Ecosystems and Biogeochemical Cycles

Flashcards covering ecosystem basics, terrestrial and aquatic biomes, and the carbon and nitrogen cycles based on lecture notes.

Individual

One single organism, such as an elk.

Population

A group of individuals belonging to the same species, such as an elk herd.

Community

All the living organisms inhabiting a specific area.

Ecosystem

All the living and nonliving things in an area, including plants, animals, rocks, soil, water, and air.

Biome

The plants and animals found in a given region, determined primarily by its climate.

Mutualism

A relationship between two organisms that benefits both parties, such as in a coral reef.

Competition

Interaction where organisms fight over a limited resource like food or shelter; this process limits population size.

Predation

An interaction where one organism uses another as an energy source, including hunters and parasites.

Commensalism

A relationship that benefits one organism while having no impact on the other, such as birds nesting in trees.

True Predators

Carnivores that kill and eat prey for energy, such as a leopard eating a giraffe.

Herbivores

Organisms that eat plants for energy, such as a giraffe eating from a tree.

Parasites

Organisms that use a host for energy, often living inside the host and usually without killing it; examples include mosquitoes and tapeworms.

Parasitoids

Organisms that lay eggs inside a host; once fixed, the larvae hatch and eat the host for energy.

Symbiosis

Any close and long-term interaction between two organisms of different species, including mutualism ($+/+$), commensalism ($+/0$), and parasitism ($+/-$).

Lichen

A composite organism consisting of fungi living with algae; algae provide sugars while fungi provides nutrients.

Resource Partitioning

Different species using the same resource in different ways to reduce competition and allow survival.

Temporal Partitioning

Using a resource at different times, such as wolves and coyotes hunting at different times of the night or day.

Spatial Partitioning

Using different areas of a shared habitat, such as plants with different length roots.

Morphological Partitioning

Using different resources based on evolved physical body features.

Taiga

One of the major terrestrial biomes characterized by its specific community of plants and animals adapted to its climate.

Temperate Rainforests

A major terrestrial forest biome characterized by significant precipitation and temperate conditions.

Temperate Seasonal Forests

A terrestrial biome with seasonal climate changes, characterized by nutrient-rich soil from leaf decomposition.

Tropical Rainforests

A biome with high temperatures and rainfall, leading to rapid decomposition and nutrient-poor, acidic soil.

Shrubland

A terrestrial biome where plants like shrubs are adapted to recover quickly from fire.

Temperate Grassland

A biome where wildflowers and shrubs store energy in roots to recover from frequent fires.

Savanna

One of the major terrestrial biomes listed as having characteristic communities adapted to climate.

Desert

A biome characterized by very low precipitation where organisms like camels and cacti have water-preserving traits.

Tundra

A cold biome with frozen soils that prevent decomposers from breaking down organic matter, resulting in low soil nutrients.

Climate

The combination of yearly temperature and precipitation that determines the plants and animals found in a region.

Latitude

The distance from the equator which determines temperature and precipitation patterns, and thus the global distribution of biomes.

Nutrient Leaching

The process in tropical rainforests where high rainfall and acidic soil carry nutrients out of the soil.

Boreal Forest Nutrient Availability

Characterized by nutrient-poor soil due to low temperatures and low decomposition rates of dead organic matter.

Shifting Biomes

The movement of biome locations on Earth as climate changes, such as boreal forests shifting north as tundra permafrost melts.

Freshwater Biomes

Aquatic ecosystems including streams, rivers, ponds, and lakes that serve as vital resources for drinking water.

Marine Biomes

Aquatic ecosystems including oceans, coral reefs, marshland, and estuaries; algae here provide a large portion of Earth's oxygen.

Salinity

The salt content in a body of water, which determines species survival and the usability of water for drinking.

Water Flow

An aquatic factor determining which organisms can survive and how much oxygen can dissolve into the water.

Littoral Zone

The shallow area of a lake with emergent plants.

Limnetic Zone

The open area of a lake where light can reach for photosynthesis; contains phytoplankton but no rooted plants.

Profundal Zone

The deep zone of a lake where sunlight cannot reach, preventing photosynthesis.

Benthic Zone

The murky bottom of a lake containing nutrient-rich sediments and invertebrates.

Wetland

An area with soil submerged or saturated in water long enough for emergent plants to grow, acting as a flood buffer and water filter.

Groundwater Recharge

The process by which wetlands absorb rainfall into the soil to replenish underground water sources.

Estuaries

Areas where rivers empty into the ocean, resulting in a mix of fresh and salt water and high plant productivity.

Salt Marsh

An estuary habitat found in temperate climates that serves as a breeding ground for many fish and shellfish.

Mangrove Swamps

An estuary habitat found in tropical climates featuring trees with long, stilt roots that stabilize the shoreline.

Coral Reef

The most diverse marine biome, built by animals that provide $CO_2$ to algae in exchange for sugar via photosynthesis.

Intertidal Zone

A narrow band of coastline between high and low tide where organisms must survive crashing waves and direct sunlight.

Desiccation

The state of drying out, which intertidal organisms avoid using shells, tough skin, or mucus.

Photic Zone

The upper area of the open ocean where sunlight reaches, allowing for photosynthesis by algae and phytoplankton.

Aphotic Zone (Abyssal)

The deep area of the ocean where sunlight cannot reach; species here rely on detritus or chemosynthetic microbes.

Carbon Cycle

The movement of atoms and molecules containing carbon, such as $CO_2$, glucose, and $CH_4$, between sources and sinks.

Carbon Sink

A reservoir that takes in more carbon than it releases, such as the ocean, plants, and soil.

Carbon Source

A reservoir that releases more carbon than it takes in, such as fossil fuel combustion or animal agriculture.

Photosynthesis

The process by which plants, algae, and phytoplankton remove $CO_2$ from the atmosphere and convert it into glucose.

Cellular Respiration

The process by which plants and animals break down glucose using $O_2$ to release energy and $CO_2$.

Direct Exchange

The quick movement of $CO_2$ between the atmosphere and the ocean surface as it dissolves into and out of the water.

Ocean Acidification

A result of increased atmospheric $CO_2$ levels which leads to higher concentrations of $CO_2$ in the ocean.

Sedimentation

The process where calcium carbonate precipitates out of ocean water and settles on the floor as sediment.

Burial

A slow geological process where C-containing sediments are compressed into sedimentary rock like limestone.

Fossil Fuels

Energy sources like coal, oil, and natural gas formed from the fossilized remains of organic matter over millions of years.

Extraction and Combustion

The mining of fossil fuels and their subsequent burning, which quickly moves stored carbon into the atmosphere as $CO_2$.

Nitrogen Cycle

The movement of nitrogen-containing atoms and molecules between reservoirs like the atmosphere, soil, and living things.

Nitrogen Fixation

The process of converting atmospheric nitrogen ($N_2$) into useable forms like ammonia ($NH_3$) or nitrate ($NO_3^-$).

Abiotic Fixation

The conversion of $N_2$ gas into useable forms by non-living processes like lightning or fossil fuel combustion.

Biotic Fixation

The conversion of $N_2$ into ammonia ($NH_3$) by soil bacteria or rhizobacteria in the root nodules of legumes.

Nitrification

The conversion of $NH_4$ into nitrite ($NO_2^-$) and then into nitrate ($NO_3$) by soil bacteria.

Ammonification

The process where soil bacteria and decomposers convert waste and dead biomass back into ammonia ($NH_3$).

Assimilation

The process of plants and animals taking in nitrogen and incorporating it into their biomass for DNA and proteins.

Denitrification

The conversion of soil nitrate ($NO_3$) into nitrous oxide ($N_2O$) gas, which returns to the atmosphere.