Human Impact on the Environment

Types of Resources

• Renewable: replaced by natural processes Ex: plants/crops, water

Types of Resources

• Nonrenewable: only available in limited amounts Ex: Metals, minerals, topsoil, fossil fuels

Coal Fossil fuels

Types of Pollution

• Pollution: contamination of soil, water, air

• Industrialization- a major source of pollution.

Types of Pollution• Air Pollution: • Primary cause is burning of fossil fuels for

electricity• Other contributors- cars, heating homes, planes• Particulates-solid particles of soot• Smog-smoke, gases, fog

Air Pollution

• Acid rain- • Sulfur oxides

and water mix to form sulfuric acid that falls to earth and lowers pH of streams/lakes, leaches nutrients from the soil

Air Pollution

• Greenhouse effect- Increased Carbon Dioxide: from increased burning of fossil fuel– Most of the greenhouse gases leave but in

excess they build up and warm up the Earth

• Leads to global warming- Earth becomes warmer over time due to change in carbon dioxide level

Air Pollution

• Ozone layer- prevents lethal doses of UV radiation from reaching earth

• Thinning of ozone caused by release of CFC’s (chlorofluorocarbons) into the atmosphere.

Types of Pollution• Water Pollution:

• Contaminants from sewers, industry, homes, farms

Pollutants trickle down into ground water;More efforts being made to correct these problems

Water Pollution• Types

– Point pollution- from a single source and easily identifiable

• Example- factories

Water Pollution

– Non-point pollution- from many sources and not easily identifiable

• Example- homes, lawns, highways, pesticides, fertilizers

Impacts of Pollutants in Ecology

• Biomagnification – as pollutants move up a food chain, its concentration increases

Results of Biomagnification

• As the pollutant or toxin is taken into an organisms body it enter its cells

• As higher order organisms obtain energy from lower order organisms, the pollutant/toxin is passed on and magnified due to the organisms usually increasing in size moving up a food chain/web.

• Results in overall magnification of the toxin through the chain or web

The Gulf Oil Spill Disaster

• http://planetgreen.discovery.com/videos/disaster-in-the-gulf-the-oil-spill-environmental-impact.html

What can be done?Three R’s of conservation

Human Impact Effects on Plants and Animal Life

• Biodiversity- the variety of life in an area

• Most diverse areas of the world are tropical rainforests

• Biodiversity is being lost due to human actions like deforestation, overhunting, overfishing, introducing a species

How do we negatively impact biodiversity?

• Deforestation: clearing of trees for open land space loss of animal habitat and niches

• Overhunting/overfishing interrupt predator prey relationships by influencing population dynamics

• Introduced Species: when we introduce a new species that does not have a natural predator overpopulation of that new species occurs. May take over other organisms niche, habitat, food resource

Effects of An Introduced Species

Importance of biodiversity

– Loss of species may have consequences for others living things (e.g.food chains and webs are disrupted)

Plant and Animal Responses To A Changing Biosphere

• Plants tropism and normal adaptation responses may be altered due to drastic environmental changes

• Animals Normal animal behavior may be altered due to drastic environmental changes

PLANT RESPONSES & ADAPTATIONS:

• Tropism: Plant’s response to its environment• Geotropism- Response to gravity; roots down,

stems up• Phototropism- Response to light; sunflower

“heads” turning toward sun• Thigmotropism- Response to touch; vine

climbing trellis• Hydrotropism- the way a plant grows in

response to water

PLANT RESPONSES & ADAPTATIONS:

• Auxins- Hormones regulate tropisms

• Gibberellin- causes plant growth

• Abscisic acid- inhibits plant growth

Normal Plant Responses and Adaptations

Plant Adaptations:• Dormant in drought• Deciduous trees- Drop leaves in winter• Thick bark to protect from fire• Flexible branches of conifers to bend with ice and snow• Cuticle- waxy coating on needles (leaves) • “hitchhiker” seeds, some blow in wind, float, etc to

disperse seeds• bright colors and fragrance in flowers to attract pollinators• nutrient exclusion – some plants aren’t worth eating (no

nutritional value)• These adaptations may be challenged due to a changing

biosphere

Normal Animal Behavior:• Inherited or innate behavior- automatic

responses, reflexes, and instincts Ex: courtship, spider web, nest building, response to heat, blinking

• Territorial behavior-: aggression, defend/ mark territory, efficient use of resources, decreases competition

Animal Behavior:

• Migration: instinctive, seasonal movement; affected by hormones, length of day, changing environmental conditions, geographical clues, use of magnetic field

• Hibernation and Estivation: Long term vs short term lowered metabolism,– stimulus – winter vs shorter

periods of drought or lack of food

Animal Behavior:

Learned Behavior: Habituation (deer feeding in yards), imprinting (turtles and salmon returning to birthplace to reproduce/spawn)

Animal Behavior

• Adaptations for defense:

• Mechanical defenses: physical structures like claws, teeth, sharp tusks, stingers, shells

Animal Behavior

• Camouflage: blend with environment– cryptic coloration- same color or pattern as

background– Disruptive coloration- color patterns

disguise silhouette, ex- herd of zebra– Countershading two-toned, Ex- fish dark on

top, light on bottom

Animal Behavior

• Schools and Herds- big group confuses predators

Animal Behaviors

• Chemical Defenses: neurotoxins, poisons, venom, poisonous fish; bombardier beetles, wasps and bee stings, plants foul tasting chemicals

The Overall Bottom Line

• Our actions not only affects our species, but all other factors (biotic/abiotic) that are on Earth.

• The more damage we do to our biosphere (Earth) by our actions, the longer it will take for it to be fixed.

• Actions must be taken now so that we save what we have on Earth.