Patterns and causes of observed piñon pine mortality in the southwestern United States

• Published in: The New phytologist Vol. 206; no. 1
• Main Authors: Meddens, Arjan J. H., Hicke, Jeffrey A., Macalady, Alison K., Buotte, Polly C., Cowles, Travis R., Allen, Craig D.
• Format: Journal Article
• Language: English
• Published: United Kingdom Wiley-Blackwell 15.12.2014
• ISSN: 0028-646X; 1469-8137

Summary 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. <table-wrap position='anchor'> Contents Summary 91 I. <ext-link href='#nph13193-sec-0002'>Introduction</ext-link> 91 II. <ext-link href='#nph13193-sec-0003'>Mortality mechanisms</ext-link> 92 III. <ext-link href='#nph13193-sec-0004'>Methods</ext-link> 92 IV. <ext-link href='#nph13193-sec-0005'>Results</ext-link> 92 V. <ext-link href='#nph13193-sec-0009'>Discussion</ext-link> 94 VI. <ext-link href='#nph13193-sec-0010'>Conclusions</ext-link> 96 <ext-link href='#nph13193-sec-0011'>Acknowledgements</ext-link> 96 <ext-link href='#nph13193-bibl-0001'>References</ext-link> 96 </table-wrap>