Muraro, Luca
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
Abstract
Swedish forestry is undergoing a transition towards more diverse and climateresilient production systems. Fast-growing broadleaved species, particularly hybrid poplars, offer high productivity and short rotations, but their establishment on acidic forest soils remains a major constraint. This thesis investigates strategies to overcome these barriers by combining species-site matching, genetic screening for aluminium (Al) tolerance, and soil amendment trials, supported by a systematic literature review. Four complementary approaches were applied. First, a multispecies field comparison across forest and forested arable land revealed strong sitedependent establishment patterns. Hybrid aspen and silver birch performed best on forest soils, whereas poplars required ash treatment to succeed on forested arable land. Second, a screening of 70 poplar clones demonstrated substantial genotypic variation in Al tolerance, with height showing moderate heritability (H² ≈ 0.45). A Composite Tolerance Index (CTI) integrating clonal growth responses and genetic merit identified tolerant clones capable of maintaining performance in acidic soils. Third, multi-site field trials tested wood ash, lime, and biochar amendments, showing that ash improved survival and growth most consistently, although effects varied with site type and application method. Finally, a systematic review of 41 studies confirmed that wood ash generally enhances growth of broadleaved species on acidic or nutrient-poor soils, but responses are context-dependent and often moderated by dose and soil type. Together, these findings highlight a dual-track strategy for deploying poplars in Swedish forestry: (i) the selection and breeding of Al-tolerant clones, and (ii) the targeted use of soil amendments, particularly wood ash, where genetic tolerance alone is insufficient. This integrated approach can expand the cultivation of fast-growing broadleaves beyond fertile farmland into underutilized forest soils, contributing to diversification, climate adaptation, and sustainable wood supply.
Keywords
Populus; poplar; hybrid aspen; aspen; aluminium tolerance; soil amendments; wood ash; forest diversification; establishment; fast-growing broadleaves
Published in
Acta Universitatis Agriculturae Sueciae
2025, number: 2025:74
Publisher: Swedish University of Agricultural Sciences
SLU Authors
UKÄ Subject classification
Forest Science
Publication identifier
- DOI: https://doi.org/10.54612/a.2qr3jvulu4
- ISBN: 978-91-8124-058-0
- eISBN: 978-91-8124-104-4
Permanent link to this page (URI)
https://res.slu.se/id/publ/142475