Growing peat

Contains fulltext : 148821.pdf (publisher's version ) (Open Access)Peat formation is a slow process and the formation of thick peat layers in large parts of e.g. Russia, Canada and Indonesia has generally taken thousands of years. Due to degradation of peatlands throughout the world, as a result of changed land use and pollution, many ecosystem services provided by peatlands have disappeared. It is therefore necessary to restore degraded systems or create new peat-forming wetlands. Information on the early stages of peat formation is scarce, however, and the biogeochemical conditions that stimulate the transition of mineral sand to growing peatland (which would have happened thousands of years ago in e.g. Russia, Canada and Indonesia) remain largely unknown. In this thesis, several pathways of peat formation are studied using three model species: Stratiotes aloides, which grows in the aquatic phase, Typha spp., which grow in the semi-terrestrial phase, and Sphagnum mosses, which grow in the terrestrial or floating mire stage. Using a combination of lab studies, mesocosm experiments and field measurements, the biogeochemical conditions and biotic interactions (such as facilitation) that stimulate or limit growth of these ecosystem engineers were studied. Furthermore, for each of these species, the contribution to the net C sequestration rate of a system -or the net build-up of an organic layer that can form peat- was determined. We found that there is a huge difference between starting peat formation “from scratch” (on mineral soils) or restoring peat formation in a degraded peatland. In this latter case, secondary peat formation can be started after habitat conditions are suitable for growth of Sphagnum mosses (e.g. by topsoil removal and rewetting). For primary peat formation, on the other hand, the main concern is the low colonisation rates of low-nutrient, mineral soils. Therefore, modifying habitat conditions to suit the requirements of target species and harnessing inter- and intraspecific facilitation is essential to transform such a system into a net C sink without having to wait a thousand years.Radboud Universiteit Nijmegen, 22 december 2015Promotores : Lamers, L.P.M., Smolders, A.J.P. Co-promotores : Roelofs, J.G.M., Kosten, S.175 p

Growing peat

Peat formation is a slow process and the formation of thick peat layers in large parts of e.g. Russia, Canada and Indonesia has generally taken thousands of years. Due to degradation of peatlands throughout the world, as a result of changed land use and pollution, many ecosystem services provided by peatlands have disappeared. It is therefore necessary to restore degraded systems or create new peat-forming wetlands. Information on the early stages of peat formation is scarce, however, and the biogeochemical conditions that stimulate the transition of mineral sand to growing peatland (which would have happened thousands of years ago in e.g. Russia, Canada and Indonesia) remain largely unknown. In this thesis, several pathways of peat formation are studied using three model species: Stratiotes aloides, which grows in the aquatic phase, Typha spp., which grow in the semi-terrestrial phase, and Sphagnum mosses, which grow in the terrestrial or floating mire stage. Using a combination of lab studies, mesocosm experiments and field measurements, the biogeochemical conditions and biotic interactions (such as facilitation) that stimulate or limit growth of these ecosystem engineers were studied. Furthermore, for each of these species, the contribution to the net C sequestration rate of a system -or the net build-up of an organic layer that can form peat- was determined. We found that there is a huge difference between starting peat formation “from scratch” (on mineral soils) or restoring peat formation in a degraded peatland. In this latter case, secondary peat formation can be started after habitat conditions are suitable for growth of Sphagnum mosses (e.g. by topsoil removal and rewetting). For primary peat formation, on the other hand, the main concern is the low colonisation rates of low-nutrient, mineral soils. Therefore, modifying habitat conditions to suit the requirements of target species and harnessing inter- and intraspecific facilitation is essential to transform such a system into a net C sink without having to wait a thousand years

Reproduction of the female common hamster (cricetus cricetus) in limburg, the netherlands

Contains fulltext : 92270.pdf (publisher's version ) (Open Access)9 p

To float or not to float: How interactions between light and dissolved inorganic carbon species determine the buoyancy of stratiotes aloides

Contains fulltext : 144080.pdf (publisher's version ) (Open Access

'Mini-Ilperveld' data on Sphagnum and diazotrophs from experiment in water bath lab in Radboud University Nijmegen with deep peat monoliths and Sphagnum from Ilperveld

Item does not contain fulltextThis dataset is used for our paper ‘Symbiosis revisited: phosphorus and acid buffering stimulate N2 fixation but not Sphagnum growth’ in Biogeosciences. It contains background data on Sphagnum in the Ilperveld field site, the Netherlands and on content of peat monoliths from deep (20 cm) soil layers from Ilperveld. These peat monoliths and Sphagnum mosses were transported to mesocosms in the water bath lab in Nijmegen in September 2013. Two species of Sphagnum (S. palustre and S. squarrosum) were applied to the peat and a flux of treatment solution was added to the mesocosms during 10 weeks. Treatments were a full factorial design of phosphorus (P) and bicarbonate (HCO3) fluxes in surface water. After 10 weeks (in February 2014) surface water nutrient concentrations were measured and an incubation experiment was done on N2 fixation activity in Sphagnum. Also Sphagnum performance data were obtained. All can be found in this data set

Simultaneous high c fixation and high c emissions in sphagnum mires

Contains fulltext : 144073.pdf (publisher's version ) (Open Access

Azolla along a phosphorus gradient: biphasic growth response linked to diazotroph traits and phosphorus-induced iron chlorosis

Contains fulltext : 189958.pdf (publisher's version ) (Open Access)8 p