Moss health is probably a better long term integrator of water available at the site for the whole of the growing season. The CWC is only measured over one 24 h period in each season and represents a point measure of likely maximal water availability. We are exploring other, better long term integrators of community water content, including the ı13 C signature of the moss turf that has been shown to correlate with growth rates and overall site wetness (Clarke et al., 2012; Wasley et al., 2006b,2012). However, these all rely on destructive sampling and ultimately a non-intrusive and non-destructive method of estimating water availability is required to avoid ongoing sampling and damage to these fragile and finite Antarctic communities. The outliers in Fig. 7 showing 0% moss health can be explained by the fact that these quadrats have a small upstream area (hence their low value on the x-axis), however, they are not directly fed by the snow pack.