Environmental Engineering Reference
In-Depth Information
number of species at each site,
S
, and the calculated biodiversity index
B
are listed in the table.
Altogether 48 species of macro-invertebrates belonging to 24 families and 44 genera were identified. The
average density and wet biomass of macro-invertebrates in the eight sampling stations were 360 ind/m
2
and 2.3934 g/m
2
, respectively. Insects were predominant group, being 77.1% of the total in taxa number,
82.7% in density, and 88.6% in wet biomass. Figure 10.43 shows the representative species of macro-
invertebrate in the sampling sites, which are dominant species or typical species at each site.
Species composition of macro-invertebrates with densities (ind/m
2
) in the parentheses
T
able 10.2
No.
Site
Species composition
S
B
1
Streamlet
Limnodrilus grandisetosus
(2); Amphipoda (488);
Baetis
sp. (53);
Setodes
sp. (5);
Tipulidae (1);
Eukiefferiella
sp. (9)
6
3.04
2
YR
channel
Amphipoda (9); Acarina (2);
Baetis
sp. (3);
Cinygmula
sp. (4);
Ephemerella
sp. (30);
Leptonema
sp. (36);
Brachycentrus
sp. (3); Naucoridae (1);
Simulium
sp. (1);
Culicidae (3);
Clinotanypus
sp. (1);
Eukiefferiella
sp. (9);
Orthocladius
sp. (2);
Cladotanytarsus
sp. (1);
Dicrotendipes
sp. (1);
Parachironomus
sp. (4);
Polypedilum
sp. (2)
17 9.86
3
Oxbow
lake
Nematoda (300);
Aulodrilus pluriseta
(6);
Radix lagotis
(3);
Radix swinhoei
(12);
Hippeutis cantori
(9);
Hippeutis umbilicalis
(36); Amphipoda (93); Acarina (3);
Caenis
sp. (6); Dytiscidae (18); Elmidae (3); Corixidae (15); Pyralidae (336);
Procladius
sp. (15);
Chironomus
sp. (18);
Cryptochironomus
sp. (3);
Microchironomus
sp. (3);
Paratanytarsus
sp. (3);
Polypedilum braseniae
(3);
Xenochironomus
sp. (9)
11.8
4
20
4
Riparian
lake
Stylaria
sp. (1);
Limnodrilus
sp. (2);
Branchiura sowerbyi
(2);
Radix ovata
(4);
Dytiscidae (8); Tipulidae (2); Culicidae (1);
Procladius
sp. (2);
Parametriocnemus
sp. (2);
Chironomus
sp. (10);
Cryptochironomus
sp. (1);
Endochironomus
sp. (1);
Paratanytarsus
sp. (17)
13 8.48
5
Dari bay
Limnodrilus
sp. (3); Amphipoda (12); Tipulidae (1);
Psectrocladius
sp. (17);
Tvetenia
sp.
(8);
Chironomus
sp. (10);
Polypedilum
sp. (13)
7
6.72
6
Eling Lake
no benthic animals
0
-
7
Riparian
wetland
Limnodrilus
sp. (1); Amphipoda (464); Culicidae (4);
Procladius
sp. (1);
Cricotopus
sp.
(10);
Microchironomus
sp. (3);
Rheotanytarsus
sp. (75)
7
3.68
8
Qinghai
Lake
Amphipoda (210); Culicidae (2); Ephydridae (2);
Cricotopus
sp. (105);
Eukiefferiella
sp. (19);
Chironomus
sp. (2)
6
5.32
The taxa richness
S
and the index
B
at each site are not high. In other words, the biodiversity of the
sampling sites are not high. The streamlet and Qinghai Lake have only 6 species and both dominated by
Amphipoda. The oxbow lake has the highest biodiversity, with 20 species and bio-community index
about 12. In general, cobble, gravel and aquatic plants are the best substrates for benthic invertebrates.
The oxbow lake, the isolated riparian lake at Dari, and the Yellow River channel at meanders have
relatively stable environment and have multiple habitats with different substrates, therefore, they have
high biodiversity. The Dari bay is an open shallow water connecting the Yellow River, its substrate
consists of only fluid mud, and the sediment from the river drifting into the bay may change the fluid
mud surface layer, thus it has relatively low biodiversity. Moreover, the species composition in the oxbow
lake and riparian lake are quite different from the river and bay. These riparian waters are important in
aquatic biodiversity.
The value of beta diversity was calculated for the source region of the Yellow River. The total number
of sampled habitats is 8, so the value of
M
is 8 in Eq. (10.11). Calculation with the sampled species from
the 8 habitats yields the beta diversity equal to 5.33, which is 66.7% of the maximum value. As a
comparison, field investigations were paid to the Juma River in the suburbs of Beijing from Shidu to
Yesanpo with a length of about 70 km. The river is a mountain stream with beautiful landscapes and
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