Environmental Engineering Reference
In-Depth Information
We observed these processes for the Meadow brown (Maniola jurtina L.), a
grassland butterfly species, in response to grassland mowing (Aviron et al. 2007 ).
This common species has no strong host-plants requirements (Vane Wright and
Ackery 1981 ) but has a limited mobility like many endangered butterfly species
(Brakefield 1982 ). We conducted a mark-release-recapture experiment at various
herbaceous patches (grasslands, lane banks and road verges) to study butterfly
movements and distribution before and after the mowing of two studied grass-
lands. This survey showed that the mowing of grasslands can lead to changes in
butterfly movements between herbaceous patches. This is illustrated by the
decreased exchange rates of butterflies between one of the mown grasslands (G4)
and surrounding patches (Fig. 14.2 a). Mowing also resulted in localized drops of
butterfly abundances in mown grasslands (G2 and G4), and a concentration of
butterflies in certain unmown, accessible grasslands (G3 and G8; Fig. 14.2 b).
(a)
Befor mowing
After mowing
L1
G2
L1
G2
L5
L5
G3
G3
RV6
RV6
G4*
G4*
G10*
G10*
RV9
RV9
G8
G8
G7
G7
Exchange rates:
Studie d patches:
200m
< 10%
10-20%
>20%
MRR patches
Grasslands under mowing
practices
(b)
250
Before mowing
After mowing
200
150
100
50
0
L1
G2
G3
G4*
L5
RV6
G7
G8
RV9 G10*
Studied patch
Fig. 14.2 Exchange rates of butterflies between studied herbaceous patches (a) and total number
of butterflies captured in patches (b) before and after grassland mowing (adapted from Aviron
et al. 2007 )
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