Weetman, G.F., R. Fournier, J. Barker, and E. Schnorbus-Panozzo, 1989b. Foliar analysis and response of fertilized chlorotic western hemlock and western red cedar reproduction on salal-dominated cutovers on Vancouver Island. Can. J. For. Res. 19:1512-1520.

Microplot and conventional plot trials (in British Columbia) were used to determine the nutritional status and required nutrient additions to bring young regeneration of western hemlock (Tsuga heterophylla) and western red cedar (Thuja plicata) out of check. The trees were growing on deep mor-humus podzols invaded by dense salal (Gaultheria shallon) vegetation. Salal removal by grubbing and application of Garlon [triclopyr] was also tested. Foliar vector analysis, used for hemlock, identified a response to N and P that was confirmed by subsequent 3-year height growth response. Salal removal only resulted in increased N uptake in red cedar. Red cedar also responded to N and P additions, but vector analysis was not feasible owing to indeterminate growth. Foliar analysis values were compared with published data. It is suggested that salal competition or allelopathy may be the primary cause of inadequate N and P nutrition.