Elevation‐dependent patterns of borer‐mediated snow‐gum dieback are associated with subspecies' trait differences and environmental variation

作者：Callum Bryant, Marilyn C. Ball, Justin Borevitz, Matthew Brookhouse, Hannah Carle, P. B. Cunningham, M. P. Davey, J D Davies, Ashleigh Eason, Joseph D. Erskine, Tomás I. Fuenzalida, Dmitry Grishin, Rosalie J. Harris, Jessica Kriticos, Aaron Midson, Adrienne B. Nicotra, Annabelle Nshuti, Jessica Ward‐Jones, Yolanda Yau, O. P. Young, Helen M. Bothwell · 发表于：Austral Ecology · 年份：2024 · DOI：10.1111/aec.13508 · 被引用次数：7 · 研究领域：Fire effects on ecosystems、Plant Water Relations and Carbon Dynamics、Forest Insect Ecology and Management

Abstract Subalpine forests worldwide face the synergistic threats of global warming and increased biotic attack, and the collapse or transition of subalpine forests is predicted in south‐eastern Australia under future climates. The recent widespread dieback of subalpine snow‐gum forests due to increased activity of a native wood‐boring longicorn beetle, Phoracantha mastersii , suggests this process may already be underway. We investigated how variation in tree tissue traits and environmental conditions correlated with elevation‐dependent spatial patterns of forest mortality. We hypothesized that increased vulnerability of subalpine snow gums to wood‐borer‐mediated dieback at intermediate elevations was associated with poorly resolved differences in traits between montane ( Eucalyptus pauciflora subsp. pauciflora) and subalpine ( E. pauciflora subsp. niphophila) snow‐gum subspecies. We first sought to characterize variation and elevation‐dependent transitions in 20 structural and drought‐related functional traits among 120 healthy trees distributed along a 1000 m elevation transect that spanned the subspecies transition zone. Secondly, we surveyed 774 trees across 53 sites between 1280 and 1980 m a.s.l. to explore associations between borer‐damage severity, elevation, subspecies and a subset of traits that differed between subspecies. We observed evidence for both continuous trait variation in response to changing elevation (10/20 traits) and discrete shifts in mean trait valu...