Ecology

Symbiosis and Succession

Ecology

• What is ecology?• The study of

organisms and how they interact with each other and their environment (the ecosystem)

• A relatively new field of science

Ecosystems

• All living and nonliving components

• Balance between producers and consumers

• Specialists and generalists

Ecosystems

• Living things fill various niches

• A niche is the way of life or the job filled by an organism in its ecosystem

• Example:– A rabbit fills the niche

of an herbivore and it is prey for carnivores

Symbiosis in the Ecosystem

• Close relationship between two different species

• There are four types– Mutualism– Commensalism– Predation– Parasitism

Types of Symbiosis

– Mutualism is when both species benefit

– Commensalism is when one benefits and the other is unaffected

– Predation is when one species actively kills and eats the other

– Parasitism is when one species benefits and the other is harmed, but not killed (at least not right away!)

Mimicry and Camouflage

• Survival techniques• Some species use

camouflage to blend into their surroundings

• Others use scare tactics to mimic a poisonous organism or a predator

Range of Tolerance

• The range of environmental factors in which an organism can survive

• Can be increased if adjusted slowly

• If factors change too quickly for an organism to acclimate, it may die

Human Impact

• Humans are changing the habitats all over the earth

• Rainforests are being destroyed by thousands of acres every minute– Fuel wood– Illegal drugs– Cattle ranching– Development

Global Warming and the Greenhouse Effect

• The earth has heated up (become tropical) several times in its history

• The earth has had several ice ages

• We are currently in a warm, interglacial period

Global Warming and the Greenhouse Effect

• Certain gases in the atmosphere act like the glass of a greenhouse– They let the sunlight

in, but do not let the heat escape

Global Warming and the Greenhouse Effect

• CO2, water vapor, & methane are a few such gases

• Also, ozone helps shield us from ultra violet rays to keep us from getting too much heat

• CFCs are chemicals that harm the ozone layer

Global Warming and the Greenhouse Effect

• The Greenhouse Effect is the theory that humans are speeding up the natural process by our activities

Human Activities may increase the Greenhouse Effect

• Burning fossil fuels (gas, oil, coal) releases CO2

• CO2 is being added faster than it can be recycled by photosynthesis

• CFCs are released when we use refrigerants and certain aerosols

The Greenhouse Effect

Succession

• The sequence that living things arrive in an ecosystem– Primary succession

begins with bare rock– Secondary succession

begins after a natural or man-made disaster. Soil is already present.

Example: Lichen can grow where there is only rock.

Succession

• Primary succession– Lichen & mosses

• Break down rock to begin forming soil

– Grasses– Shrubs – Trees

• Secondary succession– Grasses – Shrubs– Trees

Stability in the Environment

• When predators and prey are in balance, there is more diversity of species.

• When a disturbance occurs, the stability is altered

• Example:– Humans may remove all

predators from an area and the prey exceed their carrying capacity.