Health and mycorrhizal colonization response of sugar maple (Acer saccharum) seedlings to calcium addition in Watershed 1 at the Hubbard Brook Experimental Forest

We examined the health and mycorrhizal colonization
rates of sugar maple germinants on a Calcium (Ca)- treated
watershed at Hubbard Brook Experimental Forest and compared
their status to the health of seedlings growing on reference
sites. We quantified general sugar maple germinant health by
height, leaf area, biomass, and chlorophyll content. To
determine vesicular-arbuscular mycorrhizal colonization
rates, we first cleared and stained germinant roots and then
examined their structures microscopically. We found that
sugar maple seedlings on the Ca-addition site were taller,
had larger leaves, more root, leaf, and stem biomass, and
more chlorophyll per unit leaf area. These seedlings also had
a significantly larger percentage of their roots colonized by
mycorrhizal fungi. Our results indicate a correlation between
soil Ca availability, mycorrhizal colonization rates, and
overall seedling health. These data were gathered as part of the Hubbard Brook
Ecosystem Study (HBES). The HBES is a collaborative effort at
the Hubbard Brook Experimental Forest, which is operated and
maintained by the USDA Forest Service, Northern Research
Station.