Application of macroinvertebrate functional groups to estimate the ecosystem health in the downstream of the East Tiaoxi River

Abstract:

The seasonal investigation on the functional groups of macroinvertebrates and nutrient status was carried out at 9 sites in the downstream of the East Tiaoxi River from July 2013 to April 2014. The feeding evenness index (j_FD) was used to assess the ecosystem health of the East Tiaoxi River. The results showed that the gather-collectors was the most dominant group among the functional groups of macroinvertebrates in this reach. And the functional groups of macroinvertebrates had no significant difference in four seasons (P>0.05). It suggested that the small organic matters were rich in this reach. The redundancy analysis (RDA) showed that the functional feeding groups were closely related to the total nitrogen in four seasons. The j_FD value indicated that the overall ecosystem health in the downstream of the East Tiaoxi River was relatively good, but the health of some samples was poor. It suggested that there might be point source pollution in this river reach, and the water habitat might be fragmented.