EFFECTS OF LONG-TERM SUBMERGENCE ON SURVIVAL AND RECOVERY GROWTH OF FOUR RIPARIAN PLANT SPECIES IN THREE GORGES RESERVOIR REGION, CHINA
EFFECTS OF LONG-TERM SUBMERGENCE ON SURVIVAL AND RECOVERY GROWTH OF FOUR RIPARIAN PLANT SPECIES IN THREE GORGES RESERVOIR REGION, CHINA
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DOI：
10.3773/j.issn.1005-264x.2008.05.001
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发表时间：
2008-09-01
期刊：
影响因子：
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通讯作者：
Luo Fang-Li
中科院分区：
文献类型：
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作者：
Wang Hai-Feng;Zeng Bo;Luo Fang-Li
目的对三峡库区不同海拔河岸上天然分布的地果榕、荻、牛鞭草和狗牙根4种河岸植物进行了调查。为了明确它们在成库后“三峡库区消落区”长期完全水淹条件下的存活和生长情况, 实验设置对照(不进行水淹, 常规供水管理)和完全水淹两个处理, 30、60、90、120、150和180 d 6个水淹时间水平, 研究了4种植物在完全水淹条件下的存活、生物量变化和恢复生长。结果表明：长期淹水后，植物的存活与其在河岸上的分布格局有关，在淹水后恢复期，植物的总枝长、总枝数和总叶数均随淹水时间的延长而增加，而在淹水后恢复期，植物的存活与其在河岸上的分布格局有关。地果榕主要发生在高海拔地区，淹水30 d后死亡。中海拔地区的荻（Triarrhena sacchariflora）在淹水150和180 d后死亡。90%和100%的H.结果表明，在180 d的淹水条件下，高羊茅和鸭茅均能存活。淹水抑制了所有植物的生长，各物种的总生物量增长量均显著低于对照植物。所有沉水植物的地上生物量均显著下降。淹水60 d和120 d后，糖花T的地下生物量显著下降，而H.结果表明：在淹水过程中，A、altissima和C.所有存活的植物都生长了。淹水30、60和90 d后，各沉水植物的地上部总长度的相对生长速率（RGR）与对照差异不显著;而淹水120、150和180 d后，沉水植物的地上部总长度的RGR均显著高于对照。结果表明：（1）不同海拔高度下，紫花苜蓿、高羊茅和狗牙根的叶绿素含量均高于对照。淹水后，叶片数的相对生长速率始终高于对照。长期淹水后，这可能是植物产生更多新叶、加速光合作用的有效途径。
Aims Ficus tikoua, Triarrhena sacchariflora, Hemarthria altissima and Cynodon dactylon are four riparian plants in Three Gorges Reservoir Region that are naturally distributed on riverbanks of different elevations. Our objective was to determine their survival and growth after long-term submergence in the water-fluctuation zone in Three Gorges Reservoir Region.Methods We studied survival and biomass increase of plants subjected to 30, 60, 90, 120, 150 and 180 d submergence and in a control (no submergence). We measured total shoot length, total shoot number and total leaf number during the post-submergence recovery period.Important findings Survival of the plants after long-term submergence was associated with their distribution pattern on riverbanks. Ficus tikoua, mainly occurring on high-elevation sites, died after 30 d submergence. Triarrhena sacchariflora, from intermediate-elevation sites, died after 150 and 180 d submergence. 90% and 100% of submerged plants of H. altissima and C dactylon, respectively, survived after 180 d submergence. Submergence inhibited the growth of all plants, and the total biomass increase of each species was significantly lower than that of control plants. The aboveground biomass of all submerged plants decreased significantly. After 60 and 120 d submergence, the belowground biomass of T sacchariflora decreased significantly, but that of H. altissima and C dactylon did not change during submergence. All surviving plants grew. After 30, 60 and 90 d submergence, the relative grown rate (RGR) in total shoot length of all submerged plants was not significantly different with that of control plants, but after 120, 150 and 180 d submergence, the RGR in total shoot length of submerged H. altissima and C dactylon was higher than that of control plants. The RGR in total leaf number was always higher than that of control plants after all submergence durations. After long-term submergence, this might be an effective way for plants to generate more new leaves and accelerate photosynthesis.