北京植物园不同功能型植物叶经济谱

Leaf economics spectrum among different plant functional types in Beijing Botanical Garden,China

通过对北京植物园不同功能型植物的叶片光合参数、叶绿素荧光参数、叶面积、叶干质量以及叶氮含量等性状参数进行测定,分析了不同功能型植物的叶经济谱.结果表明:生活型中草本植物、生活史中一年生植物、光合型中C4植物靠近叶经济谱中快速投资-收益型物种的一端,而生活型中乔木和灌木、生活史中多年生植物、光合型中C3植物位于缓慢投资-收益型物种的一端,表明不同功能型植物通过叶片性状间的权衡采取不同的环境适应策略,验证了不同功能型植物叶经济谱的存在.不同功能型植物叶片性状具有明显差异,其中不同生活型间的叶片比叶面积(SLA)、叶氮含量(N_(mass))、最大净光合速率(A_(mass))、光合氮利用效率(PNUE)均表现出草本植物>藤本植物>灌木>乔木;不同生活史间一年生植物的SLA、N_(mass)、A_(mass)、PNUE均显著高于多年生植物;不同光合型间植物的A_(mass)、PNUE、PSⅡ实际光化学效率(ΦPSⅡ)均表现出C4>C3.N_(mass)、A_(mass)、SLA两两之间呈显著正相关,而PSⅡ有效光化学量子产量(F_v'/F_m')与SLA呈显著负相关;PNUE与SLA呈显著正相关.

We measured leaf photosynthetic and chlorophyll fluorescence parameters as well as leaf area,dry biomass,and nitrogen content of different plant functional types（ PFTs） at the Beijing Botanical Garden,and analyzed the leaf economics spectrum（ LES） among different PFTs. The results showed that the plants with the life form of grasses,those with an annual type of life history,and with a C4 photosynthetic pathway might provide a quick return on investment for the species located at one end of the LES. Similarly,the plants with a life form of trees and shrubs,with a perennial type of life history,and with a C3 photosynthetic pathway might provide a slower return on investment for the species located at the other end of the LES. This indicated that plants with different PFTs might have diverse strategies that allowed them to adapt to the environment through a trade-off among leaf traits. The results showed that the LES existed among different PFTs. Remarkable differences were observed in most of the leaf traits among different PFTs. The various life forms analyzed here were ranked in the order of grasses vines shrubs trees based on specific leaf area（ SLA）,mass-based nitrogen concentration（ N_（mass））,mass-based photosynthetic capacity（ A_（mass））,and photosynthetic nitrogen use efficiency（ PNUE）. Among the different life histories,SLA,N_（mass）,A_（mass）,and PNUE in annual species were significantly higher than those in perennial species. In addition,A_（mass）,PNUE,and the quantum yield of PSⅡ electron transport（ ΦPS Ⅱ） were higher in C4species than in C3 species. N_（mass）,A_（mass）,and SLA were significantly positively correlated with each other. SLA was significantly negatively correlated with the photochemical efficiency of PSⅡ in the light（ Fv＇ / Fm＇）,whereas it was significantly positively correlated with PNUE.