||Shifts in mollusc traits following floodplain reconnection: Testing the response of functional diversity components
||Rumm, A.; Foeckler, F.; Dziock, F.; Ilg, C.; Scholz, M.
; Harris, R.M.B.; Gerisch, M.
||floodplain; restoration; snails; spatiotemporal effects; species traits
|UFZ wide themes
of ecosystems can mitigate the global loss of biodiversity and provide
essential ecological functions and services. Although trait composition
and functional diversity (FD) are important tools in assessing recovery
processes, very few restoration projects use them to evaluate
restoration success. Consequently, little is known about trait and FD
trajectories following restoration measures.
- Here, we tested the
effect of dyke-slotting to reconnect a floodplain on the trait response
of mollusc communities over 6 years, based on a random stratified
sampling design (plots within areas) with before and after control
impact. Trait characteristics included flood resistance, drought
resistance and resilience from which community-weighted mean trait
values were derived. FD and its components (alpha, beta, gamma) were
calculated with Rao's quadratic entropy.
- Flood duration in the
restored area increased from 4–13 to 6–17 weeks/year after reconnection,
similarly to the reference area (4–10 to 6–14 weeks). Hence, the
re-connection by dyke-slotting had no substantial effect on flood
duration (due to seepage water).
- Despite that, dyke-slotting
triggered weak but significant shifts in the trait compositions of the
restored floodplain mollusc communities. Traits reflecting species’
resilience, crushing resistance and drought resistance increased in
abundance, while traits characteristically found in more stable habitats
decreased (e.g. cross-fertilisation, diet specialisation). Overall,
trait composition of the restored area progressively moved to that found
in the active floodplain.
- While there were some significant
temporal changes in FD within areas (reference, restored), there were no
significant effects of dyke-slotting on any of the FD indices.
incorporation of spatiotemporal dynamics of FD and trait composition
may facilitate the evaluation of restoration trajectories, especially
when different components (hierarchical FD configuration, single trait
distributions) are considered together. Such complementary approaches
could be integrated in future restoration monitoring programs.
|Persistent UFZ Identifier
|Rumm, A., Foeckler, F., Dziock, F., Ilg, C., Scholz, M., Harris, R.M.B., Gerisch, M. (2018):
Shifts in mollusc traits following floodplain reconnection: Testing the response of functional diversity components
Freshw. Biol. 63 (6), 505 - 517