Growth and morphology of pedunculate oak (Quercus robur L) and beech (Fagus sylvatica L) seedlings in relation to shading and drought

The effects of three intensities of shading in combination with drought on the growth and morphology of pedunculate oak and beech seedlings were studied in a pot experiment. The two species responded similarly to shading, but had different reactions to drought. Shading reduced growth, increased partitioning to stem and branches, increased leaf area and reduced partitioning to fine roots. Drought reduced growth, decreased partitioning to leaves and increased partitioning to fine root biomass. In beech, drought increased the diameter of fine roots; the increased partitioning to these roots did not increase fine root length. In oak, drought combined with high light resulted in less partitioning to stem and branches and increased partitioning to coarse roots.