摘要
林窗在人工林林分结构优化和调整上具有重要价值.为了解林窗面积对凋落物分解是否有显著影响以及哪种面积林窗下凋落物分解更快,以采伐形成的42年生的马尾松(Pinus massoniana)人工林7种不同大小的林窗(G1,100m^2;G2,225 m^2;G3,400 m^2;G4,6 25 m^2;G5,900 m^2;G6,1 225 m^2;G7,1 600 m^2)为研究对象,以林下为对照,采用凋落袋分解实验,探讨不同林窗面积对马尾松(Pinus massoniana)和樟(Cinnamomum camphora)凋落叶分解的影响.结果表明:1)林窗面积对凋落叶的分解具有显著(P<0.05)影响,即Olson经典分解模型拟合凋落叶质量损失的分解系数k值比较,马尾松为G4>G1>CK>G2>G3>G5>G6>G7,樟为G2>G4>G1>CK>G5>G6>G7>G3.可见中型(G4:625 m^2)林窗下马尾松和樟的质量损失率高于其它林窗和林下.2)马尾松和樟凋落叶(每30天)质量损失速率都表现出先升高(0-90 d)后降低的趋势.分解一年后,两种凋落叶在3个孔径凋落袋内的质量损失率比较,马尾松为0.04 mm(35%)<0.5 mm(43%)<3 mm(51%),樟为0.04 mm(42%)<0.5 mm(49%)<3 mm(60%),两者的分解95%的平均时间分别为马尾松4.35年和樟3.60年.可见樟凋落叶比马尾松凋落叶分解得更快.综上,林窗面积对凋落物分解有显著影响,在马尾松低效林改造过程中,可利用中型林窗这一显著作用,引入乡土阔叶树种樟,加速马尾松人工林的物质循环,维持林分地力.
Forest gap plays an important role in optimizing and adjusting the structure of plantation. However, researchers are not clear whether the gap size affects mass loss, or which gap size contributes more to litter decomposition. This research set up a field litterbag experiment to study the effects of different forest gap size on mass loss of Pinus massoniana （Pm） and Cinnamomum camphora （Cc） leaf litter. The Pm plantation was thinned to establish seven different gap sizes （Gh 100 m2, G2： 225 m2, G3：400 m2, G4：625 m2, G5：900 m2, G6：1 225 m2, G7：1 600 m2）; closed canopy was used as the control. The results showed 1） the forest gap size had significant effect on mass loss of Pm and Cc, with the k value of Olson decomposition model as G4 〉 G1 〉 CK 〉 G2 〉 G3 〉 G5 〉 G6 〉 G7 in Pm, and G2 〉 G4 〉 G1 〉 CK 〉 G5 〉 G6 〉 G7 〉 G3 in Cc. Compared with small and large forest gaps, those of medium sized （G4） promoted the mass loss rate of Cc and Pm. 2） In both Pm and Cc, the mass loss rate （per 30 days） first increased and then decreased in the 90-day period. After one year decomposition, the mass loss rate in 3 mesh sizes was 0.04 mm （35%） 〈 0.5 mm （43%） 〈 3 mm （51%） in Pm, and 0.04 mm （42%） 〈 0.5 mm （49%） 〈 3 mm （60%） in Cc. The 95% decomposition time was 3.6 years for Cc and 4.35 years for Pm, showing a higher mass loss rates （per 30days） in Pm than in Cc. The results indicated that forest gap size has significant effect on mass loss rate of Pm and Cc leaf litter. In reconstructing low-function forest, we can take advantage of medium-sized gaps and introduce native broad-leaf tree species Cc to accelerate nutrient cycling and maintain the soil fertility of Pm plantations.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2016年第2期292-299,共8页
Chinese Journal of Applied and Environmental Biology
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(2013SZ0067
2011SZ0239)
四川省科技厅应用基础项目(2012JY0047)
四川省教育厅科技创新团队计划项目(11TD006)资助~~
关键词
质量损失
凋落叶分解
林窗
马尾松
樟
马尾松人工林
mass loss
litter decomposition
forest gap
Pinus massoniana
Cinnamomum camphora
Pinus massoniana plantation
