Strong dispersal limitation in post-fire regeneration of Baker cypress, a rare serotinous conifer

PREMISE:  Dispersal capacity primarily determines the spatial establishment patterns that drive range expansions and contractions in tree species. For Baker cypress (Hesperocyparis bakeri  [(Jeps.) Bartel]), seedling establishment relies predominantly on fire events due to its cone serotiny, shade intolerance, and small seeds requiring the optimal conditions of fire-exposed, mineral soil seedbeds. 
 
METHODS:  This study quantified the density and spatial distribution of post-disturbance seedlings following the 2014 Eiler fire in northern California and compared the observed recruitment to predictions from a mechanistic seed dispersal model. 
 
RESULTS:  Post-fire recruitment was dense, averaging 11 seedling/m  2  , and occurred primarily in the first year after fire. We estimated the mean descent velocity of the wingless seeds as around 4 m/sec, the highest value reported for any putatively wind-dispersed tree species. The rapid seed decent contributed to markedly constrained recru...