摘要
基于辽东山地老秃顶子古冰缘地貌森林中主要树种的粗木质残体(CWD)样本,利用自然风干、室内浸泡、X荧光光谱方法,对CWD样本的吸水速率、持水率和养分元素含量进行系统分析研究。结果显示:(1)在水分保持功能方面,CWD样本在累计8h的浸泡过程中,6个主要树种CWD可吸持相当2.533mm降雨的水量,其中前15min(0.25h)吸水量占总吸水质量的60%;各性状CWD比较显示,以海拔900m以上、阔叶树种、高中腐级、根桩和倒木的CWD持水性较强。(2)在养分元素保持功能方面,CWD边材C含量为78.96%,心材为96.05%;边材中N、Ca、Si、K、Mg、P等6种养分元素的含量分别为心材的4.93、5.88、10.79、2.72、1.25、2.38倍;不同性状CWD边材中,诸元素含量略有差别,其中C元素在针叶树、高腐级、枯立木边材中含量最高,而N元素在阔叶树、低腐级、枯立木边材中含量最高。研究表明,辽东山地古冰缘地貌森林生态系统中,CWD有重要的吸持水分功能以及营养元素的缓释和富集功能,CWD中更接近外界的边材部分较心材有更强的元素缓释和富集的功能;CWD是古冰缘地貌土壤覆盖率低、土层薄而贫瘠的森林中重要的生态组分。
Based on the samples of the coarse woody debris （CWD） of major six species of deciduous and coniferous trees in paleo-periglacical landform forest of the Mt. Laotudingzi, eastern Liaoning mountainous region, by the methods of natural wind dry, indoor soak and X-ray fluorescence, this paper had a system- atic research on water-absorption rate, water-absorption ability and the nutrient element content of CWD. The results were as follows： （1） The water absorption equals a precipitation of 2. 533 mm in the 8 hours＇ constant soaking process, and 60% of it was made in the beginning 15 rains. In the comparison of each sin-gle sample, 900 m altitude trees, deciduous trees, high decay class, logs and roots showed better ability of water-absorption. （2） Element slowly releasing and enrichment function of CWD： The percentage of Car- bon is 78.96% in sapwoods and that in heartwood is 96.05%. It was also found that the element N, Ca, Si, K, Mg, P contents in sapwoods were 4.93, 5.88, 10.79, 2.72, 1.25 and 2.38 times as that in heart- woods correspondingly. The contents of nutrient elements had a minor difference in the sapwoods of each sample, among which, the CWD of coniferous trees and high decay class reveal higher carbon content while the CWD of deciduous trees and low decay class have a higher nitrogen content and above all, snags have a high content of both two elements. The research indicated that： CWD had an important function of water-holding, nutrient element slowly releasing and enrichment in the paleo-periglacical landforms forest ecosystems of eastern Liaoning mountainous region; the sapwoods play a more important role than heart- woods in the aspect of nutrient slowly releasing and enrichment. Since the land has a low soil coverage rate and the soil layer on land is thin and barren, the CWD is an irreplaceable and crucial ecological component of paleo-periglacical landform forests.
出处
《西北植物学报》
CAS
CSCD
北大核心
2016年第10期2058-2069,共12页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(41271064)
关键词
粗木质残体
森林生态系统
古冰缘地貌
养分元素
水文功能
辽东山地
coarse woody debris
forest ecosystem
paleo-periglacical landform
nutrient element
hydrologi- cal function
eastern Liaoning mountainous regions
