Many of the symptomatic trees that we have observed to date have been growing under conditions where moderate to high levels of plant stress would be expected.
(the symptomatic trees; have observed; T:to date) (Many of the symptomatic trees; have been growing; ) (moderate to high levels of plant stress; would be expected; L:conditions)
the symptomatic trees Many of the symptomatic trees moderate to high levels of plant stress
have observed have been growing would be expected
T:to date
L:conditions