ECOLOGY

Abiotic factors

Non living components (water, soil, atmosphere)

Biotic factors

Living things in an ecosystem (plants, animals, bacteria)

Population

A group of the same species (humans)

Theoretical population growth

Lag phase - slow population growth when a species is first introduced to an area

Theoretical population growth

Fast population growth - when the birth rate exceeds the death rate

Carrying capacity

Birth rate = death rate; Populations pleateau due to limited food, space, etc.

Levels of organization (top to bottom)

Biosphere, biome, ecosystem, community, population, niche

Biosphere

Area on a planet that can support life

Biome

Defined by plant life determined by climate

Ecosystem

All species and abiotic factors

Community

All the species in an area

Population

Group of same species

Niche

All biotic and abiotic resources used by an organism

Reproductive stratgeies

r and k strategists (r is common, k is rare)

r stratgegists (common)

Boom bust cycles with huge numbers of offspring. No parental care.

e.g jellyfish and rabbits

k strategists (rare)

Very few offspring, slow to grow and develop. Extensive parental care.

e.g humans and sharks.

Invasive species

A non-native organism that is introduced to a new enviorment and causes harm to the ecosystem.

Burmese Python

Found: In the everglades & thrive very well.

Predator: Main predator to them are alligators, but python are still capable of killing them.

How they’re handeld: They’re hunted and a bounty is put on them to encourage people to kill them.

Burmese pythons as an invasive species

Burmese python prey on many different organisms in the everglades, and they can also reproduce rapidly. Meaning that the python are beginning to outnumber the organisms they’re killing, and their numbers are decreasing.

They also compete with the native predators for food further impacting the wildlife.

Asian Giant Hornet (murder hornet)

Found: In the USA

Predator: None

How they’re handeld: Traps are set up, and flamethrowers are used to destory their hives.

Murder hornets as an invasive species

Murder hornets can kill entire species of native bee’s. Their method of killing them is decapitating them. The hornet's voracious appetite for honeybees and other insects could disrupt pollination and other ecological processes

Symbioses

Mutualism, commensalism, parasitism

Mutualism

Both organisms benefit

e.g hippos and oxpeckers, clownfish and anemone

Commensalism

One organism benefits, the other is indifferent

e.g bull sharks and ramora, golden jackets and tigers

Parasitism

One organism benefits and the other is harmed

e.g tapeworms, fleas

Predator-Prey relationships

• There is always more prey than predator

This is because predators need more prey to feed on. (Its an uneven ratio)

And the rule of ten (10% passed to the next)

Rule of ten

when energy flows through a food chain, only about 10% of the energy at one level is available to the next level.

Biome

An area classified according to the species that live in that location

Low to high water biomes

Desert, Savannah, Chaparral, Tropical Rain forest.D

Desert

• Low annual rainfail. (Therefore low water.)

Plant - Cacti, Aloe Vera

Animal - Fennec fox, Road Runners, Scorpions

Savannah

Transition zone between forests and deserts. Characterized by grasslands wirth scattered trees and shrubs.

Plant - Acacia, Grass

Animal - Wildebeest, Hyenas

Chaparral

Characacterized by dense shrubbery, adapted to a Mediterranean climate. Hot and dry summers, mild and wet winters.

Plant - Sagebrush, Yarrow

Animal - Coyotes, Badgers

Tropical Rainforest

Characterized by high temperatures, abudent rainfall, and dense vegitation.

Plant - Orchids, Cacao

Animal - Jaguars, sloth

Seasonal climates. Low temp + low water → High temp + high water

Polar, Tundra, Grassland, taiga, Deciduous forest

Polar

Characterized by cool summers and very cold winters. They have no dominant producers like forests and grasslands, but their main producers are tiny organisms such as microscopic algae and phytoplankton.

Plant - Moss, lichen

Animal - Arctic fox, Polar bear

Tundra

Extremely low temperatures, and low precipitation.They experience permafrost.

Plant - Moss, lichen

Animal - Caribou, Musk ox

Grassland

Moderate, annual rainfall, and significant temperature variations. Specifically in temperate grasslands. (hot summers, cold winters)

Plant - Wheat grass, blazing stars

Animal - Prairie dogs, bison, elk, deer.

Taiga

Long cold winters, short cool summers with moderate percipitation.

Plant - Pine, spruce

Animal - Lynx, Moose

Deciduous forest

Characterized by four distinct seasons. Winter spring summer fall.

Plant - Oak, maple, hickory

Animal - Rabbits, chipmunks

Polar v Tundra.

Tundra is characterized by a short growing season and low-lying vegetation like mosses and lichens, while polar regions are always covered in ice or snow, with limited or no vegetation

Taiga v Tundra

The taiga has a dense forest of conifers such as pine and spruce, while trees are entirely absent in the tundra. This is due in part to a shortage of water in the tundra, but it is also a product of permafrost.

Grassland v Savannah

Savannas are distinguished by the presence of scattered trees, while grasslands are typically treeless.D

Describe the water cylce.

- Evaporation: Water from oceans, lakes, and rivers is heated by the sun and changes from a liquid to a gas (water vapor).

- Transpiration: Plants also release water vapor into the air from their leaves.

- Condensation: As the water vapor rises, it cools and forms clouds through condensation.

- Precipitation: When the water droplets in clouds become large enough, they fall to the Earth as rain, snow, sleet, or hail.

- Collection/Runoff: Water collects in bodies of water like rivers, lakes, and oceans. Some of it also soaks into the ground to become groundwater.

- The cycle repeats: The process continually repeats, moving water through different parts of the environment.

Describe the Carbon Oxyen Cycle.

Photosynthesis: Plants take in carbon dioxide (CO₂) from the air and, using sunlight, turn it into glucose (a type of sugar) and release oxygen (O₂) back into the atmosphere.

Respiration: Animals (and plants, at night) use oxygen to break down glucose for energy. This process releases carbon dioxide back into the air.

Decomposition: When plants and animals die, decomposers break down their bodies, releasing carbon dioxide into the environment.

Combustion: Burning of fossil fuels or plant material also returns carbon dioxide to the atmosphere.

Describe the nitrogen cycle.

- Nitrogen fixation: Certain bacteria in the soil (and lightning) convert nitrogen gas from the atmosphere (N₂) into ammonia (NH₃) or related compounds that plants can use.

- Nitrification: Other bacteria convert ammonia into nitrites (NO₂⁻) and then into nitrates (NO₃⁻), which plants can absorb as nutrients.

- Assimilation: Plants take up these nitrates and use them to build proteins and other important molecules.

- Consumption: Animals eat plants (or other animals) and use the nitrogen in those plant-based molecules to make their own proteins.

- Ammonification (Decomposition): When plants and animals die, decomposers (like bacteria and fungi) break down their bodies, returning ammonia to the soil.

- Denitrification: Some soil bacteria convert nitrates back into nitrogen gas, releasing it into the atmosphere and completing the cycle.