Intro to Ecology Notes QQ#1: What is Ecology?

What is Ecology? ▪The study of interactions among organisms and between organism and their environment, or surroundings. ▪Basically… –Why animals are where they are and how they interact.

Levels of Organization ▪To understand these relationships within the biosphere, scientists ask questions about events and organisms that range in complexity from a single individual to the entire biosphere. QQ#2: What is a species?

Levels of Organization ▪Species: a group of organisms so similar to one another that they can breed and produce fertile offspring

Levels of Organization ▪Populations: Groups of individual of the same species that live in the same area

Levels of Organization ▪Communities: two or more populations that live in a defined area. QQ#3: What is an ecosystem?

Levels of Organization ▪Ecosystems: collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment

Levels of Organization ▪Biome: group of ecosystems that have the same climate and similar dominant communities

What Shapes an Ecosystem? Biotic and Abiotic Factors Niche Community Interactions Successions

Biotic and Abiotic Factors ◊Biotic factors: Biological influences on organisms within an ecosystem Living or once-living ◊Abiotic Factors: physical factors that shape an ecosystem Non-living BIOTICABIOTIC QQ#4: What are some examples of biotic factors? abiotic factors?

Biotic and Abiotic Factors ◊Examples of Biotic factors: Plants and animals Aquatic (water) Benthic (bottom- dwelling) Terrestrial (land) ◊Examples of Abiotic Factors: Temperature Water Sunlight Salinity - amount of dissolved salt Wind, rocks and soil Catastrophes - earthquakes, fires, floods, landslides, toxic spills

Biotic and Abiotic Factors ◊Biotic and abiotic factors determine the growth and survival of an organism ◊Also determine the productivity of the ecosystem in which an organism lives ◊Habitat: area where an organisms lives (biotic and abiotic included)

Niche ◊Niche: the full range of physical and biological conditions in which an organism lives and the way the organism uses those conditions. Place in the food web ◊Food it eats, how it obtains it, etc. Physical conditions needed to survive ◊Temperatures it can survive in

Niche ◊No two species can share the same niche in the same habitat. ◊Can occupy different niches that are very similar.

Community Interactions ◊Organisms that live together in ecological communities constantly interact. Competition Predation Symbiosis ◊All affect an ecosystem

Competition ◊Occurs when organisms of the same or different species attempt to use a resource at the same place and time. Resource: any necessity of life (water, food, light, space, etc.)

Competition ◊Direct competition Results in a winner and a loser Losing organism fails to survive.

QQ#5 ◊A bear catches and eats a fish for food. ◊Who benefits? ◊Who doesn’t?

Predation ◊An interaction in which one organism captures and feeds on another organism ◊Predator: the one that does the killing/eating ◊Prey: the one being eaten

Symbiosis ◊Any relationship in which two organisms live closely together Means “living together” ◊3 Main classes in nature: Mutualism Commensalism Parasitism

QQ#6 ◊The ant cares for the aphids and protects them from predators. The aphids produce a sweet liquid that the ant drinks. ◊Who benefits? Who doesn’t?

Mutualism ◊Both species benefit from the relationship Clownfish and Sea Anemone Bee and Flower

QQ#7 ◊The orchid benefits from its perch in the tree as it absorbs water and minerals from rainwater and runoff. ◊Who benefits? Who doesn’t?

Commensalism ◊One member in the relationship benefits, while the other is neither helped nor harmed. Barnacles and Whales

QQ#8 ◊A tick feeds on the blood of its host and may also carry disease-causing microorganisms. ◊Who benefits? Who doesn’t?

Parasitism ◊One organism lives on or inside another organisms and harms it. ◊Parasite obtains all or part of its nutritional needs from the host ◊Generally weakens but does not kill their host a tomato hornworm is covered with cocoons of pupating braconid wasp

Ecological Succession ◊Ecosystems are constantly changing due to natural or human disturbances. ◊Older inhabitants gradually die out and new organisms move in, causing changes in the community.

Ecological Succession ◊Ecological Succession: series of predictable changes that occur in a community over time. ◊Succession may result from: Slow changes in physical environment Sudden disturbance from human activities

Primary Succession ◊Occurs on surface where no soil exists. Where lava rock is from volcanic explosion On rock exposed when glaciers melt

Primary Succession ◊Pioneer species: first species to populate the area ◊On volcanic rock, often lichens (fungus and aglae that can grow on bare rock) When they die, add organic material to help form soil for plants to grow.

Secondary Succession ◊When the natural or human disturbance is over, community interactions tend to restore the ecosystem to its original conditions.

Succession in a Marine Ecosystem ◊Occurs when a large whale dies and sinks to the bottom. ◊Attracts scavengers and decomposers. ◊Decomposition of body enriches surrounding sediments. ◊Heterotrophic bacteria decompose oils in bone that release chemical compounds that serve as energy sources.