| Physiological integration characteristics of clonal plants has significant influence in sharing resources for colonization. Currently, clonal herb plants were usually choosed as the materials for physiological integration. That phenomenon happened between genet and ramets or between the ramets when they located in heterogeneous habitats, but that responses are all different in different species. Then Rhus typhina is a tapical clonal tree plant, also an exotic, that have strong ability with root sprouting, for that people pay more attention on it. In order to reveal the mechanism of physiological integration in Rhus typhina, in this thesis, we took the cloned sisters ramets as the material, construct different water provision, different light intensity and different fertility control experiment, then measured water potential, photosynthetic, stable isotopes of carbon and nitrogen with PSYPRO Water Potential System, Li-6400xT Photosynthesis Analyzer and MAT253 Isotope Ratio Mass Spectrometer. The results showed that:1) Under self shading habitats, the cloned fragment ramets'utilization of weak and strong light were stronger than that of the mother plant, that signified optimum light intensity of the ramets were wider than the mother plant under self shading environment. Adversely under full sunshine condition, the ability of strong light intensity utilization of the mather plant were stronger than ramet, and the ability of weak light intensity utilization of ramet were better than the mother plant. The cloned fragment of Rhus typhina may have physiological adaptive strategies to cope with self shading enviromental heterogeneity. In the hilly wastedland habitats, under man-made shading condition, the ability of weak and strong light intensity of ramet increased and that were better than the mather plant.This phenomenon is due to its further propagation to accumulation of the photosynthetic substances. Sufficient water and nitrogen conditions could improve the utilization ability of weak and strong light, this physiological response to implementation maximize the utilization of resources.2) The water and light response on cloned fragment of Rhus typhina was studied comparing the genets and ramets in different water heterogeneous patches by measuring water potential and photosynthesis with PSYPRO Water Potential System and Li-6400xT Photosynthesis Analyzer. Results showed that: 1) after adding 500 mL water to the ramets, the water potential of the genets ABSTRACT increased 48.7% and the ramets increased 82.1%; however, there were no significant differences(P> 0.05). 2) it is more sensitive than that of the ramets that the response of the net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration of the genets to the water, but it was not significant that the difference of increase between genets and ramets (P> 0.05). 3) the fitting of light response curve indicated light compensation point of the genets is lower; light saturation point, higher; apparent quantum efficiency, higher.3) Seeing genets as source of'source-sink', feeding 13C to genet, testing and analyzing the contents of each organs indicated that photosynthetic carbon nutrients and mineral nitrogen were all occered transmission sharing mechanism between vertical and horizontal directions. Thereafter, photosynthetic transmission sharing had priority in vertical directions than horizontal and mineral nitrogen were adverse.4) Maximum net photosynthetic efficiency for all five trees occurred at 12:00 noon with no midday depression. Light-use efficiency of R. typhina, R. pseudoacacia, and Z. jujuba var. spinosa were not significantly (LSD,P<0.05) different, but they were significantly greater (P = 0.05) than A. altissima and V. negundo var. heterophylla. The diurnal changes curves of water-use efficiency in Z. jujuba var. spinosa belonged to a "W-type", while the other four woody species a "V-type". Water-use efficiency of R. typhina was not significantly different from R. pseudoacacia (P>0.05) , but was significantly different from Ziziphus jujuba var. spinosa, Ailanthus altissima, and Vitex negundo var. heterophylla (P<0.05).Therefore, physiological integration of water, photosynthesis product and nutrients of nitrogen exsited within Rhus typhina cloned segment, so it help Rhus typhina using the resources of light water and nitrogen in heterogeneous habitats guarantee the resources when they speading; And comparing utilization of light and water with main woody species, Rhus typhina showed strong light and water use efficiency. |
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