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 components Physical and chemical characteristics Temperature, pH, salinity…

Humans and the Environment Exploding human population Over 6 billion people Habitat destruction Thinning ozone layer Climate changes

Ever Changing Environment Organisms have a range of tolerance Tolerance Curve Able to withstand a wide range of environmental factors

Responses to Change Acclimation Conform Regulate Escape Migrate Dormancy

Niche The role of a species in its environment Habitat - 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 evergreens Across Northern Europe, Asia, and America Snow cover insulates the ground, protecting tree roots from freezing Moose, 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 life Sloth, 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 Ponds Eutrophic -rich in organic matter, murky. Oligotrophic - little organic matter, clear. Rivers and Streams Run 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 by Birth 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 Parasite Ecoparasite 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 relationship Both 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 cycles Water and minerals such as carbon, nitrogen, calcium, and phosphorous are recycled and reused

Water Cycle

Carbon Cycle

Nitrogen Cycle