Figure 6 : Soil calcium dynamics and ecological responses of western redcedar.

From: Intertidal resource use over millennia enhances forest productivity

Figure 6

Levels of calcium in (a) soil and (b) western redcedar (T. plicata) wood, and with forest productivity metrics of (c) radial growth and (d) the proportion of western redcedar trees exhibiting top die-back (image showing redcedar with (i) and without (ii) top die-back). Red circles correspond to habitation sites with shell middens (n=6; see Table 1 for details). Blue circles correspond to control sites that were selected based on similar composition (dominance of western redcedar), high productivity and lacking a shell midden (hence was considered not to be a habitation site). Coloured circles are mean values and error bars represent standard error. Image credit: A. Trant.