Premium
Soil water dynamics and hydrophysical properties of regenerating Sphagnum layers in a cutover peatland
Author(s) -
Taylor Neil,
Price Jonathan
Publication year - 2015
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.10561
Subject(s) - peat , sphagnum , water table , bog , environmental science , hydrology (agriculture) , soil science , geology , soil water , groundwater , ecology , biology , geotechnical engineering
Abstract The physical and hydrological conditions in extracted peatlands often act as barriers to the regeneration of the keystone peat‐forming genus Sphagnum . Although previous work has suggested that Sphagnum mosses regenerating on cutover peat surfaces quickly become vulnerable to water stress as the thickness of the regenerated layer increases, uncertainties regarding the storage and transmission properties of this layer and how these might evolve over time have made this assertion difficult to evaluate. This study investigates the hydrophysical properties and hydrological behaviour of regenerating Sphagnum layers ranging from 3 to 43 years in age using both field and laboratory methods. The >40‐year‐old regenerated layers had significantly ( p < 0.001) higher bulk density and retention capacity in the 5‐cm‐thick basal layer directly overlying the cutover peat than the newer (<10 year old) regenerated layers. Capillarity was a much stronger control on surficial water content ( θ ) than precipitation, which was poorly retained in the Sphagnum canopy, suggesting that regulation of water table position is an effective method of controlling θ as a means of optimizing productivity. In general, the θ sustained at a given water table position decreased as regenerated layer thickness increased. Analysis of water table position relative to the former cutover peat surface in different areas of the site suggests that the soil water dynamics of the >40‐year‐old regenerated layers may be becoming increasingly similar to those of a natural bog peatland. Copyright © 2015 John Wiley & Sons, Ltd.