Effects Of Mowing On Growth And Recently Photosynthesized Carbon Allocation Of Krascheninnikovia Ceratoides

The paper regarded Krascheninnikovia ceratoides, the subshrub which is widely distributed in temperate desert as research object. Stable isotope tracer technique was used to study the regrowth and recently photosynthesized carbon allocation of Krascheninnikovia ceratoides response to mowing. Our purpose was to provide references for the reasonable utilization of Krascheninnikovia ceratoides resources.(1)Mowing increased the length of current year stem of Krascheninnikovia ceratoides by45.4% and the base stem diameter by 61.6%,but reduced their number by 38.6%. Mowing increased the leaf area by 42.9%.(2) Mowing significantly decreased the biomass of root. Mowing significantly increased the proportion of leaf biomass to total biomass, but decreased the proportion of root biomass to total biomass of Krascheninnikovia ceratoides.(3)The effects of mowing on the allocation of recently assimilated C were varied as time goes on.7 days after labeling, the 13C abundance of leaf and current year stem of Krascheninnikovia ceratoides in mowing were significantly higher than the control. 14 days after labeling, the 13C abundance of previous year stem and root of Krascheninnikovia ceratoides in mowing were significantly lower than the control, but the lower level of root was decresed.21 days after labeling, the influence of mowing on the allocation of recently assimilated C of Krascheninnikovia ceratoides had been gradually disappearing except to the 13C abundance of previous year stem was still lower in the mowing than the control. Over all, the 13C abundance of leaf and current year stem is gradually reduced along with the extenstion of allocation time,which consistent with control. The 13C abundance of previous year stem is gradually reduced along with the extenstion of allocation time too,but in contrast to control. The 13C abundance of root did not change significantly with time.(4)Mowing significantly increased the 13C abundance of rhizosphere soil of Krascheninnikovia ceratoides, and had a accumulation of recently photosynthesized carbon in rhizosphere soil.(5)Mowing changed the variation rate of 13C abundance of different organs of Krascheninnikovia ceratoides. The variation rate of 13C abundance of leaf, current year stem and previous year stem were accelerated in mowing, while that in root was slowed down.In conclusion, Krascheninnikovia ceratoides changed the recently photosynthesized carbon allocation strategy to adapt and improve the conditions of growth restriction caused by the lack of photosynthetic organs after mowing. The changed of recently photosynthesized carbon allocation strategy reflected in leaf size, length of stem, base stem diameter which were further promoted the rapid growth of Krascheninnikovia ceratoides after mowing.