A whole-plant perspective also suggests that plants in moister or more fertile sites
may generally have lower ecological compensation points, based on reduced root costs
(Givnish 1984), achieve higher maximum height and LA1 at a given irradiance, and
tolerate lower irradiance levels at a given height. Indeed, along gradients of increasing
rainfall, forests generally increase in stature and LA1 (e.g. Grier and Running 1977;
Waring et al. 1978). The quantitative predominance of support and root costs in setting
the ecological compensation point of Liriodendron strongly suggests that the investigation
of shade adaptation requires a synthesis of studies aimed at roots, stems and
leaves, and should incorporate the effects of water and nutrient supplies in determining
the ability of a plant to persist at a given irradiance level.