【摘要】 利用野外实验与盆栽实验 ,对不同刈牧强度下冷蒿生长与资源分配影响的研究结果表明 ,按比例刈割冷蒿的再生生长大于留茬高度刈割 .在生长季前期 ,不刈割冷蒿净生长高于刈割处理 ,而进入生长季中后期 (8月中旬以后 ) ,轻度刈割净生长高于不刈割处理 .冷蒿种群生物量分配的总体格局是根 >叶 >茎 .刈牧明显影响冷蒿生物量分配格局 ,尤其是叶和花的分配 .3/ 4刈割或留茬 4cm刈割叶生物量分配显著高于其它各处理 ,而花的生物量及其分配显著低于其它处理 ,根、茎生物量分配各处理间差异不显著 .冷蒿有性生殖分配随刈牧强度的增加而降低 ,繁殖方式发生了改变 .优先将光合产物分配给再生茎以及繁殖方式转向营养繁殖 ,通过克隆生长维持和扩大种群是冷蒿对强度放牧的生态适应对策 .更多还原

【Abstract】 In order to understand the degradation process and its mechanism of typical steppe in Inner Mongolia,this paper studied the growth and resource allocation pattern of Artimisia frigida under different grazing and clipping intensities(no grazing,light grazing 1.33 sheep·hm -2,moderate grazing 4.00 sheep·hm -2,heavy grazing 6.67 sheep·hm -2,proportional clipping and stubble clipping),which was conducted at the Inner Mongolia Grassland Ecosystem Research Station of Chinese Academy of Sciences(43°26′～ 44°08′N,116°04′～117°05′E).The results showed that the regrowth ability of A.frigida under proportional clipping was superior to that under stubble clipping,and light clipping (1/4 proportional clipping or 10 cm stubble clipping) was superior to no clipping.In early growth season,the net regrowth of A.frigida was higher under no clipping than under light clipping,but reversed in late growth season (after mid-August).The biomass allocation pattern of A.frigida was roots>leaves>stems.Grazing or clipping affected biomass allocation significantly,especially for the allocation of leaves and flowers.The biomass allocation of leaves was significantly higher under 3/4 proportional clipping or 4 cm stubble clipping than under other treatments,and reverse trend was true for the biomass allocation of flowers.There were no significant differences in biomass allocation of roots and stems among treatments.Sexual reproductive allocation decreased with increasing grazing or clipping intensities,and reproductive mode of A.frigida changed under heavy grazing.The changes in priority of biomass allocation from sexual reproductive organs to clonal growth to sustain and propagate population were important ecological strategies of the species to heavy grazing.更多还原