A leachate a day keeps the seedlings away: mowing and the inhibitory effects of Festuca paniculata in subalpine grasslands |
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Authors: | Flore Viard-Cr��tat Christiane Gallet Marianne Lefebvre and Sandra Lavorel |
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Institution: | 1Laboratoire d''écologie alpine, CNRS UMR 5553, Université Joseph Fourier, 38041 Grenoble Cedex 9, France;2Centre d''Ecologie Fonctionnelle et Evolutive, CNRS UMR 5175, 34293 Montpellier cedex 5, France;3Laboratoire d''écologie alpine, CNRS UMR 5553, Université de Savoie, 73376 Le Bourget du Lac, France;4Station Alpine Joseph Fourier-UMS 2925 UJF, CNRS-Université Joseph Fourier, 38041 Grenoble Cedex 9, France |
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Abstract: | Background and AimsIs the release of allelochemicals by the dominant tussock grass Festuca paniculata responsible for its dominance by inhibiting growth of neighbour grasses in subalpine grasslands? As such a community is also structured by mowing practices, what could be the impact of mowing on allelopathy?MethodsA design was used that isolated allelopathy from resource competition by separating donor plants (Festuca paniculata) from target plants (F. paniculata, Dactylis glomerata and Bromus erectus). Leachates from donor pots containing bare soil, unmown F. paniculata or mown F. paniculata continuously irrigated target pots containing seedlings. Activated carbon was added in half of the target pots to adsorb potential allelochemicals. C and N analyses of target potting soil were used to test for any effect of treatments on resources. Total phenol concentration was measured in the solutions flowing from donor to target pots.ResultsFestuca paniculata leachates inhibited seedling growth of D. glomerata and B. erectus. Inhibition was correlated with polyphenol concentration, and was not due to resource competition for nitrogen. Mowing the leaves of the donor plants did not significantly increase this inhibition. The activated carbon treatment was not conclusive as it inhibited the seedling growing under control pots with only bare soil.ConclusionsThe results suggest that allelopathy may be at least partly responsible for F. paniculata dominance in subalpine meadows by inhibition of colonization by neighbouring species.Key words: Allelopathy, chemical interference, mowing, activated carbon, polyphenols, Festuca paniculata, Bromus erectus, Dactylis glomerata, subalpine, competition |
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