PARENT SESSION
Oral Session #18: Herbivory: Folivory and rhizovory.
Presiding: A. Stephenson
Monday, August 5. 1:00 PM to 3:45 PM. Apache Meeting Room, TCC.
How does competition affect plant re-growth capacity after herbivory?
DelVal, Ek*,1, Crawley, Michael1, 1 Imperial College, Ascot, Berkshire, United Kingdom
ABSTRACT- Herbivory and competition are known to influence plant characteristics and communities. But how do they interact? Plants deal with herbivores by means of resistance and tolerance. Recent investigations showed that tolerance is an important strategy for plant survival but they rarely contemplate plant competition. Our aim was to evaluate how plant tolerance to herbivory changes in a competitive environment. We investigated the re-growth capacity of 4 grassland species (Trifolium repens, Rumex acetosella, Vicia sativa spp. nigra and Senecio jacobaea) in the greenhouse. Plant tolerance was assessed in each species as the capacity to compensate for 75 per cent of the aboveground biomass removed after three months. Target plants were also grown in competition with Festuca rubra and four treatments were applied: both species clipped, only F. rubra clipped, only target plant clipped and control (both unclipped). Plant biomass (above and below-ground) was measured after five months. Rumex acetosella, T. repens and S. jacobaea were able to fully compensate when grown alone (no difference with the control, p>0.05). Nevertheless when grown in competition responses were different: R. acetosella was able to compensate but clipped plants of T. repens, S. jacobaea and V. sativa spp. nigra were smaller than unclipped plants (p<0.05). Clipping F. rubra did not improve target plant performance suggesting that root competition was high. These results highlight the importance of considering plant competition, above and below ground, when studying plant responses to herbivory.
KEY WORDS: Tolerance to herbivory, Competition