Biodiversity, Ecosystem Services, and Human Impact on Natural Systems, Ecological Impact of Wolves: Trophic Cascades and Yellowstone Ecosystem, Biogeochemical Cycles: Ecosystem Nutrients & Trophic Cascades, Fire Ecology and Land Use Change: Impacts o…

What are the three main ways to measure biodiversity?

Species diversity, genetic diversity, and ecosystem diversity.

What is species diversity driven by?

Evolution, speciation, and extinction.

What is genetic diversity, and why is it important?

Genetic diversity refers to the variety of genes within a species, and it is important for resilience against diseases and environmental changes.

What historical event exemplifies the failure of genetic diversity?

The 19th century potato famine in Ireland, where a single genetic variation of potato was wiped out by a disease.

What does ecosystem diversity refer to?

The variety of different types of ecosystems present in a given area.

Why is high biodiversity important for humans?

It supports the proper functioning of ecosystems, which provide essential services such as food, water, and climate regulation.

What are the four main categories of ecosystem services?

Provisioning, regulating, cultural, and supporting services.

What does provisioning ecosystem service include?

It includes the provision of food, water, minerals, lumber, and energy.

What processes are involved in regulating ecosystem services?

Natural water filtration, decomposition, carbon sequestration, and climate regulation.

What are cultural ecosystem services?

Services that provide recreational, spiritual, historical, and educational benefits.

How do ecosystems support nutrient cycling?

Plants convert energy into usable nutrients and recycle nutrients through biogeochemical cycles.

Where is biodiversity typically highest on Earth?

In tropical latitudes, where climate stability and habitat heterogeneity are greater.

What are biodiversity hotspots?

Regions with a large number of endemic species that are under threat from human activities.

What are endemic species?

Species that are found only in a specific geographic area.

What human activities are major disruptors of biodiversity?

Habitat loss, introduction of invasive species, resource extraction, pollution, and climate change.

What is habitat loss?

The removal of vital habitats for species, such as rainforests and coral reefs.

How do invasive species affect native species?

They out-compete native species for resources, often leading to declines in native populations.

What is the current status of animal populations globally?

Over 50 percent of Earth's animal populations have declined in the last three decades.

What are the three groups of factors that contribute to extinctions?

Biotic, evolutionary, and abiotic factors.

What do biotic factors refer to?

Biological factors such as predation, reproduction rates, and competition.

What does evolutionary resilience mean?

A species' ability to adapt to new conditions or changes in their environment.

What are abiotic factors?

Non-living environmental conditions such as temperature and climate.

What is the sixth mass extinction?

A current extinction event believed to be driven largely by human activities.

What are local extinctions?

Extinctions that occur in a specific area while the species still exists elsewhere.

What are global extinctions?

Complete loss of a species across the globe.

What are mass extinctions?

Catastrophic losses of a significant number of species in a relatively short time.

What role does climate change play in biodiversity loss?

It alters habitats and conditions too quickly for many species to adapt, leading to declines and extinctions.

What is the impact of pollution on biodiversity?

Pollution can kill species, disrupt ecosystems, and trigger trophic cascades.

What is the biosphere?

The biosphere is the layer of all life systems on Earth, comprising complex interconnected systems.

What defines a biome?

A biome is a geographic area defined by specific environmental factors, such as climate and vegetation.

What are the two main types of biomes?

Terrestrial biomes and aquatic biomes.

Name three examples of terrestrial biomes.

Tropical rainforests, savannas, and temperate forests.

What are the main regions of aquatic biomes?

Freshwater regions (ponds, lakes, streams, rivers, wetlands) and marine regions (oceans, coral reefs, estuaries).

How do humans impact rainforests?

Through deforestation and biodiversity loss.

What human activities affect oceans?

Plastic pollution and overfishing.

What is a significant impact of human activity on wetlands?

Destruction for commercial development.

What are biogeochemical cycles?

Systems that help scientists understand how nutrients move between different life systems.

Name five major biogeochemical cycles.

Carbon cycle, water cycle, nitrogen cycle, sulfur cycle, and phosphorus cycle.

What causes acid rain?

The interaction of sulfur dioxide and nitrogen oxides from burning fossil fuels with water and oxygen in the atmosphere.

What are the effects of acid rain on aquatic systems?

Nutrient pollution depletes oxygen, leading to eutrophication and declines in fish populations.

How does acid rain affect terrestrial systems like forests?

It negatively impacts trees and plants by robbing soil of nutrients and stressing forest growth.

What legislation was passed to combat acid rain?

The Clean Air Act was passed in 1990 to limit emissions contributing to acid rain.

What reduction in sulfur dioxide emissions was achieved between 1990 and 2011?

An 88% reduction in sulfur dioxide emissions.

What is the impact of the Clean Air Act on nitrogen oxides?

It has driven a 50% reduction in nitrogen oxides.

Why is recovery from acid rain impacts slow?

Because nutrients get locked into soils, stream macroinvertebrates, and trees.

What should students consider when writing their position essay on biosphere change?

How power, authority, and oppression have influenced natural systems and the perspectives of those affected by these changes.

What is eutrophication?

A process where nutrient pollution leads to oxygen depletion in water bodies, harming aquatic life.

What is a significant consequence of overgrazing in rangelands?

Habitat loss.

What is the role of precipitation and temperature in determining biomes?

They are key variables that affect the location and types of biomes found in specific areas.

What is the relationship between biomes and latitude?

Similar biomes tend to appear within shared latitudes due to comparable environmental conditions.

What is a trophic cascade?

An ecological process that starts at the top of the food chain and affects all levels down to the bottom.

What significant event in Yellowstone National Park exemplifies a trophic cascade?

The reintroduction of wolves in 1995.

What happened to the deer population in Yellowstone before the wolves were reintroduced?

The deer population increased significantly due to the absence of predators.

How did the reintroduction of wolves affect deer behavior?

Deer began to avoid certain areas, particularly valleys and gorges, where they could be easily trapped.

What was one major ecological effect of the wolves' presence in Yellowstone?

The regeneration of vegetation in areas previously overgrazed by deer.

How much did the height of trees increase in some areas after wolves were reintroduced?

The height of trees quintupled in just six years.

What species increased in number as a result of the vegetation recovery in Yellowstone?

Songbirds, migratory birds, and beavers.

What role do beavers play in the ecosystem?

Beavers are ecosystem engineers that create niches for other species by building dams.

What effect did the wolves have on the coyote population?

Wolves killed coyotes, leading to an increase in the populations of rabbits and mice.

Which birds benefited from the carrion left by wolves?

Ravens and bald eagles.

How did the presence of wolves indirectly affect the bear population?

Bears fed on wolf carrion and benefited from the increased availability of berries due to vegetation recovery.

What physical changes occurred in the rivers of Yellowstone after the wolves were reintroduced?

The rivers began to meander less, experienced less erosion, and had more pools and riffle sections.

What role did vegetation play in stabilizing riverbanks?

Regenerating forests stabilized the banks, reducing erosion and allowing rivers to become more fixed in their course.

What is an ecosystem engineer?

A species that significantly modifies its environment, creating habitats for other species.

What was the impact of the wolves on the overall ecosystem of Yellowstone?

Wolves transformed both the ecosystem and the physical geography of Yellowstone National Park.

What are trophic cascades?

Trophic cascades are ecological phenomena where predators impact the abundance and behavior of prey species, which in turn affects the entire ecosystem.

What are the five main trophic levels in ecosystems?

1. Tertiary consumers (apex predators), 2. Secondary consumers (carnivores/omnivores), 3. Primary consumers (herbivores), 4. Primary producers (plants/algae), 5. Decomposers.

What role do primary producers play in ecosystems?

Primary producers, such as plants and algae, create their own food through photosynthesis and serve as the energy source for primary consumers.

What is a top-down trophic cascade?

A top-down trophic cascade occurs when a top predator controls the population of secondary consumers, impacting the entire ecosystem.

Can you give an example of a top-down trophic cascade?

An example is the removal of wolves from an ecosystem, which leads to an increase in deer populations, resulting in overgrazing of primary producers.

What is a bottom-up trophic cascade?

A bottom-up trophic cascade occurs when the abundance of primary producers influences the populations of higher trophic levels.

How does a subsidy cascade differ from other trophic cascades?

A subsidy cascade occurs when one trophic level supplements its food from a non-native source, affecting the dynamics of the ecosystem.

What impact can human activities have on trophic cascades?

Human activities such as overhunting, overfishing, and introducing non-native species can significantly disrupt trophic cascades and ecosystem balance.

What negative example of a trophic cascade involves sea otters?

The decline of sea otters due to hunting led to an overpopulation of Pacific purple sea urchins, which then overgrazed kelp forests, negatively impacting coastal ecosystems.

What is a positive example of a trophic cascade?

Stocking game fish in lakes can lead to a decrease in smaller fish biomass, which increases herbivorous zooplankton and decreases harmful phytoplankton, improving water quality.

What are apex predators?

Apex predators are the top carnivores in an ecosystem that have no natural predators and play a crucial role in maintaining the balance of the ecosystem.

What happens to primary producers when apex predators are removed?

The removal of apex predators can lead to an increase in herbivore populations, which can overgraze and damage primary producers.

What is the role of decomposers in an ecosystem?

Decomposers break down dead organic matter, recycling nutrients back into the ecosystem and supporting primary producers.

How can pollution affect trophic cascades?

Pollution can reduce plant life, which impacts herbivore populations and subsequently affects predator populations, leading to cascading effects throughout the ecosystem.

What is the significance of the concept of tipping points in ecosystems?

Tipping points refer to thresholds where small changes can lead to significant and often irreversible shifts in ecosystem structure and function.

What is the relationship between secondary consumers and primary consumers?

Secondary consumers, which can be carnivores or omnivores, prey on primary consumers (herbivores) that feed on primary producers.

What is the impact of invasive species on trophic cascades?

Invasive species can disrupt existing trophic cascades by outcompeting native species for resources, altering predator-prey dynamics.

What is the effect of abundant primary producers on predator populations?

An abundance of primary producers can lead to increased populations of secondary consumers, which in turn can support larger predator populations.

What is the ecological importance of kelp forests?

Kelp forests provide habitat and food for various marine species, help prevent beach erosion, and play a role in carbon sequestration.

What are biogeochemical cycles also known as?

Nutrient cycles

Why are nutrient cycles important?

They are vital for the functioning of all life on Earth, transforming elements and recycling matter.

What do biotic systems represent?

All life found in the biosphere.

What do abiotic systems include?

Atmosphere, hydrosphere, lithosphere, and cryosphere.

What is the primary source of energy for ecosystems?

The Sun.

What is photosynthesis?

The process by which plants synthesize energy from the Sun into usable nutrients.

What is net primary production?

The amount of energy left after plants use what they need for cellular respiration.

What happens to energy at each trophic level?

Energy is used and lost, primarily as heat during respiration.

What is the water cycle's starting process?

Evaporation, transpiration, evapotranspiration, and sublimation.

What occurs during the condensation phase of the water cycle?

Water vapor forms clouds.

How does carbon move from the atmosphere to plants?

Through photosynthesis, where CO2 is absorbed.

What is nitrogen fixation?

The conversion of atmospheric nitrogen into forms usable by plants.

What is denitrification?

The process by which bacteria convert decomposed matter back into atmospheric nitrogen.

How is oxygen produced in the oxygen cycle?

By sunlight and plant life.

What is mineralization in the phosphorus cycle?

The process of converting organic phosphorus into inorganic forms available to plants.

What role does sulfur play in living organisms?

It is a component of proteins and vitamins, essential for their functioning.