Modelling biomass and leaf area index in a sub-arctic Scandinavian mountain area

Abstract

Estimates of biomass and leaf area index (LAI) are important variables in ecological and climate models. However, very little is known about the biomass and LAI of the vegetation in the Scandinavian mountain area. In this study, extensive field data consisting of diameter at breast height for 13 000 trees and height for 550 trees were collected. Furthermore, biomass and leaf area (LA) measurements for 46 mountain birch trees [Betula pubescens ssp. czerepanovii (Orlowa) Hämet-Ahti] and biomass and LA measurements for shrubs (e.g. Salix spp., Betula nana) at 36 sample plots were carried out. Multiplicative linear models for trees were fitted to tree biomass and LA measurements using basal area at breast height, height, crown diameter and diameter at stump height as explanatory variables. Additive linear models were fitted to shrub biomass and LAI measurements using coverage of shrubs, topographic variables and soil type as explanatory variables. The functions were then used to predict the biomass and LAI for trees and shrubs for the entire test area, which covers an area of 84 km² and is located at latitude 68° N. The mean total biomass estimates were 27 493 kg ha⁻¹ for the forest and 7650 kg ha⁻¹ for snow-protected heath and meadow vegetation. The LAIs were 2.06 and 0.52, respectively. For monitoring biomass and LAI in the Scandinavian mountain area, the functions could also be applied to data from traditional field-based inventories and the estimates might further be improved by combining the estimates from the test area with auxiliary information such as remote sensing images.

Keywords:

• Abisko
• allometric relationship
• Betula pubescens ssp. czerepanovii
• ground vegetation
• mountain birch
• shrub layer

Acknowledgments

This study was part of the research programme Climate Impacts Research Centre and was funded partly by EU structural funds and partly by regional funds. Anders Pettersson, Anette Selegran and Ben Werkman contributed to the field and laboratory work.

Notes

Dahlberg, U. ^1,2 , Berge, T. W. ³ , Petersson, H. ² and Vencatasawmy, C. P. ² (¹Climate Impacts Research Centre, Abisko Scientific Research Station, P.O. Box 62, SE-98107 Abisko, Sweden, ²Department of Forest Resource Management and Geomatics, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden, and ³Crop Protection Centre, The Norwegian Crop Research Institute, NO-1432 Ås, Norway). Modelling biomass and leaf area index in a sub-arctic Scandinavian mountain area.

Additional information

Notes on contributors

Ulrika Dahlberg

Dahlberg, U. 1,2 , Berge, T. W. 3 , Petersson, H. 2 and Vencatasawmy, C. P. 2 (1Climate Impacts Research Centre, Abisko Scientific Research Station, P.O. Box 62, SE-98107 Abisko, Sweden, 2Department of Forest Resource Management and Geomatics, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden, and 3Crop Protection Centre, The Norwegian Crop Research Institute, NO-1432 Ås, Norway). Modelling biomass and leaf area index in a sub-arctic Scandinavian mountain area.