Lecture 22 Flashcards
Ecology
- Ecology is a vitally important scientific discipline
- Ecology is essential for
understanding the
existence and evolution
of life and how the
biosphere works - Ecological principles
must guide human
development if we wish
to live on Earth for a
long period of time
- Environmental Impact of humans on biosphere
I = P x A x T
I= environmental impact
P = Population
A = Per capita GDP
T = Per capita energy
Environmental monitoring:
What is it?
Goal?
What does it involve?
What is it:
* Governmental and non-governmental institutions to study and monitor environmental changes through time
Goal:
*to detect threats to environmental quality, and find ways to mitigate these threats
- Environment and Climate Change Canada (ECCC) leads many national monitoring projects Environmental monitoring
Using ecological tools to help the world around us
Typically, involves:
* Repeated measurements of variables related to abiotic environment, or structure and function of ecosystems
- Research necessary to choose appropriate
environmental indicators and to interpret data
Environmental indicators:
Environmental indicators: relatively simple measurements that represent complex aspects of environmental quality.
Choose specific ei so that they can make it cost-effective, efficient and represents complex aspects of environment
ex. Look at residues of toxins to get a quick snapshot of anthropogenic influence in environments.
- Track if it’s still in environment
- Pollutants and toxins may accumulate in
organisms and biomagnify in top predators
Environmental indicators: abundance
- population ecology type of question
- Widespread declines in abundance worrisome
- Causes of declines should be studied
- Many species considered as indicators for health of communities:
- Grizzly bear
- Spotted owl
- Orca
- Pileated woodpecker
Why are they good environmental indicators?
- Umbrella species (part of multiple environments)
- Tell us a lot about all the organisms they interact with
- They are involved with a lot
ex. Population of 1/3 of terrestrial bird
species breeding in Canada’s boreal region
are declining
Case study: Acid rain
- Starts with observation: long-term monitoring of rain pH showed increasingly acidic rainfall in Ontario
- what kinds of chemicals are making this happen?
- Causes: chemical testing revealed sulphuric and nitric acid emissions as source problems
- Consequences: Many freshwater ecosystems
saw crashing plankton and fish populations - Decline in fish and water fellas cause of acidity and trees dying.
- Action: Reduction in sulphuric and nitric acid
emissions… less acid rain
Case study: Eutrophication
- Eutrophication: too much growth of single celled organisms they consume all oxygen and lakes become anoxic and producing toxic outputs
Phosphorus is the limiting growth factor - Observation: water sampling since 1960’s revealed increasing eutrophication in Ontario lakes
- Causes: whole-lake experiments in Experimental Lakes Area confirmed phosphorus was limiting
- Consequences: algal blooms result in anoxic
deep waters, killing fish - Action: remove phosphorus from
detergents; improve waste-treatment tools
Case study: Organochlorines
Observation: eagles, osprey, and falcons showed steep population declines in 1950’s and 1960’s
- Causes: local use of DDT correlated with die-offs, where bio-magnification injured top predators
*Bioaccumulation of toxins
- Consequences: die-off at high trophic levels
changed trophic pyramids worldwide - Action: Governments began to prohibit DDT
use in the 1960’s
Case study: Fragmentation
- Observation: animal populations were divided by highways and other anthropogenic structures
- We are splitting patches apart
- Causes: traffic collisions caused mortality; some animals reluctant to cross un-vegetated route
- Consequences: lower biodiversity at genetic
and species levels - Action: create highway overpasses and
underpasses, - Areas where we can keep patches on either side of a roadway
Case study: Climate Change
- Observation: increases in atmospheric greenhouse gasses (CO2 (carbondioxyde), CH4 (methane), O3, CFCs) detected by chemists
- Causes: anthropogenic production of these
chemicals at unprecedented rates - Consequences: decreasing agricultural
production, increasing severe weather, and
rising ocean levels - Action: curb greenhouse gas production
Ecology as a career
- Ecologists are highly
qualified scientists that
play an important role
in society - Some students move
directly into ecology
careers from their BSc - Often students obtain a
graduate degree, either
at MSc or PhD level, to
pursue a career as an
ecologist
Ecology as a career
Common ecological careers:
* Scientist working in academia
* Scientist working in government
* Scientist working in private sector
* Scientist working in
Non-Government Organizations
E.g. Canadian Wildlife
Federation, Ducks Unlimited,
Nature Canada, Nature
Conservancy, Sierra Club of Canada,
World Wildlife Fund, etc.
Decline of insects
- Large biodiversity of insects
- If we could track that as an environmental indicator, that would be helpful
- All insects are declining
Whooping crane
- Numbers decreasing rapidly
- Migratory prairies of central Canada to Florida and Texas
- # are on the up-
Flagship species
- Cause conservation change
- because you care about particular organisms
