Ecological Responses And The Effects Of Division Of Labor In Clonal Plant Zoysia Japonica In Heterogeneous Habitats With Complimentary Resources

The phenomenon of division of labor popularly exists in the field of economy, and it is the engine of economic progress. A similar phenomenon also exists in clonal plants. The morphological or physiological plasticity and physiological integration are prerequisites for the effect of division of labor in clonal plants. Clonal plant can efficiently utilize the heterogeneous resources, overcome the limitation of local resource, enhance the overall biomass and population fitness, through the mechanism of division of labor.Through a series of greenhouse experiments, the characteristics and effects of division of labor in Zoysia japonica were studied. The indexes such as the diameter of creeping stolon, leaf length/width ratio, specific leaf area, multiple-node number, growth rate and biomass were used to evaluate the effects of division of labor. The resources used in the experiments were light, water and soil nitrogen. The habitats were heterogeneous habitats with complimentary resources and the contrst homogeneous habitats.In general, if the basal patch in a habitat was a lower resource treatment, the ramets in the basal and apical parts tended to adaptively respond to the resource level through morphological plasticity, so as to efficiently absorb the limiting resources. If the basal patch in a habitat was a higher resource treatment, the successive growth of the plant tended to be supported by sufficient resources, thus, it tended to absorb the abundant resources and neglect the limiting resources. In the aspect of physiological plasticity, Zoysia japonica tended to change the proline content in the leaves according to the water and light conditions in the habitats. Soil nitrogen levels did not tend to change the proline content in the leaves.The effects of division of labor in the experiments did not accord with the previous results in some aspects. Not all treatments showed obvious effects of division of labor. All the plants with obvious effects of division of labor in terms of different indexes were those growing in the habitats whose basal patches were higher resource treatments. The plants growing in the habitats whose basal patches were lower resource treatments, did not tended to form obvious effects of division of labor. Division of labor showed positive effects in terms of different indexes.