Planting Flashcards
Define Dormancy
When shoot buds(apical meristems) are not elongating they are dormant. There are 2 stages.
Define quiescence
- Beginning and end stages of dormancy, where dormancy is influenced by external environment(eg-Drought stress, unreasonable temps)
- summer quiescence is the beginning of dormancy
- spring quiescence preceeds budburst
Define rest(true dormancy)
- Dormant state maintained by plant hormone growth regulators within the bud(Late oct to mid Feb/March)
- Trees require a period of exposure to cold in order to trigger hormonal changes to bring buds to spring quiescence. Called “chilling requirement”, varies within species. Never less than 6 weeks of temperatures at <2-5°C
Define Cold Hardiness (Frost Resistance)
- A physiological state induced by temperature and day length (photoperiod) in which the tree roots and shoots (including leaves) become very resistant to external environmental stresses (mainly cold freezing temps).
- Good time to handle trees because they will be “resistant” to shock
- Plants become cold hardy slowly through decreasing temps in the fall, water is drawn from cells, cells become more concentrated so contents act like an antifreeze
Pros and Cons of Natural Regeneration
PROS:
- cheap(ish)
- suited to site
- potentially shorter rotation if successful
- biodiversity
- future commercial thinning potential
- more environmentally friendly
- relying on seeds naturally adapted to site-nothing grows better
CONS:
- Limited control of: density, species, genetic quality
- difficult to increase stocking in future(brush)
- periodicity of cone crops
Pros and Cons of Artificial Regen
PROS:
- you select: species, density, genetic quality
- microsite seleciton
- time
- less risky
Cons:
- Poor planting quality
- potential poor root development
- scheduling problems (nursery, weather, contractors, roads, etc)
- admin problems(contracts signed, etc)
- Cost
describe a planting prescription
- When a stocking survey indicates insufficient stocking, a planting prescription is usually prepared to improve stocking levels, and a contract is made to implement the prescription
how do you develop a planting prescription
- calculate number of plantable spots per hectare
- determine seedling requirements: use info on SP, silviculture survey data cards, and FG guidebook to determine species to plant
- Determine total number of seedlings required based on area of each stratum
- Describe acceptable microsites for planting including scalp width and screef detph, spacing, and latitude. Refer to the SP and planting difficulty rating for spacing.
- Use SP seed guidebook and stocktype guide to determine seedlot and propose stocktypes for prescription.
- Complete planting difficulty rating form FS 703
- Complete planting site prescription form FS 739
Describe the operational and environmental conditions that might lead to seedling mortality during planting
BOTH:
- Excess moisture: very wet sites; excess water in bags
- Excess heat: south facing slopes; storage without good air circulation
- Dessication: root exposure to air; competing veg in excess of 25% cover
- Cold temperatures: faculty storage or breakage; early fall, late spring freeze
- Physical Damage: animal damage; shaking/bumping
ENVIRONMENTAL:
- Low light: vegetation cover
- Solarization: high elevation south slopes
on site seedling storage specs for spring stock (cold store)
- suspend SilvaCool tarp
- cool spot in shade (silva cool)
- boxes on logs
- boxes can be stacked 2 high
- monitor boxes daily (frozen, flushed, temp, dry, mold)
- ensure good access
- record daily withdrawals with sign out sheet
- PLANT ASAP
- keep only enough trees on site as needed
- 1-3 days at most
on site storage for summer stock (hot stock)
- suspend SilvaCool tarp
- find a cool spot with shade (in forest, by/on a creek, on snow)
- place boxes on logs to allow circulation
- open each box and stand trees up (if stored on sides)
- do not stack boxes(need lots of space)
- keep watering cans on site to water trees
- monitor several times throughout the day
- ensure good access to and from cache
- record daily withdrawals with sign out sheet
- PLANT ASAP: 1 day of planting in cache at one time; summer trees are extremely fragile
physiological responses of seedlings to water deficiency and excess
DEFICIENCY:
- Ion or solute toxicity: cell solution becomes increasingly concentrated during water loss, decreasing activity of cellular regulations
- Cell disruption: cell membrane is ripped away from its attachments to the cell wall
EXCESS:
- Inundation (flooding): depletion of oxygen in standing water by plant roots leads to accumulation of toxic compounds in root cells
Physiological response of seedlings to low and high temperatures
LOW
- alternating low(freezing) and high temps can disrupt activity of membrane associated reactions responsible for food and energy production
- freezing that results in extracellular ice formation induces cell desiccation similar to drought stress
- freezing that results in intracellular ice formation kills the cell/tissue
HIGH
- increasing temps to between 25 and 40°C increases the food use/food production ratio, depleting reserves and reducing activity of heat sensitive regulators
- temps above 50°C destroy regulatory compounds (DNA and enzymes) within cells/tissues
Physiological response of seedlings to physical abuse (wounding/compression/tension/torque/vibration)
- short term response to abuse(0-3min) is an increase in respiration, which depletes reserves and generates heat, and alteration of membrane regulatory capacity which influences traffic control
- long term response to abuse (after 30min) is an increase in the gaseous hormone, ethylene, which signals changes in cell regulators(membranes and enzymes) to accommodate adjustment and repair
General what-to-know for picking microsite
- always define acceptable planting medium
- plant near obstacles where possible to discourage browse and cattle trampling
- plant below obstacles on steep slopes
- decide whether vegetation is competitive or beneficial(shade)
- avoid compacted soils unless rehabbed