天津于桥水库菹草的空间分布格局

为及时了解春季水生植物的实际生长情况和客观反映水深对菹草(Potamogeton crispus)分布的影响,2014年4月4日和21日对天津市蓟县于桥水库的水生植物进行初步调查。利用GPS定位和google地图,在于桥水库库区内均匀设置30个采样点,采集以样点为中心、周边1 m2内的菹草并称量鲜重,对各采样监测点的水深情况进行测量。通过数据分析,发现菹草的总体分布水深在1.5~5.0 m,2次调查时于桥水库水位分别为19.00 m和18.86 m,计算得出菹草的分布区域高程为13.5~17.5 m(大沽)。对库区菹草生物量进行调查并采用Surfer软件制作其分布等值图,结果显示,库区北岸除峰山南区域(24、27号点)以外,菹草生物量总体较南岸大;其中桃花寺一带(12号点)菹草生物量最大,为4.978 kg/m2;菹草生长受水深和光照影响较大,水深超过5 m的区域,光照强度和水温均不能达到菹草石芽萌发的条件。在一定水深范围内其生物量与水深之间存在着较明显的负相关关系,对菹草生物量(y)和水深值(x)进行回归分析,拟合方程为:y=0.2092x2-2.5191x+7.5095(R2=0.8941)。

Spatial Distribution of Potamogeton crispus in Yuqiao Reservior

The preliminary investigations of Potamogeton crispus in Yuqiao Reservior were made on April 4 and April 21 respectively. Thirty sites were sampled to analyze the spatial differentiation and biomass of Potamogeton crispus. The water level of Yuqiao Reservior for the first survey and the second survey were 19.00m and 18.86m. Through the analysis we found that the water depth and elevation for Potamogeton crispus growth were almost between 1.5 meters to 5 meters and 13.5 meters to 17.5 meters, respectively. The biomass of Potamogeton crispus in the north area was larger than that in the south area of the Yuqiao Reservior except No.24 sampling site. The most magnitude was 4.978kg/m2 and appeared in the Peach Blossom Temple area (No . 12 sampling site). Results show that the depth of water and light has great influence on the growth of Potamogeton crispus. There was a clear negative correlation between the biomass of Potamogeton crispus and water depth within a certain depth range.