LOSS OF MASS AND CHEMICAL-CHANGE IN DECAYING BOLES OF A SUBALPINE BALSAM FIR FOREST
LOSS OF MASS AND CHEMICAL-CHANGE IN DECAYING BOLES OF A SUBALPINE BALSAM FIR FOREST
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DOI：
10.2307/1939054
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发表时间：
1980-01-01
期刊：
影响因子：
4.8
通讯作者：
REINERS, WA
中科院分区：
文献类型：
--
作者：
LAMBERT, RL;LANG, GE;REINERS, WA
香脂冷杉（A.在美国新罕布什尔州白色山脉的亚高山森林上部检查了balsamea）树干。初始质量的50%在23年内丢失，90%在77年内丢失。高衰减率归因于小直径的树干，充足的水分，和富含N的环境。平均死木质量在这片森林是4.9公斤/平方米，占25%的死木，活植物生物量和森林地面有机质的总和。密度和水分的变化，以及在浓度和内容的各种化学成分的树干被跟踪的腐烂序列。纤维素，木质素，C和Na的含量的变化，随后在腐烂过程中的质量损失。Ca、Mg、K、P含量在腐解初期下降速度快于质量损失。这种最初的损失大部分是由于脱落的营养丰富的树皮，在这些小树干包括13%的干物质。在衰变后期，Ca、Mg和K的损失率与质量损失率大致相同或略小于质量损失率。经过一个陡峭的初始下降，磷含量的树干之间的12年和33年保持大致不变。此后，损失率等于质量损失。氮含量在第一个33年是大致恒定的，之后，它下降的质量损失平行。
Decay of balsam fir (A. balsamea) boles was examined in an upper subalpine forest of the White Mountains, New Hampshire, USA. Of the initial mass, 50% was lost in 23 yr; 90% was lost in 77 yr. High decay rates were attributed to the small diameters of the boles, ample moisture, and a N-rich environment. Average dead wood mass in this forest was 4.9 kg/m2, representing 25% of the sum of dead wood, live plant biomass and forest floor organic matter. Changes in density and moisture and in the concentrations and content of various chemical components of the boles were traced over the decay sequence. Changes in the content of cellulose, lignin, C and Na followed loss of mass during decay. Contents of Ca, Mg, K and P decreased faster than loss of mass in the early stages of decay. Much of this initial loss was ascribed to sloughing of nutrient-rich bark which in these small boles comprised 13% of dry mass. Later in decay, the loss rates of Ca, Mg and K were about the same or slightly less than the loss rate of mass. After a steep initial drop, P content of the boles remained approximately constant between years 12 and 33. Thereafter the loss rate paralleled loss of mass. N content was approximately constant in the first 33 yr, after which it declined in parallel with loss of mass.