Dendro Exam 1

order/priorities for a tree when allocating limited photosynthates

1. Respiration

2. Growth of leaves and fine roots

3. Primary growth

4. Seed production during bumper crop years

5. Secondary growth

6. Production of defensive compounds

site index

the height in feet of a dominant or co-dominant tree at a base age (usually age 50)

epicormic branching and what triggers them

the growth of new shoots from dormant buds located beneath the bark of a tree’s trunck or branches

triggered by stress and sudden exposure to light

indeterminate growth pattern

species that will keep expanding until they get an environmental signal (temp or dark)

many of these have a “pseudo-terminal bud” - actually a lateral that takes over end position after tip of twig dies (in mid-summer)

(most pseudo-terminal species have zig-zag twigs)

determinate growth pattern

uninodal conifers and a number of other species too,

how much they will grow next year is already determined this year, most of these species have true terminal buds

these tend to have relatively stiff twigs that form rapidly in spring

foxtailing in trees

main leader stem elongates continuously without producing any lateral branches. This results in a long, smooth, branch-free trunk that resembles a fox's tail before the tree eventually returns to a normal branching pattern

Photosynthesis

sunlight + 6H2O + 6CO2 —> C6H12O6 + 6O2

Respiration

C6

gymnosperms

trachieds only

non flowering

angiosperms

vessels (must wider) and tracheids

flowering

cavitation

formation of air bubbles when the tension of water within the xylem becomes so high that dissolved air in the water expands to fill the vessels or tracheids

embolism

the blocking of a xyelm vessel or tracheid by an air bubble

chlrophyll a and b, what makes what colors

chlorophyll a: blue-green

chlorophyll b: yellow-green

carotenoids

carotenes: orange, red

• pigment that absorbs light, acts as sunscreen

xanthophylls: yellows

• break down more slowly, become visible

flavonoid

yellows

• found leaves + flowers, ultraviolet absorption + energy production

phenolic

red, purple, blue

• infrared by pH, light, temp, In acidic conditions, anthocyanins appear as red, blue with higher pH

• anthrocyanins produced only in fall by sugars low to transport out of leaf

Tannnin

Brown

• always prevent, help protect plants from predators, bitter taste, role in growth