08/20/24

1.1 Notes- Ecosystems 

Individual: 1 single organism (1 human, 1 elk)

Population: Group of individuals of same species (elk herd, group of humans)

Community: All living organisms in an area (Trees, Grass, Rabbits, Birds, Bacteria, Fungus)

Ecosystem: All living and nonliving things in an area (Includes rocks, soil, water, air)

Biome: A large area with a similar climate condition that determine the plant and animal there (Rainforest, Desert)

Organism interactions:

Competition: BOTH species affected negatively (-,-), organisms fighting over same resource, Both species have fewer resources and fewer organisms

Predation: One species benefits positivity, one negatively (+, -), one organism using another for energy source,

• Herbivores: Gazelle eating grass

• True predator: Lion eating the gazelle

• Parasites: Use a host organism for energy, often don’t necessarily kill it, Mosquito biting human

• Parasitoid: Lay eggs inside a host organism, once eggs hatch the larvae eat host for energy, often kills host

Mutualism: BOTH species affected positively (+,+), Both benefited

Commensalism: One species benefits, one has no effect (+,0), Free rider, birds making nest in tree

Symbisisis: 

• Long term interaction between 2 organisms of different species

Can be 

Mutualism, Commensalism, and Parasitism 

Resource partitioning:

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

3 types:

• Temporal partitioning: Using it at different times, wolf hunts at night and coyote at day

• Spatial partitioning: Using different areas of a shared habitat, roots growing at diff lengths

• Morphological partitioning: Using different resources based on different evolved body features, birds that grow larger jaws so they can eat larger animals compared to birds with smaller jaws

08/22/24

1.2 Notes- Terrestrial Biomes

(Terrestrial biomes are land based)

Biome: An area that shares a combination of avg yearly temperature and precipitation (Climate)

• Organisms in biome adapt to live in it, uniquely adapted to survive

Graph of all biomes:

• Predictable pattern for where on Earth biomes are, Tundras and Boreal biomes up north (Russia Canada) (60 degree latitude and up)

• Temperate biomes in middle latitude (30 degree-go degree)

• Tropical biomes means they are closer to equator 

Nutrient availability: 

• Plants need soil nutrients to grow, availability of these nutrients determine which plants can live in a biome 

• Tundra: Soil frozen year round, lots of nutrients not recycled, less nutrients in the soil less water available, not many plants survive here

• Tropical RainForest: Soil nutrient poor (lots of competition from many plants)

• Temperate Forest: Nutrient rich as there are a lot of dead organisms and leaves that decompensate and put nutrients in forest

Shifting Biomes: Climate not stable on Earth, shifts biomes as Earth heats up, Cold soils heat up

08/22/2024 

1.3 Aquatic Biomes

• Characterized by salinity(how much salt is in a body of water)

• Depth (How much sunlight can reach plants in water)

• Flow (determines how much oxygen can dissolve in water)

• Temperature (Warmer water gets, less oxygen it can hold, less life it can support)

Freshwater: Rivers Or Lakes

• Rivers have high oxygen, nutrient rich sediments 

• Lakes are standing bodies of H2O, drinking water

Zones of lake

• Littoral: shallow water, emergent plants

• Limnetic, light can reach, only phytoplankton

• Profundal, too deep for sunlight

• Benthic, murky bottom, bigs live, nutrient rich sediments

Wetland: 

• Area with soil submerged in water at least part of year, shallow enough for emergent plants

• Plants living here have to adapt to living with roots submerged in standing water (Lily pads)

• Wetlands important because store excess water, recharges groundwater, roots of plants trap pollutants 

• High plant growth due to lots of water and nutrients

• Examples like Swamps, Marshes, and Bogs

Estuaries:

• Mix of fresh and saltwater

• Where rivers empty out to sea

• Lots of nutrients in sediments 

• Salt Marsh, Mangrove Swamps

Coral Reef: 

• Warm shallow water, beyond shoreline, most diverse biome in Ocean

• Mutualistic relationship between coral and algae

• Coral takes Carbon dioxide out of ocean, creatures the reef and provides carbon dioxide to algae 

• Algae live in reef and provide energy to the coral through photosynthesis

• Both organisms dependent on each other

Intertidal Zones: 

• Narrow band of coastline between high and low tide

• Organisms must survive crashing waves and direct sunlight

• Need tough skin/outer shell, able to cling onto something to avoid being swept away

Open Ocean:

• Low productivity, only algae and phytoplankton can survive 

• Lots of Earth’s oxygen and absorb a lot of Carbon dioxide

• Photic zone: Where sunlight can reach

• Aphotic zone (abyssal): Area too deep for sunlight, organisms need adaptations to survive here

08/26/24

1.4- Carbon Cycle

Carbon Cycle Overview:

• Movement of molecules that contain Carbon (Carbon dioxide, Glucose, ect..) between sources and sinks

• Some steps very quick others very slow

• Increasing levels of Carbon atmosphere lead to global warming 

Carbon sink: A carbon reservoir that stores more carbon than it releases, reduces number of carbon in atmosphere, examples are algae, plants

Carbon Source: Releases more carbon the stores, adds carbon to atmosphere, examples are fossil fuels, deforestation

Photosynthesis: Removes carbon dioxide from atmosphere, converts to glucose to be used for energy, carbons sink, done by plants, happens quick/balances out respiration

Cellular Respiration: Use up oxygen to break glucose down to release energy, releases carbon dioxide to atmosphere, carbon source, done by plants+animals, happens quick/balances out photosynthesis

Ocean:

• Direct exchange: CO2 moves directly between atmosphere and ocean, quick and in equal directions, Global warming means ocean becomes more acidic as carbon dioxide increasing in atmosphere increases carbon dioxide in ocean

• Algae and Phytoplankton counter this, Coral reef and marine organisms with shells also counter this

• Sedimentation: When marine organisms die, their remains sink to bottom of ocean floor, broken into sediments that contain Carbon

• Burial: Over long periods of time, water pressure condolences sedimentary rock(sand stone), become long term carbon reservoirs 

• Fossil Fuels: Coal, oil, natural gasses, formed from fossilized remains of matter like dead ferns

• Extraction and Combustion: Digging up/mining fossil fuels and burning them up for energy source, releases Carbon dioxide into atmosphere 

Take away: Burial takes long time, Extracting and Combusting doesn’t meaning we may be using up fossil fuels to fast

08/27/2024

1.5– The Nitrogen Cycle

Nitrogen cycle 

• Is movement of molecules between sinks and reservoirs 

• Holds N for relatively short period of time compared to Carbon cycle

• In plants, soil, atmosphere, Nitrogen makes up most of atmosphere-> N2 gas no useable

• Nitrogen is a critical plant and animal nutrient, all living things need nitrogen

Nitrogen Fixation

• Processes nitrogen gas, converted into biologically available ammonia and nitrate 

• Bacteria fixation: Bacteria live in the soil, plant root nodules convert Nitrogen gas into ammonia

• Synthetic fixation: Humans combust fossil fuels which converts nitrogen gas into nitrate, used as fertilizers 

Assimilation: Plants and animals taking Nitrogen in and incorporating it into their bodies, plants use roots, animals eat plants or animals that have eaten plants, plants root of assimalation 

Ammonification: Soil bacteria, microbes, and decomposers converting waste and dead biomass back into ammonia and returning it to soil

Nitrification: Conversion of ammonium into nitrate and then nitrite by soil bacteria

Denitrification: Conversion of NO3 into N2O gas which returns to atmosphere  

Human Impacts of N cycle

• Growing productions of human food contributes to greenhouse gasses-> Nitrous oxide which denitrifiers nitrate in agricultural soils

• Ammonia Volatilization: excess fertilizer leads to NH3 gas entering the atmosphere, leads to acid rain and respiratory irritation in humans, less Nitrogen in soil for crops meaning less crops produced meaning lost profits 

• Leaching and Eutrophication: Synthetic fertilizer use leads to nitrates (NO3) leaching or being carried out of soil by water 

08/29/24

1.6 The Phosphorus Cycle

• Movement of Phosphorus atoms and molecules between sources and sink reservoirs

• Rocks and sediments containing P minerals are major reservoirs

• VERY slow when compared to Carbon or nitrogen cycle as it takes long time for Phosphorus minerals to be weathers out of rocks and carried into soil/bodies of water 

• No gas phase of P so it has to travel in solid form

• Since it takes so long it is often a limiting nutrient in ecosystems, phosphorus needed for DNA+ animal bone/teeth strengthening 

Natural Phosphorus Source: 

• Major natural source is weathering of rocks that contain P minerals

• Wind and rain breaks down the rock and phosphate released and dissolved into water carries it into nearby soils and bodies of water

Synthetic Phosphorus Source: 

• Humans mine phosphate minerals to add to stuff like synthetic fertilizers

• Issue as runoff carries phosphate of soil into nearby bodies of water

Assimilation and Extraction/ Decomp

• P absorbed by plant roots and animals get it by eating plants to get P, when animals and plants die the P is returned to soil by de comp

Sedimentation and Geo. Uplift

• Phosphate doesn’t dissolve well in water, mostly at bottom of body of water as sediment (known as sedimentation) 

• Over time the weight of water compresses these sediments to make sedimentary rock

• Geographical uplift: Tectonic plate collision- forcing the rock layers to weather elements causing weathering restarting the cycle 

Eutrophication

• Body of water gets too much Nitrogen and Phosphorus, excess nutrients which causes algae growth 

• Algae blocks sunlight from reaching surface of water killing clants below surface

• Algae die and bacteria breaks down dead algae causing 0xygen to be used up killing species like fish species, the bacteria breaks those dead organisms down creating positive feedback loop-> Less oxygen, dead org, more bacterial de comp, even less oxygen 

08/29/24

1.7 The Water Cycle

• Movement of water in different states between different sources and reservoirs

• Precipitation-> Rain, Water moving from gas to liquid

• Driven by energy of Sun, Water in body of water becomes gas and evaporates

• Fresh Water Sources-> Groundwater and ice caps which are our key freshwater sources

Evaporation and Evapotranspiration

• 2 man sources that moves liquid water into vapor(gas) to enter Earth's atmosphere

• Transpiration: Process plants use to draw groundwater from roots up to their leaves, leaves use stomata allowing earth to evaporate into atmosphere so other water can come up

• Evapotranspiration: Amount of water that enters atmosphere from transpiration and evaporation combined 

• Both these processes driven by energy from the Sun

Runoff and Infiltration

• Rain flows through Earth's source into a body of water (runoff) or trickles through soil down into ground water aquifer(infiltration)

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

• Runoff reaches surface waters but can potentially carry pollutants into the water source

09/03/24

1.8 Primary Productivity

• Rate that solar energy is converted into organic compounds via photosynthesis over a unit of time, rate of photosynthesis of all producers in an area over a given period of time, also rate of plant growth

• Measured in kcal/m^2/yr, energy/area/time

• Areas with higher productivity means higher plant growth, more food and shelter available for animals meaning more biodiversity 

Calculating PP

• Plants use up some of the energy they generate via photosynthesis for cellular respiration, (taxes plants need to pay on paycheck), RL

• GPP(Gross Primary Productivity): The total amount of light that plants capture and convert to glucose through photosynthesis, total paycheck amount plant earns

• NPP(Net Primary Productivity): The amount of biomass leftover for consumers after plants have used some for respiration, (How much the plant takes home after taxes), 

• NPP=GPP-RL

Ecological Efficiency

• The portion of incoming solar energy that is captured by plants and converted into biomass, food available for consumers 

• Usually only 1% of incoming sunlight is captured and converted into GPP via photosynthesis, ONLY 40% of this is converted into biomass/plant growth

• Some ecosystems are more efficient than others 

Trends in Productivity

• More productivity= more biodiversity

• More water available, higher temperature, and nutrient availability all contribute to high productivity 

09/05/24

1.9+1.10 Trophic Levels and 10% Rule

Conservation of Matter and Energy

• Matter+energy never created or destroyed, only changes forms 

• Tree, dies all its matter returned to soil/atmosphere, didn’t lose any matter

• AKA 1st law of thermodynamics: energy never created or destroyed, demonstrated by the cycles (nitrogen, water, carbon, phosphorus

• Food Webs demonstrate conservation of energy, rabbit eats leave, leave no longer exists but the energy is still in the rabbit

2nd Law of Thermodynamics 

• Each time energy is transferred, some of it is lost as heat

• Each time energy transferred from 1 organism to another, amount of useable energy decreases

• Producers must use 90% of their energy from Sun, then the primary consumers use 90% of the energy they get from the producers, then the tertiary consumer only gets 90% of energy from primary consumers 

• As number of available energy decreases, we use pyramid as the top has least energy and base has the most energy 

• 10% rule, only 10% of energy from 1 trophic level makes it to next

Trophic Level Pyramid:

• Base is Producers, convert sunlight into glucose

• Primary Consumers: animals that eat plants (herbivores)

• Secondary Consumers: Animals that eat primary consumers or herbivores

• Tertiary Consumers: Animals at the top of food chain, feed in secondary consumers

• Only 10% of biomass can be supported, as you go up the pyramid, less organisms for each, only 10% biomass in each trophic level

To calculate biomass up a level:

• Divide bottom level by 10 and so on, used for biomass and energy