title: Patterns and causes of observed piñon pine mortality in the southwestern United States.
abstract: Recently, widespread piñon pine die-off occurred in the southwestern United States. Here we synthesize observational studies of this event and compare findings to expected relationships with biotic and abiotic factors. Agreement exists on the occurrence of drought, presence of bark beetles and increased mortality of larger trees. However, studies disagree about the influences of stem density, elevation and other factors, perhaps related to study design, location and impact of extreme drought. Detailed information about bark beetles is seldom reported and their role is poorly understood. Our analysis reveals substantial limits to our knowledge regarding the processes that produce mortality patterns across space and time, indicating a poor ability to forecast mortality in response to expected increases in future droughts.
authors.affiliation: Department of Geography, University of Idaho, Moscow, ID, 83844-3021, USA.
authors.forename: Arjan J H
authors.initials: AJH
authors.lastname: Meddens
authors.affiliation: Department of Geography, University of Idaho, Moscow, ID, 83844-3021, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Hicke
authors.affiliation: School of Geography and Development and Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, 85721-0076, USA.
authors.forename: Alison K
authors.initials: AK
authors.lastname: Macalady
authors.affiliation: Department of Geography, University of Idaho, Moscow, ID, 83844-3021, USA.
authors.forename: Polly C
authors.initials: PC
authors.lastname: Buotte
authors.affiliation: Department of Geography, University of Idaho, Moscow, ID, 83844-3021, USA.
authors.forename: Travis R
authors.initials: TR
authors.lastname: Cowles
authors.affiliation: US Geological Survey, Fort Collins Science Center, Jemez Mountains Field Station, Los Alamos, NM, 87544, USA.
authors.forename: Craig D
authors.initials: CD
authors.lastname: Allen
mesh_terms: D000818:Animals; D002980:Climate; D001517:Coleoptera / Q000502:physiology*; D055864:Droughts; D005843:Geography; D028223:Pinus / Q000502:physiology*; D018547:Plant Stems; D012987:Soil; D015206:Southwestern United States; D013312:Stress, Physiological; D013696:Temperature; D014197:Trees
chemical_list: D012987:Soil
keywords: Ips confusus; bark beetle; drought; piñon pine; southwestern USA; tree mortality