Abstract

Aims Tree roots contribute large quantities of biomass in forests and are important drivers of different ecosystem processes. However, estimation of root biomass remains a challenge. We have developed a method to quantify fine root biomass of trees, tested on Pinus sylvestris L. and Betula sp. in soils in natural environment, by applying specific qPCR primers to soil DNA extracts.Methods We first validated the molecular probes in the laboratory by constructing regression equations among known root biomass in soil and the number of gene copies obtained by qPCR. Then, to test the applicability of the method in an ecosystem setting and because Pinus and Betula are important components of boreal forests after wildfire, we quantified fine root biomass from these trees in soils from forests with different degrees of tree mortality after wildfire.Results The new primers specifically amplified ITS (Internal Transcribed Spacer) markers from DNA extracted from fine roots of Pinus and Betula, and regression equations allowed us to calculate root biomass in soil from the number of gene copies obtained by qPCR. Root biomass of Pinus correlated positively with fire-induced canopy mortality, confirming the adequacy of the method. The biomass of Betula roots in soil did not differ across the fire severity gradient due to an overall low and stochastic presence of birch, and did not relate to the establishment of new birch seedlings.Conclusions This study shows that DNA-based qPCR methods can be used for rapid, quantitative and species-specific analysis of tree root biomass in natural forest ecosystems.

Keywords

Pinus sylvestris; Betula; qPCR; Root biomass; Fire severity

Published in

Plant and Soil
2019, Volume: 440, number: 1-2, pages: 593-600
Publisher: SPRINGER

SLU Authors

• Pérez Izquierdo, Leticia

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Clemmensen, Karina

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Strengbom, Joachim

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Nilsson Hegethorn, Marie-Charlotte

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

• Lindahl, Björn

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science
Soil Science


Publication identifier

DOI: https://doi.org/10.1007/s11104-019-04096-9

Permanent link to this page (URI)

https://res.slu.se/id/publ/101125