Provenances from introduced stands of Northern Red Oak (Quercus rubra L.) outperform those from the natural distribution

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Contributors

Abstract

Northern Red Oak (Quercus rubra L.), which is native to North America, covers over 350.000 ha in Europe and is currently the most common non-native deciduous tree species in Germany. Due to its high growth potential and higher drought tolerance in relation to native oak species, its valuable ecological characteristics and the versatile use of its wood for lumber or furniture it is one of the potential alternative tree species in a future warmer climate. In this study, growth performance of Q. rubra (particularly basal area [m2 ha-1] at age 33) is analysed, using data from a provenance trial established in 1991 with three test sites located in North, East and Central Germany. We focus on 12 common provenances, six of North American origin and six sourced from introduced stands from Germany, to evaluate patterns of provenance-environment interaction (P × E). Using effect size statistics, we found a significant percent gain in productivity of German compared to North American provenances on two humid sites. Two provenances from South-west Germany further convince with a good stem form. North American provenances from Canada show an equivalent growth to those from Germany on a drier test site, while provenances from the United States show poor growth in all environments. We assessed the provenance sensitivity across the tested environments by characterising growth differences with the joint regression analysis (JRA), which confirmed a significant P × E and the growth superiority of German provenances. The application of the Weighted Average of the Absolute Scores (WAAS) as a stability parameter enables the classification of provenances into generalists and specialists. While the German provenances can be assumed to be generalists with above average performance (4 provenances) or specialists with a high productivity on humid sites (2 provenances) and therefore seem suitable for recommendations, those from Canada performed well in the dry environment, which could be promising if planted at sites with decreasing precipitation regimes. All of these aspects shall contribute to a broader use of Northern Red Oak especially in Germany in the process of forest restoration.

Details

Original languageEnglish
Article number120803
JournalForest Ecology and Management
Volume531
Publication statusPublished - 1 Mar 2023
Peer-reviewedYes

Keywords

Keywords

  • Alternative tree species, Effect size statistics, Generalists vs specialists, Provenance-environment interaction, Stability analysis