Tree propagation and maintance Flashcards
1
Q
Sexual reproduction
A
- Sexual reproduction
- Genetic recombination from 1 or more
parent trees - Unpredictable outcome
2
Q
Asexual Reproduction
A
- Asexual reproduction
- Same genetic material as parent tree
- Predictable outcome
3
Q
Propagation
A
- Producing new trees from the seeds
or vegetative tissue of parent trees - Sexual propagation
- Seeds
- Asexual propagation
- Cuttings, rhizome, stolons, adventitious
buds, suckering, tissue culture
4
Q
Natural vs managed propagation
A
- Natural – Seeds or vegetative tissue produce new trees in
nature - Excludes human intervention
- e.g., natural regeneration
- Managed – Seeds or vegetative tissue produce new trees under
managed conditions - Includes human intervention
- e.g., clonal propagation for plantation forestry
- Used for amenity/urban, horticulture, plantation forestry
5
Q
Sexual propagation
A
- Seed fall (natural) or seed collection (managed)
- Germination (natural or managed)
- When conditions are right
6
Q
Cost of sexual reproduction
A
- Flowering and fruiting is costly, so environmental resilience is
necessary (reason for reproduction beginning in mature state) - If photosynthetic yield is poor only vegetative buds, no
reproductive buds for next year
7
Q
Sexual propagaiton (stratification)
A
- Period of cold (and possibly moisture)
followed by warmer conditions - Achieved under natural conditions by
transition from winter into spring - Buried or in contact with soil
- Achieved under managed conditions
by temporary cold storage - In a medium of e.g., sand, sawdust, peat
- Breaks embryonic dormancy
- Germination follows
8
Q
Sexual propagation (scarification)
A
- Seed coat can be impermeable to
water and gas → helps to delay
germination - Seed coat needs to be broken down to
allow germination: - Mechanical (e.g., freezing)
- Thermal (e.g., fire)
- Chemical (e.g., digestion)
9
Q
Asexual reproduction features
A
- Vegetative or asexual reproduction
- No need for flowers, cones, fruits, and
seeds - Natural
- Rhizomes, stolons, adventitious buds, suckering
- Managed
- Cuttings, grafting, layering, tissue culture
- All will produce genetically identical
offspring from the parent plant without
need for seed
10
Q
Layering
A
- Roots grow from tree tissue that was
previously above ground - Tissue in contact with ground can be
intentionally wounded to promote
adventitious tissue growth → turns into roots - New tree continues to be supplied with water,
nutrients and photosynthates from parent
tree - Eventually above-ground tissue decomposes,
new tree separates from parent tree
10
Q
Grafting
A
- Tissue from one tree (scion) is
attached to another tree (root
stock) - Vascular tissues repair themselves and
bind together - Ability to optimise both the scion
and root stock for desirable
attributes
10
Q
Maximising success rate of propagation
A
- Success of propagation is called ‘taking’ or
‘striking’ - Striking for layering and cuttings can be
improved by: - Rooting hormone
- Auxin-based powder or liquid that promotes root
growth - Maintaining moist soil environment
- Maintaining humid air
- Success depends primarily on water balance
10
Q
What does a nursery do?
A
- Nursery produces trees for transplanting out into the
landscape - Bare root, ball and burlap, or container-grown trees
10
Q
Cutting
A
- Plant tissue removed from parent plant and
partially buried in rooting media - part of the shoot or root
- 5 – 15 cm for soft wood and 20 – 25 cm for hard
wood - Small hardwood cuttings (~30 cm) called wands
- Large hardwood cuttings (> 1 m) called poles
(poplar/willow) – above forage line - Cutting develops new roots and shoots - same
genetic material as parent plant
11
Q
Bare root tree features
A
- Field grown
- Undercutting and wrenching
produces dense, fibrous root
system → hardens tree against
eventual transplant
