摘要
基于人工林近自然改造,调控低山丘陵区马尾松低效林林分结构,探明马尾松人工林不同面积林窗下,凋落叶可溶性有机碳(DOC)释放规律。以长江上游低山丘陵区人为采伐形成的马尾松人工林7种林窗(100、225、400、625、900、1 225、1 600 m^2)为研究对象,研究不同面积林窗的马尾松(Pinus massoniana)、红椿(Toona ciliata)、樟(Cinnamomum camphora)、桢楠(Phoebe zhennan)等凋落叶可溶性有机碳(DOC)的损失率。结果表明:(1)林窗面积对凋落叶DOC损失率有显著影响。中小面积林窗(225~625 m^2)内凋落物的DOC损失率高于其它面积林窗。(2)经过1 a的分解,4种凋落叶的DOC损失率为61.55%~90.06%,其中:DOC损失率红椿最高,马尾松最低。(3)凋落叶的DOC损失主要集中在分解前期(0~90 d),此后凋落叶的DOC损失速率不断降低,且不同凋落物之间DOC损失速率的差异不断减小。因此,在马尾松低效林改造过程中,可利用中小面积林窗这一显著作用,引入乡土阔叶树种红椿、樟、桢楠,加速马尾松人工林的物质循环,维持林地肥力。
We adjusted the structure of forest and explored the regularity of litter dissolved organic carbon （DOC） release in sev- en gap sizes of a Pinus massoniana plantation in a hilly area of the upper reaches of Yangtze River. The experiment was set up in Pinus massoniana plantation with seven different gap sizes （ 100,225,400,625, 900, 1 225, and 1 600m2） estab- lished by artificial thinning. The contents of DOC for Pinus massoniana （Pm ） , Toona ciliate （ T ） , Cinnarnomum campho- ra （ C~ ） and Phoebe zhennan （ Pz ） were evaluated in different sized forest gaps, with closed canopy as the control. Litterb- ags were collected from the gap center and the closed canopy in December of 2013, February, May, August and November of 2014. The forest gap size had significant effects on DOC loss rate small and medium sized gaps （ 225-900 m2 ） had grea- ter effect on DOC loss rate for Pm, To, Cc, and Pz leaf litter. Over one-year decomposition, variation trend of DOC loss rate of descending order for four species was To（ 90.06% ）, Cc（ 85.17% ）, Pz（ 78.74% ） and Pm（ 61.55% ）. The DOC loss rate for four species mainly was concentrated in the early decomposition stages （first 90 days ） , and then was decreased quickly, and the difference of DOC loss rate （ per 30 days） among four species diminished gradually. Therefore, when we reconstruct the low-function forest, we can take advantage of small and medium sized gaps, introduce native broad-leaf tree species Tc, Cc, Pz to accelerate nutrient cycling, and maintain the soil fertility of Pinus massoniana plantation.
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2016年第1期23-30,共8页
Journal of Northeast Forestry University
基金
国家自然科学基金项目(31370628)
国家科技支撑计划项目(2011BAC09B05)
四川省科技支撑计划项目(12ZC0017)
四川省科技应用基础项目(2012JY0047)
四川省教育厅科技创新团队计划项目(11TD006)
关键词
可溶性有机碳
林窗
马尾松人工林
马尾松凋落叶
Dissolved organic carbon （DOC）
Forest gap size
Pinus massoniana plantation
Pinus massoniana leaf litters
