The Impact of Seed Dispersal by Clark’s Nutcracker on Whitebark Pine: Multi-scale Perspective on a High Mountain Mutualism.

The holarctic mutualisms between Cembrae Pines (Pinus, Pinaceae) and nutcrackers (Nucifraga, Corvidae) comprise important textbook examples of interaction and coevolution. However, only recently we have learned to what extent nutcracker seed caching influences the ecology and biology of these pines. The North American mutualism between whitebark pine (Pinus albicaulis) and Clark’s nutcracker (Nucifraga columbiana) demonstrates the greatest array of consequences to the pine, particularly in fire-dependent communities in the northern Rocky Mountains. The impacts of Clark’s nutcracker seed-caching on whitebark pine are evident at multiple spatial and temporal scales, from tree growth form and fine-scale genetic structure and the timing of regeneration and community development to regional and rangewide genetic structure, and post-Pleistocene range expansion. [ABSTRACT FROM AUTHOR]