Light partitioning within intercropping systems is mostly modelled by using the turbid medium analogy. Barillot et al. assess this approach by comparing it with a light-projective model based on 3-D plant mock-ups for contrasting grass–legume canopies (wheat–pea, tall fescue–alfalfa, tall fescue–clover). They find that light partitioning is accurately predicted by the turbid medium approach in most of the canopies studied; however, a more detailed description of the canopy is required for mixtures exhibiting marked vertical stratification and/or inter- or intraspecies overlapping of foliage.
The productivity and stability of grazed grassland rely on dynamic interactions between the sward and the animal. Combes et al. record 3-D canopy structures of swards of white clover (Trifolium repens) using an electromagnetic digitizer and adapted software, and synthesize virtual canopies in order to calculate bite mass of grazing animals and to determine effects on light interception efficiency (LIE) of the remaining sward. They find that bite mass and LIE values after grazing are more strongly affected by the initial structure of the sward than by bite form and placement.
Genotypic diversity is essential for maintenance of plant species. Van Mölken and Stuefer examine White clover mosaic virus and Trifolium repens and show that the effects of virus infection on plant performance can differ greatly between distinct host genotypes, resulting in changes in relative fitness between virus-infected and control treatments. This suggests that virus infections may be of considerable importance for the maintenance of genotypic diversity in these host plants. FreeLink: PDF version linked here. (Link via authors names will be made free asap.)