Question
What are the processes driving regeneration and successional pathways in Pinus contorta subsp. latifolia Douglas ex Loudon forests?
Location
Canadian Rockies, Alberta, Canada.
Methods
We used five 1‐ha long‐term permanent plots, dendrochronological stand reconstruction and detailed spatial analysis of stem‐mapped data.
Results
Establishment of shade‐intolerant species mainly occurred within 20 years post‐fire but important later recruitment of these species was observed in the drier plots, primarily in gaps in stands that had more open canopies. Shade‐tolerant species established quickly following fires on moister sites but, despite apparent seed source availability after the stand‐initiating fire, their establishment was delayed in the drier sites, most likely due to moisture limitations. Shade‐tolerant regeneration was clustered around shade‐tolerant trees that had established immediately post‐disturbance; this suggests the latter served as seed sources and perhaps created favourable microsites for establishment.
Conclusion
Competition for light, dispersal limitation and moisture limitations were all processes influencing regeneration and successional pathways in these P. contorta stands. Although initial studies in these stands had suggested some of the stands could potentially be self‐perpetuating P. contorta forests, our results suggest that all plots studied will likely transition towards dominance of shade‐tolerant species. However the rate of this transition will likely be slower in the drier sites compared to the moister sites since the density of shade‐tolerant regeneration was much lower in these sites and took longer to establish (ca. 70–90 years) post‐disturbance.