Ecosystem Ecology

Trophic Levels

All organisms that feed at a particular level in a food chain

-1st level- Producers

-2nd level- primary consumers

-3rd level- Secondary Consumers

Chain length is typically short due to what reasons

1. Production efficiency: the percentage of energy assimilated by an organism that becomes incorporated into new biomass

   → Measures the amount of energy incorporated into the biomass of a consumer per the amount of energy assimilated by that consumer

   →It considers the energy eaten, the energy lost in waste/fecal matter, the energy assimilated, and the energy used during the metabolism of the consumer

   → Invertebrates, microorganisms, young animals typically have high production efficiency

2. Trophic-level transfer efficiency: the amount of energy at one tropic level that is acquired by the trophic level above it and incorporated into biomass (about 10%)

   → Consumer doesn’t eat all the biomass in the trophic level below it

   →Animals require a significant level of energy for metabolism, therefore not much of the energy assimilated gets incorporated into biomass

Ex. caterpillar doesn’t eat bark or twigs but eats the leafs instead

Ecosystem Ecology definition

biotic and abiotic characterized by the Flow of energy and the recycling of inorganic nutrients

-Hydrosphere, atmosphere, lithosphere

Biotic components:

1. Autotrophs-producers

   → photosynthesizers

2. Heterotrophs-consumers

   →Herbivores, carnivores, omnivores, decomposers

Biomass production

quantitative estimate of total mass of living matter in a given area, relates to biome productivity

GPP

the amount of energy (solar energy) converted into the chemical energy of organic matter, especially in the body of plants, overtime

→ at a single time in a given area, or overtime

NPP

the amount of chemical energy available to a primary consumer in the biomass of produces in that particular ecosystem

→ NPP: GPP- amount of energy used by producer for their metabolism

Secondary Productivity

Amount of chemical energy available to secondary consumer in the biomass of a primary consumer

Tertiary productivity

the amount of chemical energy available to a tertiary consumer in the biomass of a secondary consumer

Types of pyramids

1. # of individuals - Snapshot of that ecosystem

2. Biomass amount - Snapshot of that ecosystem

3. Energy- period of time

-Inverted pyramid: trees take up a lot of space but can provide for a lot of animals

Biomagnification

A process by which retained substances becomes more concentrated at each higher trophic level in a food chain

*looking for pollution/ toxins

-DDT in the food chain lead to a cause in significant decline in bird populations

→Persist in environment

→High solubility in lipids

→Found in high concentrations at higher trophic levels

Builds up in the trophic layers, top of the food chain gets the most of the worst

Limiting factors effect productivity

-Hard to get nutrients

-Aquatic: light, nitrogen, phosphorus

-Terrestrial: water, temperature, nitrogen, phosphorus

CHNOPS

carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur

Biogeochemical cycles

-Reservoir: source of nutrient normally unavailable to produces EX. Carbon in fossils

-Exchange pool: Source which orgnaisms normally take their nutrients EX. soil, air

-Biotic community: ;living organisms EX. producers, consumers, decomposers

Transfer Rates

how quickly nutrients more from one component to another

Phosphorus Cycle

Common Reservoir: Rock; transfers after weathering

-Humans changed the rates (mining)

-Build up because the rate changes (overuse in fertilitizers)

→Leads to pollution (eutrophication= runoff)

-No phosphorus in the atmosphere, needed to make ATP, DNA, lipids

-Moves up the food chain (plants→snails→frogs) '

-Decomposers release phosphorus through heir roots after eating dead material

Human contribution:

-Fertilizaers, leads to runoff, eutrophication

-Algal blooms cause dead zones due to lack of O2 and change in pH

Carbon Cycle

-Relationship between photosynthesis and aerobic cellular respiration

C6H12O2→CO2 +H20

-Organisms release CO2, producers take up CO2 to make glucose

-Glucose becomes incorporated into the biomass of producers

-Humans effect it from burning of fossil fuels and burning of wood

1. Absorb co2 during pgotoysntheis (produce glucose)

2. Animals eats the plants (glucose moves up the food chain)

   → release co2 into environment

3. Decomposers (glucose from dead organisms)

   → Release Co2

Nitrogen Cycle

-75% of the atmosphere

-Most organisms cannot utilize this form even though nitrogen is an important component to the body (amino acids)

Nitrogen fixation→Nitrification→ Denitrification

Nitrogen fixation→Nitrification→ Assimilation →Ammonification

Explaination of the steps:

Nitrogen fixation: gaseous nitrogen (N2) is converted into an organic nitrogen that plants can use

→ Nitrogen fixing bacteria in soil have a mutalsimic relationship with some plants

Nitrification: ammonium is converted into nitrates (NO3)

→ carried out by soil bacteria, nitrates can be taken up by plants

Denitrification: Some nitrates will convert back into nitrogen gas by soil bacteria

Assimilation: Some nitrates will be tied up the biomass of orngiamss of food chain, including decomposers

Ammonification: nitrogen will be released back into the environment as ammonium in waste products of organisms or by decomposition of dead organic materials

Humans affect it by fertilizers

Water Cycle

-Solar energy drives this cycle

-Water evaporation from bodies of water and transportation from plants

-Water vapor collects in clouds

-Condensation causes precipiation

-Fresh water is considered renewable because it is constantly being produced from salt water

Humans affect cycle an quality of water

-Miniing of water

-Acid rain

1. Evaporation/ Transpiration

2. Water collects, condenses and produces clouds

3. Condensations occurs= precipitation

4. Water on the ground= Runoff into racers lake, ocean or soak into soil collecting as ground water (renewable)