Peat mosses (Sphagnum) are ecosystem engineers-species in boreal peatlands simultaneously create and inhabit narrow habitat preferences along two microhabitat gradients: an ionic gradient and a hydrological hummock-hollow gradient. In this article, we demonstrate the connections between microhabitat preference and phylogeny in Sphagnum. Using a dataset of 39 species of Sphagnum, with an 18-locus DNA alignment and an ecological dataset encompassing three large published studies, we tested for phylogenetic signal and within-genus changes in evolutionary rate of eight niche descriptors and two multivariate niche gradients. We find little to no evidence for phylogenetic signal in most component descriptors of the ionic gradient, but interspecific variation along the hummock-hollow gradient shows considerable phylogenetic signal. We find support for a change in the rate of niche evolution within the genus-the hummock-forming subgenus Acutifolia has evolved along the multivariate hummock-hollow gradient faster than the hollow-inhabiting subgenus Cuspidata. Because peat mosses themselves create some of the ecological gradients constituting their own habitats, the classic microtopography of Sphagnum-dominated peatlands is maintained by evolutionary constraints and the biological properties of related Sphagnum species. The patterns of phylogenetic signal observed here will instruct future study on the role of functional traits in peatland growth and reconstruction.

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Question: How many years are required for a gradient of microtopography to be initiated in revegetated cutover peatlands and become similar to natural bogs? Location: Newly formed Sphagnum carpets on cutover peatlands that revegetated spontaneously after site abandonment (in Estonia), or following active restoration (in Canada) and on undisturbed natural bogs nearby. Methods: Moss surface height was measured along linear transects above a local reference level (the lowest point for a given transect). Heights of at least 20 cm were associated with hummocks. Frequency distributions of surface height and principal component analyses (separately for Canada and Estonia) were conducted to follow the evolution of microtopography in revegetated sites and their similarity with those of natural peatlands. In Canada, regressions were also performed to estimate the time required for the microtopography in revegetated cutover peatlands to become similar to that found in natural bogs. Results: Only 10–30 yr were needed for microstructures comparable to those in natural bogs to develop on restored peatlands where Sphagnum diaspores have been reintroduced. However, this process may take more than a century in cutover peatlands left to revegetate spontaneously. Conclusions: In cutover peatlands with spontaneous revegetation, hummock–hollow formation starts on bare peat which lacks both plant propagules and viable seed banks, and the initiation of microstructures is probably more akin to the process that occurs naturally. Nonetheless, hummock–hollow microtopography resembling that found in natural bogs without pools appeared, in all of the examined cutover peatlands, over periods that are short in terms of peatland development time‐scales. Active peatland restoration could effectively reduce the time required for initiation of microtopography by about 70 yr.