Changes of biomass allocation of Artemisia frigida population in grazing-induced retrogressive communities
放牧退化群落中冷蒿种群生物量资源分配的变化

The study showed that under the disturbance of grazing,the biomass of Artemisia frigida leaves,stems,roots and total plant were increased with increasing retrogressive degree,and that of roots was increased more.The biomass of inflorescences and fruits was increased in light retrogressive community while decreased rapidly in mid retrogressive community,and no reproductive model was observed in heavy retrogressive community.With the increase of retrogressive degree,biomass allocation changed.The allocation to roots increased,but that to sexual reproduction decreased,which was badly inhibited in heavy retrogressive community,accompanying with the change of reproduction pattern.As for the dynamics of resource allocation,the resource was prior to allocate to aboveground portion,especially to photosynthesis organ from early to mid growth period,and allocate to sexual reproduction or reserve organ from mid to late growth period,with the increase of retrogressive degree.The alternation of reproductive pattern was the key that A.frigida population resisted grazing and became the established species in heavy retrogressive community.The change pattern of resource allocation made the allocation harmonious between the growth,resistance and reproduction,and was the substantial base that A.frigida population became the constructive species in heavy retrogressive community.