Ecology, Biomes, and Biogeochemical Cycles: Key Concepts and Interactions

What is a community in ecological terms?

All living organisms in an area.

What defines an ecosystem?

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

What is a biome?

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

What is mutualism?

A relationship that benefits both organisms.

What is commensalism?

A relationship that benefits one organism and does not impact the other.

What is competition in ecology?

Organisms fighting over a resource like food or shelter, limiting population size.

What is predation?

One organism using another for energy, such as hunters and parasites.

What are herbivores?

Organisms that eat plants for energy.

What are true predators?

Carnivores that kill and eat prey for energy.

What are parasites?

Organisms that use a host for energy, often without killing the host.

What are parasitoids?

Organisms that lay eggs inside a host, where larvae eat the host for energy.

Define symbiosis.

Any close and long-term interaction between two organisms of different species.

What is resource partitioning?

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

What is temporal partitioning?

Using a resource at different times, such as wolves and coyotes hunting at different times.

What is spatial partitioning?

Using different areas of a shared habitat.

What is morphological partitioning?

Using different resources based on evolved body features.

What characterizes a tundra biome?

Higher latitudes with low temperatures and low nutrient availability.

What is the relationship between latitude and biomes?

Latitude determines temperature and precipitation, influencing biome distribution.

What is a wetland?

An area with soil submerged or saturated in water for part of the year, supporting emergent plants.

What are the benefits of wetlands?

They store excess water, recharge groundwater, filter pollutants, and support high plant growth rates.

What is an estuary?

An area where rivers empty into the ocean, mixing fresh and salt water.

What defines a coral reef?

Warm shallow waters with a mutualistic relationship between coral and algae.

How do coral and algae interact?

Coral provides CO2 for algae, and algae provide sugars for coral to use as energy.

What is the significance of nutrient availability in biomes?

It determines which plants can survive, influencing the community of organisms found in the biome.

How does climate change affect biomes?

Shifting climates can cause biomes to shift in location, such as boreal forests moving north.

What is the role of flow in aquatic biomes?

It determines which plants and organisms can survive and how much O2 can dissolve into water.

What is salinity and its significance in aquatic biomes?

The amount of salt in water, determining which species can survive and its usability for drinking.

How does depth affect aquatic ecosystems?

It influences how much sunlight can penetrate and reach plants, affecting photosynthesis.

What do algae need to thrive in reef ecosystems?

A home in the reef and CO2 from the coral.

What is the intertidal zone?

A narrow band of coastline between high and low tide.

Name an adaptation of organisms in the intertidal zone.

Barnacles and sea stars can attach themselves to rocks to survive crashing waves.

How do some organisms prevent desiccation during low tides?

By having shells or tough outer skin.

What is the photic zone?

The area where sunlight can reach, allowing photosynthesis.

What is the aphotic zone?

The area too deep for sunlight to penetrate.

What is the role of algae and phytoplankton in the open ocean?

They produce a significant amount of Earth's oxygen and absorb atmospheric CO2.

What is a carbon sink?

A reservoir that takes in more carbon than it releases, such as oceans and forests.

What is a carbon source?

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

What is the process of photosynthesis?

The process by which plants and algae convert CO2 into glucose using sunlight.

What happens during cellular respiration?

Organisms use O2 to break down glucose, releasing CO2 into the atmosphere.

How does atmospheric CO2 affect ocean CO2 levels?

Increasing atmospheric CO2 leads to higher CO2 levels in the ocean, causing ocean acidification.

What is nitrogen fixation?

The process of converting N2 gas into biologically available forms like ammonia (NH3) or nitrate (NO3).

What role do rhizobacteria play in nitrogen fixation?

They live in root nodules of legumes and convert N2 into ammonia for the plant.

What is the significance of denitrification in the nitrogen cycle?

It converts soil nitrogen back into N2 gas, returning it to the atmosphere.

What is the primary source of phosphorus in ecosystems?

Weathering of rocks containing phosphorus minerals.

Why is phosphorus often a limiting nutrient?

Because its cycle is slow, leading to limited availability for plant growth.

How do synthetic fertilizers impact the phosphorus cycle?

They add phosphates to soils, which can runoff into water bodies, causing eutrophication.

What is ammonification in the nitrogen cycle?

The process where soil bacteria convert waste and dead biomass back into ammonia (NH3).

What is nitrification?

The conversion of ammonium (NH4) into nitrite (NO2-) and then nitrate (NO3) by soil bacteria.

What is the main nitrogen reservoir in the nitrogen cycle?

The atmosphere, primarily as N2 gas.

What is the relationship between carbon sources and global warming?

Carbon sources release CO2, contributing to increased atmospheric CO2 levels and global warming.

What is the role of sedimentation in the carbon cycle?

It is a slow process that stores carbon in sedimentary rock over long periods.

What happens during the burial process in the carbon cycle?

Carbon-containing sediments are compressed into sedimentary rock over geological time.

What is the impact of fossil fuel combustion on the carbon cycle?

It releases large amounts of CO2 into the atmosphere, increasing its concentration.

How do algae and phytoplankton contribute to the carbon cycle?

They take CO2 out of the ocean and atmosphere through photosynthesis.

What is the significance of the nitrogen cycle for ecosystems?

It provides essential nutrients for plant and animal growth, particularly for DNA and proteins.

What is the process of assimilation in the nitrogen cycle?

Plants and animals take in nitrogen and incorporate it into their biomass.

What is sedimentation in the phosphorus cycle?

The process where phosphate forms solid bits that fall to the bottom as sediment.

How can phosphorus sediments be transformed over time?

They can be compressed into sedimentary rock by the weight of overlying water.

What is geological uplift?

The process of tectonic plate collision forcing up rock layers to form mountains.

What can cause eutrophication in aquatic ecosystems?

Excessive input of nitrogen (N) and phosphorus (P) from sources like fertilizer runoff and waste.

What is the effect of algae blooms on aquatic plants?

Algae blooms block sunlight, killing plants below the surface.

What happens to oxygen levels in water during the decomposition of dead algae?

Oxygen levels decrease, which can kill aquatic animals, especially fish.

What is the positive feedback loop created by low oxygen levels in water?

Less O2 leads to more dead organisms, which increases bacterial decomposition and further reduces O2.

What drives the hydrologic (water) cycle?

Energy from the sun.

What is evapotranspiration?

The combined amount of water that enters the atmosphere from transpiration and evaporation.

What are the two main processes that cycle water from liquid on Earth back into the atmosphere?

Evaporation and evapotranspiration.

What is primary productivity?

The rate at which solar energy is converted into organic compounds via photosynthesis.

What does Net Primary Productivity (NPP) represent?

The amount of energy (biomass) leftover for consumers after plants have used some for respiration.

What is the 10% Rule in trophic levels?

Only about 10% of the energy from one trophic level is transferred to the next level.

What is the significance of ecological efficiency?

It measures the portion of incoming solar energy captured by plants and converted into biomass.

How does energy transfer through a food web demonstrate the conservation of energy?

Energy is transferred from one organism to another, but some is lost as heat at each trophic level.

What is the difference between a food chain and a food web?

A food chain shows a linear path of energy flow, while a food web shows interconnected food chains.

What is a trophic cascade?

The ripple effect in a food web caused by the removal or addition of a top predator.

What happens to the populations of species when a top predator declines?

The populations of prey species may increase, leading to overgrazing and ecosystem imbalance.

What role do bacteria play in the decomposition of dead aquatic animals?

They use up oxygen during decomposition, further lowering oxygen levels in the water.

What are the main freshwater reservoirs for humans and animals?

Groundwater (aquifers) and surface waters (lakes/rivers).

What factors lead to high Net Primary Productivity (NPP)?

Water availability, higher temperature, and nutrient availability.

What is the relationship between primary productivity and biodiversity?

Ecosystems with high primary productivity tend to have greater biodiversity.

How can runoff affect water sources?

Runoff can recharge surface waters but may also carry pollutants into those water sources.

What is the role of stomata in transpiration?

Stomata open to allow water to evaporate from leaves into the atmosphere.

What is the significance of the sun's energy in the water cycle?

It drives processes like evaporation and transpiration, moving water between reservoirs.

What is the impact of nutrient shortages on primary productivity?

Shortages of water, temperature, or nutrients lead to decreased primary productivity.

What happens to energy as it moves up the food chain?

The amount of usable energy decreases due to energy loss as heat.

How can one calculate the energy available to a tertiary consumer?

By moving the decimal place one spot to the left of the energy available at the previous level.