The first two axes of principal component analysis (Figure 2) accounted for 70% of the limnological data
variation. The first axis was positively related with water transparency, and negatively related with conductivity,
total phosphorus, total nitrogen and chlorophyll (Table 2). In general, it separated the samples of the macrophyte
pre-removal period (1997) from the post-removal one (2007/2008), characterized by lower transparency,
high nutrients and chlorophyll a concentrations. The second axis separated the sampling units according to the
seasonal variation, distinguishing the rainy period from the dry one in both studied periods (1997 and 2007/
2008). Chlorophyll a and DO were positively related while water temperature was negatively related with this
axis (Table 2 and Figure 2).