Physiological Ecology Study On Population Of Prunus Mongolica Maxim.in Alaxa Desert Region

In this paper, a series of studies on natural populations of Alaxa’s Wulaanchonji and Aoloonobo Prunus mongolica were exprimentized.We have studied population characteristics、photosynthesis characteristics、 element contents of funtional leaf、ability of Anti-oxidative stress、 physiological and ecological characteristics of seeds.Intended to explore the physiological and ecological characteristics of the population of P.mongolica and provide experimental evidence for the protection. The main results were as follows:1. Aspect of P. mongolica population characteristics in two area, the number of young and old-age individuals accounts a small proportion of total population, middle-age occupies big proportion. Aoloonobo P.mongolica’s population age structure tended to stable type and Wulaanchonji’s tended to recession type.The survivorship curves in two places both belong to Deevey Ⅱ and Deevey Ⅱ2. The distribution pattern tended to be clumped in both places.2. For field measurement data, Fitting the Light response curve with Rectangular hyperbolic model in the field, Maximum net photosynthetic rate of Aoloonobo and Wulaanchonji were10.29μmolCO2·m-2s-1,4.5μmolCO2·m-2s-1, Apparent quantum efficiency were0.03μmolCO2·μmol-1 and0.02μmolCO2·μmol-1.Light compensation point were17μmol·m-2s-1and10μmol·m-2s-1, Light saturation point were328μmol·m-2s-1and258μmol·m-2s-1, With sun plants characteristics.3. Studies show that the ability of anti-oxidation, the leaves’activity of CAT in Aoloonobo’s P.mongolica were higer than Wulaanchonji’s population, but Wulaanchonji’s population activity of SOD and POD were higher than Aoloonobo’s, difference were notable, the leaves of P. mongolica s population both have a certain extent of Membrane lipid peroxidation, but the difference of MDA contents’were not notable.4. The thousand seed weight of P.mongolica in Aoloonobo、Wulaanchonji were155.59g、136.00g. Thousand seed weight of ate by sheep was only107.13g indicate that water status of habitat have greater impact on mature of P.mongolicaa’s seeds, grazing have greater impact on seed rain.The P.mongolica seeds endorocarp have favourable water permeability.Without endocarp, the seed germinated after3-4d, but with endocarp, it was delated3-4d.With endocarp and without endocarp seeds Germination rate、 Germination index and Germination potential have no notable difference. The optimum germination temperature and Soil moisture of P. mongolica seeds were25℃and20%, treated with45℃> RH100%and Accelerated aging by artificial, after0>12>24>36and48h,without endocarp seeds Germination rate%Germination index and Vigor index Significantly lower than with endocarp seeds. Endocarp have varying degrees of anti-aging effect. During the period of germination, P.mongolica seeds respiration rate basically tended to increase, respiratory quotient gradually tended to reduce.Indicate that, the seeds were given priority to with anaerobic respiration at early stage of germination, substrate of respiration was fat,then transition to aerobic respiration.5.Contents of siol organic matter、total nitrogen、total phosphorus、 K and Na in Aoloonobo were7.68g·kg-1DW、0.73g·kg-1DW.0.43g·kg-1DW、4.41g·kg-1Dw and2.05g·kg-1DW.Contents of other elements order were:Ca> Al>Fe>Mg>As>Mn. Contents of siol organic matter、total nitrogen、 total phosphorus、K and Na in Wulaanchonji were：4.80g·kg-1DW、0.44gkg-1DW、0.19g·kg-1DW、3.90g·kg-1Dw and0.84g·kg-1DW. Contents of other elements order were:Ca> Al>Fe>Mg> As>Mn.P.mongolica leaves’difference of N、P contents and N:P rate were not notable. Each element contents of the order in Aoloonobo P. mongolica’s leaves and seeds were:Ca>Mg>Al>Fe>As>Pb and Ca>Mg>Al>Fe>As>Zn. Each element contents of the order in Wulaanchonji P. mongolica’s leaves and seeds were:Ca>Mg>Al>Fe>Sr>As and Ca>Mg>Al>Fe>As>Zn.