Joosten, H. | bioRxiv Science

bioRxiv2020

Axenic in-vitro cultivation of nineteen peat-moss (Sphagnum L.) species as a resource for basic biology, biotechnology and paludiculture

O_LIThe cultivation of Sphagnum mosses reduces CO2 emissions by rewetting drained peatlands and by substituting peat with renewable biomass. Sphagnum farming requires large volumes of founder material, which can only be supplied sustainably by axenic cultivation in bioreactors. C_LIO_LIWe established axenic in-vitro cultures from sporophytes of 19 Sphagnum species collected in Austria, Germany, Latvia, Netherlands, Russia and Sweden, namely S. angustifolium, S. balticum, S. capillifolium, S. centrale, S. compactum, S. cuspidatum, S. fallax, S. fimbriatum, S. fuscum, S. lindbergii, S. medium/divinum, S. palustre, S. papillosum, S. rubellum, S. russowii, S. squarrosum, S. subnitens, S. subfulvum, and S. warnstorfii. These species cover five of the six European Sphagnum sections, namely Acutifolia, Cuspidata, Rigida, Sphagnum and Squarrosa. C_LIO_LITheir growth was measured in axenic suspension cultures, whereas their ploidy was determined by flow cytometry and compared with the genome size of Physcomitrella patens. We identified haploid and diploid Sphagnum species, found that their cells are predominantly arrested in the G1-phase of the cell cycle, and did not find a correlation between plant productivity and ploidy. C_LIO_LIWith this collection, high-quality founder material for diverse large-scale applications but also for basic Sphagnum research is available from the International Moss Stock Center (IMSC). C_LI

plant biology↗

bioRxiv2019

Prompt rewetting of drained peatlands reduces climate warming despite methane emissions

Peatlands are strategic areas for climate change mitigation because of their matchless carbon stocks. Drained peatlands release this carbon to the atmosphere as carbon dioxide (CO2). Peatland rewetting effectively stops these CO2 emissions, but also re-establishes the emission of methane (CH4). Essentially, management must choose between CO2 emissions from drained or CH4 emissions from rewetted peatland. This choice must consider radiative effects and atmospheric lifetimes of both gases, with CO2 being a weak but persistent and CH4 a strong but short-lived greenhouse gas. The resulting climatic effects are, thus, strongly time-dependent. We used a radiative forcing model to compare forcing dynamics of global scenarios for future peatland management using areal data from the Global Peatland Database. Our results show that CH4 radiative forcing does not undermine the climate change mitigation potential of peatland rewetting. Instead, postponing rewetting increases the long-term warming effect of continued CO2 emissions. Warnings against CH4 emissions from rewetted peatlands are therefore unjustified and counterproductive.

ecology↗