Odonata - Entomological Society of Latvia - Latvijas Daba

The Calluna vulgaris and Andromeda polifolia vegetation structure had the largest mean
percent cover in transects, i.e. on average 24.8% of the area of sampling plots and open water area,
i.e. on average, 21.7% of the area of sampling plot, respectively (Figure 6).
%
30,0
25,0
20,0
15,0
10,0
5,0
0,0
Water
Lielais Ķemeru Bog
Sudas-Zviedru Bog
Water with Sphagnum mosses
Wet sunken Sphagnum
mosses
Sphagnum mosses with Carex
limosa
Hummocks of Sphagnum
mosses
Sphagnum mosses with
Eriophorum spp.
water and vegetation structures
Sphagnum mosses with
Rhynchospora alba,
Scheuchzeria palustris
Ledum palustre and Vaccinium
uliginosum
Calluna vulgaris and
Andromeda polyfolia
High Carex spp.
Figure 6. Mean percent cover of water and vegetation structures in sampling plots in Sudas-Zviedru
Bog (16 sampling plots) and Lielais Ķemeru Bog (16 sampling plots) in 2007.
The DCA analysis identified a gradient of dragonfly species that were related to cover of
immerged Sphagnum mosses, Calluna vulgaris with Andromeda polifolia as well as the open water
(Figure 7). DCA Axis 1 separated dragonfly communities on their vertical distribution in relation to
vegetation structure. On the right side of the ordination are species such as Leucorrhinia dubia,
which fly low ower macrophytes, such as Erythromma najas, which fly very close to the surface of
water. In the middle of the ordination dragonfly species such as Lestes sponsa, Leucorrhinia
albifrons, whose individuals are usually seen on caulescent plants of different heights and small
shrubs at shores of bog water bodies. On the left side of the ordination are species such as Anax
imperator and Aeshna juncea, which fly high over water or vegetation. DCA Axis 2 is related to a
moisture gradient from open water and water with Sphagnum moss at the bottom and relatively dry
microhabitats (Calluna vulgaris and Andromeda polifolia) at the top. Aeshna juncea, Aeshna
grandis and Anax imperator which patrol above water are located at the bottom of the ordination.
Also Lestes sponsa, Enallagma cyathigerum and Leucorrhinia albifrons appear to be related to the
vegetation close to water, Leucorrhinia dubia was associated with dry sites comparatively far away
from water bodies.
There was a significant correlation of sites between the number of dragonfly species in
sampling plots and the cover of open surface (r=0.450, p≤0.05, n=30) as well as between the
number of dragonfly species and water with Sphagnum mosses (r=0.376, p≤0.05, n=30). There was
also a close positive correlation between open water cover and E. cyathigerum (r=0.645, p≤0.01,
n=30) and also L. albifrons (r=0.578, p≤0.01, n=30). There was also a close positive correlation
between E. cyathigerum and the Ledum palustre and Vaccinium uliginosum vegetation type (r=560,
p≤0.01, n=30).
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