Environmental Engineering Reference
In-Depth Information
Fig. 4.9
Ordination diagram
based on Canonical
Correspondence Analysis
(CCA) of the macroinverte-
brate community with respect
to environmental variables
among various Himalayan
river basins. The acronyms
are similar to Fig.
4.5
Forest type
ep
ly
p
o
co
pl
a
g
Landuse
lip
ps
dr
hy
br
lm
g
o
dx
lr
h
m
pr
A
xix
1
sa
Slope
hp
ba
ph
rh
bl
lp
g
l
cr
sp
el
ps
c
a
si
−
1.5
1.0
Among the streams the characteristic taxa
varied with change in the land use (forest,
forest-agriculture, forest-urban-agriculture
and agriculture). In the forest land use, i.e. at
higher elevation, where the streams are hetero-
trophic, conditions inhospitable and forest
laws restrict human habitation, predators are
observed to be the characteristic taxa. The for-
est-agriculture-type land use is characterised
by shredders, collectors, gatherers, filterers
and predators.
basins, while the abundance of Trichoptera and
Diptera families is restricted to some basins. The
faunal composition depicts that Bhagirathi and
Mandakini basins are distinct from Yamuna,
Ramganga and Pindar basins. However, most of
the streams of Alaknanda basins grouped and
show similarity with Bhagirathi and Mandakini.
The characteristic taxa varied from oak in the
west to pine forest type in the east. The scrapers
(Blephariceridae, Limnephilidae, Planorbidae,
Lymnaeidae), predators (Dixidae, Perlidae) and
gatherers (Ephemerellidae, Baetidae,
Hydropsychidae) characterised the pine forest.
Similarly, shredders and fi lterers (Simuliidae)
characterised the oak forest, while scrappers
(Elmidae, Dryopidae) and predators
(Rhyacophilidae, Agrionidae) the pine-oak forest.
Slope and forest type emerged as the main envi-
ronmental factors that cause 66.67 % and 33.33 %
variation in the taxonomic composition, respec-
tively. Slope caused variation in taxonomic com-
position and distribution of caddisfl y with case
(Limnephilidae, Leptoceridae, Philopotamidae)
along with mayfl y (Leptophlebiidae, Baetidae)
and stonefl y (Perlodidae). As slope is a manifesta-
tion of altitude, it indirectly indicates the role of
altitude and hence the forest.
Conclusions
The macroinvertebrate fauna in the river basins
of Uttarakhand region consists of Trichoptera,
Ephemeroptera, Diptera, Coleoptera and
Plecoptera. The relative abundance of Trichoptera
is higher both among and within the basins.
Trichoptera is the abundant taxon in the share of
Trichoptera, and Ephemeroptera is relatively low
in the Yamuna river basins but dominate from
Bhagirathi to Ramganga basin. At family level
Leptoceridae and Glossosomatidae and
Glossosomatidae and Philopotamidae are the
abundant taxa in the river Alaknanda and
Mandakini, respectively. Heptageniidae is
dominant in the Ramganga and Yamuna, while
Heptageniidae and Glossosomatidae are
simultaneously dominant in the Pindar. The
assemblages of abundant taxa varied among the
basins. Heptageniidae and Baetidae among
Ephemeroptera are abundant in most of the
Acknowledgements
The authors acknowledge the
fi nancial support in the form of research projects
granted by the Department of Science and Technology
(DST), New Delhi. Such wide-scale studies could
hardly be accomplished without fi nancial support of
desired magnitude. We thank Professor H. R. Singh,
Vice Chancellor, University of Allahabad, for his
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