模拟牧食损害对轮叶黑藻(Hydrilla verticillata)生长的影响

摘要

在露天池塘中,通过试验模拟轮叶黑藻受到牧食损害(动物牧食对植物造成的损害)的情况,研究其对轮叶黑藻生长的影响.结果表明:3种不同损害形式(去除植物顶部0.5 cm、去除植物50％的叶片、同时去除植物顶部0.5 cm与50％叶片)对轮叶黑藻的生长率的变化、主枝与分枝长度的改变、植物干物质以及氮、磷含量变化等方面均产生了不同程度的影响.其中,去叶和去顶去叶两种方式均显著抑制了轮叶黑藻的生长,相对生长率分别是未受损植株的58.5％与71.4％;去顶和去顶去叶两种方式在停止轮叶黑藻主枝的生长的同时使植物的分枝显著生长;去叶损害在主枝与分枝长度方面均对植株生长无明显抑制作用,但对分枝重量的减少有显著影响.去顶处理方式能显著增加了植株中氮的含量,而去顶和去顶去叶两种处理方式能显著地增加了植物中磷的含量.对受损轮叶黑藻的生长机理分析表明,牧食损害能够显著影响轮叶黑藻在生态池塘的生长,通过改变轮叶黑藻的生长方式,促进轮叶黑藻种群数量的增加.%In outdoor ponds,the outdoor experiments were conducted to examine effects of damage on the growth of submerged macrophyte Hydrilla verticillata.There were three damage treatments:growing tips removed,50％ defoliation,and both 50％ defoliation and growing tips removed.The results showed that three damage treatments affected plant relative growth rate,length of main shoot and lateral shoots,and content of dry mass,nitrogen and phosphorus of plant tissue.Compared with undamaged plant,plant relative growth rate was only 58.5％ for 50％ defoliation treatment,and 71.4％ for 50％ defoliation and growing tips removed treatment.The main shoot growth of plant in removed growing tips treatment and both 50％ defoliation and growing tips removed treatment almost stopped,but lateral shoots grew significantly.50％ defoliation in the main branch and branch length had no significant inhibitory effect on plant growth,but the branch weight reduction had a significant impact.Removal of the top 0.5 cm treatment could significantly increase the content of nitrogen in plant,and the removal of the top 0.5 cm and 0.5 cm removal and removal of the top 50％ leaves of two kinds of treatment could significantly increase the phosphorus content in plants.On the impaired Hydrilla verticillata growth mechanism was analyzed.The grazing damage could significantly affect the Hydrilla verticillata in the growth of ecological pond,by changing the growth mode of Hydrilla verticillata,to promote the increase of Hydrilla verticillata population.