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 ı13C 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.