Life history characteristics may be as important as climate projections for defining range shifts: An example for common tree species in the intermountain western US

Aim

Predictions of future suitable habitat for plant species with climate change are known to be affected by uncertainty associated with statistical approaches, climate models and occurrence records. However, life history characteristics related to dispersal and establishment processes as well as sensitivity to barriers created by land‐use may also play important roles in shaping future distributions with climate change. We compared the uncertainty in predicted distributions associated with climate projections to uncertainty associated with species interactions related to dispersal and establishment and land‐use barriers with four common animal‐dispersed tree species in pinyon–juniper woodlands in the western United States, a region experiencing increasing fragmentation due to land‐use.

Location

Western USA.

Methods

We compared the effects of life history characteristics related to species interactions (long‐distance dispersal and facilitation), land‐use fragmentation and variation in climate projections on species distributions with climate change using a simulation model. We evaluated the impacts of these factors on three characteristics of species distributions, area occupied, range size, and distance between patches, across four 30‐year intervals centred on 2020, 2040, 2060 and 2080.

Results

We found that uncertainty associated with climate projections and the potential effects of facilitation on establishment had the greatest impact in distribution characteristics. The effects of all factors varied by species, despite their overlapping initial distributions and relatively similar dispersal traits, highlighting the impact of life history characteristics on model outcomes.

Main conclusions

These results suggest that assessments of species future range shifts and vulnerability to climate change should incorporate land‐use barriers and life history traits related to dispersal and establishment, particularly for species with strong facilitative interactions.