Pre-Test #1 Flashcards
Gymnosperm
‘naked seed’
wind pollinated
held to the surface of a cone scale or structure NOT enclosed in an ovary of a flower that becomes a fruit.
Conifers
woody plants
gymnosperms
female and male reproductive structures in separate cones or strobili rather than flowers
Coniferous trees and shrubs
Typically bear both female and male cones on the same plant= monoecious
Strobile
a cone or inflorescence resembling a cone
Angiosperm
flowering plants.
Classified into two major groups monocotyledons and eudicotyledons.
Seeds are enclosed in an ovary of a flower that becomes a fruit.
Monoecious, dioecious or perfect
Taxonomy
the systematic classification, naming, and identification of plants.
Genus Specific epithet
species
Genus
one or more related species that are more like each other than to other species
Specific Epithet
often descriptive (morphology, location, person, colour, etc.)
Species
A classification of related organisms sharing common characteristics species presumably come from a single ancestral population.
Within the species
Variety, cultivars, hybrid and common names
Variety
naturally occuring population, not selected by someone
Cultivars
selected/bred by someone- they may or may not be true breeding
Hybrid
can arise naturally or artificially by crossing between species (interspecific) or genera (intergeneric)
Genus- Abies
Common name- Fir
Genus- Juniperus
Common name- Juniper
Genus- Larix
Common name- Larch
Genus- Pinus
Common name- Pine
Genus- Picea
Common name- Spruce
Genus- Thuja
Common name- Cedar
Genus- Ulmus
Common name- Elm
Genus- Fraxinus
Common name- Ash
Genus- Betula
Common name- Birch
Genus- Populus
Common name- Poplar
Genus- Aesculus
Common name- Buckeye
Genus- Acer
Common name- Maple
Genus- Sambucus
Common name- Elder
Genus- Alnus
Common name- Alder
Genus- Salix
Common name- Willow
Genus- Elaeagnus
Common name- Oleaster
Genus- Quercus
Common name- oak
Genus- Tillia
Common name- Linden
Genus- Celtis
Common name- Hackberry
Genus- Crataegus
Common name- Hawthorn
Genus- Sorbus
Common name- Mountain Ash
Genus- Caragana
Common name- Caragana
Genus- Halimodendron
Common name- Siberian Salt Bush
Genus- Cornus
Common name- Dogwood
Genus- Physocarpus
Common name- Ninebark
Genus- Forsythia
Common name- Forsythia
Genus- Berberis
Common name- Berberis
Genus- Cotoneaster
Common name- Cotoneaster
Genus- Mahonia
Common name- Oregon Grape
Genus- Euonymus
Common name- Burning bush
Genus- Symphoricarpos
Common name- Western snowberry
Genus- Prinsepia
Common name- Cherry Prinsepia
Genus- Viburnum
Common name- High Bush Cranberry
Significance of trees and shrubs
Ecosystem and biodiversity
Urban community
Tourism
Dutch Elm Disease
Caused by 2 species of fungus- block xylem and phloem.
Spread by bark beetles or contaminated pruning equipment
Urban community social benefits
Create gathering areas and a sense of community.
Reduce stress and improve mental health
Reduce exposure to UV by providing shade and absorbing up to 95% UV radiation
Reduce recovery time after surgery
Lower blood pressure
Economic benefits of urban community
Increase property values as much as 20%
Attract and maintain business and tourism
Moderate temperatures and reduce energy needs for heating and cooling.
Tourism- General Sherman example
2 millions ppl/year
Biggest tree on earth by volume
2200 years old
Important for local economy
What- planting trees
Design elements and diversity: line, texture, colour, form. genetic diversity
Where- planting trees
bad for infrastructure bad for the tree
How- planting trees
Right season: spring or fall
Bare root vs. container (more common)
Bare root=spring
Container=spring or fall, more flexible
Check for root/pot bound-loosen/cut
Check soil texture and structure-amend is needed- peat alternatives: compost, coconut coir, hulls, etc.
Peatmoss harvesting
an ecological disaster
peat takes hundreds of years to form, it is not being sustainably harvested.
Planting depth
Grafted vs own root
Grafter= graft union below soil surface
Own root= same depth as their container
Planting: Aftercare
water well
nutrients- especially important in rapidly growing/young plants
woody plants are slow to take up fertilizers- opt for a foliar applied product when a symptom is urgent
How to identify a tree
1) ID book groupings
2) Botanical keys
3)Morphology
1) Groups
Based on leaf shape and arrangement
Use ID key to find the group
Then find the genus within that group through visual images and descriptions
Then look at the descriptions/drawings/images to find the species
Pros: Easy to use
Con: Specific to ID books
2) Botanical Keys
Pro: simple to use
Con: often too simplified
Dichotomous- general>specific
3) Morphology
Often used for identification in the field.
Based on external distinctive traits: form, colour, shape, buds, leaves, fruits, cones, etc.
Why do we care about identifying what the plant is?
Diagnosing problems
Identifying suitable growing conditions
Selecting proper plant for the specific site
For the curious
Evergreen
can be trees or shrubs
Narrow-leaved and broad-leaved
Deciduous
can be trees or shrubs
narrow-leaved and broad-leaved
Coniferous
cone bearing (fleshy or dry)
Not always evergreens; larch (larix)
stems
last season’s growth
twig
current years growth
bud arrangement
alternate, opposite, whorled, sub-opposite
pith
is the central part of stems; can be solid, hollow or chambered
bud scars
when the leaf falls off
catkin
spike-like inflorescence found only in some woody dicots (willow, birch, poplar, oak)
thorns
stiff, modified branch; hawthorn
spines
modified leaves or stipules; barberry, caragana
prickles
sharp outgrowth of the epidermis or bark; rose
Inter-Regional Climates
large areas of landmass grouped by defining features ex) the prairies (AB, SK, MB)
Intra-regional climate
the variation within the inter-regional ex) boreal forest in the north, grassland in the south (central saskatchewan)
Mesoclimate
small area but larger than a microclimate, influenced by proximity to a body of water or existence within a dense urban center (saskatoon, varsity view)
microclimate
the climate of the immediate surrounding. Influenced by other plants and infrastructure (next to a west facing fence and pine trees)
Adaptation
an evolutionary developed traits- primarily genetic-irreversible in the organisms lifespan
Modification
ability to change during development as a response to the environment-irreversible
reversible adjustments are known as
acclimation or physiological adjustments
Paradormancy
inhibition of bud growth due to internal factors outside of the bud (e.g. apical dominance)
Endodormancy
inhibition of bud growth due to internal factors within the bud itself (true dormancy or rest)
Ecodormancy
inhibition of bud growth due to environmental factors (e.g. low temperatures)
Dormancy- response to environmental cues
photoperiod
temperature
drought
dormancy is essentially a condition of the meristem
Step 1: phytochromes in leaves detect environmental cue (photoperiod)
Step 2: GA is downregulated- Cessation of elongation growth
Step 3: Re-direction of organ development- leaf primordia>bud scales
Step 4: Acclimation to cold and dehydration: suppression of meristematic activity, mediated by hormone signaling pathways
Phytochromes
Proteins present in the leaves.
Control photoperiodic induction of vegetative bud set, growth cessation, dormancy induction and cold hardiness
PHYA and PHYB are most important in dormancy
GA (Gibberelic Acid) reduction
GA19 to GA20 blocked prior to bud set
Localization: 5-10 mm below apical meristem
GA are involved in cell elongation, reducing them stops growth
Bud Scales
Primordia–>bud scales
Hormone mediated (ABA, ethylene and GA)
When does dormancy occur?
After terminal bud set in trees
Acclimation
Once dormant, the ability to survive freezing temperatures depends on the ability to cold acclimate.
Cold acclimation
Cold Acclimation
the process by which plants actively undergo changes in gene expression and biochemistry that enhance their ability to withstand low temperature and dessication stress.
Actively growing plants cannot cold acclimate.
Plants severely depleted in photosynthate cannot cold acclimate.
Cold Acclimation levels
1) Dormancy induction
2) Low Temp. 1st Acclimation
3) Freeze 2nd Acclimation
Dormancy induction
Short day photoperiod: small amount of freezing tolerance acquired
Low Temp 1st Acclimation
Temperatures above freezing but below 10 degrees is the first step in cold acclimation
Freeze 2nd acclimation
Cellular dehydration leading to maximum freezing tolerance
What is the signal to induce growth cessation?
Short days- via phytochromes
What is the organ which perceives the signal and transmits it to the bud?
The leaf
What mediates the signal?
Reduction of GA
Global warming problem in tree dormancy:
insufficient chilling temperatures: uneven/reduced bud break in spring, uneven shoot growth in spring
Slow shut down of growth in the fall; not enough time to prepare for winter
Phenology:
the study of the timing of annual developmental stages in relation to climate: date of flowering, date of leaf drop, date of bud set, date of bud burst, etc.
International Phenological Gardens (IPG)
26 species
Genetically identical plants
Genotype x environment: remove genotype and we are looking at just environment
Data collected over a 45 yr period
Onset of spring
Diverse Genotypes x Diverse Environment=
Ecotype
Ecotypes
Same species, but not genetically identical
Chilling requirement
the period of low temp that is necessary to permit 100% of the buds to break species dependent
Stratification
the process in which a seed is exposed to moist, cold or warm conditions in order to break dormancy.
Vernalization requirement
(floral promotion in spring)
the process by which prolonged exposure to cold temperatures promotes flowering
