Ecology and Ecosystems: Interactions and Global Change

Why is ecology important?

Ecology helps mitigate damage and promote sustainability in the environment, and it aids in understanding how environmental factors affect human health.

What are biotic factors in an ecosystem?

Biotic factors include living components such as plants, animals, bacteria, fungi, competition, predation, and symbiosis.

What are abiotic factors in an ecosystem?

Abiotic factors include non-living components such as sunlight, water, temperature, soil composition, air, and climate.

How does sunlight influence an ecosystem?

Sunlight is essential for photosynthesis, influencing plant growth and energy flow.

Why is water vital for ecosystems?

Water is vital for all life forms, affecting species distribution and ecosystem productivity.

How does temperature affect ecosystems?

Temperature determines the metabolic rates of organisms and influences habitat suitability.

What role does soil composition play in ecosystems?

Soil composition affects plant growth by providing nutrients and support.

How do air and climate influence ecosystems?

Air and climate influence weather patterns and long-term climate conditions, impacting ecosystems globally.

What is the atmosphere?

The atmosphere is the layer of gases surrounding Earth.

What is the hydrosphere?

The hydrosphere includes all water bodies, including oceans, rivers, and glaciers.

What is the cryosphere?

The cryosphere refers to frozen water, which is part of the Earth's system.

What is the biosphere?

The biosphere encompasses all living organisms and ecosystems.

What is the geosphere?

The geosphere is the solid Earth, encompassing rocks, minerals, and landforms.

What is the anthroposphere?

The anthroposphere includes human societies and their activities.

What are primary producers?

Primary producers produce their food using sunlight or chemical energy and form the base of the food chain in an ecosystem.

How do consumers obtain energy and nutrients?

Consumers obtain energy and nutrients by eating other organisms and are classified as heterotrophs.

How does energy flow through ecosystems?

Energy flows in a one-way stream from the sun to primary producers and then to consumers, with decomposers recycling nutrients.

What percentage of energy is transferred between trophic levels?

About 10% of energy is transferred from one trophic level to the next; the rest is lost as heat or used for life processes.

What is the pyramid of energy?

The pyramid of energy shows the amount of energy at each trophic level, shaped like a pyramid because energy decreases as you move up levels.

What is the pyramid of biomass?

The pyramid of biomass shows the total mass of living matter at each level and can sometimes be inverted in certain ecosystems.

What is the pyramid of numbers?

The pyramid of numbers shows the number of individual organisms at each level and doesn't always resemble a pyramid.

How do predator-prey interactions affect population sizes?

Predator-prey interactions create regular cycles in population sizes, as the number of predators and prey are closely linked.

What is the result of predator-prey interactions?

These interactions create regular cycles in population sizes, often represented as waves on a graph.

What is the sequence of peaks in predator and prey populations?

Prey populations peak first, followed by a predator peak, then both decline and repeat the cycle.

How does matter flow between trophic levels?

Matter flows through biogeochemical cycles, where producers absorb nutrients, consumers gain those nutrients by eating producers or other consumers, and decomposers return nutrients to the environment.

What role do producers play in matter flow?

Producers, such as plants and algae, absorb nutrients from the soil, air, or water.

What role do consumers play in matter flow?

Consumers, including herbivores and carnivores, eat producers or other consumers to gain nutrients.

What role do decomposers play in matter flow?

Decomposers, like fungi and bacteria, break down dead organisms and waste, returning nutrients to the soil, water, or atmosphere.

How does matter differ from energy in ecosystems?

Unlike energy, which flows in one direction and is lost as heat, matter is reused and recycled.

What are the main processes of the water cycle?

Evaporation, transpiration, condensation, precipitation, runoff, infiltration and percolation, and collection.

What is evaporation in the water cycle?

Water from oceans, lakes, and rivers turns into water vapor due to the sun's heat.

What is transpiration in the water cycle?

Plants release water vapor into the air through their leaves.

What is condensation in the water cycle?

Water vapor cools and changes back into liquid droplets, forming clouds.

What is precipitation in the water cycle?

Water falls from the atmosphere as rain, snow, sleet, or hail.

What is runoff in the water cycle?

Water flows over land and collects in rivers, lakes, or oceans.

What is infiltration and percolation in the water cycle?

Some water soaks into the ground, replenishing groundwater supplies.

What is collection in the water cycle?

Water gathers in bodies of water like oceans, which are the main reservoirs.

Why is the water cycle important?

It distributes fresh water across the Earth, supports all living things, regulates the climate, and helps cycle nutrients.

What are the key components of the carbon cycle?

Carbon moves between the atmosphere, living organisms via respiration and photosynthesis, and fossil fuels.

What is nitrogen fixation?

The process where atmospheric nitrogen (N2) is converted into a usable form, primarily ammonia (NH3), that plants can utilize.

What is denitrification?

A biological process where certain bacteria convert nitrate (NO3-) into gaseous nitrogen (N2) under anaerobic conditions.

What is nitrification?

A biological process where ammonia (NH3) is converted to nitrite (NO2-) and then to nitrate (NO3-) by specialized bacteria.

What is assimilation in the nitrogen cycle?

The process where plants and other organisms incorporate inorganic nitrogen, like nitrates and ammonia, into organic molecules such as amino acids and proteins.

What is ammonification?

The process where microorganisms convert organic nitrogenous waste and dead tissues into ammonia (NH3) or ammonium (NH4+).

What is the phosphorus cycle?

Phosphorus cycles through soil, rocks, water, and organisms, but not the atmosphere.

How does nutrient availability affect primary productivity?

Nutrient availability directly affects the growth and productivity of primary producers, impacting the entire ecosystem.

What is primary productivity?

The rate at which primary producers convert energy (usually from the sun) into organic material through photosynthesis.

What is Gross Primary Productivity (GPP)?

The total energy captured by primary producers.

What is Net Primary Productivity (NPP)?

The energy left after producers use some for themselves, calculated as GPP minus respiration.

Which nutrients are especially important for primary productivity?

Nitrogen and phosphorus.

How do low nutrient levels affect productivity in oceans and freshwater?

In oceans, productivity is often limited by nitrogen or iron; in freshwater, it's often phosphorus.

What is the relationship between nutrient availability and productivity in land ecosystems?

Poor soil nutrients limit plant growth, leading to lower productivity.

What are the effects of high nutrient availability on productivity?

High nutrient availability can lead to high productivity, but excessive nutrients can cause problems like algal blooms.

How do abiotic factors influence the distribution of life on Earth?

Abiotic factors like terrain, water, and nutrients shape ecosystems by influencing the types of organisms that can survive and thrive.

What role do mountains play in shaping ecosystems?

Mountains have cooler temperatures and thinner air, limiting plant and animal life at higher elevations.

How do valleys affect biodiversity?

Valleys often collect water and nutrients, supporting diverse life.

What is the impact of water availability on ecosystems?

Water is essential for all life; it influences cell function, temperature regulation, and nutrient transport.

How do dry areas like deserts support life?

Dry areas support drought-resistant species such as cacti and reptiles.

What is the significance of nutrient-rich areas like river deltas?

Nutrient-rich areas support high productivity and biodiversity.

What is the impact of deforestation on nutrient cycles?

Deforestation disrupts nutrient cycles as tree roots help hold nutrients in the soil, which are washed away when forests are cleared.

How do aquatic ecosystems depend on water chemistry?

Aquatic ecosystems depend on water chemistry (salinity, pH, oxygen levels) to support different organisms.

What happens to species in areas with poor soil like tundra or desert?

They support fewer, specialized organisms.

How do species adapt to abiotic conditions?

Species evolve to adapt to their specific abiotic conditions, shaping ecosystems worldwide.

What human activities change the atmosphere and climate?

Cars and public transport contribute to air pollution and greenhouse gas emissions; deforestation impacts ecosystems and nutrient cycles.

What are the major impacts of deforestation?

Deforestation disrupts nutrient cycles, reduces biodiversity, and alters ecosystems.

What is leaching in the context of deforestation?

Leaching refers to the washing away of nutrients from the soil when forests are cleared.

What happens to nutrients when forests are cleared?

Nutrients are washed away by rain, leading to poor soil quality and reduced plant productivity.

How does deforestation affect carbon storage?

Fewer trees mean less carbon dioxide (CO₂) is absorbed from the atmosphere, contributing to climate change, and cutting trees releases stored carbon back into the air.

What percentage of the world's terrestrial species are found in forests?

About 80%.

What is one major consequence of deforestation on biodiversity?

Deforestation destroys habitats, which can lead to extinction of species.

How do trees affect the water cycle?

Trees absorb and release water through transpiration; without them, the water cycle is disrupted, leading to drier climates and increased drought risk.

What is ocean acidification?

The ongoing decrease in the pH of the ocean caused by the absorption of excess carbon dioxide (CO₂) from the atmosphere.

How much atmospheric CO₂ does the ocean absorb?

About 30-40%.

What chemical reaction occurs when CO₂ is absorbed by seawater?

CO₂ reacts with seawater to form carbonic acid, which lowers the ocean's pH.

Why is ocean acidification harmful to marine life?

It makes it harder for organisms like corals, shellfish, and plankton to build their calcium carbonate shells and skeletons.

What effect does ocean acidification have on coral reefs?

Coral reefs become bleached and brittle, threatening biodiversity and coastal protection.

How does ocean acidification affect fisheries?

Many commercially important species are vulnerable, threatening food security and livelihoods.

What is acid rain?

Rain or precipitation that is more acidic than normal due to air pollution, especially from sulfur dioxide (SO₂) and nitrogen oxides (NOₓ).

How does acid rain form?

SO₂ and NOₓ released by factories and vehicles react with water vapor and other chemicals to form sulfuric and nitric acids.

What is one effect of acid rain on ecosystems?

Soils lose important nutrients, harming plant growth, and lakes become too acidic, killing fish and aquatic life.

How does acid rain harm forests?

It weakens trees by leaching nutrients from the soil and damaging leaves or needles.

What materials are eroded by acid rain?

Buildings and statues, especially those made of limestone or marble.

How does acid rain affect human health?

While not directly harmful, the pollutants causing acid rain can lead to respiratory problems like asthma and bronchitis.

What is a keystone species?

A species that has a disproportionately large effect on its environment relative to its abundance.

Examples of keystone species?

Otters, which regulate the sea urchin population and protect kelp. Kelp are essential habitats for other species.

Gray wolf, controls elk population which prevents overgrazing & allows vegetation to recover.

Bees, which pollinate a wide range of plants that form the base of food webs. Without them, ecosystems and food production systems could collapse.

How does agriculture disrupt nutrient cycles?

The use of synthetic fertilizers adds extra nitrogen and phosphorus to the soil, affecting natural nutrient cycles.

What is leaching?

The process by which nutrients are washed away from the soil by rain.

What are the consequences of poor soil quality due to deforestation?

Reduced plant productivity and compromised ecosystem health.

What happens to excess nutrients from fertilizers?

They run off into rivers, lakes, and oceans, disrupting aquatic ecosystems by causing algal blooms.

What occurs when algae die and decompose in aquatic environments?

Oxygen is depleted, leading to dead zones where aquatic life can't survive.

How do excess nutrients impact nutrient cycles?

They alter the nitrogen and phosphorus cycles, speed up the movement of nutrients from land to water, and reduce soil quality over time.

List some impacts of climate change on human health.

Health damage includes heat stroke and diseases.

What are some ecosystem impacts of climate change?

Death to many aquatic species due to ocean acidification, unhealthy environments, stressors, and pollution affecting land species.

How can climate change affect food security?

It can lead to food shortages.

What role does science play in responding to global change?

Science helps understand the scale, causes, and consequences of global changes, informs policy, drives innovation, monitors climate trends, and promotes global collaboration.

How does science contribute to understanding climate change?

It provides evidence through research and data collection on environmental shifts like rising temperatures and ocean acidification.

What is the role of the Intergovernmental Panel on Climate Change (IPCC)?

The IPCC assesses climate risks and provides recommendations for mitigation and adaptation.

How does scientific research drive technological innovation?

It leads to advancements in renewable energy, sustainable agriculture, carbon capture, and geoengineering.

What is the importance of monitoring in climate science?

Ongoing monitoring allows assessment of climate action effectiveness and informs adaptive strategies.

How does science promote global collaboration?

It provides a shared understanding of global challenges, facilitating cooperation on issues like climate change and pollution.