The spectral behaviour of Sphagnum canopies under varying hydrological conditions

We tested the extent to which the spectral response (0.4–2.5 μm) of Sphagnum can be used to indicate changes in near‐surface hydrological conditions in northern wetlands. Via laboratory experimentation on three typical Sphagnum species we found that: (1) there is a clear link between (a) a ratio of SWIR/NIR reflectance (ETM+ Ch 5/Ch4) and (b) the relative depth of the water absorbion feature centred at 1.205 μm (RDI), and near‐surface volumetric moisture content (VMC) of the three species, (2) the changes in this ratio seem to be distinct for each species, and (3) data relating to the red‐edge inflection point (REIP) for the Sphagnum species may also yield important information on variations in photosynthetic activity with near‐surface VMC.