11种温带树种粗木质残体分解初期结构性成分和呼吸速率的变化  

Changes in structural components and respiration rates of coarse woody debris at the initial decomposition stage for 11 temperate tree species

作　　者：张利敏[1,2] 王传宽[1] 唐艳[1] 

机构地区：[1]东北林业大学生态研究中心,哈尔滨150040 [2]哈尔滨师范大学,黑龙江省普通高等学校地理环境遥感监测重点实验室,哈尔滨150025

出　　处：《生态学报》2011年第17期5017-5024,共8页Acta Ecologica Sinica

基　　金：国家“十二五”科技支撑项目(2011BAD37B01);林业公益性行业科研专项(200804001);国家自然科学基金(30625010);国家林业局重点项目(2006-77)

摘　　要：采用长期定位跟踪实测方法,比较分析我国东北温带森林11个主要树种粗木质残体(CWD)分解初期3 a中结构性成分的差异、变化以及与其呼吸速率(RCWD)的关系。测定树种包括:软阔叶树种(白桦、山杨、紫椴)、硬阔叶树种(胡桃楸、蒙古栎、色木槭、春榆、黄檗、水曲柳)和针叶树种(兴安落叶松、红松)。结果表明:11个树种CWD木质素含量(Lc,%)和综纤维素含量(Hc,%)差异显著(P<0.001),其中软阔叶树种的Lc最低。木质素含量与N含量的比值(Lc/N)依次为:针叶树种>硬阔叶树种>软阔叶树种。经过3 a的分解,大部分树种(除了紫椴和春榆)的Lc略有增加,但变化不显著(P>0.05);而其木质素密度(Ld,g/cm3)和综纤维素密度(Hd,g/cm3)都有不同程度的减小(P<0.05),软阔叶树种损失最多,针叶树种损失最少。所有树种Lc/N值均增大。将RCWD标准化成温度为15℃时(R15)比较发现,在CWD形成初期(2005年)不同树种的R15有所差异;阔叶树种的R15及其温度系数(Q10)均高于针叶树种。经过3 a的分解,除兴安落叶松、色木槭和水曲柳外,其它树种的R15出现了不同程度减小。总体看来,软阔叶树种R15减少了32.0%,而针叶树种R15则增加了23.1%。另外,针叶树种的Q10增大,而阔叶树种的Q10则基本保持不变。R15与Hc呈正相关,与Lc和Lc/N呈负相关。CWD分解初期3 aR15的变化率与Hc的变化率之间呈正相关关系,表明结构性成分的变化是导致CWD分解初期RCWD变化的主要因素之一。A long-term tracking experiment on coarse woody debris（CWD） decomposition of 11 temperate tree species was established in northeastern China in 2004.The objectives of this study were to（1） compare differences and changes in structural components of the CWD and CO2 flux released from CWD decomposition（RCWD） during the initial three years;and（2） examine relationships between the structural compositions and RCWD during this period.The experimental design was completely randomized blocking design with 11 species × 6 blocks × 4 sites.The tree species investigated included softwood species（Betula platyphylla,Populus davidiana,and Tilia amurensis）,hardwood species（Juglans mandshurica,Phellodendron amurense,Quercus mongolica,Acer mono,Fraxinus mandshurica,and Ulmus japonica） and coniferous species（Pinus koraiensis,Larix gmelinii）.The four sites were a dry oak forest,a wet hardwood forest,a medium moist pine plantation,and an open field.The RCWD was measured with an infrared gas exchange analyzer（LI-6400 IRGA） from May to October in 2005 and 2008.Three 5 cm thick dics of CWD samples for each tree species were randomly sampled in October 2005,and six samples in October 2008 at each site for determining lignin concentration（Lc,%）,lignin density（Ld,g/cm3）,holocellulose concentration（Hc,%）,and holocellulose density（Hd,g/cm3）.The results indicated that the Lc and Hc differed significantly among the species（P0.001）,with the softwood tree species being the least Lc.The ratio of lignin to nitrogen concentration（Lc/N） ranked as： coniferous species hardwood tree species softwood tree species.The Lc during the initial three years of decomposition increased for all species except for T.amerensis and U.japonica,but the changes were insignificant（P 0.05）.The Hd and Ld decreased to some degrees（P0.05）,with the minimum loss in the coniferous species and the maximum loss in the softwood species.The Lc/N increased during the decomposition for all species.The normalized RCW

关 键 词：倒木 木质素 纤维素 呼吸 温度系数 

分 类 号：S718.4[农业科学—林学]