Biomass conversion factors (density and carbon concentration) by decay classes for dead wood of Pinus sylvestris, Picea abies and Betula spp. in boreal forests of Sweden

Abstract

For estimating the amount of carbon (C) in dead wood, conversion factors from raw volume per decay class to dry weight were developed using three different classification systems for the species Norway spruce (Picea abies L. Karst), Scots pine (Pinus sylvestris L.) and birch (Betula pendula Roth and B. pubescens Ehrh) in Sweden. Also the C concentration in dead wood (dry weight) was studied. About 2500 discs were collected from logs in managed forests located on 289 temporary National Forest Inventory (NFI) sample plots and in 11 strips located in preserved forests. The conversion factors were based on an extensive data compilation with a wide representation of different site-, stand-, species-and dead wood properties and were assumed to represent the population of fallen dead wood in Sweden. The density decreased significantly by decay class and the range in density for decay classes was widest for the NFI decay classification system, suggesting this to be the most suitable. The C concentration in dead wood biomass increased with increasing decay class and in average Norway spruce (Picea abies) showed a lower C concentration than Scots pine (Pinus sylvestris). The average dead wood C store of Swedish forests was estimated to 0.85 Mg C/ha.

Decomposition of Norway spruce and European larch coarse woody debris (CWD) in relation to different elevation and exposure in an Alpine setting

“…In our study area, the CWD volume was ranging between 16 and 78 m 3 ha -1 , thus at the lower end of the above-mentioned range. The measured Cstocks in the CWD corresponded well to values reported in the literature for similar sites (Sandström et al 2007). CWD is a nonnegligible C reservoir in subalpine forests.…”

Description of a new procedure to estimate the carbon stocks of all forest pools and impact assessment of methodological choices on the estimates

“…In the case of coarse woody debris, dead standing trees, and snags, deadwood decomposition was taken into account by applying to the CS a reducing factor (based on Yatskov et al (2003) and Sandström et al (2007)) corresponding to the decomposition degree among the three classes observed on the field: 1, if no decomposition occurred; 0.75, if decomposition was in progress; and 0.5, when the wood was highly decomposed. The litter CS was calculated based on the litter carbon data of 120 RFIW plots.…”

Cultural treatments and woody debris: the study case of beech forests in Casentino (Italy)

“…Per tali motivi, data anche la difficoltà di misura della necromassa di piccole e medie dimensioni in termini di volume (Sandström et al 2007) si è optato per la determinazione del peso secco del materiale legnoso.…”

“…Inoltre, considerato che le caratteristiche del materiale legno so al suolo sono condizionate dalle dinamiche che hanno portato alla morte della pianta o parte di essa (Gilg 2004, Christensen et al 2005, Mircu et al 2006 e che il quantitativo e la tipologia di CWD cambiano a seconda degli stadi successionali della foresta, è lo gico affermare che col crescere dell'età del bosco la quantità di legno aumenti così come anche le dimen sioni medie del materiale accumulato (Harmon et al 1986, Wolynski 2001. Diversi autori (Wolynski 2001, Christensen et al 2005, Ekbom et al 2006, Sandström et al 2007) affermano che la quantità di CWD è mi nore in boschi sottoposti a tagli colturali rispetto a quella presente in soprassuoli lasciati alla naturale evoluzione. Di Filippo et al (2004) sostengono che l'abbondanza di necromassa come conseguenza del l'assenza delle utilizzazioni forestali è uno degli ele menti più rappresentativi della vetustà di una fore sta.…”