Sacrificial nurse trees (sown or planted in the same spot / hole) is well-known but limited used and documented in Denmark.
The common nurse species is Sitka spruce protecting more vulnerable conifers – like Douglas fir or silver fir.
Picture shows protection against red deer – until Sitka is removed! It needs to be removed or “reduced” (cut down to e.g. 1 m to release the main species) – not too late – not too soon!