Funding for this research was provided by:
U.S. Forest Service (12-JV-11221637-136)
Received: 25 July 2018
Accepted: 5 March 2019
First Online: 20 May 2019
Ethics approval and consent to participate
: Not applicable.
: Consent for publication not applicable as we did not use data from individual people.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.