All flashcards
Flashcard 1: What is the relationship between GPP, respiration, and NPP?
Answer: NPP=GPP−R. NPP is energy remaining after plants use some for respiration.
Flashcard 2: What is biodiversity (species richness) in a community?
Answer: Number of different species present in a defined area. Higher richness generally indicates healthier, more stable ecosystems.
Flashcard 3: What evidence suggests an ecosystem is recovering after a disturbance?
Answer: Increasing native species richness and stable nutrient cycling. Indicates restoration of ecological structure and function.
Flashcard 4: Which evidence most directly indicates eutrophication in a lake?
Answer: High nitrate/phosphate with low dissolved oxygen and algal blooms. Nutrients fuel algae; decomposition depletes oxygen levels.
Flashcard 5: What is resistance in an ecosystem?
Answer: Ability to remain relatively unchanged when disturbed. Stable systems show high resistance to environmental changes.
Flashcard 6: If NPP=500 and R=300, what is GPP?
Answer: 800. Add respiration to net primary productivity: 500+300.
Flashcard 7: What is a trophic cascade?
Answer: Indirect effects across trophic levels triggered by predator changes. Classic example: wolves controlling deer populations affects vegetation.
Flashcard 8: If GPP=1200 and R=800, what is NPP?
Answer: 400. Subtract respiration from gross primary productivity: 1200−800.
Flashcard 9: What is the relationship between GPP, respiration, and NPP?
Answer: NPP=GPP−R. NPP is energy remaining after plants use some for respiration.
Flashcard 10: What is species evenness?
Answer: How evenly individuals are distributed among species. High evenness means no single species dominates the community.
Flashcard 11: What is an indicator species?
Answer: Species whose presence or absence reflects specific environmental conditions. Used for monitoring ecosystem health and environmental quality.
Flashcard 12: Which measurement is a direct indicator of primary productivity in an ecosystem?
Answer: Net primary productivity (NPP) rate. Measures energy available to support higher trophic levels.
Flashcard 13: Which statement correctly distinguishes correlation from causation in ecosystem change?
Answer: Correlation shows association; causation requires evidence of mechanism and control. Experimental design and controls help establish causal relationships.
Flashcard 14: What is ecological succession?
Answer: Directional community change over time after disturbance or new habitat. Involves predictable stages from pioneer to climax species.
Flashcard 15: What is primary succession?
Answer: Succession beginning on bare substrate with no soil present. Requires soil formation before plant establishment can occur.
Flashcard 16: What is secondary succession?
Answer: Succession after disturbance where soil and seed bank remain. Faster than primary succession due to existing soil infrastructure.
Flashcard 17: What is a pioneer species?
Answer: Early colonizer that tolerates harsh conditions and initiates soil formation. Examples include lichens on rock and grasses after disturbance.
Flashcard 18: What evidence most strongly indicates primary succession on new rock?
Answer: Lichens and mosses colonizing bare rock with minimal soil. These organisms break down rock to create the first soil.
Flashcard 19: What evidence most strongly indicates secondary succession after a fire?
Answer: Rapid regrowth from surviving roots and existing soil nutrients. Shows secondary succession utilizing pre-existing soil resources.
Flashcard 20: What is a disturbance in ecosystem ecology?
Answer: An event that disrupts community structure and resource availability. Can be natural (fire, flood) or human-caused (logging, pollution).
Flashcard 21: What is resilience in an ecosystem?
Answer: Ability to recover structure and function after disturbance. Measured by speed and completeness of recovery processes.
Flashcard 22: What is hypoxia in aquatic ecosystems?
Answer: Low dissolved oxygen levels that stress or kill aquatic organisms. Results from algal decomposition consuming dissolved oxygen rapidly.
Flashcard 23: What is biomagnification?
Answer: Increase in toxin concentration at higher trophic levels. Fat-soluble toxins accumulate through predator-prey relationships.
Flashcard 24: Which observation is best evidence of biomagnification?
Answer: Top predators show highest concentrations of persistent pollutants. Demonstrates toxin concentration increasing up food chains.
Flashcard 25: What is bioaccumulation?
Answer: Toxin buildup within an organism over time. Occurs within individual organisms, unlike biomagnification across levels.
Flashcard 26: What is carrying capacity (K)?
Answer: Maximum population size an environment can sustainably support. Determined by resource availability and environmental constraints.
Flashcard 27: Which population pattern best indicates overshoot of carrying capacity (K)?
Answer: Rapid increase followed by sharp decline (crash). Population exceeded K then crashed due to resource depletion.
Flashcard 28: What is a limiting factor?
Answer: Resource or condition that restricts population growth or distribution. Could be food, water, space, or any essential resource.
Flashcard 29: Which evidence best indicates negative effects of habitat fragmentation?
Answer: Reduced gene flow and increased local extinctions in isolated patches. Small patches cannot support viable populations long-term.
Flashcard 30: What is an invasive species?
Answer: Non-native species that spreads and causes ecological or economic harm. Lacks natural predators or competitors in new environment.