posted on 2016-10-13, 09:17authored byPankaj Koparde
Odonates are considered to be good ecological indicators,
hence, they are used in biological assessment of habitat quality. However,
species responses may vary spatiotemporally and therefore, it is useful to
establish species-habitat relationships at a regional level. To test if
tropical urban odonates respond to seasons, and to explore species-habitat
relationships with an emphasis on water pollution, I studied six wetlands in
the city of Pune for a year. I also investigated whether combining data on
dragonflies and damselflies, as is often done in many studies, skews the
results. I recorded seasons, water pollution and habitat attributes as
predictors of the odonate diversity and assemblage. I analyzed the data on
dragonflies, damselflies and odonates (dragonfly-damselfly combined) separately
for seasonal variation, and species-habitat relationships. I used multiple
regression and canonical correspondence analyses. Forty-four species were
recorded during the study. No seasonal variation was detected, except for
damselflies, which showed an increase in the diversity and species number
post-monsoon. Multiple regression analysis showed that damselfly and dragonfly
diversity varied as a function of season and water pollution, and monsoon
respectively. In pre-monsoon, damselfly diversity marginally increased with
pollution. Both the analyses suggest that combining data on dragonflies and
damselflies may skew the end results. Therefore, I recommend further intensive
and long-term research using accurately sampled habitat and pollution
attributes, as well as habitat restoration through conserving urban green
spaces and promoting gardens with streams and ponds.