2012 News items from Spearfish Canyon Society:

1. 480-acre Land Gift: The Society is working on a land gift to the public from the Deadwood Standard Gold Mining
Company once it has completed its 10-year mining schedule and reclamation. The project is beyond the East rim at Savoy.

2. Bridal Veil Observation Deck: The Society was successful in promoting the construction of an observation deck at
Bridal Veil Falls by the US Forest Service at a USFS/ County RAC Meeting back in 2011. The $240,000
construction is scheduled to be completed this fall.

3. Fall Colors for 2011: The Society president, Jerry Boyer, has been reporting canyon fall colors to media and public
since 1994. Estimates are over 100,000 visitors soak in the colorful rhapsody each year.

Why autumn leaves? - For dummies like me:

In autumn, Nature's Call is comprised of three events: the days get darker, temperatures begin to cool, and the air becomes dry.

Leafy trees head Nature's Call and the chlorophyll in the leaves that once convert sunlight to food stops. The dark green leaves start to fade, and other color pigments show through. The trees drop their leaves to protect themselves from drying out in the winter.

The Colors:
Green leaves: the chlorophyll pigment
Lime green leaves: the chlorophyll pigment dissipates
Yellow leaves: the xanthophyll pigment emerges.
Gold leaves: the xanthophyll pigment dissipates
Rust leaves: leaves don't fall and remain on the tree.
Orange and Red leaves: the carotene pigment.
Purple leaves: the anthocyanin pigment.

The evergreen factor:
Unlike leafy trees and plants, the evergreens trees have needles, and they're coated with wax. They do not shed their needles since they can keep enough moisture inside during the dry-air winter.

For those who need chemistry - It's Greek to me:

In describing plants that decide to lose their leaves by sensing the length of nights, the word Photoperiodism comes from the Greek words for "a light/time system". For plants, the important thing is not that the amount of light has decreased, it's that the amount of dark has increased.

In describing leafy trees that drop their leaves in the autumn, the word Deciduous comes from Latin words meaning "to fall or cut".

Along with cold air in the autumn comes dry air. Cold air cannot hold as many water molecules, so, deciduous trees drop their leaves as a means to keep moisture inside--to keep from drying out.

Leaves become colorful because photosynthesis requires not only green chlorophyll, but also chemical interactions with a few other specialized pigments that provide our wonderful fall colors.

The process of a deciduous tree stopping its food-making process for the winter is chemically complicated. When the days get darker, plants have complex biochemistry that sets a series of events in motion. As the amount of light per day goes down, photoperiodic plants produce ethylene and a substance called abscisic acid. That leads to a change in the ratio of the hormones auxin and cytokinin. Scientists named these compounds by their functions. Auxin is the hormone that makes cells elongate or grow, similar to the word augment. Cytokinin comes from words that mean "put division in motion." When cells divide, they're growing. As the ratios of these specialized plant hormones change, trees stop making the famous energy-producing chemical chlorophyll. They pull in all the nutrients they can from the leaves, and cut the leaves off from their main stems.