To examine the causes of landscape variation in forest community compositio
n we have quantified sapling mortality as a function of growth and soil moi
sture for seven dominant species in transition oak-northern hardwood forest
s of the northeastern USA. We located saplings in sites that encompassed a
wide range of variation in soil moisture and light availability. In mesic c
onditions, the probability of mortality decays rapidly with increasing grow
th among shade tolerant species and more gradually among shade intolerant s
pecies: the rank order of survivorship at low growth rates is Tsuga canaden
sis > Fagus grandifolia > Acer saccharum > Fraxinus americana > Acer rubrum
> Quercus rubra > Pinus strobus. The relationship between probability of m
ortality and growth does not vary with soil moisture among species insensit
ive to drought: Tsuga canadensis, Quercus rubra, and Pinus strobus. However
, probability of mortality increases substantially with decreasing soil wat
er availability for the other four species. Acer saccharum and Fagus grandi
folia have high mortality rates under xeric conditions even when their grow
th is not suppressed. Acer rubrum and Fraxinus americana exhibited a steady
but more gradual increase in the probability of mortality with decreasing
soil moisture. Among the five deciduous hardwood species me examined there
is a weak inverse relationship between the ability to survive growth suppre
ssion, a measure of shade tolerance, and the ability to survive in xeric co
nditions, a measure of drought tolerance. Tsuga canadensis, however, is tol
erant of growth suppression and exhibits high survivorship in xeric conditi
ons, while Pinus strobus is intolerant of growth suppression but insensitiv
e to soil moisture. Species differences in water-dependent mortality are co
nsistent with the species distributions across landscape gradients of soil
water availability.