封育条件下白茅繁殖对策研究

在对云南马龙县退化山地草甸围栏封育恢复过程中，白茅Imperata cylindrical是草地中优势植物，在整个群落的演替过程中有着重要影响。因此，对封育条件下白茅的无性繁殖器官根茎特征变化进行研究具有非常重要的意义。研究结果表明：封育使3个退化梯度形成了3个不同的生态系统群落。在轻度退化封育区，白茅的根茎随封育时间的延长而变长，分蘖枝数无明显变化，但枝条密度随封育时间的延长而逐年增加，封育促进了该区白茅无性繁殖。在中度和重度退化封育区，白茅的根茎随封育时间的延长而变短、变细，重度退化封育区变化差异极显著（P＜0.01），中度退化封育区变化差异显著（P＜0.05），分蘖枝数减少，封育使白茅无性繁殖在中度和重度退化区受到抑制。

Effect of fencing on reproduction strategies of Imperata cylindrical

Imperata cylindrical was a dominant plant in the degraded mountain meadow that was in the restoration process by fencing,in Malong of Yunnan Province.The features of asexual organs of I.cylindrica in the meadow were studied.The results showed that three different types of vegetation community were formed at a gradient with three degradation levels under fencing condition.In fenced light degraded area,the rhizomes of I.cylindrical became longer with the fencing time,but the number of tiller branches did not change,and the stem density increased with the fencing time.In fended moderate and heavy degraded areas,the rhizomes of I.cylindrical became shorter and thinner with the fencing time while the change of rhizome number in heavy degraded area was significant(P<0.01)and the change in moderate degraded area was significant(P<0.05).The growth through asexual reproduction was limited in moderate and heavy degraded areas.