Ecosystem Ecology and the Human Microbiome

Vocabulary practice flashcards covering ecosystem ecology, primary productivity, nutrient cycles, isotopic tracking of atmospheric carbon dioxide, and gut microbiome dynamics.

Ecosystem

A biological community of interacting organisms together with their abiotic environment, interconnected through continuous biological, geological, and chemical processes.

Ecosystem ecology studies interactions

Nutrient flow, primary productivity, human impacts

Nutrient flow

a representation of the nitrogen cycle in a backyard ecosystem, also think of phosphorus,carbon, sulfur, and water

primary productivity

pools of energy from which all other organisms must draw, photosynthetic organisms both on land and in the ocean.

human impact

refers to the effects of human activities on ecosystems, including pollution, habitat destruction, and climate change. Long been a primary driver of ecological changes in the air, land, and oceans,

Primary producers

photosynthetic organisms that use the energy from the sun to convert inorganic CO2 into organic, bioavailable carbohydrates (sugars)

Energy transfer from primary producers is

highly inefficient

An organisms energy must be used for what processes

metabolic processes and other activities.

Why does an organism energy not reach high consumers

lost to the subsequent levels, which is why tertiary consumers receive only a fraction of primary producers energy.

Gross Primary Productivity (GPP)

The total amount of carbon fixed or energy produced per year through photosynthesis by primary producers in an ecosystem.

Net Primary Productivity (NPP)

The energy or biomass remaining after primary producers have met their metabolic and cellular respiration requirements ($\text{NPP} = \text{GPP} - R$), representing the energy available to consumers.

Which energy is available for consumers that make up the rest of the food web

Net primary productivity NPP

Through what industry do humans also contribute to NPP and consume it

Agriculture

What is available for consumers that is all carbon and is converted to the primary producers biomass which can be eaten.

net primary productivity (NPP)

What are the most productive terrestrial ecosystems

tropics and temperate zones.

GPP in tropics

GPP on land is driven by plants, which depend upon favorable temperatures and precipitation. In the tropics, GPP is high due to abundant sunlight and warm temperatures, supporting rapid plant growth and photosynthesis.

Major GPP source

oceans particularly near shore and tropics

What does GPP depend on for aquatic ecosystems

nutrient availability more than anything else

Why is the shoreline particularly productive

its due to runoff from the land as well as upwelling of nutrients from the ocean floor to the surface.

Why is upwelling particularly important

it supports roughly 50% of the fish harvest, despite affecting only roughly 1% of ocean area.

What drives GPP in oceans

phytoplankton (unicellular)

Upwelling cycle

is the process where deep, nutrient-rich water rises to the surface, enhancing productivity in marine ecosystems. Wind that is parallel to the coastline can push water away from the coast.

water pushed away in upwelling

water is warm and nutrient-depleted

what replaces displaced water

cold, nutrient rich water from the seafloor

what accounts for almost half of NPP

the ocean and tropics

Energy flow of an ecosystem

unique in each ecosystem and based on the properties of its producers and consumers

What shows how energy moves through ecosystems

pyramids

Energy flow in forrest

large primary producers, little primary consumers, and even fewer secondary consumers.

energy flow in grasslands

large primary producers, moderate primary consumers, less secondary consumers

energy flow of open ocean

large primary producers, less primary consumers than grassland, and same amount of secondary consumers in grasslands.

biomass of forrest

very large primary producers, very small primary consumers, even less secondary consumer

biomass grasslands

large primary producers, moderate primary consumers, very slim secondary consumers

biomass of open ocean

moderate primary producers, very large primary consumers, small amount of secondary consumers

regardless of ecosystem, what is the majority of energy with

primary producers, but that energy is not equally accessible everywhere.

Energy transfers

predatory-prey interactions

How can primary consumers be drawn or diagramed

can be tightly enmeshed in food webs

Primary consumer food webs

show deep connects to other organisms, show predators, prey, and competitors.

What is the result of disturbing a food web

trophic cascade

Upwelling

An oceanographic process where surface winds drive warmer surface waters offshore, causing colder, nutrient-rich deep water to rise to the surface and support high primary productivity.

Inverted biomass pyramid

A pattern characteristic of marine open-ocean ecosystems where primary producers (unicellular algae) have a smaller standing biomass than primary consumers because they reproduce and turn over extremely rapidly.

Trophic cascade

An ecological phenomenon where the removal or addition of top predators indirectly alters the populations of lower trophic levels, including herbivores and primary producers.

Primary producers

Autotrophic organisms, such as plants and phytoplankton, that utilize solar radiation to convert inorganic $\text{CO}_2$ into bioavailable organic carbohydrates.

Keeling Curve

A continuous graph of atmospheric $\text{CO}_2$ concentrations recorded at the Mauna Loa Observatory in Hawaii since 1958, demonstrating an ongoing long-term rise with seasonal annual oscillations.

CO2 added to the atmosphere by

geologic inputs such as volcanoes, mid-ocean ridges, biological inputs (ex. respiration), human activities (ex, deforestation, burning fossil fuels)

CO2 removed from the atmosphere by

gelogic removal (ex. chemical weathering of rocks), biological sequestration (ex. photosynthesis and storage in organisms)

what ice provides a snapshot of historic CO2 levels

antarctic ice, correlation between increasing CO2 content of the atmosphere and human activities.

Carbon-12 ($^{12}\text{C}$)

The most abundant, stable isotope of carbon ($\approx 99\%$ of all carbon) that is preferentially utilized by photosynthetic enzymes during biological processes.

Carbon-13 ($^{13}\text{C}$)

A stable carbon isotope comprising roughly $1\%$ of carbon that is discriminated against by enzymes in living organisms; a declining atmospheric $^{13}\text{C}/^{12}\text{C}$ ratio indicates that added $\text{CO}_2$ originates from organic matter rather than volcanic emissions.

Carbon-14 ($^{14}\text{C}$)

A rare radioactive carbon isotope with a half-life of roughly 5,730 years; its declining atmospheric concentration demonstrates that added carbon stems from ancient fossil fuel sources whose $^{14}\text{C}$ has completely decayed.

Carbon sequestration

The process of capturing and storing atmospheric carbon dioxide over long periods in biological reservoirs (such as trees and soil organic matter) or geologic formations.

Sediments and sedimentary rock reservoir

The largest carbon reservoir on Earth, containing an estimated $66{,}000{,}000$ to $100{,}000{,}000\,\text{GtC}$.

Clostridium difficile

An opportunistic intestinal bacterium that colonizes disrupted gut niches, releasing potent toxins that cause diarrhea and inflammation, and surviving treatments via antibiotic-resistant spores.

Fecal microbiota transplant (FMT)

A clinical treatment involving the transfer of healthy donor gut microbiota into a patient to re-establish microbial diversity and halt recurrent Clostridium difficile infections.

Christensenellaceae

A beneficial bacterial taxon within the human gut microbiome known for promoting host health, which notably increases in relative abundance in the elderly and centenarians.