title: Tree biomass in the Swiss landscape: nationwide modelling for improved accounting for forest and non-forest trees.
abstract: Trees outside forest (TOF) can perform a variety of social, economic and ecological functions including carbon sequestration. However, detailed quantification of tree biomass is usually limited to forest areas. Taking advantage of structural information available from stereo aerial imagery and airborne laser scanning (ALS), this research models tree biomass using national forest inventory data and linear least-square regression and applies the model both inside and outside of forest to create a nationwide model for tree biomass (above ground and below ground). Validation of the tree biomass model against TOF data within settlement areas shows relatively low model performance (R2of 0.44) but still a considerable improvement on current biomass estimates used for greenhouse gas inventory and carbon accounting. We demonstrate an efficient and easily implementable approach to modelling tree biomass across a large heterogeneous nationwide area. The model offers significant opportunity for improved estimates on land use combination categories (CC) where tree biomass has either not been included or only roughly estimated until now. The ALS biomass model also offers the advantage of providing greater spatial resolution and greater within CC spatial variability compared to the current nationwide estimates.
authors.affiliation: Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903, Birmensdorf, Switzerland. bronwyn.price@wsl.ch.
authors.forename: B
authors.identifier: http://orcid.org/0000-0003-3555-2588
authors.initials: B
authors.lastname: Price
authors.affiliation: Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903, Birmensdorf, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Gomez
authors.affiliation: Nategra LLC, Nydeggstalden 30, 3011, Bern, Switzerland.|Sigmaplan AG, Thunstrasse 91, 3006, Bern, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Mathys
authors.affiliation: School for Agricultural, Forest and Food Sciences, Bern University of Applied Sciences HAFL, Länggasse 85, 3052, Zollikofen, Switzerland.
authors.forename: O
authors.initials: O
authors.lastname: Gardi
authors.affiliation: Climate Division, Federal Office for the Environment FOEN, 3003, Bern, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Schellenberger
authors.affiliation: Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903, Birmensdorf, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Ginzler
authors.affiliation: Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903, Birmensdorf, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Thürig
mesh_terms: D018533:Biomass; D002244:Carbon / Q000032:analysis; D057965:Carbon Sequestration; D004784:Environmental Monitoring / Q000379:methods; D065928:Forests; D008962:Models, Theoretical; D014197:Trees
chemical_list: D002244:Carbon
keywords: ALS; Aerial imagery; Image point clouds; Tree biomass; Trees outside forest (TOF)