Transcript human impact on ecosystems

HUMAN IMPACT ON
ECOSYSTEMS
‘The human species is unlike any other. Its
population is growing virtually unchecked by
the natural factors that limit other species’
populations.’ Hunter
Fact #1: The Earth contains finite resources.
Fact #2: Human population growth has grown
rapidly and consistently over the past
several decades.
Fact #3: Human technology has developed.
Fact #4: Human limiting factors have been
progressively eliminated.
Fact #5: Natural resources are being depleted.
Fact #6: Human species is rapidly approaching
the point at which it will be unable to
sustain continued growth.
Fact #7: Humans have used the Earth’s natural
resources at an alarming rate.
Fact #8: Conservation and recycling are just
beginning.
Every component of an ecosystem is connected
To every other component in order to maintain
An equilibrium.
Natural ecosystems provide basic processes
that affect humans.
a. Atmosphere quality
b. Generation of soil
c. Nutrient cycles
d. Removal of wastes
e. Energy flow
f. Recycling
When the human impact disrupts this balance,
multiple disruptions will result and the effects
produced will be long term. The ecosystem will
not have the processes needed to repair the
damage in a short term period.
Sahara desert: 2000 years ago was a forested area.
Deforestation
soil erosion and dehydration
From sun and wind
stable forest ecosystem altered
Native species died or emigrated out of area.
Interestingly, the desert is growing at a rate of
100 square miles a year.
Warning signs
Deformed species
Decreased populations
Declining health
Loss of biodiversity
Chemicals:
Nitrates: fertilizers, septic systems, wastewater
overuse: runoff into water=lack of oxygen
algae bloom
heart related birth defects
animal contamination
damage to ozone layer from NO2
**Safe
Drinking Water Act
Asbestos: natural insulator for heat and electricity
overuse: damages lung function, leads to
lung cancer.
**Special techniques to remove and seal asbestos
CFC: (chlorofluorocarbons) used as refrigerantnontoxic to humans and inflammable
overuse: depletes ozone layer= global
warming, increased UV levels
**International law to phase out use of CFCs
Phosphates: used to soften water for better cleaning
overuse: runoff, soil and water contamination
detrimental to aquatic life
algae bloom
oxygen level depletion
**Individual state laws to prohibit use of phosphates
In detergents.
Dioxin: byproduct of backyard burns and paper mills.
overuse: moves up the food chain=humans
infected through food.
carcinogen-soft tissue cancers
birth defects
**EPA strict controls on incinerators and waster.
Mercury: thermometers, thermostats, fillings
overuse: birth defects, brain disease, water
pollution
moves up the food chain
**Mercury products are closely controlled or prohibited, special disposal procedures are in place.
Hydrocarbons: plastics, adhesives, fuels, paints
overuse: oil spills, lung diseases, fatal
**controls on the use of hydrocarbons in residential
Use, regulations on the transportation of fuels.
Lead: (low solubility) plumbing, jewelry, paints
overuse: water contamination, brain damage,
fruit and vegetable contamination.
**Low Lead Impact Act-reduced lead levels in paint,
Toys and furniture.
Plastics: had its origin during WWII for parachute
cords, found just about everywhere
overuse: biggest problem presents with disposal
And animal entanglement
**recycling
Pesticides: controls the activities and growth of
pests and insects.
overuse: air, water, land contamination
affects almost all living organisms
all symptoms of poisoning
**Federal control of insecticides/pesticides for
Residential use, restriction of some, promotion of
Natural chemicals for same purpose
Fossil Fuel Use: animal fats and oils always used
for fire. After Industrial Revolution and invention of the automobile, need for fuel
overuse: air pollution, nonrenewable resource
global warming
**alternate fuels
Fracking: process to extract natural gas left after
traditional means, gas is trapped in shale
overuse: chemicals used cause water and
ground contamination. Any organism
feeding off the land and water would be
poisoned
**To date no action has been taken to stop fracking
Ecycling: reuse and recycling of digital and computer
devices
overuse: became a noticeable problem when
landfills became main disposal
for all electronics
secondary effects-plastics, Hg, gas
**legislature in 2010 established means for
Localities to establish ecycling centers
Disposal: establishment of landfills or dumping
ground for unwanted waste
overuse: land pollution and misuse of land
**recycling has helped limit the amount
Technology has reduced size of many personal items.
Soil Contamination: pesticides, disposal, plastics,
hydrocarbons, lead, mercury, phosphates,
nitrates.
overuse: nausea, respiratory problems, birth
decline, insect and bird death, water
pollution
**Control on chemicals used
Strip mining: soil and earth removed to expose
coal. Mining strips down to bedrock.
overuse: with loss of soil, there is a loss of
plants, and organisms that live
off the land
**Surface Mining Control and Reclamation Act
Mandates that companies mine with permits and
That land is recovered by the companies
Global Warming: increased temperature of earth,
melting of polar caps,
loss of shorelines