叶片损害强度与基质营养水平对苦草补偿性生长的影响

通过室外双因子控制试验,研究了叶片损害强度与基质营养水平对沉水植物苦草补偿性生长的影响.结果表明：叶片损害与基质类型对苦草的累积生物量、生物量的分配（根叶比）及分株数均有显著影响.与未受损植物相比，强受损使苦草的累积生物量及无性分株数显著降低，根叶比明显升高，而弱受损与未受损处理之间没有明显差别.与营养贫瘠的岸泥相比，生长在肥力较高湖泥中的苦草的累积生物量较高，而根叶比与分株数较低；叶片损害与基质类型对苦草的相对生长率也有显著影响，受损使苦草的生长率明显提高，而两受损处理之间无显著差别.未受损与强受损时,湖泥中苦草的生长速率明显高于岸泥，弱受损时则相近.并初步探讨了水生植物受损后的补偿生长机理.

Effects of leaf damage and sediment type on compensatory growth of submerged macrophyte Vallisneria spiralis.

Through a 2 × 2 factorial outdoor experiment, the effects of leaf damage and sediment type on the compensatory growth of submerged macrophyte Vallisneria spiralis were examined. The results showed that leaf damage and sediment type had significant effects on the cumulative biomass, biomass allocation, and ramet number of V. spiralis. Compared with undamaged plant, the strongly damaged one had a decrease of cumulative biomass and ramet number and an increase of biomass allocation, but no evident difference was observed between weakly damaged and undamaged plants. The cumulative biomass of undamaged and strongly damaged plants was lower in infertile sediments (bank sediment) than in fertile sediments (lake sediment), but that of weakly damaged plant was almost the same in the two sediments. The biomass allocation and ramet number of V. spiralis were higher in bank sediment than in lake sediment. Leaf damage and sediment type also affected the relative growth rate (RGR) of V. spiralis. Leaf damage resulted in an increase of RGR, but the difference of RGR between weak damage and strong damage was not evident. The RGR of undamaged and strongly damaged plants was significantly higher in lake sediment than in bank sediment, but that of weakly damaged plant was almost the same in the two sediments. The mechanisms of the compensatory growth of V. spiralis were discussed.