Ecology Concepts and Biomes Overview

Ecology

The study of interactions of organisms with each other and their physical surroundings

Biosphere

Part of the Earth where life exists

Ecosystem

given physical areas (abiotic) and the living organisms that inhabit that area (biotic factors)

Communities

collective terms for all species living in one ecosystem

Weather

day to day conditions of the Earth's atmosphere in a given year

Climate

the average year-to-year conditions of temperature and precipitation

Greenhouse gases

carbon dioxide (CO2), methane (CH4), and water vapor (H2O)

Nutrients

elements we need to grow and build molecules such as nitrogen

Producers

capture energy from the sun (such as photosynthetic algae or phytoplankton) or another inorganic source like chemosynthetic bacteria

Primary consumers

feed on the producers

Secondary consumers

feed on the primary consumers

Tertiary consumers

feed on secondary, etc.

Decomposers

break down dead organisms (bacteria and fungi)

Herbivores

eat plants

Carnivores

eat animals

Omnivores

eat both plants and animals

Detritivores

eat dead organic matter; such as crabs, mites, earthworms

Food Webs

a system of interdependent food chains

Keystone species

an organism that helps define an entire ecosystem without it, an ecosystem would be dramatically different or ceases to exist altogether

Biomass

the total mass of organisms at one trophic level

Pyramid of biomass

shows that there is less energy in higher trophic levels

10% Rule

When energy is passed from one trophic level to the next, only 10% (on average) of the energy will be passed on

Biomagnification

The increase in concentration of a substance (such as a pesticide) in the tissues of organisms at successively higher levels in a food chain

Ecological Succession

start of a new community

Primary (1°) Succession

no life before (ie volcanic islands like Galapagos)

Secondary (2°) Succession

one community replaces another (ie a pond begins to fill with organic matter and becomes a marsh land, then becomes solid over time)

Pioneer Species

organisms that begin to colonize areas that did not have living things before (they start 1° succession) [i.e lichens]

Climax Community

a stable collection of organisms in an area

Primary Productivity

the rate at which organic matter is created by producers

Limiting nutrients

substances that limit the primary productivity (introduced nutrients can cause algal blooms)

Biomes

Environments that have a characteristic Climax Community

Tundra

Northernmost (Arctic), Almost treeless Lichens, moss, grass. Permafrost layer stunts plant growth from year to year. Ground thaws a bit in summer; marsh-like. Reindeer and caribou are typical animals. Many species migrate south in winter. (-94 °F)

Chaparral

hot shrubland, prone to fires. Some plants require fire to germinate

Taiga (Boreal Forest)

Deep snow, mild summers, long, cold, snowy winters, moose elk, bears, conifers, and pines .

Temperate Grasslands

Deep, rich soil → many grasses. Prairie dogs, herd animals, most rain falls in 1 season, hot summers, cold winters.

Savanna Grassland

Wet + Dry seasons. Trees, grasses, zebras.

Tropical Rainforest

Warm, moist rain out of any biome. Trees form canopy, insects, frogs, monkeys, birds.

Desert

Very dry, warm during day and cold during the night. Cacti, tumbleweed, shrubs, birds, insects, reptiles.

Aquatic Biomes

Freshwater (3%) and Saltwater.

Intertidal Zone

Organisms that thrive in low tide (barnacles, crabs, etc.).

Neritic Zone (Coastal Ocean)

From low tide to continental shelf some fish present. Lots of nutrients, algae, lobsters/crabs crawl across ocean floor

Pelagic Zone

Open ocean where surfers go and fish are found.

Photic Zone

Light for photosynthesis species like algae.

Aphotic Zone

No light and tons of pressure.

Benthic Zone

No light so scavengers, decomposers, and chemosynthetic organisms.

Coral Reef Zone

Found in tropical waters with a lot of light essential to coral's survival.

Symbiosis

Close interaction between species (coral provides space for algae to photosynthesize and coral gets food).

Salt marshes

Temperate zone and dominated by salt tolerant grasses above water level and sea grass underwater (Chesapeake Bay Area).

Mangrove swamps

Tropical and dominated by salt tolerant trees called _____ (Florida's Everglades).

Biogeochemical Cycles

Nutrients move through in a series of physical or biological processes.

Limiting Factors

Those nutrients that limit growth in an ecosystem.

Water Cycle

Water evaporated into the atmosphere, or its lost from plants through transpiration and will condense and fall back to Earth in the form of rain or snow.

The Nitrogen Cycle

Process that all living things use to assemble molecules like amino acids and nucleotides.

Nitrogen Fixation

Bacteria (often living in symbiosis with plants) can fix nitrogen (N2) into a usable form through nitrogen fixation.

Eutrophication

Process by which a body of water is overly enriched in nutrients leading to plentiful growth of simple plant life.

The Carbon Cycle

Biological process involving photosynthesis, respiration, decomposition.

Community Interactions

Communities interact with each other constantly shaping the ecosystem.

Mutualism

Both species involved benefit (i.e. Clownfish and sea anemone, plants and their pollinators).

Commensalism

One is helped and other species isn't affected (i.e. barnacles benefit by movement of water that allows them to catch food while whales aren't affected).

Parasitism

One species benefits and the other is harmed (i.e. internal tapeworms or external ticks).

Dodder

A parasitic plant which pushes its roots into the host and can do minimal photosynthesis.

Population Density

The number of individuals per unit area.

Exponential Growth

If a population is abundant in space and food, etc. It has the potential to grow exponentially.

Logistic Population Growth

Occurs when the population is limited by its environment (growth rate = zero at carrying capacity).

Carrying Capacity

The number of individuals the environment can carry.

Density Dependent Factors

Limits on the population size that are based on the size of the population including competition, predation, parasitism, and disease.

Density Independent Factors

Unrelated to population density, and doesn't affect all populations in similar ways regardless of their size (i.e. natural disasters, rainstorms, extreme hot/cold conditions).

Energy Flows

The flow of energy through an ecosystem, starting with the sun and moving through producers and consumers.

Nitrogen Cycle

A cycle where nitrogen is converted into multiple chemical forms as it circulates among the atmosphere, terrestrial, and marine ecosystems.

Water Cycle

The continuous movement of water on, above, and below the surface of the Earth.

Carbon Cycle

The biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.

Nitrogen Fixation

Molecular nitrogen (N2) is converted into ammonia (NH3), then ammonium ( NH_4). (Step 1)

Nitrification

Ammonium (NH4) is converted into nitrite (NO2) and then nitrate (NO_3).

Assimilation

Nitrogen becomes part of organic molecules in living organisms. (Step 3)

Denitrification

Nitrogen from dead organisms is converted back into molecular nitrogen (N_2).

Ammonification

Nitrogen from decaying tissue is converted back into ammonium (NH_4) in the soil. (step 5)

Eutrophication

Fertilizers containing nitrogen cause runoff into bodies of water, leading to overgrowth of algae.

Water Cycle (Steps)

Water evaporates and is transpired by plants, then condenses in the atmosphere before precipitating back to Earth.

Carbon Cycle Steps

CO2 to plants via photosynthesis, cellular respiration releases CO2, decomposition returns CO2, combustion releases CO2.

CO2 Impact

The increase of CO2 leads to temperature increase and global warming, resulting in climate change.