Module 6 PB Flashcards
Herbivory
Interaction between 2 orgnanims where one of these, the herbivore consumes planted
Exploitative interaction
Involves non lethal consumption of plants
Prickly pear and cochineal
Herbivory
Cactus moth
Moth caused general collapse and destruction of most of the original stands of prickly pear
Herbivores can have a significant impact on _________________
Plant populations
Why are not more plants eaten
- Predators decrease herbivore population
- Many plants have defences
Morphological defences of plants
Viscous spines and thorns of cactus and raspberry plant
Chemical warfare defences of plants
Many plants produce toxic “secondary” chemicals that reduce herbivory
Example of chemical warfare
Bursera
Bursea
TOxic to insect herbivores
Predation
Interaction between 2 organisms where one of these, the creator captures and feeds on another organism (ANIMAL) THAT SERVES AS PREY
Morphological adaptations of predators
Teeth and claws
Jaws
Strength
Tongue
Vision
Smell
Hearing
Senses adaptations of predators
Stalking
Sit and Wait
Group hunting
killer whales live in
Prefer cold waters
But can survive in warm tropical waters
Echolocation
Used by killer whales
Sound waves from the whales song are reflected in an echo and travel back to the whale
Carousel feeding
They go around to herd the fish in a circle and take turns to feed the fish
Humpback whale
Does the same with zooplankton and form circle by blowing bubbles
In Argentina orcas eat __________
The South American SEA LIONS
in argentina killer whales use the ___________
Beaching strategy
In antarctica killer whales use the _________
Foraging strategy
Foraging Strategy
Hunting is packs
Creating waves to wash seals off ice
Adaptations of Prey (Senses)
Sight
Smell
Hearing
Adaptation of Prey (Behavioural)
Meercats
Live in groups so they smell and send out signals
Defence prey
Morphological - Spikes, Shells and Thorns
Chemicals - Camoflauge
Speed
Co evolution
one species evolves its adaptations to math the needs of the adaptation of another specie
Orange bellied Newt
Skin releases toxins if eaten (very toxic)
Affects Sodium
What is resistant to the orange newt
Common garter snake
Resistant to newt toxin
Common garter snake
Resistant to newt
Loss of speed and temporary lack of movement
Newt and Common garter snake is an example of
Co evolution
Two components on species diversity
- Species Richness
- Relative Abundance
Species Richness
Total number of species
How diverse/rich is the community
Relative abundance
How common or rare a species is relative to other species in a community
Species area relationship
More Area More species
Eruption of Mount St. Helens
volcano
Succession
Gradual and continuous change in species composition and community structure over time
Primary Succession
Succesion on a newly exposed site that lacks soil and vegetation
Secondary Succesion
Succesion on a site that has already supported life that has a undergone a disturbance, such as a fire, tornado, hurricane or flood
Steps of Primary Succession
- Lichens are often the first colonists
- Mosses then colonize the patches of soil and grow quickly
- As soil accumulates hardy opportunistic plants colonize site from surrounding sites
- When they die, they decompose and make the soil more rich
- A climax community is dominated
lichens
Fungus and green alga or cyanobacteria
How to lichens derive nutrients
From rain and bare rock
Secrete mild acids that erode rock surfaces
Slow development of soil
mosses are __________
Bryophytes
Climax community
Dominated by trees with woody trunks and branches
These tress have large root systems and acquire water and nutrients from the soil
New species rarely join the climax community
Secondary succesion
Pioneer species - Intermediate species - Climac community
Early stages in faster because soil is already present
Ecosystem
Included the biotic communities and abiotic environment affecting the community
Ecosystem Ecology
Study of the movement of energy and materials through organisms and their communities
Energy moves in __________
One direction
From Autotrophs to __________
Heterotrophs
Food chains
Linear
Food webs
Complex
Energy moves up as carnivores __________
Increase
Primary production
Autotrophs
Light energy being converted to chemical energy
Secondary production
Chemical energy being converted to the consumers own biomass
Not 100% of energy is used for growth
True
high trophic levels have
Low amount of available energy
Most of the food energy that enters a tropic level is lost as _________
Heat
Detritus
The material long with dead remains of animals and waste products
Organisms that get energy from detritus
Decomposers
Trophic Cascade
The removal of top carnivores form a terrestrial ecosystem
What happens in trophic cascade
- Small predators dominate
- Simplifies plant community
- Lower songbird diversity
- Numerous large herbivores
Dominant Species
Are the most abundant species in a community or have the highest biomass (=total mass of organic matter)
As a result they can exert a powerful control over the occurrence and distribution of other species
Example of dominant species
Sugar maples
Keystone species
More important
Not abundant in a community
Exert strong control on community structure NOT by numerical but by their pivotal ecological role
Picaster
Example of keystone species
Feeds on mussels
When picaster was removed mussels took over and eliminated more invertebrates and algae
Sea otters
Keystone species
They eat urchins are other vertebrates that graze of kelp
No sea otters
No kelp
Food chain before killer whales
More organisms
Food chain after killer whales
Less organisms
North American Beaver
Keystone species
Transform their territory from a stream to a pond or swamp
Positives form beaver dams
Akkows young trees to grow in their place
Salt Marsh with Juncus
Juncus: Key stone species
Affect reproduction rates of plant species
Brown Tree Snake
Invasive species
Introduced Accidentally
Decimated native bird population
Threat to many native small mammals and other reptiles
Zebra Mussel
Invasive species
Extreme Biofouling activity, nuisance to humans
Outcompeted native mussel species
Wild Boar
Invasive Species
Purple loosestrife (weed)
Grows exponentially
Plant invades native wetland
Fast growing and aggressive plant with no natural predators or diseases
It quickly shades out competition
Why are invasive species successful
- Better competitors then the native species
- Pioneer species
- Few native predators
- Prey organisms lack anti predator defenced
- No parasites
Extinction
A species is no longer in existence globally
Functional Extinction
- Only a reduced number of individuals are left
- Populations no longer viable
- Chances of reproduction are low
Extinction vortex
Downwards spiral of population caused by interbreeding and genetic drift
Extirpated
A species has been lost locally
Greater prairie chicken
Extirpated in Canada
Sea mink
Globally extinct
Great Auk
Globally extinct
Endangered
A species that is facing imminent extirpation to extinction
Threatened
A species likely to become endangered
Special concern
A SPECIES THAT MIGHT BECOME threatened or endangered because of a combination of biological characteristics and threats
Approx _________ of all Canadian mammals are listed as endangered / threatened or special concern
1/3
Beluga Whales
declined 50% since 1985
Predicted to go extinct within 20 years
Swift fox
Threatened species
Extripated in 1928
Background Extinction rate
Rate of species loss in the absence of human activities
