陕西千湖国家湿地公园不同类型湿地土壤种子库变化特征及对不同浇水方式的响应

The Characteristic of Different Wetland Types and the Response to Different Watering Modes in Shaanxi Qianhu National Wetland Park

为明确陕西千湖国家湿地公园土壤种子库的变化特征以及不同浇水方式对种子库特征的影响结果,采用室内萌发的方法,对千湖湿地不同类型湿地,河流湿地,塘库湿地和沼泽湿地的土壤种子库特征进行调查研究.结果表明:千湖湿地平均种子库密度为4446粒/m^2,其中以沼泽湿地种子库密度最高为(6135±984)粒/m^2,其次为河流湿地(3803±1286)粒/m^2,而塘库类型湿地最低为(3401±556)粒/m^2;千湖湿地种子库共萌发38种植物,隶属于18科36属,其中河流湿地、库塘湿地、沼泽湿地土壤种子库萌发物种数分别为29种,26种和32种.千湖湿地萌发物种以一、二年生草本植物为主.不同类型湿地种子呈现垂直分布的特征,0~5 cm土层的种子密度显著高于5~10 cm土层.不同类似湿地,Simpson多样性指数和Margalef丰富度指数呈现出不同的变化特征.不同浇水方式显著影响湿地种子库的特征,水淹处理和干湿交替处理显著降低湿地种子库的密度和萌发物种数,而在水淹处理和干湿交替处理萌发的物种主要以沉水性水生植物,诸如金鱼藻(Ceratophyllum demersum)和红蓼(Polygonum orientale)构成.陕西千湖湿地公园土壤种子库密度总体上处于中等水平,而种子库萌发物种数较低,特别是一些沉水性水生植物,因此在维持千湖湿地公园生物多样性以及抵抗土壤干湿转变过程中,需重视沉水性水生植物的作用.

In order to identify the characteristics of soil seed bank and the influence of different watering modes on soil seed density and the number of germination species in three different wetland types in Shaanxi Qianhu National wetland park,the seed germination experiments were conducted.The results showed that the average soil seed density of three different wetland types was 4446 seed/m^2,the marsh wetland had the highest seed density(6135±984 seed/m^2),followed by the river wetland(3803±1286 seed/m^2),the pond wetland had the lowest seed density(3401±556 seed/m^2).A total of 38 species were identified in the soil seed banks with the germination method,belongs to 36 genera in 18 families.The number of species found in the soil seed bank was 29,26,and 32 species in marsh wetland,river wetland,and pond wetland,respectively.Soil seed bank mainly composed by annual and biennial herb.There was vertical distribution trait in soil seed band and the densities of soil seed bank in 0-5 cm significant higher than that in 5-10 cm soil layer.There were different characteristics on Simpson biodiversity index and Margalef richness index in different wetland types.The different watering modes significant influenced the seed number and density.The dominate species were submerged aquatic plant,such as Ceratophyllum demersum and Polygonum orientale in flooding and CK+flooding treatments.The seed density was acceptable in Shaanxi Qianhu National wetland park compared with other wetlands,however,the number of species was low,particular in submerged aquatic plant.So the role of submerged aquatic plant should be pay attentions,when consideration maintain the biodiversity and resistance on the process of the soil alternate drying-rewetting.