科尔沁沙地植物成熟叶片性状与叶凋落物分解的关系  

Relationships of fresh leaf traits and leaf litter decomposition in Kerqin sandy land

作　　者：李玉霖[1] 孟庆涛[1] 赵学勇[1] 崔建垣[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所

出　　处：《生态学报》2008年第6期2486-2494,共9页Acta Ecologica Sinica

基　　金：国家科技支撑计划课题资助项目(2006BAC01A12)~~

摘　　要：采用室内培养的方法,对科尔沁沙质草地20个主要植物种(10个单子叶植物种和10个双子叶植物种)叶凋落物的CO2释放量和释放速率进行比较,同时测定了20种植物成熟叶片的热值、镁浓度、磷浓度、氮浓度、钾浓度、碳浓度、碳氮比、氮磷比、比叶面积、干物质含量以及叶面积等11项叶片性状,分析20种植物叶凋落物的CO2释放量和释放速率与11项叶片性状的相关关系。结果表明,20种植物的叶片性状在物种间变异范围很大,大多数指标的最大值和最小值的差异在3倍以上,而个别指标如叶镁浓度差异更大,接近9倍之多。由于本项研究中的20种植物均来自于同一样地,因此认为20种植物的自身性状和遗传特性决定了其叶片性状的变异。20种植物叶凋落物培养28d的CO2释放量平均值为(4121±1713)μgkg-1,释放量最大的是尖头叶藜(8767±177)μgkg-1干土,释放量最小的是马唐(1669±47)μgkg-1,二者相差5倍以上。但20种植物叶凋落物CO2释放速率表现相同的变化趋势,培养初期凋落物分解迅速,后期分解相对缓慢。比较分析发现,双子叶植物和单子叶植物叶凋落物CO2释放量、CO2释放速率,以及成熟叶片的叶氮浓度、叶碳浓度、叶C/N和叶干物质含量之间差异显著。相关分析揭示,20种植物成熟叶片叶氮浓度、叶碳浓度、叶C/N和叶干物质含量与叶凋落物分解过程中的CO2释放量和释放速率之间呈显著的相关关系,说明可以利用成熟叶片的N浓度、C浓度、C/N以及干物质含量间接的预测叶凋落物的分解速率。In this study, we investigated leaf traits of 20 plant species （10 monocots and 10 dicots） in the Kerqin sandy land, Inner Mongolia, China. The leaf traits include caloric value, concentration of Mg, P, N, K and C, C/N ratio, N/ P ratio, dry weight, leaf area, and specific leaf area. We also measured CO2 release rates from the powdered leaf litter of these species under HC1 incubated conditions, and analyzed the relationships between the leaf traits and the rates and amount of CO2 release by means of the product-moment correlation coefficient. The results showed that values of leaf traits varied greatly among 20 species. The range of variation of each leaf trait was very large with the maximum values usually three times higher than the minimum values, even more than nine times for leaf Mg concentration. For the studied 20 species grown in the same habitat, such a variation is probably attributed to their hereditary factors. Correspondently, CO2 release among leaf litters of 20 species also varied greatly. The average amount of CO2 release for 20 species is about （4121±1713）μg·kg^-1. The maximum value （（8767±177）μg·kg^-1） was from leaf litter of Chenopodium acuminatum, and the minimum value （（1669±47）μg·kg^-1） was from leaf litter of Artemisia scoparia. N, and C concentrations, leaf C/N ratios and dry weight of leaves were significantly different between monocots and dicots. There was also significant difference of CO2 release between monocots and dicots. Since litter decomposition is mainly affected by litter quality in the same environment, we could conclude that such a difference may be attributed to the difference in litter chemical properties between monocots and dicots. The correlation analysis shows that N and C concentrations, C/N ratios and dry weight of the leaves were significant correlated to CO2 release of leaf litter for these 20 plant species. Therefore, the N and C concentrations, C/N ratios and dry weight of the leaves may be valuable for predicting leaf litter dec

关 键 词：CO2释放量 单子叶植物 双子叶植物 沙丘 

分 类 号：Q948[生物学—植物学]