SHORT COMMUNICATION Allometric equations for biomass assessment of subalpine dwarf shrubs Tasneem M. Elzein • Olivier Blarquez • Olivier Gauthier • Christopher Carcaillet Received: 10 May 2011 / Accepted: 17 August 2011 Ó Swiss Botanical Society 2011 Abstract Shrubs are an important component of moun- tain ecosystems in terms of productivity and diversity. The estimate of shrub biomass via allometric equations repre- sents a non-destructive alternative to obtain quantitative data. We propose allometric equations to estimate above- ground biomass from easily acquirable descriptive parameters of plant height and cover using linear models for five of the most abundant subalpine shrub species in European mountain or boreal ecosystems: Rhododendron ferrugineum, Vaccinium myrtillus, V. uliginosum, V. vitis- idaea and Juniperus sibirica. Samples used for the estab- lishment of the equations are from non-disturbed Pinus cembra–Larix decidua stands, and from adjacent stands frequently disturbed by snow avalanches. The equations adequately predict shrub biomass for all species except V. uliginosum. They thus provide a useful and non- destructive method for estimating aboveground shrub bio- mass in subalpine ecosystems. Keywords Method  Mountain  Ecosystem  Disturbance  Avalanche  Forest Introduction Forest biomass assessment via allometric equations repre- sents a useful tool in the study of terrestrial ecosystems as it offers a non-destructive and time-affordable method (Case and Hall 2008; Liu and Westman 2009). Most applications of this approach in Europe have focused on the estimation of tree biomass (e.g. Muukkonen 2007) because it is the prin- cipal sink of carbon sequestration in forests (Beedlow et al. 2004). Shrubs have been neglected but are key drivers of forest productivity and diversity, notably in the cold eco- systems like the subalpine or boreal types (Ponge et al. 1998; Nilsson and Wardle 2005; MacKenzie and DeLuca 2006). Mountain forests are largely subjected to global changes and are facing severe land-use abandonment (Tasser and Tap- peiner 2002; Motta and Lingua 2005; Chauchard et al. 2010), which can alter the shrubs’ dynamics and biomass (Tappeiner et al. 2008; Rammig et al. 2010) and thus the forest productivity and functioning. Indeed, a clear rela- tionship has been observed between the cover of dwarf shrubs and the course of the secondary succession in sub- alpine forest after land-use abandonment, which is also linked to the elevation status of the community, whether close to the forest limit or not (Tasser and Tappeiner 2002). When the shrub density is much too high, the tree recruit- ment is impacted (Tasser et al. 2007). Finally, dwarf shrubs play an important role in increasing the probability of ava- lanche release (Viglietti et al. 2010). For these reasons, the measurement of the shrub biomass offers valuable data that complement the forest tree biomass data, and should help to decipher the functional role of this ecosystem compartment. Here, we test allometric equations based on descriptive parameters (plant height and plant cover) for subalpine dwarf shrubs of the European Alps, assuming that these parameters are convenient enough to model specific T. M. Elzein and O. Blarquez are co-first authors and contributed equally to this paper. T. M. Elzein  O. Blarquez  O. Gauthier  C. Carcaillet Paleoenvironments and Chronoecology (PALECO EPHE), E ´ cole Pratique des Hautes E ´ tudes, Institut de Botanique, 163 rue Broussonet, 34090 Montpellier, France T. M. Elzein  O. Blarquez  O. Gauthier  C. Carcaillet (&) Centre for Bio-Archaeology and Ecology (UMR5059 CNRS), Institut de Botanique, Universite ´ Montpellier 2, 163 rue Broussonet, 34090 Montpellier, France e-mail: christopher.carcaillet@univ-montp2.fr Alp Botany DOI 10.1007/s00035-011-0095-3 123