Ecology Lecture Notes

These flashcards encompass key concepts and definitions from the ecology lecture notes to aid in exam preparation.

What is an organism?

An individual living thing characterized by organized structure, growth, reproduction, response to stimuli, and metabolism.

How is a species defined?

A group of organisms sharing the same characteristics and can interbreed to produce fertile offspring.

What led to the speciation of the Svalbard reindeer?

Isolation due to glaciers and sea level rise, leading to evolution through natural selection.

What is a community?

All populations in an ecosystem.

Define ecosystem.

A set of biotic and abiotic factors.

What is mutualism? Give an example.

Two species help each other; for example, clownfish and sea anemones.

What is parasitism?

One organism lives off another, harming the host species.

What is the purpose of dichotomous keys?

To identify species based on physical characteristics through a series of two-answer questions.

Define niche.

A set of biotic and abiotic factors on which a population depends, including temperature, sunlight, water, and more.

What is the realized niche?

The actual location where a species is found, which may differ from its fundamental niche.

What are density dependent factors?

Factors that impact population size and regulate it around carrying capacity, often biotic in nature.

What are density independent factors?

Environmental influences that affect population size regardless of the number of individuals present, often abiotic.

Outline the capture-mark-release method.

Capture organisms, mark them, release, then recapture to estimate total population size using the Lincoln Index.

What is the difference between R strategist and K strategist species?

R strategists reproduce quickly with little parental care, while K strategists have fewer offspring and provide greater parental care.

What does sustainability in ecosystems refer to?

A natural property of ecosystems where a balance between outputs and inputs maintains a stable equilibrium.

What is a keystone species?

A species with a unique role that maintains the structure of an ecosystem; if removed, the ecosystem may collapse.

Describe the impact of wolves in Yellowstone.

Wolves regulated elk populations and their removal led to a trophic cascade, destabilizing the ecosystem.

What are autotrophs?

Primary producers that use photosynthesis to convert sunlight into glucose.

What is the first law of thermodynamics?

Energy cannot be created or destroyed, only transformed.

Explain biomass increase measurement in plants.

Measure dry mass, record weight changes over time as biomass increase.

Define bioaccumulation.

Increased concentration of persistent organic pollutants in an individual.

What are carbon sinks?

Areas where the inflow of carbon is greater than the outflow, like oceans and forests.

What is ocean acidification's effect?

Carbon dioxide reacts with water to become carbonic acid, harming shells and coral.

Describe nitrogen fixation.

Gaseous nitrogen is converted into ammonia or nitrate, either by lightning or nitrogen-fixing bacteria.

What is the role of Rhizobium bacteria?

They form mutualistic relationships with legume roots, providing nitrogen in exchange for glucose.

Define successional communities.

Communities that change over time after disturbances, progressing from pioneer species to climax communities.

What is primary succession?

A series of changes in an area with no soil, such as after a volcanic eruption.

What influences climax communities?

Local bedrock properties, topography, weather events, and other environmental factors.

What is GPP and NPP?

GPP is Gross Primary Productivity, and NPP is Net Primary Productivity, calculated as NPP = GPP - R.