Ecosystem Disturbance
Shoot to Double your points: Name one natural disturbance and one human-caused disturbance that can change an ecosystem.
Natural: wildfire, hurricane, flood, volcanic eruption; Human-caused: deforestation, pollution, overharvesting, urban development.
What is ecological succession?
Succession: the gradual change in species composition in an ecosystem over time.
What is eutrophication in simple terms?
Eutrophication: nutrient enrichment (usually nitrogen and phosphorus) causes algae blooms, which can reduce oxygen when they decompose.
Shoot to remove the points of any team: What does biodiversity mean?
Biodiversity: variety of life — species diversity, genetic diversity, ecosystem diversity.
Name three abiotic (nonliving) factors that influence an ecosystem.
Examples: temperature, sunlight, water availability, pH, salinity, nutrients, oxygen, energy production, waste management, air quality.
What is the immediate effect on an ecosystem when a keystone species is removed?
Loss of keystone species often causes large shifts in community structure and can lead to population declines or cascading extinctions.
Shoot to Double your points: Differentiate primary succession from secondary succession in one sentence each
Primary: starts on new substrate with no soil (e.g., lava); Secondary: occurs where soil remains after disturbance (e.g., after fire).
List two sources of pollution that can cause eutrophication in lakes.
Sources: agricultural fertilizer runoff, sewage discharge, lawn runoff, animal waste from farms.
Give one positive ecosystem service provided by high biodiversity.
Service example: pollination, water purification, soil fertility, pest control.
How does temperature as an abiotic factor affect where species can live?
Climate change can cause increased extreme weather that affect animals habitats.
Shoot to remove the points of any team. Define "overharvesting" and give a clear example that affects population size.
Overharvesting: harvesting a species faster than it can reproduce (e.g., overfishing cod); causes population decline.
After a volcanic eruption covers land with new rock, what are the first kinds of organisms that usually appear? Name the group and why they can live there.
Pioneer species: lichens, mosses, some bacteria — can colonize bare rock, begin soil formation.
Explain ocean acidification: what chemical change happens when CO2 dissolves in seawater, and one effect on marine life.
CO2 + H2O → carbonic acid forms, lowering pH and reducing carbonate ion availability; effect: difficulty forming shells for corals, mollusks; reduced growth and survival.
Define "invasive species" and give one real-world example that affects native species.
Invasive species: nonnative organism that harms ecosystems — e.g., python, zebra mussels, kudzu, cane toad.
What are 4 ways humans can promote ecosystem stability listed in the notes and the content review?
Monitor, Model, Act, Regulate.
DAILY DOUBLE: How can disease spread more quickly in a population that has low genetic diversity?
Low genetic diversity: fewer resistant alleles; inbreeding increases susceptibility; disease spreads faster due to similar immune responses and close relatedness.
Explain how succession can increase biodiversity over time in a recovering ecosystem.
As succession proceeds, soil and plant structure become more complex, supporting more niches and species, increasing biodiversity.
Shoot to double your score: Give two ways habitat destruction and pollution together can reduce a population’s size.
Habitat destruction reduces living space; pollution can increase mortality or reduce reproduction; together they reduce carrying capacity and increase stress/disease.
Explain one ecological reason why invasive species often outcompete native species.
Reasons: rapid reproduction, lack of predators/diseases in new range, broad diet or tolerance to conditions.
Shoot to double your score: Describe how ocean acidification can affect the carbonate shells of marine organisms and why that matters for the food web.
Acidification reduces carbonate ion concentration, making it harder to build calcium carbonate shells; fewer shell-building organisms weakens food-web links and reef structures.
Explain why Habitat Destruction as a result of human impact directly impacts the population of a species and how it affects an ecosystem.
The disappearance of habit as a result of human impact makes it impossible for most species to survive. Also many organisms are forced to seek out new habitats or risk extinction.
Shoot to remove the points of any team: Describe a plausible 3-step sequence (types of communities) in secondary succession after a forest fire in a temperate region.
Example: grasses and herbs → shrubs/young trees → mature mixed forest with canopy species.
According to our Content Review, describe a measurable plan home homers could take to reduce runoff.
Property owners can install porous surfaces, such as gravel driveways and brick walkways, that allow rainwater to drain into the ground and recharge groundwater supplies.
Explain why Biodiversity increases the amount of resources in an ecosystem.
Possible answer: More different organisms provide food sources, cooperation, and resources for the entire community.
Explain how a long-term increase in average temperature (climate warming) could change species distributions, biodiversity, and ecosystem stability in one coherent paragraph.
Warming can shift species ranges poleward (colder climates) or to higher elevations; — overall biodiversity may drop in some areas, altering interactions and making ecosystems less stable and more prone to collapse.