1. Growth Trends of Coniferous Species along Elevational Transects in the Central European Alps Indicate Decreasing Sensitivity to Climate Warming
- Author
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Werner Kofler, Jacob Geier, Barbara Waldboth, Ursula Bendler, Vanessa Gamper, Gerhard Wieser, Walter Oberhuber, Anna Hölzl, and Hanna Krismer
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,growth trend ,elevational transect ,Growing season ,010603 evolutionary biology ,01 natural sciences ,Basal area ,climate warming ,basal area increment ,0105 earth and related environmental sciences ,biology ,European Larch ,Global warming ,Forestry ,lcsh:QK900-989 ,Evergreen ,Krummholz ,biology.organism_classification ,Deciduous ,conifers ,lcsh:Plant ecology ,Environmental science ,Physical geography ,Larch ,European Alps - Abstract
Tree growth at high elevation in the Central European Alps (CEA) is strongly limited by low temperature during the growing season. We developed a tree ring series of co-occurring conifers (Swiss stone pine, Norway spruce, European larch) along elevational transects stretching from the subalpine zone to the krummholz limit (1630&ndash, 2290 m asl, n = 503 trees) and evaluated whether trends in basal area increment (BAI) are in line with two phases of climate warming, which occurred from 1915&ndash, 1953 and from 1975&ndash, 2015. Unexpectedly, results revealed that at subalpine sites (i) intensified climate warming in recent decades did not lead to a corresponding increase in BAI and (ii) increase in summer temperature since 1915 primarily favored growth of larch and spruce, although Swiss stone pine dominates at high elevations in the Eastern CEA, and therefore was expected to mainly benefit from climate warming. At treeline, BAI increases in all species were above the level expected based on determined age trend, whereas at the krummholz limit only deciduous larch showed a minor growth increase. We explain missing adequate growth response to recent climate warming by strengthened competition for resources (nutrients, light, water) in increasingly denser stands at subalpine sites, and by frost desiccation injuries of evergreen tree species at the krummholz limit. To conclude, accurate forecasts of tree growth response to climate warming at high elevation must consider changes in stand density as well as species-specific sensitivity to climate variables beyond the growing season.
- Published
- 2020
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