Lecture 7: Terrestrial Communities Flashcards
define succession
over time, a species occupying a space will change until it reaches a “climax opportunity’ - sustained longterm until next major disturbance
-involves process of colonization, establishment and extinction which act on the plant species
how can you recognize stages of succession?
-recognized by the collection of species that dominate at that point in succession
t or f ; most communities reach a constant climax/ stable equilibrium
false; constantly changes as a result of disturbances disturbance = norm
what is the difference between a meadow and prairie
meadow: not at climax stage in succession; transitional grasslands
prairie: climax communities
define characteristics of meadow (3)
- highly unstable, constant state of flux, sun exposure key
- dom by herbaceous plants
- <50% woody groundcover or <25% trees ; and more community would be considered ‘early pioneer woodland’
what does meadow characteristics assume?
What is plant composition dependent on?
- assumes availability of moderate soils, moisture and sun
- dependent on where it is, soil composition and moisture
what are the 4 stages of meadows
- early old field meadow
- Perennial Herbaceous Meadow
- Scrubland
- Shrubland
define 3 characteristics all colonizers have
- can withstand harsh conditions
- have rapid root growth
- are capable of breaking up compacted soil
t or f; stages of meadows/ ecosystems are discrete
false; not discrete, depends on location, local actual conditions
describe stage 1 of meadows
1: early old field meadow
- lasts 2-5 years after initial disturbance, characterized by colonizer species
describe stage 2 of meadows
2: Perennial herbaceous meadow
- 4-5 years after disturbance, can last 10- 25 yrs wile mat and organic layers build
- by year 3 this stage starts to transfer to perennials
describe plants in meadow stage 2
–all plants are more durable, have deeper roots, are longer lived and can withtsand drought
describe stage 3 of meadow
3: scrub land
- entrance of pioneer shrubs and trees, can last 10-25 years
- intermediate stage 15-30: woody shrubs and wines, <25% tree canopy –> decline in herb per
describe stage 4 meadows
- final stage before considered pioneer woodland
- 30-50% woody, <25% tree cover
- sun lovers replaced with stage lovers
- depend on periodic fires to prevent succession to forest
name 3 ways to manage meadows
- arressting succession; maintian early stages via burning, mowing a
- encourage native species; don’t introduce invasive species
- non native hort plants should be restricted to civic landscapes far removed from natural areas
name 3 plants to manage out of meadow?
garlic mustard, quack grass and crown vetch
name 5 invasive woody species to avoid/ eliminate?
buckthorn, black locust, russian olive, tartian honeysuckle, european mtn ash
why should you be aware of “meadow in a can?
Seed mix doesn’t contain natives, dont include enough clump grasses
what is the main characteristic of praries
What is the characteristic of prairie plants?
- largely result of a climate that favoured grasslands, not forests
- plants deep root system so can survive drought, prevents non native prairie species from developing –> add organic material as break down
- long living perennials, able to survive poor growing conditions and periodic grazing
describe 3 dif types of prairies in NA
- west receives less precipitation and has shortgrass prairie
- east is wetter ( Southern ON) tall grass prairie
- region inbetween is mixed prairie , intermed height
list 5 characteristic of Tallgrass prairie communities
- associated with carolinian community; >800 species
- <10% tree cover
- requires burning to remain as climax community
- takes 3-4 years to develop thatch layer
- requires more moisture than regular prairies
describe savanna characteristics
-similar to prairie but with more tree cover ( inbetween open prairie and closed forest)
-fire dependent
-less grass cover, more ferns and wildflowers
10-35% tree cover
what is oak savanna?
- transition zone between prairie grassland and oak forests
- over 99.93% altered/ devastated
- fire dependent - kills exotic species
what are alvars
- naturally open habitats with either thin covering or no soil over limestone base
- few trees, prairie species can usually survive
- occur in Baltic countries and Great lakes Basin
what % of southern ON original “old-growth forest”
0.07%
what is the main reason deforestation occurs
economic –> agricultural
t or f teh deciduous forest region has most diverse forest life in ON
true
where is the deciduous forest located?
- most southernly and is situated North of lake erie
what is the Great Lakes St Lawrence forest region
central ON to lake huron and west of lake superior along border with Minnesota
what is ON official tree
white pine
define boreal forest region location
- below hudson bay lowlands
t or f the boreal forest region is the largest forest region in ON and Canada
true
what are predom species in boreal forest
white spruce, jack pine, balsam fir, tamarack and eastern white cedar, polar and white birch
what distinguishes the hudson bay lowlands
-distinguished by bogs and fens, slow growing forest and tundra - most north eastern ON forest region
what 2 criteria most be met in order for a designed planting to become a community?
- all plants chosen should be able to grow and thrive within teh same env’t stresses and disturbances
- plants must be compatible in terms of their competitive strategies
what are the 5 principle of designed plant communities?
- related pop’ns, not related indv
- stress as an asset
- cover the ground densely by vertically layering plants
- make it attractive and legible
- management not maintenance
the principle that plants shouldn’t be treated as objects placed like furniture but instead as compatible species that interact with each other and the site is?
- related pop’ns not isolated indv
which principle states to embrace a more limited palette of plants that can tolerate a variety of conditions and to accept teh env’tal constraints of the site? what is the result?
- stress as an asset
- only fittest plants survive, new plants more adaptive ecological niche
which principle uses the idea of green mulch ? what should be avoided?
- cover the ground densely by vertically layering plants
- avid invasive ground covers - instead layer vertically
who came up with the ‘cues to care’ principles? what does this principle consist of ?
LA Joan Nassauer
-surround wild plantings with neat frames ie mown lawn, clipped hedge, and hardscape elements
what 4 things are done in the management over maintenance principle? what is avoided?
- mowing, burning, selective removal or selective additions
- watering, mulching, spraying, pruning and leaf litter removal
what % should filler plants be? what is a filler plant?
5-10%; short lived perennials, biennials and annuals
-useful for showiness and ability to cover soil quickly until longer perennials est.
what % makes of the groundcover layer? what is considered a ground cover?
50% ; more utilitarian than showy, job is to suppress weeds, control erosion and provide nectar
what are the 4 components that make up a designed plant community and their %?
- filler plants 5-10%
- groundcover layer 50%
- seasonal theme25-40%
- structural framework 10-15%
what % makes the seasonal theme layer? what is this layer?
25-40%; mid height plants, showy that grow in masses and drifts
what % makes up the structural framework layer? what is this layer consist of?
10-15%; formed by tall grasses and forbs - winter interest, trees shrubs and upright perennials
