Characteristics of Coarse Woody Debris in Different-Age Natural <i>Larix gmelinii</i> Forests in Daxing’anling Mountains

Abstract

Coarse woody debris (CWD) is composed of dry wood, fallen wood and large branches, and it is an important element for structure and function in forest ecosystems. In this paper, we studied the characteristics of coarse woody debris (CWD) of natural Larix gmelinii forests with different ages in Daxing’anling Mountains. The results show that (1) the CWD volumes in near-mature, middle-age and young forests are 88.55 m3•hm-2, 52.07 m3•hm-2 and 3.96 m3•hm-2, respectively; and their biomasses are 52.96 t•hm-2, 36.22 t•hm-2 and 2.35t•hm-2, respectively. Which indicate that the CWD volumes and biomasses increase with forest ages addition; (2) The CWD volume and biomass follow normal distribution in middle and near-mature forest; (3) the CWD volume and biomass decrease with forest age increasing within decay classes I and II, whereas increase in decay classes III, IVand V; (4) the volume of middle-age and young forests present a near normal distribution with decay class increasing.

Effects of Stand Origin and Near-Natural Restoration on the Stock and Structural Composition of Fallen Trees in Mid-Subtropical Forests

“…Conversely, the biomass of fallen trees in Ncf was less than that in Pinus tabulaeformis secondary forests in the Qinling Mountains [32], and Korean pine forests in the Changbai Mountains [33]. Compared with Larix gmelinii forests in the Daxing'anling Mountains, the biomass of fallen trees in Ncf was determined to be at the middle level [34]. However, the biomass of fallen trees in Acf was higher than those in coniferous forests in Guangzhou [30], artificial Castanopsis kawakamii forests and Chinese Fir forests in Sanming [31], but less than the biomass of fallen trees in mixed coniferous forests and broad-leaved forests in Guangzhou [30] (Table A2).…”

“…These may allow the storage of a greater carbon stock of fallen trees in a forest ecosystem [2,3]. The distribution of the diameter class of fallen trees was affected by the structural composition of forest stands, site conditions and disturbance [32][33][34]. For example, Liu et al [35] reported that coarse woody debris in evergreen broadleaved forests after an ice storm in Northern Guangdong Province yielded a large diameter class of forest stands on windward slopes that facilitated the formation of a large number of fallen trees, whereas the small diameter class of forest stands on leeward slopes was affected by low temperature and frost damage [35].…”