Field investigation.xlsx

In Lake Dianshan, the DIN concentration decreased gradually from May and reached the lowest value of 0.18 mg/L in August, and after that, the DIN value re-rose to a high level. Concurrently, the carbohydrate content of <em>Microcystis</em> biomass exhibited an opposite trend and showed a peak value of 24.3% in August. A strong negative correlation (R=-0.892, <em>p</em>&lt;0.05, n=6) was found between the DIN concentration in the lake and the carbohydrate content. Similarly, the data on spatial variability of DIN concentration and carbohydrate content of <em>Microcystis</em> in August also suggest opposite trend. The correlation coefficient between the DIN concentration and the carbohydrate content was also negative (R= -0.748, <em>p</em>&lt;0.05, n= 10). The results shown the temporal and spatial distribution of the DIN concentration in the lake and the carbohydrate content of <em>Microcystis</em> and provided field evidence for a strong negative correlation between them for the first time.