The Norwegian Sphagna: a field colour guide

Colour plates illustrate fifty-four Sphagnum taxa, 50 species and 4 subspecies. This constitues all the known peat mosses from Norway including arctic Svalbard. Macroscopic keys to sections and species within the different sections are presented. These keys used in combination with the colour plates and a hand lens should in most cases enable the correct determination of the Norwegian peat mosses in the field

Three species of Sphagnum endemic to Ile Amsterdam, Terres Australes et Antarctiques Françaises: S. cavernulosum sp. nov., S. complanatum sp. nov. and S. islei

International audienceThe taxonomy of three recently collected species of peat mosses (Sphagnales) from Iˆle Amsterdam, Terres Australes et Antarctiques Franc¸aises, is reviewed. Two species belong to Sphagnum subgenus Subsecunda, while a third has uncertain taxonomic affinity. One of the Subsecunda species has previously been described under the name S. islei Warnst. based on material from Iˆle Amsterdam and we provide an amended description. A second species is described as S. complanatum sp. nov. Both species share morphological characteristics with S. capense Hornsch., known from Southern Africa, Malawi, Madagascar, and Reunion. The third species is distinguished by several morphological characteristics and is described as S. cavernulosum sp. nov. It has morphological characteristics that are shared with the subgenera Sphagnum and Acutifolia, and also subgenus Subsecunda. Among known Sphagnum species, the closest morphological relative seems to be S. novo-caledoniae Paris & Warnst., described from southern Melanesia in Oceania. The morphology of these three species is described. At present, these three species appear to be endemic to Iˆle Amsterdam. Their phylogenetic affinities and likely evolutionary histories are discussed based on their morphological characteristics. Molecular data are necessary for further evaluation of their phylogeny, taxonomic relationships, and phylogeography, but repeated attempts to obtain gene sequences have so far failed

Sjekkliste over norske mosar. Vitskapleg og norsk namneverk

Frisvoll, A.A, Elvebakk, A., Flatberg, K.L & Økland, R.H. Sjekkliste over norske mosar. Vitskapleg og norsk namneverk. NINA Temahefte 4: 1-10

Environmental drivers of Sphagnum growth in peatlands across the Holarctic region

The relative importance of global versus local environmental factors for growth and thus carbon uptake of the bryophyte genus Sphagnum – the main peat-former and ecosystem engineer in northern peatlands – remains unclear. 2) We measured length growth and net primary production (NPP) of two abundant Sphagnum species across 99 Holarctic peatlands. We tested the importance of previously proposed abiotic and biotic drivers for peatland carbon uptake (climate, N deposition, water table depth, and vascular plant cover) on these two responses. Employing structural equation models, we explored both indirect and direct effects of drivers on Sphagnum growth. 3) Variation in growth was large, but similar within and between peatlands. Length growth showed a stronger response to predictors than NPP. Moreover, the smaller and denser Sphagnum fuscum growing on hummocks had weaker responses to climatic variation than the larger and looser S. magellanicum growing in the wetter conditions. Growth decreased with increasing vascular plant cover within a site. Between sites, precipitation and temperature increased growth for S. magellanicum. The structural equation models indicated that indirect effects are important. For example, vascular plant cover increased with a deeper water table, increased nitrogen deposition, precipitation and temperature. These factors also influenced Sphagnum growth indirectly by affecting moss shoot density. 4) Synthesis Our results imply that in a warmer climate, S. magellanicum will increase length growth as long as precipitation is not reduced, while S. fuscum is more resistant to decreased precipitation, but also less able to take advantage of increased precipitation and temperature. Such species-specific sensitivity to climate may affect competitive outcomes in a changing environment, and potentially the future carbon sink function of peatlands

Environmental drivers of Sphagnum growth in peatlands across the Holarctic region

The relative importance of global versus local environmental factors for growth and thus carbon uptake of the bryophyte genusSphagnum-the main peat-former and ecosystem engineer in northern peatlands-remains unclear. We measured length growth and net primary production (NPP) of two abundantSphagnumspecies across 99 Holarctic peatlands. We tested the importance of previously proposed abiotic and biotic drivers for peatland carbon uptake (climate, N deposition, water table depth and vascular plant cover) on these two responses. Employing structural equation models (SEMs), we explored both indirect and direct effects of drivers onSphagnumgrowth. Variation in growth was large, but similar within and between peatlands. Length growth showed a stronger response to predictors than NPP. Moreover, the smaller and denserSphagnum fuscumgrowing on hummocks had weaker responses to climatic variation than the larger and looserSphagnum magellanicumgrowing in the wetter conditions. Growth decreased with increasing vascular plant cover within a site. Between sites, precipitation and temperature increased growth forS. magellanicum. The SEMs indicate that indirect effects are important. For example, vascular plant cover increased with a deeper water table, increased nitrogen deposition, precipitation and temperature. These factors also influencedSphagnumgrowth indirectly by affecting moss shoot density. Synthesis. Our results imply that in a warmer climate,S. magellanicumwill increase length growth as long as precipitation is not reduced, whileS. fuscumis more resistant to decreased precipitation, but also less able to take advantage of increased precipitation and temperature. Such species-specific sensitivity to climate may affect competitive outcomes in a changing environment, and potentially the future carbon sink function of peatlands