Horticulture - Bristlecone Pines

Edmund Schulman

Dendrochronologist at the University of Arizonawho studied the Bristlecone Pine trees. He is known for his work on climate change and tree-ring chronology.

• 1953 began exploring the Inyo National Forest (Ancient pine trees; Bristlecone Pines) and their age

• In 1957, discovered an area of trees 4000+ years old

• Oldest names Methuselah, 5000+ years old

Increment Borer

A tool used by dendrochronologists to extract core samples from trees, allowing them to study the tree's age and growth patterns, particularly useful in analyzing ancient trees like Bristlecone Pines.

• Extract a section of wood tissue from a living tree with relatively minor injury to the plant itself

Secret to Longevity

Tree allows parts of itself to die so the whole can live

Science of Fall Color in Temperate Deciduous Plants

• Decreasing daylength (increasing night length)

• Gradually decreasing temperatures

• Beginning of “dormancy”

• Condition of low respiration

• Abscission

Dormancy

a period in which a plant's growth is temporarily stopped, characterized by reduced metabolic activity and respiration, usually in response to adverse environmental conditions such as cold or drought.

• Allows it to withstand cold temperatures

Physical changes to plant during dormancy

2 kinds of water inside

• Intracellular and intercellular water

Abscission

the process by which plants shed leaves, flowers, or fruits, often in response to environmental cues such as changes in day length or temperature.

• Leaves fall off of tree

Fall Color Process

• Decreasing temperature and photoperiod stimulate the beginning of the formation of the abscission layer  

• Flow of water and nutrients slows down (traffic jam) 

• Flow of sugars out of the leaf slows down (sugar pool farms) 

• Chlorophyll production slows and existing chlorophyll goes away 

• Leaf fades in green color, other pigments show through  

• Xanthophylls and Carotenoids were always there helping 

Development of red pigmentation is a function of

daily climate

Red pigment has to be made in the

fall

The key to maximum red pigment production

The right combination of sunlight and temperature

Red Lead Pigmentation

• Warm sunny days (builds up sugar in the leaf)

• Cool clear nights (minimizes excess respiration)

• Night temps to be below 40-45 degrees F

• The large sugar pool and the < 40-45 degrees F stimulate the conversion of sugar to Anthocyanin

Anthocyanin

a group of antioxidants found in red, purple, and blue fruits and vegetables

Decreasing temperature and photoperiod stimulate the beginning of the formation of the

Abscission layer

Influences of fall color

• “From the mountains to the coast”

• Rainfall

• Unusually warm fall season

• Native species in a particular region

• Microclimates