Stipa tenacissima Does not Affect the Foliar δ^(13)C and δ^(15)N of Introduced Shrub Seedlings in a Mediterranean Semi-arid Steppe

作     者：Fernando T.Maestre Susana Bautista Jordi Cortina 

作者机构：Departamento de EcologiaUniversidad de AlicanteApartado de correos 9903080 AlicanteSpain Department of BiologyDuke UniversityPhytotron BuildingScience DriveBox 90340DurhamNorth Carolina 27708-0340USA Centro de Estudios Ambientales del MediterraneoC/ Charles Darwin 1446980 PaternaSpain 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2006年第48卷第8期

页      面：897-905页

核心收录：

学科分类：0710[理学-生物学] 09[农学] 0903[农学-农业资源与环境] 0901[农学-作物学] 0703[理学-化学] 0902[农学-园艺学] 

基　　金：Supported by the REDMED collaborative research project(contract number ENV4-CT97-0682) supported by the National Natural Science Foundation of China(30424813) Science Publication Foundation of the Chinese Academy of Sciences 

主　　题：facilitation Medicago arborea Pistacia lentiscus Quercus coccifera stable isotopes steppe Stipa tenacissima. 

摘      要：Recent studies have shown that the tussock grass Stipa tenacissima L. facilitates the establishment of late-successional shrubs, in what constitutes the first documented case of facilitation of woody plants by grasses. With the aim of increasing our knowledge of this interaction, in the present study we investigated the effects of S. tenacissima on the foliar δ13C, δ15N, nitrogen concentration, and carbon ： nitrogen ratio of introduced seedlings of Pistacia lentiscus L., Quercus coccifera L., and Medicago arborea L. in a semi-arid Mediterranean steppe. Six months after planting, the values of δ13C ranged between -26.9‰ and -29.6‰, whereas those of δ15N ranged between -1.9‰ and 2.7‰. The foliar C ： N ratio ranged between 10.7 and 53.5, and the nitrogen concentration ranged between 1.0% and 4.4%. We found no significant effect of the microsite provided by S. tenacissima on these variables in any of the species evaluated. The values of δ13C were negatively correlated with predawn water potentials in M. arborea and were positively correlated with relative growth rate in Q. coccifera. The values of δ15N were positively correlated with the biomass allocation to roots in the latter species. The present results suggest that the modification of environmental conditions in the are surrounding S. tenacissima was not strong enough to modify the foliar isotopic and nitrogen concentration of shrubs during the early stages after planting.