Plant functional types and temperature control carbon input via roots in peatland soils

Autor:	Luca Bragazza, Juul Limpens, Karsten Kalbitz, Björn Erhagen, Lilli Zeh
Jazyk:	angličtina
Rok vydání:	2019
Předmět:	0106 biological sciences Peat Peatland ved/biology.organism_classification_rank.species Soil Science Plant Ecology and Nature Conservation Plant Science Graminoid 01 natural sciences Shrub Root carbon input Soil respiration Dissolved organic carbon Sedges δ C WIMEK Chemistry ved/biology Vascular plants food and beverages 04 agricultural and veterinary sciences Soil carbon Plant functional type Agronomy Soil water 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Plantenecologie en Natuurbeheer Shrubs 010606 plant biology & botany
Zdroj:	Plant and Soil, 438(1-2), 19-38 Plant and Soil 438 (2019) 1-2
ISSN:	0032-079X
DOI:	10.1007/s11104-019-03958-6
Popis:	Aims: Northern peatlands store large amounts of soil organic carbon (C) that can be very sensitive to ongoing global warming. Recently it has been shown that temperature-enhanced growth of vascular plants in these typically moss-dominated ecosystems may promote microbial peat decomposition by increased C input via root exudates. To what extent different plant functional types (PFT) and soil temperature interact in controlling root C input is still unclear. In this study we explored how root C input is related to the presence of ericoid shrubs (shrubs) and graminoid sedges (sedges) by means of a factorial plant clipping experiment (= PFT effect) in two peatlands located at different altitude (= temperature effect). Methods: By selective clipping of shrub and sedge shoots in mixed vegetation at two Alpine peatland sites we interrupted the above- to belowground translocation of C, thus temporarily inhibiting root C release. Subsequent measurements of soil respiration, dissolved organic carbon (DOC) concentration and stable isotope composition ( 13 C) of DOC in pore water were used as proxies to estimate the above- to belowground transfer of C by different PFT. Results: We found that soil respiration rates and DOC concentrations temporarily decreased within 24 h after clipping, with the decrease in soil respiration being most pronounced at the 1.4 °C warmer peatland after clipping shrubs. The transient drop in DOC concentration coincided with a shift towards a heavier C isotope signature, indicating that the decrease was associated with inhibition of a light C source that we attribute to root exudates. Together these results imply that shrubs translocated more C into the peat than sedges, particularly at higher temperature. Conclusions: We showed that plant functional type and temperature interact in controlling root C input under field conditions in peatlands. Our results provide a mechanistic evidence that shrubs may potentially promote the release of stored soil C through root-derived C input.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e86e92d835889aabdb59789d7700a8e7 https://doi.org/10.1007/s11104-019-03958-6 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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