Study On Leaf Traits Of Elaeagnus Mollis In Shanxi Province

Take Elaeagnus mollis as the main object of the study In Elaeagnus mollis Nature Reserve of Shanxi Yicheng County,select Rosa xanthina, Vitex chinensis and other 10 species of woody plants, the leaf area estimated with Li-3000A Leaf Area Meter, the saturated photosynthetic rate (Parea) with Li-6400 portablephotosynthesis system, and the nitrogen content was measured by spectrophotometric method; Quantifying correlations among LDMC,SLA,The net photosynthesis based On mass (Pmass), leaf nitrogen content per unit area (Narea), leaf nitrogen content per unit mass(Nmass), photosynthetic nitrogen use efficiency (PNUE) and trait differences between plant species.The results showed that:(1)With the increase of Elaeagnus mollis'age class, leaf area, water content and SLA showed a clear downward trend,while the LDMC showed a rising trend ,Parea, Pmass and PNUE first decreased and then increased; about 10cm size class, Parea, Pmass and PNUE reached the minimum value, indicating that the photosynthetic capacity and PNUE of E. mollis about 10cm size class was comparatively low,so pressure of survival was greater;(2)The leaf area of Elaeagnus mollis was significantly positively correlated with SLA ( p<0.01 ) ,and positively correlated with the Nmass(p<0. 05), but significantly negatively correlated with the Nmass(p<0. 05).The correlation analysis among photosynthetic parameters showed that Parea, Pmass and PNUE also showed a significantly positively correlation (p<0.05), Shows that the leaf traits of Elaeagnus mollis grew toward conducive direction because of the increase of leaf area.(3) The Nmass of Elaeagnus mollis was significantly positively correlated with Parea and Pmass(p<0.01), The SLA was significantly positively correlated with Parea,Pmass,PNUE(p<0.01), The PNUE was significantly positively correlated with Parea and Pmass(p<0.01), Demonstrated the regularity features of Elaeagnus mollis'leaf traits at different developmental stages; (4)In the survey of 5 months, In late July,Elaeagnus mollis has minimum SLA,the highest Nmass and Narea, indicating that the leaves have higher water use efficiency , capacity of organic accumulation and,meanwhile, higher capability of drought-resistant and stress resistance,so it's the active growing period of Elaeagnus mollis;( 5 ) In the 8 different plant spices of Elaeagnus mollis community, Elaeagnus mollis has the lowest SLA , water content,and the highest Narea, comparing with other plant in communities, Elaeagnus mollis is more sensitive to environmental stress,and can't adapt to the environment definitely, which maybe a reason of it's endangered,(6)LDMC is the Characteristic Parameters of species leaves as it's small and Constant Standard deviation;(7) Compared with Elaeagnus umbellala, Elaeagnus mollis has lower SLA and PNUE,higher Narea and LDMC, It shows that in similar environmental conditions, Elaeagnus mollis has a wider ecological niche, and can better adapt to local environmental conditions;(8) From the survey of all species about the common relationship between leaf traits, Elaeagnus mollis has the same or similar discipline with other plant species, indicating that the intraspecific leaf relationship of Elaeagnus mollis is the same with interspecific leaf relationship of all other species , it is suggested that the relationship of leaf traits doesn't change because of the different species,and is common existence of plant species in Elaeagnus mollis distribution area surveyed.