APES Unit 1

Ecosystem

A location on Earth distingused by its paritcular mix of interacting biotic and abiotic components

Biotic

Are the living parts of an ecosystem

Abiotic

Are the nonliving parts of an ecosystem

Autotroph

Uses suns energy to produce usable forms of energy, make their own food

Heterotroph

Incapable of photosynthrsis and must obtain energy by consuming organisms

Herbivore

Eats only plants

Omnivore

Eat both plants and animals

Carnivores

Eats only other animals

Scavengers

Eat animals that have already died

Decomposers

Organisms that get energy by breaking down dead organisms

Mutualism

Organisms of diff. species living close together in a way that benefits both

Coral

provide reef structures & CO2 for algae; alage provides sugars for coral to use as energy

Lichen

Composite organism of fungi living with algae; algae provide sugars & fungi provides nutrients

Commensalism

relationship that benefits one organism & doesnt impact the other

Mutualism

relationship that benefits both organisms

Competition

organisms fighting over a resource like food or shelter limits pop. size

Predation

one organism using another for an energy or food source

Parasitism

one organism lives on/inside another usually causing it harm

Competition

The struggle of individuals to obtain a shared limiting resource. Reduces population size & survival - due to fewer resources

Competitive Exclusion

no two org. will occupy the same niche, one will also out-compete the other for the source leading to resource partitioning

Resource partioning

Different species using the same resource in diff ways to reduce competition

Temporal partitioning

using resources @ different times, such as wolves & coyotes hunting @ different times (night vs. day)

Spatial partitioning

using different areas of a shared habitat (nearby trees, different length roots for soil nutrients)

Morphological partioning

species develop distinct physical traits to specialize in using differen resouces in the same habitat

Biome

the plants & animals found in a region based on annual temp + percipitation (climate)

Tropical RF

nutrient-poor soil (high temp. & rainfall —> rapid decomposition of org. matter; acidic soil +high rainfall —> nutrient leaching)

Boreal forest

nutrient-poor soil (low temp & low decomposition rate of dead organic matter)

Temp. forest

nutrient-rich soil (lots of dead organic matter leaves & warm temperature/molisture for decomposition)

Salinity

How much salt there is in a body of water, determines which species can survive & usability for drinking (Fresh water vs. estuary vs. ocean)

Flow

Determines which plants & organisms can survive, how much O2 can dissolve into water

Depth

Influences how much sunlight can penetrate and reach plants below the surface for photosynthesis

Temperature

Warmer water holds less dissolved O2 so it can support fewer aquatic. organisms

Littoral

shallow water - has rooted plants

Limnetic

where light can reach (photosynthesis)

Profundal

too deep for sunlight (no photosynthesis)

Benthic

murky bottom where inverts (bugs) live, nutrient rich sediments

Wetlands

area with soil submerged/saturated in water for at least part of the year, but shallow enough for emergent plants

• Stores excess water during storms, lessening flood damage to property

• recharges groundwater by absorbing rainfall into soil

• roots of wetland plants filter pollutants from water draining

• High plant growth rates due to lotes of water & nutrients (dead organic matter in sediments

Estuaries

areas where rivers empty into the ocean, a mix of fresh & salt water, high productivity due to nutreints in sediments depositied in esturaries by river

Salt Marsh

• Estuary hab. along coast in temperate climates

• Breeding ground for many fish & shellfish

Mangrove Swamps

• Estuary hab. along coast of tropical climates

Coral Reef

Warm shallow waters beyond the shoreline; the most biodiverse and productive marine biome on earth

• Coral takes CO2 out of the ocean to create a calcium carbonate exoskeleton & also provides CO2 to the algae

• Alage live in the reef & provide sugar to the coral through photosynthesis

Intertidal Zones

Narrow band of coastline between high & low tide, organisms must be adapted to survive crashing waves & direct sunlight/heat during low tide

Open Ocean

So large that algae and phytoplankton of the ocean produce a lot of earth’s O2 and absorb a lot of atmospheric CO2

Carbon Sink

Reservoir that take in more carbon than it releases

• Ocean (algae and sediments)

• Land: plants soil, rainforest, rocks

Atmosphere

Is key carbon resrvior; increasing levels of Carbon in atmosphere leads to global warming

Carbon Source

reservoir that releases more carbon that it take in

• Fossil fuels (oil, coal, natural gas) combustion

• Animal (CH4)

• Deforestation releases CO2 from trees

Photosynthesis & Cellular Respiration (quick processes)

Plants, algae, and phytoplankton, remove CO2 from the atmosphere and convert it to glucose which causes a CO2 sink,

• Done by plants and animals to release stored energy

• uses O2 to break glucose down and release energy

• Releases CO2 into the atmosphere

• CO2 sources

CO2 in ocean/atmosphere

CO2 moves directly between the atmosphere & the ocean by dissolving into & out of ocean water at the surface (very quickly)

• Because of this, increasing atmospheric CO2 leads to an increase in ocean CO2, leading to ocean acidification

• Algae and phytoplankton take CO@ out of the ocean & atmosphere through photosynthesis

• Coral also takes CO2 out of the ocean to make calcium carbonate exoskeletons

Sedementation

calcium carbonate precipitates out as sediment & settles on the ocean floor

Burial

Over long periods of time, the pressure of water compresses (containing sediments on ocean floor into sedimentary rock (limestone, sandstone), long-term carbon reservoir

• slow process that stores C in undergorund sinks like sedimentary rock or fossil fuels

Fossil Fuels

Formed from fossilized remains of organic matter into coal or oil. Their decomposition produces natural gas CH4

Extraction & Combustion

digging up or mining FFs and burning them as an energy source; releases CO2 into the atmosphere

• Burial (formation of FFs) takes longer than extraction & combustion, which means they increase concentration of CO2 in atmosphere

Nitrogen Cycle Overview

• Movement of N-containing molecules between sources & sinks/reservoirs

• N reservois hold N for relavitly short periods of time compared to C cycle

• Atmosphere = main N reservoir

• N = critical plant & animal nutrient

Nitrogen molecules

Nitrogen gas N2

Ammonium NH4

Ammonia NH3

Nitrites NO2(-)

Nitrates NO3(-)

Nitric Oxide NO3

Nitrous Oxide N2O

Assimilation (N cycle)

Plants & animals taking in and incorporating it into their biomass

• plants roots take in NO3(-) or NH3 from soil, animals assimilate by eating plants or other animals

Ammonification (N cycle)

soil bacteria & decomposers converting waste back into NH3 and returning it to soil

Nitrification (N cycle)

conversion of NH4 or NH3 into nitrite (NO2-) & then nitrate (NO3) by nitrifying soil bacteria

Denitrification

conversion of soil N (NO3z) into nitrous oxide (N2O) gas which returns to the atmosphere

Climate (Human impact of N cycle0

N2O = greenhouse gas which warms earths climate

Leaching & Eutrophication

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

• Nitrates run off into local waters, causing algae blooms that block sunlight & kill other aqautic plants

Phosphous Cycle Basics

Movement of P atoms & molecules b/w sourses & sinks and reservoirs

• Rocks & sediments containing P minerals = major reservoirs/sinks

• P cycle is very slow compared to C/H2O/N cycles

• No gas phase of P (doesn’t enter atmosphere)

• Because the cycle is so slow it is a limiting nutrient, meaning plant growth in ecossytems is often limited by P availaility in soil/water

Phosphorus Sources

A major natural source of P is the weathering of rocks that contain P minerals

• Wind & rain break down rock, and phosphate (PO4(-3) is released and dissolved into water; rain carries this into nearby soils & bodies of water

• Synthetic (human) sources of P are mining phosphate minerals & adding to products like synthetic fertilizers & detergents, which are added to lawns or ag. Field runoff carries P into nearby bodies of water

Assimilation & Excretion/Decomp (P cycle)

P is absorbed by plant roots & assimilated into tisues; animals assimilate P by eating plants or other animals

• Animal wate, plant matter & other biomass is borken down by baceria/soil decomposers that return phosphate to soil

Sedimentation & Geological Uplift

Phosphate doesnt dissolve very well into water; much of it forms solid bits of phosphate that fall to. the bottom as sediment (sedimentation)

• P can be compressed into sedimentary rock over long time periods by weight of overlying water

Geological Uplift

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

Eutrophication (too much P and N)

B/c theyre limiting nutrients in aquatic ecosystems extra input of N and P leads to eutrophication (excess nutrients) which fuels algae

• Algae blooms cover the surface of the water, blocking sunlight & killing plants below the surface

• . Creates a positive feedback loop: less O2 → more dead org. → more bacterial decomposition → less O2

Water cycle overview

Movement of H2O between sources & sinks

• State of matter (soild/liquid/gas), as well as where water is moving, are key in the H2O cycle

• Energy from the sun drives the H2O cycle

• Ocean = largest water reservior

• Ice caps & groundwater are smaller reservoirs but contain fresh, useable water for humans

Transpiration (W cycle) → main sources of water (processes that cycle if form liquid back into the atmosphere)

• Process plants use to draw groundwater from roots up to their leaves

• Leaf openings called stomata open, allowing water to evaporate. into the atmosphere. from leaf

Evapotranspiration

Amount of H2O that enters atm. from transpiration & evaporation combined

Precipitation (rain)

Precipitation recharges groundwater through infiltration but only if ground is permeable (able to let water pass through)

• runoff recharges surface waters, but can also carry pollutants into water sources

Primary Productivity

Rate at which solar energy is converted into organic compounds (glucose) via photosynthesis over a unit of time

• Amount of plant growth in an area over a given period of time

• High PP = plant growth = lots of food & shelter for animals

Calculating PP

NPP = GPP - RL

Net Primary Productivity

The amount of energy (biomass/plants) left over for consumers after plants have used some energy for respiration

Gross Primary Productivity

The total amount of sun energy that plants capture and convert to energy through photosynthesis

Respiration Loss (RL)

plants use up some of the energy they generate via photosynthesis for necessary processes such as cellular respiration (movement, internal transportation, etc)

Ecological Efficiency

The portion of incoming solar energy that is captured by plants & converted into biomass

• Only 1% of all incoming sunlight is captured & converted into GPP via photosynthesis

• Differs by ecosystem

Trends in productivity

• The more productive a biome is, the wider the diversity of animal life it can support

• Water availability, higher temperatures, and nutrient availability are all factors that lead to high NPP → shortage of any of these factors will lead to decreased NPP

Conservation of Matter & energy

Matter can never be created or destroyed; it only changes forms

1st law of thermodynamics

Food webs demostrate conservation of energy it cannoto be created or destroyed

2nd Law of Thermodynamics

Each time energy is transferredsome of it is lost as heat

10% Rule

In trophic pyramids, only about 10% of the energy form one level makes it to thenext level: the other 90% is used by the organism & lost as heat

Producers

Plants produce - really convert suns light energy into chemical energy (glucose)

Primary consumers

animals that eat plants (herbivores)

Secondary consumers

Animals that eat primary consumers or herbivores

Tertiary consumers

animals that eat secondary consumers or carnivores & omnivores (only 10% from one level other the next)

Food Webs

Show how matter& energy flow through an ecosystem from organism to organism (arrows in a web indicate direction of enery being transferred)

Trophic Cascade

Removal or addition of a top predator has a ripple effect down though lower trophic levels