College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture/Key Laboratory of Agroecology and Rural Environment of Guangzhou Regular Higher Education Institutions, Guangzhou 510642, China.
Earthwatch Institute (Hong Kong), Room 1402 Breakthrough Centre, 191 Woosung Street, Kowloon, Jordan.
Sci Total Environ. 2017 Jul 15;590-591:361-369. doi: 10.1016/j.scitotenv.2017.02.032. Epub 2017 Mar 10.
During 2015, we studied the temporal patterns of nutrient concentrations and turbidity in water bodies with different degrees of agricultural and urban pressures across Guangzhou and Foshan (China). Data and observations were made by trained citizen scientists and professional researchers. Our study shows that all monitored water bodies, with the exception of Qiandeng Lake and Fengjiang River, had elevated NO-N concentrations, which ranged from 0.10 to 6.83mg/L and peaked in late winter and early spring and reached a minimum in summer and mid-autumn. PO43-P concentrations ranged from 0.01 to 0.25mg/L and peaked during the winter, late-summer and late autumn. Turbidity values were highest at sites with agricultural activities, with maximums in the late winter and autumn, and the highest frequency (16% and 25%) of algae presence occurred in the spring and autumn. To better understand the characteristics and drivers of the algae occurrences, measurements of phytoplankton composition and physicochemical characteristics were conducted in three key seasons in the agricultural process, fallow, sowing and rainy season in 2016. Our focused study found that the occurrence of Bacillariophyta, Euglenophyta, Xanthophyta, Cryptophyta, Chrysophyta were positively correlated with dissolved oxygen and phosphorus concentrations, while Chlorophyta and Cyanophyta had positive correlations with turbidity, oxygen demand and nitrogen concentrations. Bacillariophyceae counted for the highest proportion of phytoplankton during the fallow season, comprising up to 60+% of the phytoplankton among the sites. During the rainy season, Chlorophyceae species were the majority, comprising up to 90+% of phytoplankton among the sampled sites. Our results pointed to the complexity of nutrient and phytoplankton dynamics in water bodies under multiple pressures, and to the value of using citizen scientists to determine contextual information to benefit more focused studies.
2015 年期间，我们研究了广州和佛山（中国）不同农业和城市压力程度水体中营养物浓度和浊度的时间模式。数据和观测由经过培训的公民科学家和专业研究人员进行。我们的研究表明，除了千灯湖和汾江河外，所有监测的水体均具有升高的硝态氮浓度，范围从 0.10 到 6.83mg/L，在冬末和早春达到峰值，并在夏季和中秋达到最低值。PO43-P 浓度范围从 0.01 到 0.25mg/L，冬季达到峰值，夏末和深秋达到峰值。在有农业活动的地点，浊度值最高，冬季和秋季达到最大值，春季和秋季藻类出现的最高频率（16%和 25%）。为了更好地了解藻类出现的特征和驱动因素，我们在 2016 年农业过程的三个关键季节（休耕、播种和雨季）进行了浮游植物组成和理化特征的测量。我们的重点研究发现，硅藻、眼虫、黄藻、隐藻、金藻的出现与溶解氧和磷浓度呈正相关，而绿藻和蓝藻与浊度、需氧量和氮浓度呈正相关。在休耕季节，硅藻计数占浮游植物的比例最高，在所有采样点中占浮游植物的 60%以上。在雨季，绿藻是主要的浮游植物，在所有采样点中占浮游植物的 90%以上。我们的结果表明，在多重压力下水体中的营养物和浮游植物动态具有复杂性，并且利用公民科学家来确定背景信息以有益于更有针对性的研究是有价值的。
