Ecosystems: Interactions and Changes

• Ecosystems are always changing due to natural causes like droughts and floods
• Ecosystems are changed by results of human activity like forest clear cutting, and dams

Ecosystems

• Scientists study ecosystems in order to investigate the distribution of living organisms
• This can be done by recording actual sightings of species in an area, or by estimating using samples
• Data obtained tells scientist whether a species is living successfully in an environments or experiencing difficulties
• Plant and animal populations are not spread evenly throughout a physical space in an ecosystem.

Quadrat

• Large distribution implies species is well suited to ecosystem's current conditions
• Small distributions implies species is not well suited to ecosystem's current conditions
• A quadrat is a tool created by researchers to study one area or do quadrat analysis

Interactions and Changes in Ecosystems

• Problems occur if there is an imbalance within an ecosystem of either biotic or abiotic factors
• Drained wetlands used as farmland destroys many plants and animals within that ecosystem

Bioinvasion

• Bioinvasion occurs through the introduction of non-native species
• Non-native species are not originally from the introduced area
• They take over the area because there isn't a lack of predators or a naturally stronger species already present
• Zebra Mussels are an example of this

Competition

• Living things compete with each other within their community
• Competition occurs in gathering food, water, air, shelter and space

Predation

• Predation occurs when an animal hunts another animal for food
• The animal being hunted is the prey, and the animal hunting is the predator
• An increase in predators equates to a decrease in prey, which results in increases in competition
• A decreases in predators equates to an increase in prey creating a decreased in competition

Weather and Climate

• Poor conditions, or natural disasters can kill or stop plant growth
• These extreme weather conditions can also kill animals

Succession: How Ecosystems Change Over Time

• Succession refers to change in either species composition, structure, or architecture of vegetation through time
• Scientists call the first species to occupy a barren or lifeless piece of land the pioneer species
• They are adapted to harsh conditions and can live on bare rock or area scorched by fires

Primary Succession

• Occurs in an area where no life exists due to an absence of soil
• Examples include barren tundra, you volcanic islands and rocks left behind glaciers

Secondary Succession

• Occurs when a community has been disturbed or perturbed, by man or natural causes
• Examples include after forest fire, large hail storm, drought
• Fireweed or morels growing after a fire are examples of organisms using Secondary Succession to generate

Human Activiites

• Human activities have both intended and unintended consequences within ecosystems

DDT Case Study

• DDT was a pesticide used in the 1950s to kill mosquitos
• DDT was meant to minimize malaria
• Consequences caused an increase in deaths of cats - by effecting bugs with a cat eats
• Due to these issues DDT was banned

Bioaccumulation

• Refers to the concentration of a chemical over time

Biomagnification

• Refers to the concentration of a chemical as it progresses through the food chain
• The concentration of DDT increases up the food chain

Conserving Biodiversity

• Biodiversity goes through natural cycles of increases and decreases
• An environment changing to quickly, organisms have difficulty adapting

Loss in Biodiversity Caused by Humans

• Habitat loss & Deforestation
• Illegal trade of animals, parts & exotic species
• Overhunting & Poaching
• Climate Change
• Introducing invasive species

Threatened Species

• Populations are declining
• Wood bison and burrowing owl

Endanagered

• Species is in serious danger of becoming extinct
• Beluga whales and whooping cranes

Extict

• Species no longer exist
• Examples include dodo birds and woolly mammoth

Captive breeding Programs

• Captive breeding seeks to breed endangered species, ensuring genetic diversity, to increase numbers

The Golden Toad of Monteverde

• Was found missing since 1988, and researchers don't know why
• There was no habitat destruction
• Top theories include climate change, pollution, increase UV radiation, thinning of ozone layer
• The science is unclear

Humans and Technology

• Humans try to use technology to help animals
• Sometimes the use of tec does not work as intended
• Overpasses and underpasses are often created to allow wildlife to corss highways without getting killed
• Monitoring devices have spotted elk, deer, and coyotes
• Wolves rarely use overpasses, though do utilize underpasses

Ecological Footprint

• Every time you step on the ground you are affecting abiotic and biotic factors under the the location that is stepped on
• An imprint is left on the environment by actions

Ecological footprint Inventors

• Mathis Wackernagel and William Reese developed the idea to determine human impacts on the environment
• They calculated how much energy, land and materials were used, plus how much land was utilize to dispose waste
• Average use of resources that Canadian utilizes equates to 7.7 hectares
• This is a great strain as Edmontonians need 75 times more land to supprot their lives, compared to amount of land Edmonton has access to
• World uses equates to 2.2ha, and Canadian utilizes 4 earths compared to others