USD BIO 311: Eco. Final Exam

Nutrients needed in large amounts and are used to make key biomolecules.

Carbon, Nitrogen, Phosohorous, Silicone, Oxygen, and Hydrogen

Nutrients needed in smaller amounts. Examples: Zinc, Iodine, Potassium, Iron, Copper, Calcium, Chlorine, Sodium, and Magnesium

Growth is limited by the element in the lowest supply relative to need. You can tell the limiter by using nutrient addition bioassays

An environment experiment that tests which nutrients limit the growth of organisms such as bacteria or algae in water sample by ADDING THE NUTRIENTS IN DIFFERENT COMBINATIONS AND OBSERVING THE BIOLOGICAL RESPONSE.

Average amount of time an atom spends in an ecosystem or component of it. Pool Size / Total Flux Out

Proportion of material replaced by flow through in a given time interval

Rate of transfer between pools, movement, and transformation

Mass and form of a nutrient in a particular place and time, acts as storage.

S = VT
Where S = Spiraling length, V = Average downstream velocity of a nutrient atom, and T = Average time to complete a cycle.

Mostly Nitrogen Gas (N2) and Nitrogen Oxides (N20, NO)

Held more tightly by soil, related form is Ammonia (NH3)

More mobile, can be leached, related form is Nitrate (NO2-)

Organic molecules in living plants

Organic molecules in microbes (bacteria, fungi) or detritus

This study started in 1963. In the study they cut forest on one side of a water shed and left another section uncut. They monitored streamflow amount and chemistry. They found that the plant uptake stopped in areas without a buffer, causing more nitrate to be exported in stream water. The form most likely to be leached is Ammonium because ...

Inputs - Outputs
Rate at which nutrients accumulate in the ecsystem.

Inputs - Stream Outputs
Rate at which nutrient is prevented from entering surface waters (and having downstream effects).

Details of internal fluxes may be ignored, but measure inputs and outputs. Need to measure all imputs and outputs for storgae rate.

(Retenion Rate / Inputs) x 100%

Increases retention (artifical ponds, street sweeping) and reduces input (fertilizaer reductions).

Subsystems --> Terrestrial, Atmosphere, Oceanic, and Geologic.
Key Pools --> Soils & freshwater, terrestrial biota (terrestrial), N2 gas (atmosphere), deep & surface ocean waters, marine biota (oceanic), and sediment & rock (geosphere).
Key Fluxes --> (look at image for fluxes T^T)
Human Influences --> Increase in anthropogenic nitrogen fixation emissions, changed how nitrogen interacts/moves from the atmosphere to the biosphere and vice versa.

Subsystems --> Geologic, Oceanic, and Terrestrial.
Key Pools --> Benthic sediments, mineable P. (geologic , deep & surface ocean waters (oceanic), and soils (terrestrial).
Key Fluxes --> (look at image for fluxes T^T)
Human Influences --> Phosphate rock mining, fertilizers, detergents, etc. Major post-industrial increase in P. inputs, outputs, and storage in terrestrial ecosystems.

A process in which nutrients accumulates in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water, possibly causing hypoxic or dead zones.
--> Phosphorus is the main cause for it in lakes
--> Nitrogen is the main cause for the dead zone in the Gulf of Mexico.

Acid rain occurs when the pH of the rain is ≤ 4.5.
Main Causes --> SO2 (fossil fuels, ore smelting) and NO/N2O/NO2 (vehicle emissions, natural side products of nitrification and denitrification).
Effects on Aquatic systems --> Threshold of pH 5 for fish and decomposers. Acidity harms these ecosystems and organisms.
Effects on Terrestrial systems --> Direct damage to vegetation, shifts soil pH, nutrient loss via leaching, mobilization of aluminum, reduced ability of plants to take up nutrients, and makes plants suseptible to other stressors.
Elimination --> Policies reduced acid rain since 1990. Cap-and-trade for sulfur dioxide emissions. 92% decline in SO2 and 84% decline in NOx deposition (1990-2017)

Plant activity & growth in spring & summer draws in CO2, lessening the amount in the atmosphere during that time.

Sea Bird Nutrient Transport: Seabird popluations are declining worldwide, which is an issue becasue theey transport nutrients across ecosystems (circular seabird economy). They do this by feeding at sea & then deposits nutrients on islands through guano, which adds nitrogen, phosphorus, and trace minerals to the ecosystem. Due to this soil nitrogen & phosphorus levels increase, plant biomass rises, vegetation structure shifts, and invertebrates & reptiles increase in abundance. Seabird populations are threatened by invasice predators, overfishing, climate change, and pollution. Overall, seabird populations play important roles in island and marine ecosystems through increasing nutrients and biomass to these communities.

Arthur Tansley defined Ecosystem as the whole system, including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment of the biome.

A dynamic, interacting, interrelated set of biotic and abiotic components in a particular location.

Energy flows due to the fact that it runs on a one-way path from the sun through producers to consumers & decomposer, with energy being lost as heat at each transfer, while nutrients are recycled through cycles via processes like decomposition & mineralization, allowing for resuse.

Gross Primary Production --> GPP = NEP + Re or for Aquatic = (light bottle DO) - (dark bottle DO)
Total amount of energy captured by primary producers per unit time.

Net Primary Production --> NPP = GPP - Ra
Difference, per time unit, between the total energy captured by primary producers and the energy they lose via respiration.

Net Ecosystem Production --> NEP = GPP - Re or for Aquatic = (light bottle DO) - (initial DO)
Difference, per unit time, between the total energy captured by an ecosystem's primary producers and the energy lost via respiration from all of the organisms in the ecosystem.

Autotrophic Respiration --> Ra = Re - Rh
Rate at which autotrophs, primarily plants, break down organic compounds to release energy

Ecosystem Respiration --> Re = Ra + Rh or for Aquatic = (initial DO) - (dark bottle DO)
Sum of autotrophic and heterotrohic respiration

Heterotrophic Respiration --> Rh = Re - Ra
Rate an ecosystem's heterotrophs - including animals, microbes, and fungi - break down organic compounds to release energy

Estimates Re and NEP through measuring CO2

Precipitation & temperature on broad scales, soils, nutrients, light, and competition on finer scales.

Nutrients N, Fe, Si, P, sunlight, temperature, and oxygen levels.

Wetlands, Tropical Rain Forests, Coral Reefs, and Estuaries.

Barren rock/ice fields, Desert shrubs, and Open Ocean (large areas but low productivity).

Tropical Rain Forests (small areas but high productivity) and Open Oceans (huge area but low productivity).

Biomass the accumulaes in heterotrophs

TE = CE x AE x PE
Where CE = consumer efficiency, AE = assimilation efficiency, and PE = production efficicency.

Efficiency of feeding.
CE = Ingestion/Plants

Energy extraction efficiency from food.
AE = Ingestion/Egestion (feces)

Growth efficiency on extracted energy.
PE = Assimilation-Respiration

Higher quality food have lower C:N & C:P ratios.

Elemental ratios compared to need. Most efficient when C:N, C:P ratios of food are similar to consumer tissues.

Ectotherms have higher production efficiency compared to endotherms.

Predators have higher production efficiency compared to herbivores.

Larger body mass contributes to higher production efficiency compared to organisms with smaller body masses.

Detrital is more common in all systems.
Detrital (decomposers) are active (common) in all ecosystems while grazers only have high numbers in grasslands.

The proportion of energy the flows through each is determined by the ecosystem and food quality available within it.
Detrital --> Terrestrial ecosystems (forests & grasslands) due to larger portions of plant material not consumed (hard to digest) or is digested & excreted by the herbivores.
Grazer --> Aquatic ecosystems (lakes/oceans) due to the large amounts of high-quality food like phytoplankton consumed.

Autotrophic systems are more common because they rely on primary producers, organisms that can synthesize their own food, to form the base of the food chain.
Heterotropich ecosystems depend entirely on organic matter produced elsewhere & usually occur in places where light is absent.

Pyramids represent the distribution of energy, biomass, or numbers across trophic levels in an ecosystem.
An energy pyramid is always upright because energy decreases at each level due to the 10% rule.
Implies that the limitation of energy shapes community structure. Ex.) There can only be a few top predators because energy is scarce at higher levels.

They are rare because they are at the highest level where energy is least available and due to their size they have a higher energy demand.

Biomass pyramids can be inverted beause phytoplankton have low biomass but high productivity (Aquatic) and zooplankton & fish have higher biomass because they live longer.
Numbers pyramids can be inverted when small producers support fewer but larger consumers (Aquatic) or when a few larger producers (trees in forests) support many herbivores.

Ecological Footprint is the amount of land and water we need to provide the food, energy, and resources we use and to absorb the waste we create. How much nature we use vs. how much nature the Earth can provide.
Has a total of 6 componets: Cropland, Forest, Pasture, Carbon Footprint, Built-up Land, & Fisheries

The current demand to contribute to each person's footprint is about 2.7 ha/person, however the Earth's capacity is 1.6 ha/person.
Biggest cause of Footprint increase is carbon emissions, so things like fossil fuel burning.

Necessary for the production of all other services. Ex.) Soil formation, nutrient cycling, primary production, habitat provision, etc.

Products we obtain from ecosystems. Ex.) Food, freshwater, timber & fiber, medicinal plants, etc.

Benefits from the regulation of ecosystem processes. Ex.) Climate regulation, pollination, water purification, flood control, etc.

Non-material benefits people get from ecosystems. Ex.) Recreation, spiritual & religious value, aesthetics, etc.

Temperature --> Average global temps will rise, with land areas warming faster than oceans.
Precipitation --> More rainfall due to stronger evaporation & mositure transport in high latitudes/tropics. Less rainfall and more intense droughts in subtropical regions.

Geographical --> species will move toward higher latitudes to stay within their preferred temperature range. Warm-adapted may expand into new areas, while cold-adapted may lose habitat.
Topographic --> Species in mountainous regions will move higher in elevation to find cooler conditions. Species may run out of space near the mountain top.
Temporal --> Flowering, leaf-out, and insect emergence occur earlier. Pollinators & plants and migratory birds & available food may become out of sync.

Timing of food availability and the timing of consumer needs no longer align due to environmental changes. Ex.) Birds migrate based on day length, but insects emerge earlier in spring due to warming. When birds arrive, insect abundance has already passed, causing food shortages for chicks.

1.) Individuals vary
2.) Offspring resemble parents/Variation is heritable
3.) Survival & reproduction are selective/non-random

Adaptation --> Long-term, genetic change in a pop. over many generations.
Acclimation --> Short-term, physiological or behavioral adjustment by an individual organism to cope w/ environmental changes.
If the trait is heritable and persists across generations, it’s adaptation. If the change disappears when conditions return to normal, it’s acclimation.

Is a coevolutionary concept that explains how species must evolve new adaptations to avoid extinction in response to other organisms. It also stresses the importance of sexual reproduction over asexual. This is due to the need for variation in a population in order to evolve.

r-selected species --> high repro. rate, short lifespan, early maturity. Maximizes pop. growth in unstable environments. Ex.) insects and annual plants
K-selected species --> low repro. rate, long lifespace, parental care. Maximizes pop. growth in stable environments. Ex.) large mammals & trees

Competitors (C) --> Thrive in resource-rich, stable environments (tall trees).
Stress-tolerators (S) --> Adapted to harsh, resource-poor conditions (desert plants).
Ruderals (R): Rapid colonizers of disturbed habitats (weeds).

Three axes:
Opportunistic --> Small, early maturity, low juvenile survival (guppies).
Periodic --> Large, late maturity, many offspring, low juvenile survival ( sturgeon).
Equilibrium --> Moderate size, parental care, high juvenile survival (cichlids).
Represents trade-offs among fecundity, juvenile survivorship, and age at maturity.

Semelpartiy --> Repro. once in their lifetime, then die. Invest all energy into a single, huge repro. event. Ex.) Agaves (century plants) store energy for decades, then produce a huge flowering stalk and die.
Iteroparity --> Repro. multiple times over lifetime. Ex.) Yuccas produce flowers repeatedly over many years.

Source-Sink --> Small populations are continually augmented or rescued by immigrants from large growing populations. One way movement patches are defined sources or sinks.
Metapopulation Dynamic --> Composed of sub-populations distributed among spatially isolated patches but connected by exchange of individuals among patches. No inherent source/sink, all moving, more dynamic.