Details

Autor(en) / Beteiligte

• Charlet de Sauvage, Justine
• Bugmann, Harald
• Bigler, Christof
• Lévesque, Mathieu

Titel

Species diversity and competition have minor effects on the growth response of silver fir, European larch and Douglas fir to drought

Ist Teil von

• Agricultural and forest meteorology, 2023-10, Vol.341, p.109664, Article 109664

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •401 trees were sampled for tree-ring analysis, and their neighborhood was measured.•The growth sensitivity to drought was higher for larch than for the two other species.•No effect of species diversity on tree radial growth over the period 2000–2020.•The drought resilience of Douglas fir was increased in a more diverse neighborhood.•Competition did not always have an effect on tree growth and drought resilience. With climate change, the frequency and duration of droughts are increasing, strongly impacting forest ecosystems. Therefore, a thorough understanding of the factors influencing tree response to drought is needed. Particularly, it remains unclear how competition and species diversity influence the drought sensitivity of tree species. Thinning (i.e., lowering competition) and mixing species (i.e., increasing diversity) are two common forest management practices that are thought to help forests to cope with droughts. However, their actual effects are still controversial. We sampled and measured tree-ring widths of 401 conifer trees with a wide range of competition and species diversity in their neighborhood across a bioclimatic gradient in Switzerland. Based on mixed-effects models and correlations, we examined the climate sensitivity of silver fir, European larch and Douglas fir and analyzed how competition and species diversity affect their radial growth and drought sensitivity. Silver fir was the least sensitive species to temperature, precipitation, and climatic water balance. When we analyzed the combined effects of the climatic water balance, competition and species diversity on tree radial growth over the past 20 years, we found that competition usually had a negative effect on radial growth of the three species, while species diversity had no effect. However, when focusing on drought resilience, competition had a negative effect for silver fir only, and a more mixed neighborhood enhanced the drought resilience of Douglas fir. Larch showed a higher drought sensitivity than silver fir and Douglas fir. At most sites, radial growth of all species recovered within two years after the severe droughts of 2003 and 2018. Overall, our results suggest that competition and species diversity have minor effects on the drought resilience of silver fir, larch and Douglas fir in Switzerland. [Display omitted]