What is Ecology?

What is Ecology?? The study of interactions that take place between organisms and their environment. It explains how living organisms affect each other and the world they live in.

Habitat & Niche Habitat is the place a plant or animal lives. The area for its food, water, shelter and space. Niche is an organism’s way of life, its job, its role or place in an ecosystem

copyright cmassengale Niche copyright cmassengale

Businesses have niches too Businesses have niches too. Think about McDonald’s, Taco Bell, and Subway… How are their niches similar? Different?

The Nonliving Environment Abiotic factors- the nonliving parts of an organism’s environment. Examples include air currents, temperature, water, light, and soil. Abiotic factors affect an organism’s life.

The Living Environment Biotic factors- all the living or once living organisms that inhabit an environment. All organisms depend on others directly or indirectly for food, shelter, reproduction, or protection.

Abiotic or Biotic? Biotic

Abiotic or Biotic? Abiotic

Abiotic or Biotic? Abiotic

Abiotic or Biotic? Biotic

Levels of Organization

What are the Simplest Levels? Atom Molecule Organelle Cell Tissue Organ System Organism

Levels of Organization Ecologists have organized the interactions an organism takes part in into different levels according to complexity.

1st Level of Organization Organism: An individual living thing that is made of cells, uses energy, reproduces, responds, grows, and develops

2nd Level of Organization Population: A group of organisms, all of the same species, which interbreed and live in the same place at the same time.

3rd Level of Organization Biological Community: All the populations of different species that live in the same place at the same time.

4th Level of Organization Ecosystem: Populations of organisms that interact with each other in a given area with the abiotic components of that area. (terrestrial or aquatic)

5th Level of Organization Biosphere: The portion of Earth that supports life.

The Biosphere Life is found in air, on land, and in fresh and salt water. The BIOSPHERE is the portion of Earth that supports living things.

Populations and Relationships in a Community

Characteristics of Populations Three important characteristics of a population are its: geographic distribution population density growth rate 22

Population Growth Factors that affect population size: the number of births the number of deaths the number of individuals that enter or leave the population 23

Population Growth Immigration, the movement of individuals into an area, is another factor that can cause a population to grow. Emigration, the movement of individuals out of an area, can cause a population to decrease in size. 24

Exponential Growth Under ideal conditions with unlimited resources, a population will grow exponentially. Exponential growth occurs when the individuals in a population reproduce at a constant rate. The population becomes larger and larger until it approaches an infinitely large size. 25

Copyright Pearson Prentice Hall Exponential Growth Exponential Growth In the presence of unlimited resources and in the absence of predation and disease, a population will grow exponentially. Both hypothetical graphs show the characteristic J-shape of exponential population growth. Copyright Pearson Prentice Hall 26

Logistic Growth As resources become less available, the growth of a population slows or stops. Logistic growth occurs when a population's growth slows or stops following a period of exponential growth. 27

Logistic growth is characterized by an S-shaped curve. This graph shows the S-shaped curve of logistic growth. As resources become less available, the population growth rate slows or stops. The growth of this population has leveled off at its carrying capacity. Copyright Pearson Prentice Hall 28

Carrying Capacity The death rate increases and the birth rate declines causing the growth rate of the population to slow way down.

Carrying Capacity can be seasonal!

Limiting Factors In the context of populations, a limiting factor is any factor that causes population growth to decrease.

Density-Dependent Factors If it depends on the population size it is called a density-dependent limiting factor: competition predation parasitism disease

Density-Dependent Factors Competition When populations become crowded, organisms compete for food, water, space, sunlight and other essentials.

Moose and wolves depend on each other to keep their populations stable Wolf and Moose Populations on Isle Royale The relationship between moose and wolves on Isle Royale illustrates how predation can affect population growth. In this example, the moose population was also affected by changes in food supply, and the wolf population was also affected by disease. Moose Wolves

Density-Dependent Factors Predation An interaction between two species in which one species (predator) feeds on another species.

Density-Independent Factors If it directly effects the environment it Density Independent unusual weather natural disasters

Density-Independent Factors seasonal cycles certain human activities—such as damming rivers and clear-cutting forests

Natural changes in the Environment Succession

Succession What does this mean? Can the ecological environment evolve? Or change over time?

Ecological Succession: when ecosystems change over time when one community replaces another.

Ecological Succession Consists of 2 types: Primary Succession Secondary Succession

Primary Ecological Succession -When a community begins to establish from bare soil. This occurs after a glacier recedes or after a volcanic eruption.

Primary Ecological Succession After a volcanic eruption or a glacier recession, Pioneer species are the first organisms to arrive these are usually lichens or mosses. They secrete acids that can break down rock to soil!

Primary Succession After the pioneer species (mosses and lichens). Eventually small weedy plants begin to form and animals start to live there. As these organisms die, additional soil is created and becomes enriched.

Primary Succession Seeds brought in by animals, water and wind begin to grow in the soil. Eventually enough soil is present for shrubs and trees to grow.

Primary Succession The stable, mature community that eventually develops from bare rock is called a climax community.

Secondary Succession Disturbances like: fire, flood, or windstorms can disrupt a community. After a disturbance, new species of plants and animals might occupy the habitat.

Secondary Succession Pioneer species in secondary succession are usually plants that begin to grow in the disturbed area. This is much faster than primary succession

Relationships in a Community

Symbiotic Species In symbiosis two or more species live together in a close relationship. At least one organism will benefit.

Types of interactions that leads to Co-Evolution depends on the interactions between two species. Types of interactions that leads to co-evolution: Competition Predation Commensalism Mutualism Parasitism

Competition & Predation when two species fight for the same resources. Predation: (+/-) when one species hunts and eats another. A type of symbiosis

Competition Example: Zebras, Wildebeests and Gazelles have evolved a taste for different parts of the same plant. Behavioral Isolation: “Zebras migrate with well over a million wildebeests and gazelles. A taste for different plant parts keeps the grazing competition down.” -NatGeo 2003-09sept

Predation example: Snake can detach its jaw to fit a mouse inside. Behavioral Isolation: “Zebras migrate with well over a million wildebeests and gazelles. A taste for different plant parts keeps the grazing competition down.” -NatGeo 2003-09sept

Predator-Prey Interactions Make a T chart… Survival Adaptations in Prey …in Predators

Some Adaptations in Predators Speed Weapons Stingers Venom Sensors Agility Camouflage Intelligence

Some Adaptations in Prey Speed Weapons Poison Sensors Camouflage Deceptive markings Warning coloration Mimic a harmful species

Which adaptation? Camouflage: canyon tree frog

Deceptive markings: False eyespots Which adaptation? Deceptive markings: False eyespots

Which adaptation? Poison Arrow Frog Warning coloration

Which adaptation? Mimicry Green parrot snake (venomous) Hawk moth larva (non-venomous Insect larva) Mimicry

Another example of Mimicry Cuckoo bee (tastes bad) Yellow jacket (tastes bad) Two inedible species mimic each other

Which adaptation? What does this look like to a bird? Deceptive coloration

Deceptive Coloration Deceptive coloration

Other Interactions that lead to Co-Evolution: Parasitism: (+/-) When one species uses and harms another species, but keeps it alive. Mutualism: (+/+) When both species benefit from the interaction. Commensalism: (+/0) One species benefits and the other is unaffected.

Parasitism In parasitism one organism feeds on and usually lives on or in another organism. flea Parasites do not usually kill their prey (known as the “host”). Rather, they depend on the host for food and a place to live.

Parasitism leech lamprey

Parasitism tapeworm

The guinea worm is coiled under the skin of an 18 year old man The guinea worm is coiled under the skin of an 18 year old man. This is not good for the man. What type of interaction? Dracunculiasis, more commonly known as Guinea worm disease (GWD), is an infection caused by the parasite Dracunculus medinensis (also known as "Guinea worm"). Dracunculus comes from the Latin "little dragon". parasitism

Mutualism Mutualism is a symbiotic relationship in which both participating species benefit. Examples: ants and acacia tree butterflies and flowers

Both ants and acacia trees benefit. What type of interaction? Mutualism

The green color is from photosynthetic algae that live in the tissue of this anemone. What type of interaction? And, for review, what is the anemone’s phylum, and what are its stinging cells called? Mutualism

Mutualism eel/shrimp Remora fish/sea turtle

Commensalism A third form of symbiosis is commensalism, one species benefits and the other is neither harmed nor helped. barnacle and whale clown fish/sea anemone

Egret gets a perch and a free ride. Water buffalo is unharmed Egret gets a perch and a free ride. Water buffalo is unharmed. What type? Commensalism

Commensalism orchid/tree egret/cow

What type of interaction? Predation Lioness snags a kudu

What type of interaction? Commensalism