The Plants of Autumn Foliage Color
Conifers, yellow and red leaved flowering shrubs and trees are the most important plants in providing color during the autumn at the Harvard Forest. For the most part, these are the plants that we have studied, and information about them will be provided in the science sections. The above photograph provides a look at their leaves together in mid-October, when the colors are at their peak.
The species in the photograph are:
- witch hazel
- hobble bush
- northern wild-raisin
- sugar maple
- red maple
- ash
- black cherry
- high bush blueberry
- Yellow birch
- beech
- Striped Maple
CONIFERS
Conifers provide the green backdrop during the autumn color changes in New England forests. These are principally white pine and hemlock, although other pines may be introduced in plantations. Larches are the only conifers in these forests which lose their needles completely during the fall. These trees produce an autumn show of bright yellow in the swampy areas where they grow. The European larch may be introduced in plantations or in landscaping, to provide more autumn yellow color.
Red-leaved Flowering Shrubs and Trees
All of these shrubs and trees produce varying amounts of anthocyanins during senescence. Sometimes these pigments are produced uniformly in the leaves, but often distinct patterns.
- Alternate-Leaved Dogwood
- Black Cherry
- Black Chokeberry
- High-Bush Blueberry
- Hobblebush
- Northern Wild Raisin
- Red Maple
- Red Oak
- Red-Osier Dogwood
- Scarlet Oak
- Juneberry (Serviceberry, Shadbush)
- Black (Sour) Gum
- Sugar Maple
- Stag-horn Sumac
- White Ash
- White Oak
Yellow-Leaved Flowering Shrubs and Trees
All of these species turn yellow during the autumn, due to the breakdown of chlorophyll and the retention of some carotenoid pigments in their plastids. In a few cases, small amounts of anthocyanins may be produced, sometimes only in a few individuals in a population.