When the weather cools, the trees make a tissue that seals off the leaf from the tree, which concentrates the sugars in the leaves.
(the weather; cools; ) (the trees; make; a tissue that seals off the leaf from the tree,; T:When the weather cools) (a tissue; seals off; the leaf) (the tree; concentrates; the sugars)
the weather the trees a tissue the tree
cools make seals off concentrates
a tissue that seals off the leaf from the tree, T:When the weather cools
the leaf
the sugars