Abstract

Retention forestry involves saving important forest structures for flora and fauna during the final felling of a stand, including dead wood and variable amounts of living trees, i.e. green tree retention (GTR). Here we evaluate the long-term effects on avian diversity from GTR by surveying forest birds in 32 mid-rotation stands in southern Sweden, in which broadleaf GTR was present or absent. Complementing the many studies that have assessed GTR in clear-cuts, our results indicated that bird assemblages can also benefit from broadleaf GTR several decades after final felling in conifer dominated production stands. The GTR stands harboured a higher bird abundance and species richness than the control stands without GTR, and also appears to have benefited several important guilds, such as broadleaf-associated birds and cavity nesters. However, variation in the number trees retained, the species composition of retained trees, and their environmental context within the stand (e.g. density and proximity of surrounding production trees), limited our capacity to detect threshold requirements for GTR. In summary, our study provides a "glimpse into the future" as mid-rotation production stands with such old and large retained trees are unusual in today's landscape, but are expected to become more common in the decades to come, in Sweden and many other nations. Our study thereby provides provisional support for the continued and future use of this practice, and indicates that the biodiversity contribution of retention trees continues to occur several decades into the stand's rotation.

Keywords

Avifauna; Biodiversity; Broadleaved forest; Forest birds; Green tree retention; Norway spruce; Production forests

Published in

Forest Ecology and Management
2022, Volume: 515, article number: 120223
Publisher: ELSEVIER

SLU Authors

• Lindbladh, Matts

  • Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
    

• Hedwall, Per-Ola

  • Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
    

• Holmström, Emma

  • Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
    

• Felton, Adam

  • Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1016/j.foreco.2022.120223

Permanent link to this page (URI)

https://res.slu.se/id/publ/117992