三峡水库消落区模拟水淹对4种草本植物生长的影响

通过对狗牙根(Cynodon dactylon)、香附子(Cyperus rotundus)、芦苇(Phragmites australis)和羊茅(Festuca ovina)等4种草本植物在长江实际水域进行模拟水淹试验,水淹深度为5 m、10 m、15 m、20 m和25 m,水淹时间为180 d,出水恢复时间为50 d,观测其水淹期间以及出水后盖度的变化,揭示不同水淹条件对4种试验植物生长的影响,从而进一步探讨每种植物在三峡水库消落区植被修复过程中适宜种植的高程。结果表明:水淹导致植株盖度下降,水淹深度越低盖度下降越显著;出水后,除香附子和芦苇在深度为25 m的处理组不能进行恢复生长外,其余皆能恢复生长,但随着水淹深度的加深,越难恢复至淹前水平;各适生植物在消落区的适宜生存范围和最适生存范围:狗牙根和羊茅,175 m～150 m和175 m～155 m;芦苇,175 m～155 m和175 m～160 m;香附子,175 m～155 m和175 m～165 m。

The effects of simulate submerged test in three gorges reservoir hydro-fluctuation area on growth of 4 species of herbs

Our objectives were to reveal the effects of different depths submerged treatments on growth and re-growth of 4 species of herbs in Yangtze River,including Cynodon dactylon,Cyperus rotundus,Phragmites australis and Festuca ovina,and to discuss the corresponding altitude of each species fit to plant of vegetation restore at the Three Gorges Reservoir hydro-fluctuation area.Simulate submerged in Yangtze River area was executed.The depths were 5m,10m,15m,20m and 25m.Each plant was submerged during 180 d and then emerged 50 d.We recorded the coverage at 0 d,60 d,120 d and 180 d during submerged,and 10 d,20 d,30 d,40 d and 50 d during emerged.The results showed that submergence led to coverage decrease,and the depth was deeper,the decrease was more significant.After emerged,all trial plants could re-grow,except the depths 25m groups of Cyperus rotundus and Phragmites australis.Also the depths was deeper,the re-growth was harder to arrive pre-submerged levels.The appropriate and optimal survival altitude ranges of 4 species of herb were confirmed,respectively.Cynodon dactylon and Festuca ovina,175m-150m and 175m-155m;Phragmites australis,175m-155m and 175m-160m;Cyperus rotundus,175m-155m and 175m-165m.