The decomposition rate of non-stem components of coarse woody debris (CWD) in European boreal forests mainly depends on site moisture and tree species

Abstract

The decomposition rate of CWD is a key missing link for a quantitative understanding of forest ecosystem functioning. We examined factors influencing decomposition rates of bark, roots and branches from aspen (Populus tremula), birch (Betula pendula, B. pubescens), fir (Abies sibirica), spruce (Picea abies, P. obovata), Scots pine (Pinus sylvestris) and Siberian pine (Pinus sibirica) CWD in three primeval European boreal forests. The chronosequence approach with estimates of single exponential decomposition rate (k) based on calculation of mass loss was used. The k of non-stem parts increased in the order: branches (0.006 year -1 for P. sibirica and 0.020 year -1 for other species), roots in poorly drained sites (0.025 year -1 ), roots in well-drained sites (0.034 year -1 ) and bark (0.110 and 0.138 year -1 and 0.147 and 0.255 year -1 under poorly and well-drained conditions and from 1 to 3 m and [3 m above the root collar, respectively). Our results predict that the rate of decomposition of whole CWD pieces in European boreal forests is a function of vegetation zone, site conditions, tree species and size.

Bryophyte and polypore richness and indicators in relation to type, age and decay stage of coarse woody debris of Picea abies

“…Mean time to reach an advanced stage of decay of spruce logs was estimated to be 34 to 40 in the Midnorthern boreal regions of Sweden (Jonsson 2000;Kruys et al 2002), similar to the results of our study, but less than the estimated 100 years in the mid-boreal region of Norway (Storaunet, Rolstad 2002), > 45 years in southern to northern boreal zones in Russia (Shorohova, Kapitsa 2016), and 70 to 80 years in the subalpine zone in Poland (Zielonka 2006a). The large discrepancy in rate of decay might be explained by differences due to vegetation zone, site type, CWD size (Shorohova, Kapitsa 2016) and the mortality agent.…”

“…We found no effect of diameter on age within a decay stage, and thus no evidence for effect of diameter on decay rate, in contrast to previous studies (Storaunet, Rolstad 2002;Shorohova, Kapitsa 2016). There was also no evidence that tipped logs, which are held above ground by a root plate, remain in initial decay stage 1 and 2 for a longer period of time than snapped logs.…”

“…The large discrepancy in rate of decay might be explained by differences due to vegetation zone, site type, CWD size (Shorohova, Kapitsa 2016) and the mortality agent. The decay rate in the hemiboreal vegetation zone, and particularly in richer site types, as in the present study, would be expected to be more rapid than in northern regions in poor site types.…”

Quantifying carbon in dead and living trees; a case study in young beech and spruce stand over 9 years

“…The differences are often associated with dissimilar lignin and nutrient contentsof leaves and needles (Berger & Berger 2014) and possibly with higher diversity of microbial decomposers in broadleaved than coniferous forests (He et al, 2007). As for woody debris, Shorohova & Kapitsa (2016) commented that the decomposition rate in European forests depends on site moisture andon tree species. As for inter-specific differences, Hermann et al (2015) found significantly higher decomposition rates of beech woody parts than those of spruce.…”

川西亚高山森林林窗对凋落枝早期分解的影响

“…1W, the first winter; 1GS, the first growing season; 2W, the second winter; 2GS, the second growing season; 3W, the third winter; 3GS, the third growing season; 4W, the fourth winter; 4GS, the fourth growing season. (Baptist et al, 2010;Wu et al, 2010); (2)雪被的绝热保温作用维持耐寒 生物种群活动和生物活性同样能提高冬季凋落叶和 枝条降解率 (Baptist et al, 2010;Christenson et al, (Gavazov, 2010;Shorohova & Kapitsa, 2016;Cha et al, 2017) …”