Ecological Adaptability Of Clonal Traits Of The Natural Shrub, Sabina Vulgaris To Sandy Habitats In Mu Us Sandland

Distributing pattern of soil properties, including soil moisture and nutrients beneath the natural shrubs of Sabina vulgaris and its ecological adaptability of clonal traits to sandy habitats in Mu Us sandland were studied using field experiments. The results are as following:The soil nutrients, such as organic matter, total N, available K and hydrolytic N, and the soil moisture under the shrubs of S. vulgaris were heterogeneously distributed. It has shown an evident phenomenon, called "island of fertility" in the shrubs because there were high content of medium-fine soil particles(0.25~0.02mm) and relatively abundant soil moisture, organic matter, total N, available K and hydrolytic N on the soil surface under the shrubs, and furthermore, the content of soil moisture and nutrients gradually decreased from the center of the shrubs to its edge in this soil layer. However, the soil moisture under the layer of 20cm showed the opposite changing trend. Plant cover and some differences in plant traits have notably effected on the local soil heterogeneity.The internode length, branching intensity and branching angle exhibited plasticity. With extension of the stolon, changes of the internode length, branching intensity and ramet length were fit to exponential model. It seemed to "flexibly" adapting to the habitat because the clonal architecture of S. vulgaris had both the traits of "guerilla" and "phalanx". Basipetal and epitropic integration of resources acquired from adventitious roots instantaneously occurred in stolon. After the stolon had suffered from severing disturbance, clonal ramets could keep photosynthetic organ from being damaged through the plastic responses of the chlorophyll fluorescence traits, such as increasing nonphotochemical quenching of chlorophyll fluorescence(NPQ), decreasing actual photochemical efficiency of PS II in the light( â–³F/Fm' ) and photochemical electron transport rate(ETR). Moreover, the clonal ramets could also increase water use efficiency by means of decreasing stomatal conductance. Clonal integration was important to maintaining survival of the ramets undergone various of disturbance.A phenomenon of "specialization for abundance" might occur in both photosynthetic ramets and adventitious roots during the clonal growth of S. vulgaris, and it was a kind of clonal behavior of labor division, which was benefit to the genet to using heterogeneous resources. Clonal plasticity, resources sharing and clonal labor division wereadaptive strategies of S. vulgaris to sandy habitats in Mu Us sandland.