FOR 232 lecture exam 1

1. false terminal bud

2. aborted terminal bud/twig scar

3. terminal bud

4. lenticel

5. vegetative bud

6. bud scale

7. leaf scar

8. bundle scar

9. pubescence

10. flower bud

11. superposed bud

12. lateral bud

13. bud scale scars

14. pith chambered

15. pith continuous

what leaf arrangement?

alternate

what leaf arrangement?

opposite

what leaf arrangement?

whorled

what leaf type?

simple

what leaf type?

compound

4 functions of tree roots

1. anchorage

2. storage

3. absorption

4. conduction

pith

small and pulpy core running up the center of the trunk

heartwood

sapwood that has been clogged with resins, gums and other extractives; supports tree

bark

insulates tree against temperature extremes; keeps sapwood and phloem from drying out

phloem

thin, spongy layer of tubes that carry dissolved sugars and growth hormones from the leaves to other parts of the tree

• travels nutrients from top to bottom

• “phlo low”

cambium

thin reproductive layer that forms new tissue, adding to the phloem and sapwood to increase tree’s girth

xylem/sapwood

active part of the tree’s wood through which water and mineral are conducted from the roots to the leaves; also stores nutrients and helps to support the tree

• water movement

• “xy high”

ray

carries nutrients laterally through the wood; also stores nutrients

growth ring

concentric ring divided into earlywood and latewood indicating the amount of wood added to a tree’s diameter in one growing season

tree diagram

1. bark

2. phloem

3. cambium

4. xylem/sapwood

5. growth ring

6. heartwood

7. pith

8. ray

cavitation

occurs if the water potential becomes too negative

water potential is

greater during the day than at night

indeterminate growth

= free growth

• roots and stems

• increase in length/girth

determinate growth

= fixed growth

• leaves and flowers

• reach a fixed size and stop growing

what is auxin?

hormone used for growth

• better site = higher ___ production

what is abscisic acid?

hormone used in stomate closure and senescence

apical dominance

height first then diameter growth

• gymnosperms: strong

• angiosperms: weak

root production is always first and important

plant tropisms

1. geotropism

2. thigmotropism

3. phototropism

geotropism

negative: stem grows away from gravity

positive: root grows towards gravity

phototropism

negative: roots grow away from light

positive: plant bending towards light

thigmotropism

vines or things that respond to touch

• response to grow or protect

forest succession based on shade tolerance

shade tolerance ratings and examples

• very tolerant - 10 - ex: sugar maple, eastern hemlock

• tolerant - 8 & 9 - ex: eastern hophornbeam/ironwood

• moderately tolerant - 6 & 7 - ex: american elm

• moderately intolerant - 4 & 5 - ex: white oak, northern red oak

• intolerant - 2 & 3 - ex: red pine, northern pin oak

• very intolerant - 1 - ex: paper birch, jack pine

leaf characteristics related to shade and sun exposure

sun adapted plants:

• smaller, more divided

• thicker leaf

• thicker cuticle

• fewer stomates

• stomates on lower surface

• stomates close quickly

shade tolerant plants:

• broader

• thinner leaf

• thinner cuticle

• more stomates

• stomates on both surfaces

• stomates less responsive

pioneer species

• apical dominance less important

• short-lived, intolerant

• opportunistic regeneration strategies

  • aggressive resprouting

  • small, numerous, widely disseminated seeds

• ex: aspen, sumac, paper birch, jack pine

gap-phase species

• apical dominance very important

• mid-tolerant species regeneration

  • moderate competition, sufficient moisture

  • persist, wait for breaks in the canopy (gaps), then fast growth

• ex: basswood, american elm, white ash, yellow birch

tolerant species

• apical dominance moderately important

• persist in very little light

  • moisture

  • very slow growth

• ex: sugar maple, eastern hemlock, american beech, balsam fir

light compensation point

where photosynthesis = respiration