Transcript Types and Categories of Plants

Types and Categories of
Range Plants
Jen Peterson
Jen Peterson
Growth Forms of Rangeland Plants
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4 major growth forms:
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Grasses
Grass-likes
Forbs
Shrubs
Jen Peterson
Grasses
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Most important and abundant kind of range
plant
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Cover more than 1/5th of the earth’s land surface
Jointed stems
Stems are hollow between
the joints (nodes)
Leaves are in 2 rows along the stem
Veins in the leaves are parallel
Jen Peterson
Grasses
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No showy flowers
All grasses are herbaceous (i.e., not woody)
Size = very small to very large
Great morphological variation
Poacea family (the grass family)
has 500 genera & 8,000 species
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K. Launchbaugh
Grass-like Plants
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Look like grasses but have solid stems
without joints
Stems are often triangular
Veins in the leaves are parallel
Includes sedges and rushes
www.livinglandscapes.bc.ca
Forbs
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Herbaceous plants
Broad leaves and showy flowers
Above-ground growth dies back each year
Veins in the leaves are net veins
although some forbs have
veins that are parallel
Range wildflowers and weeds
K. Launchbaugh
Shrubs
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Woody plants with several main stems
Usually have broad leaves
Jen Peterson
K. Launchbaugh
Shrubs
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Efficiently use water - invade into grasslands
Deep roots to tolerate xeric environments
Defenses against grazing:
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Chemical
Physical
Large plants
Jen Peterson
Life Span
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Length of time from the beginning of
development to death of the plant
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Annuals – live for one growing season
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Winter annuals
Summer annuals
Biennials – live for two growing seasons
Perennials – live from one year to the next
Winter Annuals
Summer
plant dies
Spring
Fall
germinate
produce seed
Winter
dormant
Summer Annuals
Summer
grow
Spring
Fall
germinate
produce seed
Winter
plant dies
Biennials
Spring
Summer & Fall
Winter
germinate
go dormant
produce rosette & developed roots
Spring
Winter
plant dies
Summer
produce flowering stalk
produce seed
Perennials
produce seed
build up root reserves
flower
1st Winter
go dormant
go dormant
2nd Spring
new plant from root
germinate
build up root reserves
flower
produce seed
Summer
Cycle continues until
plant eventually dies
Season of Growth
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Cool Season
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Make most growth in cool weather of spring and
fall
Flower mostly in early summer
Provide spring/fall forage at lower elevations and
summer forage at high elevations
Adapted to cool, wet conditions
Most plants in Idaho and northern states
Season of Growth
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Warm Season
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Make most growth in warm summer periods
Flower from mid-summer to early fall
Provide forage in summer months
Adapted to hotter, drier conditions
Some of the warm regions of Idaho have a few
warm season plants
Common in southern states
Origin
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Area where the plant evolved
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Native plants – originated in North America
Introduced plants – Intentionally or accidentally
brought to North America
Invasive Species (Noxious Weeds) – weeds that
have been specifically identified as “noxious” by
state law
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64 Noxious weeds in Idaho
47 Noxious weeds in Nevada
27 Noxious weeds in Utah
Plant Terminology
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Native
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Introduced
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Invasive
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Weed
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Native on Indigenous
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Originated where they now occur without the
help of humans.
For example, native to North America
Well adapted to the local climate, soils,
animals, and microbes.
How long have they
been here?
Western Yarrow - widely distributed
throughout North America
Introduced, Exotic or Non-native
http://www.youtube.com/watch?feature=player_profilepage&v=eDji4I1v4-E#!
Introduced, Exotic or Non-native
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An organism occurring outside of its natural
home range
Other names include alien, foreign, nonindigenous
Introduced by humans
Introduced, Exotic or Non-native
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Humans introduced non-native plants as:
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Grains and food crops
Seeds in Ship Ballast
Ornamentals
Plants for erosion control
Plants with higher forage value
Accidental
Introductions of exotics continues today
Invasive Species
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An organism that spreads and establishes over
large areas and persists
Growth characteristics that allow it to
dominate the ecosystem
Invasive Species Website =
http://www.invasivespeciesinfo.gov/
Invasive Species
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Often non-native (or alien) to the ecosystem
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Not all non-natives are invasive
Whose introduction causes or is likely to cause
economic or environmental harm or harm to human
health.
Cheatgrass
Juniper
Characteristics of Invasive Plants
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Abundant seed producers
Rapid population establishment
Long-term survival of seeds
Occupy disturbed sites
Competitive
Lack of natural enemies
Cheatgrass
Juniper
Weed
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Plant of little value or a plant “out of place”
Competes with crops and native species
Troublesome pest that affects the health an productivity
of native landscapes
“a plant whose virtues have not yet been discovered”...
Ralph Waldo Emerson
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“plants that interfere with the growth of desirable plants
and that are unusually persistent and pernicious. They
negatively impact human activities and as such are
undesirable” Ross & Lembi – Applied Weed Science. 1999
Impacts of Weeds
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Reducing biological diversity
Altering hydrologic conditions
Altering soil characteristics
Altering fire intensity and frequency
Interfering with natural succession
Competing for native pollinators
Replacing complex communities with monocultures
Displacing rare plant species
Noxious Weeds
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Noxious = plant species that
have been designated “noxious”
by law.
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The word “noxious” simply means
deleterious
Weeds are declared noxious by
states or counties.
In Idaho, hundreds of weed species
exist. However, only 64 are
designated noxious by Idaho law.
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www.agri.idaho.gov/Categories/PlantsInsects/NoxiousWeeds/watchlist.php
www.cals.uidaho.edu/weeds2/IWR/iwr-v6_website/files/Download/BUL816.pdf
Plant Terminology
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Native
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Introduced
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Introduced by humans, exotic or not native
Invasive
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Originated where they now occur without the help of humans
Growth characteristics that allow it to spread and dominate
the ecosystem
Weed
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Troublesome pest that affects the health an productivity of
native landscapes
Noxious Weeds = designated “noxious” by law