| Seed mass and specific leaf area are two representative parameters of plant reproductive and vegetative trait,both of which are important parameters in the life-history strateg -y.Seed mass play an important role in seed germination and seedling recruitment,then affect the structure of plant communities and species distribution.SLA directly affected by the leaf thickness,shape,and weight.it reflects the ability of light intercept by the leaves and in the light of self-protection capabilities under the strong light to some extent.SLA associate with the strategy of growth and survival of plant,and reflects the characteristic of plant to adapt to different habitats,and it is also one of the indicators to evaluate whether the level of community productivity and community structure are reasonable.In this paper,we measured the seed mass and SLA of 808 common species in the alpine meadow,analysis the relationship between seed mass and SLA in the alpine meadow of Qinghai-Tibet plateau,and Attempting to how the altitude and other non-biological factors influence them.The results were demonstrated as follow:1.Seed mass was not correlated with SLA(p＞0.05);2.There is significantly negative correlation between the variation in seed mass and SLA with altitude(P＜0.05),and seed mass decreased with altitude increasing.The effect of altitude on seed mass and SLA has different patterns among growth form,slope,and altitudinal gradient;3.Under different phylogenetic levels,the variation of seed mass and SLA is different too.Seed mass of Saxifragaceae & Caryophyllaceae was significantly negative correlated with the altitude(p＜0.001),and there significant negative correlation between send mass of Rubiaceae,Caprifoliaceae,Cyperaceae & Juncaceae and the altitude(p＜0.05),while there was no effect of altitude on other families.Altitude has significant effect on seed mass of 22.2%families.Toward SLA,plants of Boraginaceae,Fabaceae and Liliaceae were very significant negative correlated with altitude,and there significant negative correlation between plants of Gentianaceae,Ranunculaceae & Crassulaceae and altitudinal gradient was significant negative correlation while there is no effect of altitude on other families.Within family,altitude has significant effect on SLA of 25.8%families;4.Habitat factors have no significant impact on seed mass in the overall area,but seed mass were biggest under the tree,while the smallest in disturb or barren habitats; Synergy of habitats and altitude could significant impact on seed mass,there is significantly negative relationship between the variation of seed mass and altitude under the tree while there is no effect of altitude on other habitats.Within family,the impact of habitats on seed mass of the plants of Apaceae,Poaceae,Asteraceae,Rubiaceae and Cyperaceae is significant,and very significant in Asteraceae;Habitat contrast significantly affected to the SLA of the plants of Asteraceae,Scrophulariaceae,Fabaceae,Gentianaceae,Rubiaceae and Cyperaceae,which was very significant in the plants of Gentianaceae;5.Growth form significantly affected both seed seed mass and SLA.Effects of altitude to seed mass of different growth form were also different.seed mass of herb decreased with altitude increasing,and the correlation of altitude and the seed mass of shrub and tree was not significant;Toward SLA,there is significantly negative correlation between the variation of shrub&herb's SLA and altitude while not significant in tree;6.Climatic factors significantly affected both seed mass and SLA,and has the consistent quality.There is significantly positive correlation between seed mass& SLA and mean annual temperature,and a significantly negative correlation between seed mass &SLA mean annual precipitation and mean annual sunshine;7.There is significantly relationship between SLA and slope.SLA in southward smaller than northward,it's means that the southward have thicker leaves.Under different slopes, effects of altitude to the variation of SLA were different too.There were significantly negative correlation between altitude and SLA in northward,semi-northward and semi -southward except southward,which were very significant in northward and semisouthward;8.A simple model including atitude,climate,habitat,growth form and slope explains 5%,9.2%,1.4%,11.2%and 0.4%of the variation in seed mass,8%,12.6%,13.4%,4.3% and 11%in SLA.
|
PDF Full Text Request