Study On Current-year Twigs Biomass Allocation Of 43 Woody Species In Chongqing

In the present papar,characteristics in annual twig of woody species with different life forms between different interference conditions in Chongqing were studied.Independent t-test was conducted to detect the differences of annual twig between life forms and among different interference conditions in city.Pearson correlation analysis was used in order to detect the correlation coefficient between different traits in twig.Standardized Major Axis Estimation(SMA)was used to detect the allometric relationships between twig cross-sectional area with individual leaf area?twig cross-sectional area with total leaf area?stem mass with total leaf mass?stem mass with total leaf area?individual leaf area with individual leaf mass?stem mass with fruit mass?stem mass with seed mass?twig cross-sectional area with fruit mass?twig cross-sectional area with seed mass?total leaf mass with fruit mass?total leaf mass with seed mass?pericarp mass with seed mass.Also analysis the differences of these relationships between life forms and among different interference conditions.The study results are supposed to provide insights into the understanding of the mechanism of species coexistences.The major conclutions were described as follows:(1)Stem?leaves?fruits of branchlet are generally correlated.But there is no correlation between leaf number and other trait.Showing that leaf number is relatively autonomous.(2)Twig traits had difference between species and the coefficient variation(CV)of various characters were different.Aaverage CV is 181%.The biggest CV is 340% in stem mass and smallest CV is 134% in total fruit mass.(3)Twig traits existed significant differences between life forms.The stem length?individual leaf area?total leaf area?twig cross-sectional area?stem mass?specific leaf area(SLA)?seed mass of evergreen species were bigger than that of deciduous species,but the petiole mass and specific leaf weight(SLW)of evergreen species were bigger than deciduous species.Showing the different bionomic strategy of different life type.There is no significant difference between different interference conditions in city.(4)The SMA analysis for all plants datas showed that the relationships between twig cross-sectional area and individual leaf area?twig cross-sectional area and total leaf area?individual leaf area and individual leaf mass?stem mass and fruit mass?stem mass and seed mass?pericarp mass and seed mass were both isometric relationships.It is allometric relationships between other traits.(5)The allometric relationship of twig traits exist difference between different life forms.In the relationship of pericarp mass with seed mass,there is no common slope and the growth index of evergreen species was significantly higher than deciduous species.In the relationships between twig cross-sectional area and leaf area,the Y intercept of deciduous species is significantly higher than evergreen species.In the relationships between individual leaf area with individual leaf mass,the Y intercept of evergreen species is significantly higher than deciduous species.(6)The allometric relationship of twig traits exist difference between different interference conditions in city.In the relationships between twig cross-sectional area with fruit mass?twig cross-sectional area with seed mass?total leaf mass with fruit mass?total leaf mass with seed mass?total leaf area with fruit mass,the Y intercept of species in semi-natural area was significantly higher than species in natural area and artificial area.Showing that species in semi-natural area will have bigger fruit mass and seed mass when there is a constant leaf mass?leaf area?twig cross-sectional area.Also,the slope of species in semi-natural area was more gently than species in natural area and artificial area.