Transcript Unit B Ecosystems and Population Change

Ecosystems and their Diversity
Biosphere
Ecosystems
Community
Population
Organism
 Ecosystem
Community of populations together with
its abiotic and biotic factors that
surround and affect it
Small (lichen covered boulder on a hill
side) or large (hill side)
Aquatic and terrestrial
 Ecotone
 grey area between ecosystems
 Transition area where organisms from both ecosystems
interact
 Lots of species diversity in this region
pond
ecotone
field
 Artificial Ecosystems
 Living community is planned or maintained by
humans
 School yard, local parks, farms, managed forests
 Natural Ecosystems
 Living community is free to interact with physical
and chemical environment
 not untouched just not planned or maintained by
humans
 Lakes, rivers, forests, deserts, meadows
 Canada has:
 2 major Aquatic biomes
1.
Freshwater
2.
Salt water/marine
 4 major Terrestrial biomes
1.
Taiga (most)
2.
Tundra (north)
3.
Temperate Deciduous Forest (great lakes)
4.
Grasslands (prairies)
 Alberta’s aquatic ecosystems fit into the freshwater
 Lakes, rivers, streams, ponds etc
 Alberta’s terrestrial ecosystems fit into the Taiga and
grassland biomes
 Taiga (boreal forest)
 Muskeg (bogs in boreal forest)
 Grassland
 Parkland, Foothills (ecotones)
 Deciduous
 Use the table of some of abiotic and biotic factors found
in the four major ecosystems of Alberta
 Take a piece of chart paper and divide the paper into
four quarters and label appropriately
Taiga
Grassland
Muskeg
Deciduous Forest
 Place each factor in the quarter where you think it
belongs be sure to justify
 When finished give a brief description of each ecosystem
Ecosystem
taiga
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Alberta Ecosystems
Abiotic factors
northern and central
changeable weather
soil contains some water and is acidic
precipitation 50–250 cm/a
Biotic community
black and grizzly bears
wolverine
weasels
moose
deer
grouse
owls
spruce and pine trees
shrubs, ferns, mosses, and lichens
muskeg
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cold temperatures
short growing season
permafrost layer beneath soil
low precipitation: 50–150 cm/a
black bear
caribou
ptarmigan
rapidly flowering plants, moss, and
lichens
grassland
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ecosystems
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central and southern
more sunlight and warmer temperatures than muskeg or taiga
bison
deer
rabbits
hawks
yellow-bellied sapsuckers
fescue grasses
grasshoppers
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ecosystems
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central
more sunlight and warmer temperatures than muskeg or taiga
deciduous
forest
rich, fertile soil
precipitation 25–100 cm/a
rich, fertile soil
precipitation 75–250 cm/a
black bears
weasels
moose
deer
woodpeckers
deciduous trees
shrubs
 A group of organisms of one species that interbreed
and live in the same place at the same time (e.g. deer
population).
 Ecologists sample random populations within
ecosystems to collect data that helps them better
understand the species
 Sampling Populations
Count species of a few samples of entire
population then average them
Transects
Quadrants
Populations have a number of attributes that may be of
interest to ecologists and we that we can measure
during sampling:
 Migration
 Distribution and Abundance
 Composition
 Dynamics
 Movement of individuals into (immigration) and out
(emigration) of population
 Affects density, distribution, dynamics and
composition of a population
Tells us more about the numbers of the pop
 Density-# of organism per unit area (avg number of
individuals per quadrant and dividing by size of
quadrant) Total abundance can be determined from
this
 Distribution-Location of individuals within an area
(random, clumped or uniform)
 Carrying Capacity-max # of individuals that can be
supported
Data that enables up to determine whether the pop is
declining or increasing
 Sex ratios-# of organisms of each sex
 Population fertility-reproductive capacity of the females
 Age structure-# of organisms of different ages
 Capacity for survival-# of offspring that reach
reproductive age
 Length of reproductive life-age of sexual maturity & # of
years the individual can reproduce
 What is it?
Information that helps us understand what is happening
within the pop
 Growth Rate-change in the total population per unit
time
 Birth Rate- # of organisms born per unit time
 Mortality Rate- # of organisms dying per unit time
 Breeding Frequency-# of times that a organism
reproduces each year
 Birth Potential- # of offspring per birth
Ecologists study the following to find out more about
specific species within a population:
 Habitat and Range
 Ecological Niche
 Factors that limit growth
 Abiotic and biotic factors
 A place or area with a particular set of
characteristics, both biotic & abiotic
 Each species is found in a specific habitat that its
physical, physiological and behavioural adaptations
equip it to survive and reproduce
 One large area or a bunch of small areas that are
similar
 Geographical area where the species is found
 Species will only be found where its habitat is present
Functional position of an organism in its
environment, comprising of its habitat
and resources obtained there, and the
periods of time which its active
 terrestrial and aquatic ecosystems can support a
diversity of organisms because they have a variety of
habitats and niches
 Terrestrial Niches/habitats
 Aquatic Niches/habitats
Canopy
Understorey
Forest floor
 Canopy
 Upper area of vegetation, lots of sunlight, diverse number
of birds
 Sub canopy
 Usually shrubs and smaller trees, many browsers such as
deer and moose
 Forest floor
 Lowest area, continuous shade, shelter nesting sites,
supports many types of insects, shade loving plant
 Soil
 Temperature levels determine decomposition & organic
matter
Benthic zone
 Littoral zone
 Shallow, most productive part of the lake, plants and algae
take full advantage of sunlight for photosynthesis
 Limnetic zone
 Enough light for photosynthesis to occur, plankton is the
food for the higher level consumers
 Profundal zone
 Not enough light for photosynthesis, not alot of oxygen,
carp and other invertebrates that can handle low o levels
 Benthic zone
 The :ground”, rooted and bottom dwelling organisms,
amount of sunlight and temperature depend on depth of
water
 Abiotic and biotic conditions that limit the number of
individuals
 Species cannot grow in an unlimited fashion for a
sustained period of time
 Control the growth, distribution, survival of a species
 Anything in short supply (e.g. nutrients or sunlight)
 Soil
Provides nutrients for all plants that grow on
land
Determined by nature of rock in which it was
formed, nature of plants & H2O acidity
 Water (availability, depth of water table,
pressure)
Organisms need water to survive
Determined by amount & type of ppt, how
much collects then stays in soil, depth of water
 Temperature
Affects other abioitc and biotic factors
Vary throughout year
 Sunlight
Provides energy to system
Depends on closeness to equator, seasons
and location in ecosystem
 Chemical Nutrients
Important to survival of organisms
Determined by seasons, soil, temperature, ,
amount dissolved
 Competition
 Intraspecific= members of same population compete with
each other for limited resource (food, water, sunlight,
mates, shelter, breeding sites etc)
 Interspecific= members of two different populations
compete (exotic species) resulting in extinction of one or
both of the populations
 Predators
 Parasitism=one organism (parasite) derives its
nourishment from another organism (host) which is
harmed in some way
 Scientists use classification system to understand
similarities and differences between species
 Science of classifying =Taxonomy (Taxonomists)
 7 levels of classification
 Kingdom
 Phylum
 Class
 Order
 Family
 Genus
 Species
Representative
organisms
Kingdom
General characteristics
Cell wall
Eubacteria
● simple organisms lacking nuclei
(prokaryotic)
● either heterotrophs or autotrophs
● all can reproduce asexually
● live nearly everywhere
● prokaryotic
● heterotrophs
● live in salt lakes, hot springs, animal
guts
● most are single celled; some are
multicellular organisms; eukaryotic
● some are autotrophs, some are
heterotrophs, some are both
● reproduce sexually and asexually
● live in aquatic or moist habitats
● most are multicellular
● all are heterotrophs
● reproduce sexually and asexually
● most are terrestrial
● all are multicellular
● all are autotrophs
● reproduce sexually and asexually
● most are terrestrial
● all are multicellular
● all are heterotrophs
● most reproduce sexually
● live in terrestrial and aquatic habitats
often present
(contains
peptidoglycan)
bacteria,
cyanobacteria
present (does not
contain
peptidoglycan)
methanogens,
extreme
thermophiles,
extreme halophiles
algae, protozoa
 Eubacteria
 Archaebacteria
Archaebacteria
 Protista
Protista
 Fungi
Fungi
 Plantae
Plantae
 Animalia
Animalia
absent
present
mushrooms, yeasts,
bread moulds
present
mosses, ferns,
conifers, flowering
plants
absent
sponges, worms,
lobsters, starfish,
humans
 Developed by Carl Linneaus as a way to scientifically
name and classify organisms
 Based on physical and structural features (anatomy,
embryology, and ancestry)
 More features in common the closer the relation
 2 part name (usually Latin)
 Genus species
Pg 139
 Classification manuals that are constructed to help
conduct their identification work
 A series of choices about the structure of the
organisms must be made and each choice leads to a
new branch
 If each choice is made correctly then the end result
will be the organisms name
The Key
1. (a) baleen plates
Go to 2.
(b) teeth
2. (a) dorsal fin
Go to 4.
Go to 3.
3. (a) long pectoral fin
(b) no dorsal fin
bowhead whale (Balaena mysticetus)
humpback whale (Megaptera novaeangline)
(b) short pectoral fin
4. (a) no dorsal fin
blue whale (Balaenoptera musculus)
Go to 5.
(b) large dorsal fin
5. (a) small nose
killer whale (Orincus orca)
Go to 6.
(b) large projection from nose
6. (a) mouth on ventral surface
(underside) of head
narwhal (Mondon monoceros)
sperm whale (Physeter macrocephalus)
(b) mouth at the front of head
Pg 162
beluga (Delphinapterus leucas)