Ecology Notes

What is the general relationship between latitude and species richness?

The closer you are to the equator, the greater the species richness.

What are the reasons for greater species richness near the equator?

Longer growing seasons lead to more plants, which provide more food and habitats.

What are the four primary causes of population decline known as HIPO?

Habitat loss, invasive species, pollution (including climate change), and overharvesting.

the current extinction event caused by humans

The Anthropocene.

What are some ways to protect ecosystems?

Conservation, restoring damaged ecosystems, reducing pollution, ecotourism, and captive breeding.

niche

An organism's role in its environment, often described as its 'job'.

keystone species

A species on which other species in an ecosystem largely depend; its removal would drastically change the ecosystem.

an invasive species

Non-native species that enter a new ecosystem and threaten existing native populations.

What is biodiversity?

The variety of life in an area.

species richness?

The number of species in a community.

species evenness

It compares the population sizes of all populations in a community.

What is the water cycle?

The repeated movement of water between Earth's surface and atmosphere.

the water cycle

1. Evaporation & Transpiration, 2. Condensation, 3. Precipitation, 4. Collection.

What are the four main carbon reservoirs?

1. In atmosphere as CO2 gas, 2. In ocean as dissolved CO2 gas, 3. On land in organisms, rocks, soil, 4. Underground as fossil fuels and calcium carbonate.

Why is carbon important for living organisms?

Carbon is found in all the building blocks of cells (macromolecules) and is essential for glucose production during photosynthesis, which is the fuel for all living things.

What is the role of nitrogen in living organisms?

Nitrogen bases are crucial for DNA and RNA, and adenine is used in ATP. Although 79% of the atmosphere is nitrogen gas (N2), it cannot be used directly by organisms.

What processes can break the strong bond in nitrogen gas (N2)?

Lightning, volcanic activity, and a few special bacteria can break the bond in nitrogen gas.

What is nitrogen fixation?

Nitrogen fixation is the process by which bacteria in the soil convert nitrogen gas (N2) from the atmosphere into ammonia (NH3), a form usable by plants.

What is an ecological relationship?

An ecological relationship refers to the interconnectedness of all living and nonliving things in an ecosystem, where changes to one component can impact the entire system.

competition

occurs between the same or different kinds of organisms as they vie for available resources.

predation?

is the interaction where one organism hunts and kills another to meet its energy needs.

cooperation

occurs when the same kind of organisms live together and help each other.

What is symbiosis?

Symbiosis is a close association between different kinds of organisms.

What are the three kinds of symbiosis?

Mutualism (both benefit), commensalism (one benefits, the other is unaffected), and parasitism (one benefits at the expense of the other).

mutualism

a type of symbiosis where both organisms benefit from the interaction.

Give an example of mutualism.

Birds eat parasites from the hides of giraffes and rhinos; birds get food, while the rhinos/giraffes get cleaned.

commensalism

a type of symbiosis where one organism benefits while the other is neither helped nor harmed.

parasitism

a type of symbiosis where one organism benefits at the expense of the other.

resources in an ecological context

anything needed by an organism for life, such as nutrients, water, light, and space.

What is a limiting factor in an ecosystem?

A limiting factor is a nutrient that is in short supply or cycles slowly, which limits the growth of the population.

algal bloom

is a dramatic increase in population that occurs when an ecosystem receives a large input of a limiting nutrient, such as fertilizer runoff.

What are some examples of cooperation among organisms?

Examples include sharing food, childcare responsibilities, grooming each other, taking care of the sick, hunting in packs, and providing protection.

the nitrogen cycle

a crucial for converting nitrogen into forms usable by living organisms, thus supporting the production of proteins, ATP, and nucleic acids.

What is ecology?

The study of interactions between organisms and the living and nonliving parts of the environment.

the study ecology

ecosystem services that provide direct benefits to humans, such as food production, air/water purification, raw materials, and recreation.

biotic factors

The living components, including animals, plants, and microorganisms.

What are abiotic factors in an ecosystem?

The nonliving parts, such as sunlight, temperature, and soil condition.

producers

Organisms that make organic molecules (food), also known as autotrophs, primarily through photosynthesis.

consumers

Organisms that eat other organisms for energy, also known as heterotrophs.

a primary consumer

An herbivore that eats plants.

a secondary consumer

A small carnivore that eats primary consumers.

a tertiary consumer

An organism at the top of the food chain.

decomposers

Organisms that break down dead or decaying organisms and return nutrients to the soil, often referred to as 'Nature's Recyclers'.

decomposers.

Fungi, bacteria, and earthworms.

What is a food chain?

A linear representation of energy flow through different trophic levels.

What is a food web?

An illustration of all the complex, inter-related food chains in an ecosystem.

trophic level

An organism's position in a food chain.

What does the energy pyramid show?

The amount of energy available at each trophic level, indicating that only about 10% of energy is transferred to the next level.

What happens to most of the energy consumed by organisms?

It is used up and lost as heat.

atom

The smallest part of matter, which is non-living.

molecule

Two or more bonded atoms that form compounds, which are non-living.

What are macromolecules?

Very large molecules, such as proteins, fats, carbohydrates, and nucleic acids, which are non-living.

What are organelles?

Tiny organs made of macromolecules.

a cell

The basic unit of structure and function in living organisms, made of organelles.

What is a tissue?

A group of the same kind of cells working together.

What is an organ?

Tissues that work together.

a system

Organs that work together.

organism?

An entire living thing, which may be made of systems or be a single cell.

a population

The same type of organisms living together.

community

Several populations (species) living together and interacting.

ecosystem

A biotic community plus the abiotic features.

What is a biome?

Similar ecosystems grouped together.

the biosphere?

The whole living layer around the globe on Earth, including abiotic features.