不同光照强度和底质营养对三种沉水植物的影响

Effects of different light intensity and sediment nutrition on three submerged macrophytes

沉水植物的生长不但与光照强度的关系密切,也受底质营养的影响,因此研究光照强度和底质营养两种环境因子的共同作用对沉水植物的影响尤为重要。本文选择轮叶黑藻(Hydrilla verticillata)、苦草(Vallisneria natans L.)和大茨藻(Najas marina L.)3种沉水植物为研究对象,设置3种光照强度(高、中、低)和2种底质营养(高、低)处理,通过测定植物生长指标(生物量和叶绿素)及水质指标(水体溶氧量和pH)的变化反映光照强度与底质营养对三类沉水植物生长的影响。结果表明:(1)高底质营养处理促进了三种沉水植物的生长,生物量、叶绿素含量、水体溶氧量和pH均高于低底质营养处理组。(2)高底质营养处理组中,轮叶黑藻在中光照强度处理下其生物量最高为4.87 g,苦草在低光照强度处理下生物量最高为3.13 g,大茨藻在高光照强度处理下生物量最高为4.71 g,相应的叶绿素含量和水体溶氧量也都达到了最大值。因此根据修复湿地环境中的光照和底质条件,因地适宜的选择沉水植物必须研究各种沉水植物不同的生态影响因子。

In order to study the combined effects of different light intensities and nutrient sediment conditions,three submerged plants(Hydrilla verticillata,Vallisneria natans L.and Najas marina L.)were selected,with three kinds of light intensity(high,medium,low)and two kinds of nutrition sediment(high,low)as a processing.The growth indicators including biomass and chlorophyll,and water quality indicators including dissolved oxygen and pH in water were measured.Our results showed that H.verticillata had the highest biomass,chlorophyll,dissolved oxygen and pH under high nutrient sediment conditions and middle light intensity while V.natans L.under high nutrient sediment conditions and low light intensity.N.marina L.had the highest biomass,chlorophyll and dissolved oxygen under high nutrient sediment conditions and light intensity but no significant pH differences.Therefore,it is important to select proper species according to the light conditions and sediment conditions of target water for restoration.