【摘要】 测定福建万木林自然保护区12种不同层次优势植物叶片碳(C)、氮(N)含量和热值大小,分析探讨C、N、C/N的季节变化动态及其与热值的相关性.结果表明:叶片C、N含量年均值分别为47. 79%和1. 77%,与全球陆生植物相比,表现为C含量高,N含量低,即N素受限,高C/N表明该地区植物养分利用效率高; 12种优势植物叶片平均C、N含量呈:夏季>春季>秋季>冬季,C/N呈:秋季>冬季>春季>夏季,C含量季节间差异达极显著水平(P <0. 01);不同植被层次植物叶片C含量为:乔木层>灌木层>草本层,而N含量为:灌木层>乔木层>草本层,差异均达极显著水平(P <0. 01); 12种优势植物叶干质量热值(GCV)、去灰分热值(AFCV)与C含量极显著正相关,灰分含量(AC)与C含量显著负相关; AFCV与N含量显著正相关.表明C含量可反映热值的高低.上述结果可为科学估算福建万木林自然保护区森林生态系统植物C、N库贮量,合理开发利用生物质资源提供理论依据.更多还原

【Abstract】 The concentrations of carbon( C) and nitrogen( N) and caloric values in leaves of12 dominant species from different tree layers in Wanmulin Nature Reserve of Fujian Province were determined. The seasonal dynamics of C,N and C/N and the relationship with caloric value were analyzed. The results showed: The mean annual concentrations of C and N in leaves were 47. 79%and 1. 77%,respectively. Compared with the global terrestrial plants,the C concentration was higher and the N concentration was lower,appeared N limited; and the higher C/N indicated the nutrients utilization of plants in this area was highly efficient. The average C and N concentrations in leaves of 12 dominant species decreased in the following order: summer,spring,autumn and win-ter,C/N was appeared: autumn > winter > spring > summer,and the C concentration had extremely significant difference between seasons( P < 0. 01). The concentrations of leaf C between different layers of forest were decreased from the arbor layer to the shrub layer to the herb layer,and rank order of the N concentrations was: shrub layer > arbor layer > herb layer,and both of them were extremely significant different( P < 0. 01). The gross caloric value( GCV) and ash free caloric value( AFCV) in leaves of 12 dominant species were significantly positively correlated with the C concentration,and the ash content( AC) was significantly negatively correlated with the C concentration. The AFCV was only significantly positively correlated with the N concentration. It showed that the concentration of C could reflect the level of calorific value. The above conclusions could provide a theoretical basis for the scientific estimation of the reserves of plant C and N in the forest ecosystem,and the rational development and utilization of biomass resources in Wanmulin Nature Reserve of Fujian Province.更多还原