Review on the decomposition and influence factors of coarse woody debris in forest ecosystem

Abstract

Coarse woody debris (CWD) is an important and particular component of forest ecosystems and is extremely important to forest health. This review describes the decomposition process, decomposition model and influence factors. CWD decomposition is a complex and continuous process and characterizes many biological and physical processes, including biological respiration, leaching, and fragmentation. All these processes have closed relationships between each other and work synergistically. During decomposition, there are many controlling factors mainly including site conditions (temperature, humidity, and O 2 /CO 2 concentration), woody substrate quality (diameter, species and compound) and organism in CWD. The decomposition rate is generally expresses through a constant k which indicate the percent mass, volume or density loss over time, and can be determined by long-term monitoring, chronosequence approach and the radio between input and the total mass. Now using mathematical models to simulate decomposition patterns and estimate the decomposition rate is widely applied, especially the exponential model. We brought forward that managing and utilizing for the CWD in forest was a primary objective on all forest lands. And it is should be intensified to integrate many related research subjects and to carry a comprehensive, long-term and multi-scale research which mainly focus on seven sections.

Carbon and nitrogen stocks in dead wood of tropical lowland forests as dependent on wood decay stages and land-use intensity

“…A dense canopy cover and high basal area in the natural forest are clear reasons for lower air temperature and higher air humidity than in the jungle rubber system (Kotowska et al 2015). These microclimate properties in the natural forest plots represent favourable conditions for microorganism degrading dead wood (Zhou et al 2007). Conversion of natural forest into jungle rubber systems may not only impact the microclimate conditions, but may likely alter also other environmental factors such as soil organic matter composition, which therefore alter the microbial and fungal community as well which in turn will influence the dead wood degradation.…”

Deadwood volume in strictly protected, natural, and primeval forests in Poland

“…mean age and structure), managed forests differ significantly from natural and strictly protected ones (Bobiec 2002;Stachura-Skierczyńska and Bobiec 2008;WISL 2014). The forests of Poland constitute an important part of Central Europe's forests.…”

“…The average age of forests managed by the SFNFH is 58 years with a stand volume of 272 m 3 /ha, while the corresponding figures for national parks are 74 years and 348 m 3 /ha. Tree stands which are 100 years old or older account for 24.1% of forests in national parks (WISL 2014). Another type of nature conservation in Poland encompasses 1480 reserves with different protection statuses (strict, active, landscape), which occupy a total area of 165.7 thousand ha (CSO 2014).…”

Effects of decay classes and diameter classes on physico-chemical properties of Pinus koraiensis log in a typical mixed broadleaved-Korean pine forest

“…The carbon concentrations of the sapwood showed a trend of gradual increasing during decomposition, and there was an accumulation in nitrogen (N) and phosphorus (P) concentrations of the heartwood and sapwood with an increased decay class, simultaneously. Only N and P concentrations of the heartwood increased and then decreased with an increasing 2015)。倒木是森林生态系统的重要组成部分, 对于 维持生物多样性以及林木的更新具有重要作用; 同 时, 倒木也是重要的养分库和C库, 其养分的缓慢 释放, 对于提高林地的生产力有重要意义 (Harmon et al, 1986;Laiho & Prescott, 2004)。倒木在物理、 化学和生物(特别是微生物、昆虫)等作用下进行的 分解过程不仅可为分解者(如微生物、无脊椎动物、 鸟类等)提供生存环境和必需的营养元素 (Sollins, 1982), 而且能够释放大量的化学元素到土壤中, 丰 富土壤有机质含量和种类, 促进土壤结构和功能的 发育 (Spears et al, 2003)。影响倒木分解的因素有基 质质量、 分解者活性以及环境因素等(如温度、 水分、 气体) (Harmon et al, 1986) (Johnston & Crossley, 1996;Chamber et al, 2001)。影响倒木分解的化学因素主要是其易分 解成分和难分解有机成分(如木质素等)的含量, 其 中氮(N)、磷(P)、木质素、纤维素、C:N、C:P等是 常见的衡量倒木质量的指标 (Berg et al, 2000), 它 们不仅可以表征倒木分解过程中基质的质量变化和 养分限制状况 (Wassen et al, 2005), 而且可以指示 物质循环和能量流动的方向 (Zhou et al, 2007 ; 心材腐烂等级III-V的P含 …”