Effects of climate change and simulated herbivory on growth responses and leaf characteristics of silver birch (Betula pendula) seedlings

Abstract

Post-dispersal seed predation is an important source of mortalityin plant populations. If this phenomenon is better known in tropicaland woody systems, information is lacking for weeds in French agrosystems.In this paper, we evaluated seed predation variability in an organicwheat field by conducting experiments on weed seed preference andon spatial and temporal variation in predation rates. Weed seed predationpreferences followed a species rank: Viola arvensis = Stellaria media> Alopecurus myosuroides = Chenopodium album > Sinapis arvensis =Anagallis arvensis = Galium aparine > > Plastic globules (for control),with weekly mean predation rates between 19 and 84%. The experimenton spatial variation in seed predation did not reveal a field borderedge effect on predation rate with S. arvensis. However, a strongtemporal variability has been found within a single season. Simpleseeds characteristics as well as meteorological conditions were notdirectly correlated to predation rates obtained. High predation ratesobserved here underline the potential importance of this phenomenonon weed population dynamics. A future challenge would be to quantifythe impact of post-dispersal seed predation on weed communities inorder to assess the potential of seed predation for biological weedmanagement.