conservation; Soils; Vascular plants; ANE, Sweden; Plant-soil interactions; Dissolved organic matter chemistry; FDA; Plant functional types; Enzymatic activity; FT-IR; Sphagnum-dominated peatlands
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-015-2710-3

Background and aims Northern peatlands are large repositories of carbon. Peatland vascular plant community composition has been functionally associated to a set of biogeochemical processes such as carbon cycling. Yet, we do not fully understand to what extent vascular plant functional types (PFTs) affect the quality of dissolved organic matter, and if there is any feedback on soil microbial activity. Methods Using a longer-term plant removal experiment in a boreo-nemoral peatland in Southern Sweden, we relate the dominance of different vascular plant functional types (i.e. ericoids and graminoids) to the chemistry of the dissolved organic matter (DOM) and microbial enzymatic activities (fluorescein diacetate hydrolysis, FDA). Results Our results show that PFTs modifies the composition of DOM moieties, with a decrease of low molecular weight organic compounds after vascular plant removal. The decrease of enzymatic activity by up to 68 % in the plant removal plots suggests a reduction in DOM mineralization in the absence of vascular plants. Conclusions Our results show that plant-derived low molecular organic compounds enhance peatland microbial activity, and suggest that an increase of vascular plant cover in response to climate change can potentially destabilize the OM in peatlands, leading to increased carbon losses.