3种湿地植物克隆生长及其生物量对不同水淹的响应

Response of Clonal Growth and Biomass Allocation of 3 Aquatic Plant Species to Different Inundation Levels

通过人工模拟水位控制试验,研究不同水位梯度处理对3种水生植物梭鱼草、菖蒲和黄花鸢尾株高、克隆分株数、生物量积累及生物量分配格局的影响。试验设置固定水位和周期波动水位2种处理,固定水位分别为自由水面淹没苗钵的1/2(低水位),全淹(中水位)和高出苗钵上口径12cm(高水位)3个梯度;波动水位为低水位处理14 d,然后转至高水位处理7 d,以此往复循环,持续56 d。结果表明:不同水位梯度对3种水生植物的株高、克隆分株数、生物量积累与分配格局等指标均有显著影响(P<0.05);株高、克隆分株数(黄花鸢尾除外)在波动水位处理下均显著高于固定水位(P<0.05),固定水位中的高水位和波动水位处理后梭鱼草根状茎、叶和根生物量均显著高于中水位和低水位梯度。波动水位和固定水位中的高水位处理仅对菖蒲的叶质量有显著影响,且明显高于中水位和低水位。黄花鸢尾各构件生物量在各水位处理中无显著差异(P>0.05)。综合来看,波动水位更有利于3种水生植物种群的建立。

The effects of different water level gradients on the stem length,number of clonal ramets,biomass accumulation and biomass allocation patterns of 3 aquatic plants,namely Pontederia cordata,Acorus calamus,and Iris wilsonii were studied through artificial simulation of water level control experiment.Two sets of treatments were designed with water levels for the fixed water levels（including low water level that submerged 1/2 of the pot height,medium water level that reached to the right top of pots and high water level which exceeded the pot top by 12 cm） and the fluctuated water level（i.e.low water level to 1/2 of the pot height for 14 d,then transferred to high water level that exceeded the pot top by 12 cm for 7 d）,and the 2 water levels alternated in turn for 56 d,and the entire test duration was 8 weeks.The results showed that the water level gradients significantly affected on the above indexes observed of all the 3 species.The indexes of plant height,number of ramets of Pontederia cordata,Acorus calamus plants treated with the fluctuated water level were all significantly higher than those plants treated by the fixed water level（P0.05）.The biomasses of the rhizomes,leaves and root system of Pontederia cordata plants treated with the fixed high water level as well as with the fluctuated water level were all significantly higher than those plants treated by the fixed medium and low water level.Only the leaf biomass of Acorus calamus was significantly affected by the fluctuated and the fixed high water levels treatments,whose value was significantly higher than that of treated by the fixed medium and low water level.There was no significant difference in the biomasses of leaves,rhizomes and roots of Iris wilsonii among the different water level treatments（P0.05）.Comprehensive speaking,the fluctuated water level treatment was more beneficial to the population establishment of the three aquatic plant species.