New jack pine seedlings grow
well after a hot fire. Fire causes the cone of an older jack pine
tree to open up and release seeds. Cones that need heat, such
as the heat from fire, in order to open are called serotinous
. When the heat causes the cones to open, seeds are
released and fall to the ground (see animation below).
In Michigan, the Department of Natural
Resources (DNR) lights fires in the Jack Pine Ecosystems to help
new jack pine trees grow. This is because the Kirtland's Warbler
will only build nests under the young jack pine trees.