# Developing Allometric Equations for Estimating Shrub Biomass in a Boreal Fen

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Department of Geography, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada

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Department of Geography and Environmental Management, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada

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NAIT Boreal Research Institute; 1R2, 8102 99 Ave Peace River, AB T8S 1R2, Canada

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Author to whom correspondence should be addressed.

Received: 18 June 2018 / Revised: 11 September 2018 / Accepted: 13 September 2018 / Published: 15 September 2018

(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)

Allometric equations for estimating aboveground biomass (AGB) from easily measured plant attributes are unavailable for most species common to mid-continental boreal peatlands, where shrubs comprise a large component of the vegetation community. Our study develops allometric equations for three dominant genera found in boreal fens: Alnus spp. (alder), Salix spp. (willow) and Betula pumila (bog birch). Two different types of local equations were developed: (1) individual equations based on genus/phylogeny, and (2) a general equation that pooled all individuals regardless of genera. The general equation had a R

^{2}= 0.97 (n = 82), and was not significantly different (p > 0.05) than any of the phylogenetic equations. This indicated that a single generalized equation is sufficient in estimating AGB for all three genera occurring in our study area. A closer look at the performance of the general equation revealed that smaller stems were predicted less accurately than larger stems because of the higher variability of leafy biomass found in small individuals. Previously published equations developed in other ecoregions did not perform as well as our local equations.