翅果油树及其群落中7种优势木本种类的叶性特征比较

Comparison on leaf traits of Elaeagnus mollis and seven dominant woody species in its community

植物的叶片性状与其适应环境的基本行为有直接关系,能够反映植物适应环境变化的生存对策,部分叶片性状与植物的生存策略以及植物利用资源的能力紧密相关.例如,叶片含氮量高而比叶面积低的种类,通常具有较高的水分利用效率;叶片的干物质含量能够指示植物对资源的利用情况,光合速率能够反映植物对特定环境的适应方式,而光合氮素利用效率则是植物利用环境资源能力的关键生理因素.

Taking Elaeagnus mollis Diels and seven dominant woody species in its community from Yicheng County of Shanxi Province as research objects,leaf traits including specific leaf area( SLA),nitrogen content in leaf per unit area( Narea),leaf dry matter content( LDMC) and photosynthetic nitrogen use efficiency( PNUE) were compared,and correlations of SLA value with LDMC and PNUE values were analyzed. The results show that there are different degree variations in four indexes of leaf traits of E. mollis,Vitex negundo var. heterophylla( Franch.) Rehd.,Broussonetia papyrifera( Linn.) L’ Hér. ex Vent.,Lespedeza bicolor Turcz.,Caragana microphylla Lam.,Rosa xanthina Lindl.,Amygdalus davidiana( Carrière) de Vos ex Henry and Periploca sepium Bunge,in which,SLA value with the largest coefficient of variation( 40. 4%),and LDMC value with the lowest coefficient of variation( 10. 3%). Compared with other tested species,SLA and PNUE values of E. mollis are the lowest( 103 cm^(-2)· g^(-1) and 108 μmol · mol^(-1)· s^(-1),respectively),while its N_(area) value is the highest( 0. 243 g · m^(-2)),and its LDMC value is also relatively high( 0. 380g·g^(-1)). SLA value of eight tested species show an extremely significant positive correlation( P<0. 01) with PNUE value,and a significant negative correlation( P < 0. 05) with LDMC value,correlation coefficient are 0. 923 and-0. 718,respectively,indicating that SLA value is an important parameter of leaf photosynthetic capacity and resource utilization ability. It is suggested that compared with other dominant woody species,E. mollis is more sensitive to environmental change,and has a poor environmental adaptability.