Biological responses of tree species to future climate change at a large scale are mainly embodied in tree migration to track their climatically suitable conditions, which includes range shifts, as well as shifts in species composition and abundance. These responses will be more complex when interacting with the effect of disturbance. Disturbances may speed changes in community composition, but the interactions among climate change, disturbance and competitive interactions to produce tree migration are poorly understood. Thus, we investigated 1) what are the interactive effects among forest disturbance, tree species competition, and seed dispersalon climate-induced range boundary shifts; 2) what are the effects of climate change and disturbance on species’ geographic abundance distributions (quantified by species centroid movement)? and 3) which species benefit in abundance the most from disturbance interacting with climate change? We used a physiologically-based mechanistic landscape model to study these interactions in the northeastern United States. We designed a series of disturbance scenarios to represent varied disturbance regimes in terms of both disturbance extent and intensity. We simulated forest succession by incorporating climate change under a high emissions future, disturbances, seed dispersal, and competition using the landscape model parameterized with forest inventory data.
Results/Conclusions
Simulated tree species range boundary shifts in New England over the next century were far below that required to track the velocity of climate change under a high emissions scenario.Simulated species` ranges shifted northward at both the leading edge (northern boundary) and trailing edge (southern boundary). Disturbances may expedite species` recruitment into new sites, but they had little effect on the velocity of simulated range boundary shifts. Compared with species range shifts, shifts in species composition and abundance were more sensitive responses for understanding the interacting effects of climate change and disturbance on tree species migration. Disturbance didn`t accelerate obviously geographic changes in abundance center of total biomass, however, disturbance showed obvious influences on shifts in abundance center for individual species.High intensity disturbance will accelerate the abundance of early successional species (e.g., black cherry, black ash, and balsam poplar in this study) at the expense of a decline in the abundance of mid and late successional species (e.g., eastern white pine, white ash, balsam fir and sugar maple). We further found that high intensity disturbance moved the abundance centroid of most early successional species moved northward whereas abundance centroid for most late successional species moved to the south.