Earth - One Enormous Ecosystem

Biodiversity and Environmental Health

Pa Standard 4.12.3.B

Ecology

• The study of interactions between organisms and their environments.

• Looks at the fine balance between biotic and abiotic factors

Principles of Ecology

1. Everything is related to everything else.

• Example A decrease in the mosquito population

seems beneficial to humans, but the absence of these insects disrupts the food chain (tadpoles and fish)

Principles of Ecology

2. Everything must go somewhere.

Think of sewage treatment worksheet….

Example:

Bald eagle and DDT

Principles of Ecology

3. Nature knows best.

We must share the planet with the rest of the biosphere.

Our small changes in the environment are more likely to do more harm than good.

Aldo Leopold

• A famous ecologist that stressed humans must live in harmony with the Earth, and whatever is taken from the Earth is simply borrowed.

Nonpoint source pollutants (NPS) pg 133

• These pollutants are carried far from their source by rain and melting snow.

• Ex: fertilizers, pesticides, oil, grease, sediment, bacteria, and nutrients

• Can you think of where these originated?

NPS

• Is the leading cause of water quality problems throughout the US.

• Responsibility of reducing the amount of NPS falls on government and State hands.

How can we reduce the amount of NPS?

• Keeping litter, pet wastes, leaves, and debris out of the street gutters which channel directly into watershed bodies.

• Use lawn fertilizers sparingly

• Dispose of household chemicals properly

• Control erosion by planting groundcover

Point Source Pollutants (PS) Pg 133

• Pollutants that are discharged or emitted from an identifiable source.

• Ex: output from factory pipes, leaking landfills, slaughter houses

• In 1996, PA ranked in the top 10 states for PS emissions.

PS

• Legislation has helped reduce the amount of PS in PA.

• Some factories have taken their own initiative to reduce their PA more than is required by law.

Chesapeake Bay

Detecting pollutants

• Hazardous waste: seismic vibrations to cast images of waste material underground

• Air: continuous emission monitoring system(CEMS) measures the gas or particulate matter

• Researchers are working to develop state of the art devices to detect pollutants more efficiently.

Natural events & Environmental Health

• El Nino is a disruption in the relationship between Earth's hydrosphere and atmosphere system in the tropical Pacific Ocean.

El Nino

• Occurs about every 4 years

• Results in floods, droughts, hurricanes

• Can also disrupt the ecosystem around the world.

El Nino

• Trade winds blow east to west, increase in warm water in the Pacific

• To replace this water, cold nutrient rich waters rise from the deep ocean along the coast of S America which feeds a lot of marine life.

• During El Nino, the trade winds die down and the water built up in the western Pacific migrates westward.

• The nutrient rich waters do not rise up which causes many marine kills.

Volcanic eruptions

• Send tons of gases, ash, and dust high into atmosphere

• In 1991, Mt Pinatubo in the Philippines erupted 30 million tons of SO2 into air which formed

suspended particles in the air that spread rapidly around the globe.

Mt Pinatubo eruption

• This caused cooler climates in the Northern Hemisphere due to decreased sunlight for years.

• Caused a large hole in the ozone layer in the Southern Hemisphere.

• Satellites tracked the ash cloud as it moved several times around the globe.

• Still there are hot spots left from the volcanic debris

Biodiversity & Environmental Health

• Biodiversity: the variety of living organisms on Earth

• When a ecosystem is in equilibrium, the number of species is balanced by the resources and vice versa.

• The removal of 1 species can disrupt the entire system.

Biomonitoring

• Monitoring an ecosystem’s health by using biological factors.

• The basic premise is that certain types of organisms occur and thrive within a limited range of conditions. When the conditions change, so does the number and distribution of organisms.

Macroinvertebrates

• Used to indicate water quality because:

Found in almost all ecosystems and easy to identify

Organisms have limited mobility Sensitive to change

• Biotic Index to determine stream quality

Humans and Species Extinction

• Experts estimate that up to 50,000 species are becoming extinct each year.

• 10,000 times faster than the “normal” or “natural” rate.

• Major cause: habitat loss

Habitat loss in PA

• Common causes: Sprawl Pollution Logging Mining Forest fire suppression

Sprawl

• Urban sprawl is unplanned development that results in more and more suburbs.

• Contributes significantly to water and air pollution

• In Philly, 1 acre of open space/hour is currently being developed

Pollution

• Results in habitat loss

• Affects organisms directly (DDT)

Logging & Mining

• Destroyed habitats

• Polluted ecosystems with sediment, soil, AMD

Fire Suppression

• The ecological succession of many pine forests depends on naturally occurring forest fires

• Leave native plants vulnerable to competitors, because they grow faster but would not adapt as fast as natives to fire

Passenger Pigeon

• Once abundant in Northern PA became extinct due to habitat loss, over-hunting, agriculture, development and industry.

• Last pigeon died in 1914 in a zoo in Ohio