Fig. 3. Seasonal variations in diversity indexes of FFG of
macroinvertebrates in Jingui River.
3.4 Relationship between species diversity and functional diversity
Using stepwise regression analysis to study the impact of species
diversity on functional diversity, the lowest values of FEve and RaoQ
were observed in wet season, and those of FRic and FDis were in normal
season and dry season, respectively. FEve, FDis, and RaoQ showed the
highest values in normal season, and FRic showed it in dry season (Fig.
4). Species richness varied greatly among Jingui river, ranging from 53
to 96 in each season, and FRic varied even more profoundly, ranging from
0.01 to 80.544 in each season (Fig. 4a). Moreover, species richness was
significantly positively related with functional richness
(R2 = 0.344, p < 0.001; Fig.
5a). In addition, it indicated a rather strong correlation between FEve
and Margalef index (R2 = 0.366, p< 0.001; Fig. 5b). FDis was strongly correlated with Simpson
index (R2 = 0.208, p < 0.01;
Fig. 5c). FDis varied between 0.066 and 0.271, and RaoQ varied between
4.294 and 13.445. Although RaoQ was also significantly positively
related with Simpson index (R2 = 0.234,p < 0.01; Fig. 5d), FDis was on average lower than
RaoQ.