珠三角河网初级生产力时空差异及其影响因素

Spatial and temporal difference of primary productivity and its influencing factors in the Pearl River Delta

为评价珠三角河网初级生产力,于2015年3月、6月、9月、12月对其进行取样调查,采用多元统计方法研究初级生产力时空差异及其与环境因素关系。结果表明,珠三角河网初级生产力(碳,C)为98.81~927.21mg·(m^2·d)^(-1),均值为346.51 mg·(m^2·d)^(-1)。调查区域初级生产力季节变化明显,总体上表现为春季>冬季>夏季>秋季。各站位初级生产力均值以珠江桥站位最高[600.61 mg·(m^2·d)^(-1)],市桥站位最低[232.60 mg·(m^2·d)^(-1)]。初级生产力与透明度、氮磷营养盐、叶绿素a呈正相关关系(P<0.01,n=52),与硅酸盐呈负相关关系(P<0.01,n=52),与水体富营养化综合指数(EI)呈线性相关关系。珠三角河网以中营养、富营养为主体,与其他水域相比,初级生产力较低,污染程度较严重,需防止其向富养化发展。

To evaluate the primary productivity in the Pearl River Delta, the spatio-temporal distribution of primary productivity and its relationship with environmental factors were investigated by multivariate statistical methods during March, June, September and December in 2015. The concentration of primary productivity （C） ranged from98.81 mg·（m^2·d）^-1 to 927.21 mg·（m^2·d）^-1 with an annual average of 346. 51 mg·（m^2·d）^-1. The primary productivity varied in different seasons （spring〉winter〉summer〉autumn）. The annual average of primary productivity ranged from232.60 mg·（m^2·d）^-1 at Shiqiao to 600.61 mg·（m^2·d）^-1 at Zhujiangqiao. Positive relationship was found between primary productivity and transparency, nitrogen and phosphorus as well as chlorophyll a（P〈0.01, n=52）, whereas the primary productivity showed negative correlation with silicate（P〈0.01, n=52）. The primary productivity and eutrophication composite index （EI） showed linear relationship. Compared with other watersheds, the Pearl River Delta was at medium or high eutrophication status with relative low primary productivity, so it is needed to prevent pollutions with a tendency towards heavy eutrophication.