摘要
为更全面地了解淦河流域生态系统的健康状况,于2012年初春测定了淦河干流及其主要支流的水体理化指标、底栖藻类叶绿素a(Chl a)含量和无灰干重(AFDM),同时测定了部分样点底栖藻垫的磷含量及形态组成。结果显示:淦河上游各支流及干流水体的总磷(TP)、总氮(TN)和化学需氧量(COD)分别为0.014~0.072、0.282~1.204、0.77~13.26 mg·L-1,水质较好;流经市区的干流下游河段水体受到一定程度的污染,TP、TN和COD分别为0.214~0.252、2.039~2.748、9.09~16.48 mg·L-1;就总氮、总磷的含量来看,样点S1到S15的水质为Ⅱ类水,S16~S20超过Ⅴ类。各支流底栖藻类Chl a的含量在6.6~16.1μg·cm-2之间,而淦河干流样点为13.5~47.3μg·cm-2,所有样点底栖藻类的AFDM(645~3050μg·cm-2)和Chl a显著相关。底栖藻类对磷的滞留能力在一定范围内随水体营养浓度的增加而增强,下游底栖藻垫的总磷含量比上游高,最高可达82μg·cm-2;底栖藻垫中的磷形态组成以铁结合态磷(Fe-P)为主,占总磷的34%~73%,说明Fe-P对底栖藻类-水界面的磷循环起着主要的作用。研究结果对提高水体监测的认识,加强淦河流域管理和完善淦河生态系统健康状况评价具有一定的参考价值。
To understand ecosystem health of Gan River, physical and chemical variables of the mainstream and tributaries of Gan River were measured in Spring, 2012. Meanwhile, chlorophyll a(Chl a) and ash-free dry mass(AFDM) of benthic algae at all sites were determined. Phosphorus concentrations and forms in benthic algae in several sites were also measured. Results showed that the water quality of the upper reaches of Gan River was better than that of the lower reaches. Total phosphorus(TP), total nitrogen(TN) and chemical oxygen demand(COD) of water in the upper reaches were 0.014~0.072 mg·L-1, 0.282~1.204 mg·L-1and 0.77~13.26 mg·L-1, respectively, while those in the lower reaches were respectively 0.214~0.252 mg·L-1, 2.039~2.748 mg·L-1and 9.09~16.48 mg·L-1. Based on TN and TP, the water quality in sites S1 to S5 belonged to Class Ⅱ, while it exceeded Class Ⅴ in sites S16 to S20. The contents of Chl a in benthic algae ranged from 6.6 μg·cm-2to 16.1 μg·cm-2for all tributaries and from 13.5 μg·cm-2to 47.3 μg·cm-2for the mainstream of Gan River. There was a significant correlation between AFDM(645~3050 μg·cm-2) and Chl a. In certain concentration ranges, higher concentrations of nutrients in river water led to higher phosphorus retention by benthic algae. The total phosphorus was up to 82 μg·cm-2at the lower reaches. FeP was a dominant form in benthic algae, accounting for 34%~73% of total phosphorus in all sampling sites. These findings would help assess ecosystem health and improve watershed-scale management of Gan River, China.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2015年第3期532-537,共6页
Journal of Agro-Environment Science
基金
国家自然科学基金(30970550)
中央专项基金(CZW14003)
关键词
底栖藻类
淦河流域
生物量
磷形态
水质
benthic algae
Gan River basin
biomass
phosphorus forms
water quality
