Combining Tree-Ring Width and Density to Separate the Effects of Climate Variation and Insect Defoliation

0574222 - ÚVGZ 2024 RIV CH eng J - Journal Article
Kunz, M. - Esper, Jan - Kuhl, E. - Schneider, L. - Büntgen, Ulf - Hartl, C.
Combining Tree-Ring Width and Density to Separate the Effects of Climate Variation and Insect Defoliation.
Forests. Roč. 14, č. 7 (2023), č. článku 1478. E-ISSN 1999-4907
R&D Projects: GA MŠMT(CZ) EF16_019/0000797
Research Infrastructure: CzeCOS IV - 90248
Institutional support: RVO:86652079
Keywords : climate change * dendrochronology * European Alps * global change ecology * insect outbreaks * tree rings * extreme event detection
OECD category: Climatic research
Impact factor: 2.9, year: 2022
Method of publishing: Open access
https://www.mdpi.com/1999-4907/14/7/1478

Though frequently used in dendroclimatology, European larch (Larix decidua Mill.) is regularly defoliated by mass outbreaks of the larch budmoth (Zeiraphera griseana Hb., LBM). The near-cyclic growth depressions are unrelated to but possibly coincide with cold summers, which challenges signal detection on interannual timescales. LBM defoliation events cause sharp maximum latewood density declines and irregular earlywood/latewood ratios in the outbreak year, followed by one or two anomalously narrow rings. Here, we present a process-based method integrating these diverse response patterns to identify and distinguish LBM-related signals from climate-induced deviations. Application to larch sites along elevational transects in the Swiss Alps reveals the algorithm to perform better than existing extreme event detection methods, though our approach enables additional differentiation between insect- and climate-induced signatures. The new process-based multi-parameter algorithm is a suitable tool to identify different causes of growth disturbances and will therefore help to improve both tree-ring-based climate and insect defoliation reconstructions.
Permanent Link: https://hdl.handle.net/11104/0344565