10.17637/rh.5711968 Alice Milner Alice Milner A.J.Baird A.J.Baird A.Blundell A.Blundell G.Swindles G.Swindles P.J.Morris P.J.Morris Data from: Microform-scale variations in peatland permeability and their ecohydrological implications Royal Holloway, University of London 2017 peatlands raised bog acrotelm-catotelm model permeability microform ecological memory persistence Ecology Hydrology 2017-12-18 13:45:46 Online resource https://royalholloway.figshare.com/articles/online_resource/Data_from_Microform-scale_variations_in_peatland_permeability_and_their_ecohydrological_implications/5711968 1. The acrotelm-catotelm model of peatland hydrological and biogeochemical processes posits that the permeability of raised bogs is largely homogenous laterally but varies strongly with depth through the soil profile; uppermost peat layers are highly permeable while deeper layers are, effectively, impermeable. 2. We measured down-core changes in peat permeability, plant macrofossil assemblages, dry bulk density and degree of humification beneath two types of characteristic peatland microform – ridges and hollows – at a raised bog in Wales. Six 14C dates were also collected for one hollow and an adjacent ridge. 3. Contrary to the acrotelm-catotelm model, we found that deeper peat can be as highly permeable as near-surface peat and that its permeability can vary by more than an order of magnitude between microforms over horizontal distances of 1-5 metres. 4. Our palaeo-ecological data paint a complicated picture of microform persistence. Some microforms can remain in the same position on a bog for millennia, growing vertically upwards as the bog grows. However, adjacent areas on the bog (< 10 m distant) show switches between microform type over time, indicating a lack of persistence. 5. Synthesis. We suggest that the acrotelm-catotelm model should be used cautiously; spatial variations in peatland permeability do not fit the simple patterns suggested by the model. To understand how peatlands as a whole function both hydrologically and ecologically it is necessary to understand how patterns of peat physical properties and peatland vegetation develop and persist.