Ecology

What is ecology?

The study of interactions between organisms with living and nonliving components of the environment

The Environment

Levels of organization:Biosphere

Ecosystem

Community

Population

Organisms

Interconnectedness

All organisms interact with other organisms and their surroundings, living and nonliving

Models

Ecologists use models to study ecology

Create models to test hypothesis

Models are used to make predictions about the environment

Environmental Factors

Bioitc - living components of the environment

Plants, animals…

Abiotic - nonliving componentsPhysical and chemical characteristics

Temperature, pH, salinity…

Humans and the Environment

Exploding human populationOver 6 billion people

Habitat destruction

Thinning ozone layer

Climate changes

Ever Changing Environment

Organisms have a range of toleranceTolerance Curve

Able to withstand a wide range of environmental factors

Responses to Change

Acclimation

Conform

Regulate

EscapeMigrate

Dormancy

Niche

The role of a species in its environmentHabitat - address

Niche - profession

Fundamental niche

Realized niche

Biomes

Large ecosystems, terrestrial and aquatic, that contain a number of smaller but related ecosystems within

Tundra

Cold, and mostly treeless belt across northern North America, Europe, and Asia

Permafrost - permanently frozen later of soil under the surface

Little precipitation, short growing periods

Caribou, musk oxen, snowy owls, artic foxes, lemmings, and snow shoe hares.

Taiga

Forest dominated by cone bearing evergreensAcross Northern Europe, Asia, and AmericaSnow cover insulates the ground, protecting tree roots from freezingMoose, bears, wolves, and lynx.

Temperate Deciduous Forest

Characterized by tree that lose their leaves in the fall

Eastern North America, Europe, parts of Asia, and Southern Hemisphere

Pronounced seasons, precipitation

White tailed deer, foxes, raccoons, and squirrels.

Temperate Grasslands

Dominated by grasses, in the interior of continents, also known as a prairie.

Rich fertile soil

Grazzing mammals, bison, cows, sheep.

Used as farmland

Deserts

Low levels of rainfall, sparse vegetation.

Not always hot, can get very cold at night.

Plants adapted to reduce water loss.

Kit foxes, lizards, and snakes.

Savannas

Tropical or subtropical grasslands with scattered trees and shrubs. Found in Africa, South America, and Australia.

Wet and dry seasons.

Lions, Leopards, cheetahs, zebras, wildebeest, giraffes, and gazelles.

Tropical Rain Forests

Charaterized with tall trees, found near the equator.

Stable year round growing season with abundant rainfall.

Very diverse animal and plant lifeSloth, monkeys, snakes, lizards.

Ocean Zones

Intertidal Zone

Neritic Zone

Photic Zone

Aphotic zone

Pelagic Zone

Benthic Zone

Estuaries

Occur where freshwater rivers and streams flow out into the sea.

Bays, mud flats, salt marshes.

Freshwater Zones

Low levels of dissolved salts

Lakes and PondsEutrophic -rich in organic matter, murky.

Oligotrophic - little organic matter, clear.

Rivers and StreamsRun down a gradient or slope toward its mouth.

Measuring Populations

A population is all the members of a species that live in a given area at one time.

How do we measure a population?

Growth Rate

Affected byBirth rate

Death rate

Immigration

Emigration

Growth rate = birth rate - death rate

Exponential

Logistic

Accounts for influence of limiting factors

Carrying capacity - K

Cycles

Human Growth

Changes in Population Size

Human Activity

Natural Causes

Invasive and Non-native Species

Communities

Group of populations living close together that have potential for interaction

Symbioses

Relationship between different species living in close association with one another.

Predator - Prey

Predator - captures, kills, and consumes other individuals.

Prey - indiviual that is captured, killed, and consumed by another individual

Natural Selection

Mechanism of evolution

Organisms adapt to improve efficiency

Mimicry - a harmless organism resembles an organism that maybe poisonous or distasteful

Plant - Herbivore Interaction

Plants can form secondary compounds to avoid predation

chemicals that are poisonous, irritating, or bad-tasting

Parasitism

Species interation with another where one benefits and one is harmed

ParasiteEcoparasite

Endoparasite

Host

Competition

Occurs when fundamental niches overlap.

Niche - role the species plays in its environment

Compete for Resources

Types of competition

Competitive exclusion

Resource partitioning

Invasive species

Non-native species

Mutualism and Commensalisms

Mutualism - cooperative relationshipBoth species benefit

Commensalisms -One species benefits, the other is unaffected

Richness and Diversity

Species richness – the number of species in a community

Species diversity – number of species in a community relative to the abundance of each species

Patterns of Richness

Changes in Communities

Succession – series of predictable changes that occur over time

Primary

Secondary

Succession after a volcanic eruption

Energy

Essential to carry out functions such as growth, movement, maintenance, and reproduction.

Energy flows through ecosystems through organisms

Producers - Autotrophs

Capture energy to make their own organic molecules

Primary productivity - rate at which producers capture energy

Biomass - the organic material

Consumers - Heterotrophs

Carnivores

Herbivores

Omnivores

Detrivores

Decomposers

Food Chain

Single pathway of feeding relationships

Food Web

Interrelated food chains in an ecosystem

Energy Flow

Trophic level - position of an organism in the sequence of energy flow

Energy Transfer

Ecosystem Recycling

Biogeochemical cyclesWater and minerals such as carbon, nitrogen, calcium, and phosphorous are recycled and reused

Water Cycle

Carbon Cycle

Nitrogen Cycle