The photosynthetic rate was measured for 3 to 5 sunny days during April (spring), July, October and January, using a LI-
6400 portable photosynthesis measurement system (LI-COR, USA). Five leaves were measured in each wetland and each leaf
was measured three times to obtain the average photosynthetic rate. The plants were measured once every 2 h from 7:00 to
17:00.