Severe droughts during the past several years, including 1999, have stressed many hemlock trees in the park, and greatly reduced their ability to withstand HWA infestations.
(Severe droughts during the past several years, including 1999; have stressed; many hemlock trees; L:in the park) (Severe droughts during the past several years, including 1999; reduced; their ability to withstand HWA infestations)
Severe droughts during the past several years, including 1999 Severe droughts during the past several years, including 1999
have stressed reduced
many hemlock trees L:in the park
their ability to withstand HWA infestations