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1  We mapped the locations of live and dead trees in a large forest plot dominated by pioneer Douglas fir (Pseudotsuga menziesii) with an understorey of the invading late‐successional species western hemlock (Tsuga heterophylla) and western red cedar (Thuja plicata) on Vancouver Island, British Columbia, Canada, to test for intra‐ and interspecific density‐dependent effects on tree survival.

2  We analysed both the spatial patterning of trees in the plot and the relationships between neighbourhood density and tree survival. We also examined the effects of additional variables (principally elevation) as covariates in our neighbourhood analyses.

3  Both the spatial and initial neighbourhood analyses suggested strong intra‐ and interspecific density‐dependent effects on tree survival. Douglas fir survival was significantly higher in less dense patches of conspecifics and non‐random tree death led to …