Abstract

Warmer climates induced by elevated atmospheric CO2 (eCO(2)) are expected to increase damaging bark beetle activity in pine forests, yet the effect of eCO(2) on resin production-the tree's primary defense against beetle attack-remains largely unknown. Following growth-differentiation balance theory, if extra carbohydrates produced under eCO(2) are not consumed by respiration or growth, resin production could increase. Here, the effect of eCO(2) on resin production of mature pines is assessed. As predicted, eCO(2) enhanced resin flow by an average of 140% (P = 0.03) in canopy dominants growing in low-nitrogen soils, but did not affect resin flow in faster-growing fertilized canopy dominants or in carbohydrate-limited suppressed individuals. Thus, pine trees may become increasingly protected from bark beetle attacks in an eCO(2) climate, except where they are fertilized or are allowed to become overcrowded.

Keywords

bark beetles; carbon allocation; Free Air CO2 Enrichment; Pinus taeda; resin flow; resistance

Published in

Tree Physiology
2012, volume: 32, number: 6, pages: 752-763
Publisher: OXFORD UNIV PRESS

Authors' information