Saproxylic beetle (Coleoptera) diversity in subalpine whitebark pine and lodgepole pine (Pinaceae) trees killed by mountain pine beetles (Coleoptera: Curculionidae)

Abstract

AbstractWhitebark pine,Pinus albicaulisEngelmann (Pinaceae), a foundational species of North American subalpine ecosystems, is endangered across its range and continued decline is inevitable. Little is known about the invertebrate fauna associated with this species which, if specific to whitebark pine, may also be threatened or endangered. We compared the composition of saproxylic beetle assemblages associated with whitebark pine and co-occurring lodgepole pine,Pinus contorta latifolia(Engelmann) Critchfield (Pinaceae), recently killed by mountain pine beetle (MPB),Dendroctonus ponderosaeHopkins (Coleoptera: Curculionidae), in subalpine forests in Alberta, Canada. Redundancy and rarefaction analyses revealed that beetle assemblage composition was influenced by snag class (i.e., time since death) but differed little among the two pine species within snag classes. However, a subset of the assemblage known to be associated with the MPB differed significantly in composition between the two pines. No common species were exclusively associated with whitebark pines; however, seven species were rarely collected only on whitebark pine. With the possible exception of these rare species, felling and burning infested whitebark pines to control the MPB will not likely endanger saproxylic beetles associated with this tree.