Seasonal growth Flashcards
What are budscales and what is their role?
Budscales are modified leaves
- prevent dessication meristem
- insulate against heat loss
- produce growth inhibitors
What is a bud?
what are its parts?
An embryonic shoot
- apical meristem
- nodes
- internodes
- leaf primordia
- budscales
What is meant by the term “flush”
cellular expansion of leaf primordia and division fro internode extension
What are the 4 major growth types in woody plants?
- Short spurs
- epicormic shoots
- late season shoots
- determinate long shoots
- indeterminate long shoots
List several points about short spurs
- preformed in lateral vegetative buds
- little internode extension
List several points about epicormic growth
- brought on by sudden light exposure to bole
- grow upward
- more prominent in certain species
- arise from dormant buds on bole
- result in knot formation
What does the term Lammas growth refer to?
Second flushing of apical buds in early summer/late fall due to warmth and moisture
What is late season growth?
Once buds have set they can flush again in late summer/early fall due to heat and moisture
What is prolepsis?
Prolepsis is late season growth that takes place on lateral buds
What are two main growth patterns when it comes to the formation of new shoots?
Determinate long shoots
-growth is predetermined in preceding year
Indeterminate long shoots
-buds form only a portion of the next years growth
Elaborate on determinate long shoots by listing some points where does it happen? when does it happen? when does actual growth take place? species examples?
- all parts of apical growth are determined in preceding year
- shoots are pre-formed in terminal vegetative buds
- growth happens early in the season
- temperate forests
- Fd, S, P, Yew
- symmetricaly formed trees
Elaborate on indeterminate long shoots
- Growth that happens continuously in response to environmental cues and is largely undetermined until those environmental cues present themselves
- happens during current growth season
- Basal part is pre-formed
- Balance is indeterminate
- hw, L, Cw, Birch, Cottonwood
- slower than determinate growth
What is phenology?
The study of temporal aspects of plant growth and development and their relation to climate.
goal is to program growth
What can be done in phenology to control plant growth?
-photoperiodism response to duration of light attempting to inhibit phytochrome from signalling senescence -moisture control -temperature control
what hormone is responsible for senescence?
Phytochrome
outline some growth patterns for temperate zone trees
- short period of shoot elongation (3 months)
- lengthy dormancy period
- trees and seeds go into dormancy to survive winter
what is dormancy?
a trees survival adaptation to survive the stresses of winter. Active growth and energy production are arrested until conditions become favourable again
Outline the stages of dormancy
Quiescense
Dormancy
Quiescence
budbreak and growth
what is happening hormonally during dormancy?
accumulation of growth inhibitors
describe quiescense
quiescense is a pre and post dormancy state where environmental cues are resulting in the accumulation of growth inhibitors in the fall and growth producing hormones in the spring. Due to conflicting hormones the trees are not actively growing but are not yet fully dormant in the fall or “awakened” in the spring
What are the two processes involved in cold hardiness
Tolerance
-movement of water in cell to extracellular spaces where freezing will not cause as much damage
Freezing avoidance
- accumulation of solutes in cytoplasm which act as a biological antifreeze
- not only does the antifreeze prevent freezing, this also allows the plant to reduce evaporation when it gets hot
What are the two main environmental cues?
Photoperiod -mild, short days -requires cessation Temperature -cool, short days -cool days, cold nights
when is shoot growth most prominent?
Summer (end of march - end of July)
when is root growth most prominent?
Spring and Fall
when would you plant trees on the coast?
mid february to march
when would you measure diameter for accurate data?
late fall / early spring
What is the shoot to root ratio?
What is a good ratio for nursery trees?
shoot to root ratio is the ratio of shoot to root… duh
a good ratio would be widespread roots and short boles for nursery trees
