Tree-Ring Reconstruction of Bark Beetle Disturbances in the <i>Picea schrenkiana</i> Fisch. et Mey. Forests of Southeast Kazakhstan

• Main Authors: Ann M. Lynch, Nurjan S. Mukhamadiev, Christopher D. O’Connor, Irina P. Panyushkina, Nursagim A. Ashikbaev, Abay O. Sagitov
• Format: Article
• Language: English
• Published: MDPI AG 2019-10-01
• Series: Forests
• Subjects: bark beetles; hauser’s engraver; schrenk’s spruce; windstorm; blowdown; dendrochronology; <i>ips duplicatus</i>; <i>ips hauseri</i>; <i>ips sexdentatus</i>; <i>ips typographus</i>
• Online Access: https://www.mdpi.com/1999-4907/10/10/912

<i>Ips hauseri</i> Reitter is the most important bark beetle on <i>Picea schrenkiana</i> in southeast Kazakhstan, but its biology, ecology, and outbreak dynamics are poorly known. We dendrochronologically reconstructed a 200-year history of disturbances in the Kazakh Tien Shan <i>P. schrenkiana</i> forests. Only localized, low-severity bark beetle events occurred during the reconstructed period, indicating that extensive high-severity bark beetle outbreaks have not occurred historically in the Tien Shan spruce forest, unlike bark beetle outbreaks in spruce forests in North America, Europe, and Russia. Disturbance frequency doubled after about 1965, probably due to warming climate. Results, combined with the failure of an outbreak to fully develop after blowdown events associated with hurricane-force windstorms in 2011, indicate that prolonged drought may be necessary to sustain <i>I. hauseri</i> outbreaks, or that year-to-year variation in the Tien Shan weather prevents outbreak development. <i>I. hauseri</i> is probably less aggressive than <i>I. typographus</i>, at least on their natural hosts within their natural ranges.