Abstract

Reliable assessment measures are crucial for tracking changes in biodiversity and for evaluating the state of biodiversity. Two of the main drivers of biodiversity are habitat heterogeneity and resource amount. These drivers are used as proxies of biodiversity but assessing both is costly, limiting their practical use. To test which of the drivers best predicts the number and abundance of sessile species of conservation concern (including macrofungi, lichens, bryophytes, and vascular plants), we assessed forest stand heterogeneity using a method developed in Sweden ('Habitat Heterogeneity Score HHS'), and quantified the resource amount and quality of ecologically important structural variables (deadwood volume, basal area of living trees, proportion of broadleaved trees, and the age of the oldest tree in the stand). We conducted the assessments in 77 boreal coniferdominated forest stands in two regions of Sweden. Despite some group-specific organism differences, HHS was the best predictor of both number and abundance of all species of conservation concern, regardless of the region. Further, HHS was the best predictor of red-listed species number and abundance in the southern region, while a model including the volume of deadwood and the age of the oldest tree performed best in the northern region. Deadwood (CWD) volume was the single best resource amount predictor of the number and abundance of species of conservation concern, emphasizing the critical role that dead trees have for biodiversity. In addition, we calculated threshold values for deadwood volume and HHS depicting the level above which the number of red-listed species is significantly higher, and found this value to be higher in the southern region (22.4 m(3) ha(-1) deadwood and a HSS value of 17) than in the north (20.0 m(3) ha(-1) and 16). These values can be used as guidance when identifying coniferous forests with high enough qualities to support red-listed species. To conclude, the method of assessing habitat heterogeneity presented in this study is a practical and reliable way to identify forests of high biological diversity, and can therefore be part of the toolbox for sustainable forestry in boreal forests.

Keywords

Deadwood, coarse woody debris, conservation; Habitat amount; Indicator; Structural complexity

Published in

Ecological Indicators
2023, Volume: 148, article number: 110069

SLU Authors

• Hekkala, Anne-Maarit

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

• Jönsson, Mari

  • SLU Swedish Species Information Centre, Swedish University of Agricultural Sciences
    

• Kärvemo, Simon

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Strengbom, Joachim

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Sjögren, Jörgen

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network
SLU Forest Damage Center


Sustainable Development Goals

Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Forest Science
Ecology


Publication identifier

DOI: https://doi.org/10.1016/j.ecolind.2023.110069

Permanent link to this page (URI)

https://res.slu.se/id/publ/122302