APES UNIT 1

Ecosystem

Ecosystem

A community of biotic and abiotic components of an environment, interacting as a system.

Abiotic

Non-living factors in an ecosystem, such as sunlight, temperature, and soil.

Biotic

Living factors in an ecosystem, including plants and animals.

Organism

A living thing.

Population

A group of individuals of the same species.

Community

All living organisms in a specific area.

Biome

A large area with similar climate conditions that determine plant and animal species.

Predator-prey relationships

Interactions where one organism (predator) hunts and eats another (prey).

Symbiotic interactions

Close and long-term interactions between two organisms of different species

→ coral + algae

Competition

The struggle between organisms for limited resources, which can occur between and within species.

Herbivores

Organisms that eat plants for energy.

True predators

Carnivores that kill and eat prey for energy.

Parasites

Organisms that use a host for energy, often without killing the host.

Parasitoids

Organisms that lay eggs inside a host, with larvae consuming the host for energy.

Mutualism

A symbiotic relationship that benefits both organisms involved. ++

Commensalism

A symbiotic relationship that benefits one organism without impacting the other. + 0

Parasitism

A symbiotic relationship in which one organism benefits at the expense of the other. + -

→ fleas/ticks

→ even though they harm rarely cause death

Limiting resource

Any resource that can restrict population growth or affect survival.

Resource partitioning

Different species using the same resource in different ways to reduce competition.

Temporal partitioning

Using resources at different times to avoid competition.

temp = time

Spatial partitioning

Using different areas of a shared habitat to reduce competition.

spatial = space

Morphological partitioning

Using different resources based on evolved body features.

intraspecific competition

competition within a single species

Carbon cycle

The movement of carbon atoms and molecules between sources and sinks in the environment.

biomes are defined by which factors

temperature

precipitation

what role does latitude play in biomes

determines temp and precipitation

tropical RF biome

• nutrient poor soil

• high temp + rain

• rapid decomposition of organic matter

boreal forest biome

• nutrient poor soil

• low temp

• low decomposition rate

temp forest

• nutrient rich soil

• lots of dead organic matter

• warm temp

• more moisture

shifting biomes

biomes shift due to change in climate

salinity

amount of salt in body of water

flow

determines which plants and animals can survive in water

depth

influences how much sunlight can reach plants in water

temperature

warmer water → less O2 → less organisms

Photosynthesis

The process by which plants convert carbon dioxide into glucose using sunlight.

rivers + lakes

• have high O2

• carry nutrient-rich sediment

---

• standing bodies of fresh H2O

littoral zone in fresh water

shallow water at edge with emergent plants (roots deep but plant part on water)

limnetic zone in fresh water

light can reach + no rooted plants

profundal zone in fresh water

the deep part + no sunlight → no photosynthesis

benthic zone in fresh water

murky bottom where bugs live + nutrient rich sediment

wetlands

area with soil saturated in water for atleast part of the year + shallow enough for emergent plants

• plants here have adapted to roots submerged in standing/still water

wetland benefit

1. stores water during storms → less flood damage

2. absorbs rainfall

3. roots of plants filter water

4. more nutrients → high plant growth rates.

estuaries

where rivers join oceans

• mix of fresh and salt water

• high plant growth

salt marsh est

along coast in temperature climates

breeding ground

mangrove swamp est

along coast of tropical climates

habitat for many ispishes

coral reef

1. warm shallow waters

2. diverse

3. mutualistic relationships

• corals take CO2 → make calcium carbonate exoskeleton → while giving CO2 to algae

• algae give sugar to coral - photosynthesis

intertidal zones

1. btw high/low tide

2. orgs adapt → outer skin hard + prevents drying out during low tides

open ocean

• so big that algae and phytoplankton can produce most of worlds o2 and absorb co2

• photic zone → sunlight can reach = photosynthesis = plants can survive

• aphotic zone → no sunlight = some species can live here through other vents for energy

whats the key C resevoir carbon

atmosphere

carbon sink

resevoir take more carbon than it releases

1. algae

2. phytoplankton

3. coral

4. mollusks

5. plants

6. soil

carbon source

resevoir releases more carbon than it can take

1. fossil fuel

2. animal

3. deforestation

photosynthesis vs respiration

phot

• plants

• removes CO2 from atmosphere and converts it to glucose

• CO2 sink = removes

---

resp

• all organisms

• uses O2 to break down glucose → releases energy

• CO2 source = adds

direct excahnge CO2

CO2 moves directly btw atmos and ocean

increases both atmosphere and ocean CO2 making ocean acidic

sedimentation CO2

calcuim carbonate precipitates out as sediment and settles on ocean floor

burial

over long periods of time

→ pressure of water compresses C turning sediments into sedimentary rock

Respiration

The process of breaking down glucose to release energy, returning carbon dioxide to the atmosphere.

Decomposition

The breakdown of organic matter, returning carbon to the soil or water.

Nitrogen cycle

The movement of nitrogen atoms and molecules between sources and sinks.

Nitrogen fixation

The process of converting nitrogen gas into usable forms by lightning or soil bacteria.

biotic fixation

certain bacteria that live in the soil, or in symbiotic relationship with plant root nodules convert N₂ into ammonia (NH₃)

abiotic fixation

Lightning converts N₂ gas into nitrate (NO₃^-) and FF combustion converts N₂ gas into ammonia (NH₃)

Ammonification

The conversion of fixed nitrogen into ammonia.

Nitrification

The process of converting ammonia into nitrites and then nitrates by soil bacteria.

Assimilation

The uptake of nitrates by plants and their consumption by animals.

Denitrification

The conversion of nitrates back into nitrogen gas by soil bacteria.

Phosphorous cycle

The movement of phosphorus atoms and molecules between sources and sinks.

Weathering

The process that releases phosphate ions from rocks into soil and water.

Leaching & Eutrophication

: synthetic fertilizer use leads to nitrates (NO₃) leaching, or being carried out of soil by water 

phosphorus cycle [p cycle]

movement of P atoms btw sources

rocks containing P = major resevoirs

never enters atmosphere

which cycke is slowest

P cycle

sources of phosphorus

1. weathering of rocks containing P minerals

2. human mining of P

Assimilation & excretion/decomp

form a mini-loop within P cycle just like assimilation & ammonification in N Cycle,  photosynthesis & resp. in C cycle

geological uplift

tectonic plate collision forcing up rock layers that form mountains;  P cycle can start over again with weathering & release of phosphate from rock

Hydrologic cycle

The movement of water in its solid, liquid, and gaseous phases between sources and sinks.

eutrophication

too much N and P

• fuels algae growth

  • blocks sunlight and kills plats below the surface

  • when algae dies and uses of O2 to decompose killing off aquatic animals as well

  less O₂ → more dead org. → more bacterial decomposition → less O₂

  
  

Evaporation

The process of water turning into vapor due to heat from the sun.

Transpiration

The process by which plants absorb and release water into the atmosphere.