Ecology
predators, competitors, pathogens, parasites are examples of...
Biotic factors
What factors determine the
distribution of a species? Give an example of each.
Dispersal ability, abiotic factors, biotic factors
Which interaction would result in a positive impact for one species however a negative impact for another, and why?
predation, parasitism, herbivory
What's the difference between ecological footprint and available ecological capacity? What happens if the AEC is less than the EF?
Ecological footprint: amount of land & water “needed” per person to produce the resources we use and to absorb the
wastes we generate
Available Ecological Capacity: amount of land & water available
per person to produce the resources we use and to absorb the wastes we generate
What is a shark's niche?
– Describe a physiological or behavioral adaptation to its abiotic environment
– Describe a physiological or behavioral adaptation to its biotic environment
Various answers
What's the difference between clumped and random dispersion patterns? What could cause clumped pattern vs random pattern?
Clumped – individuals aggregated in patches
• Uneven distribution of resources
• Often driven by mating behavior and predation defense
Random - positions of individuals independent of other individuals; unpredictable spacing pattern
• Resources are evenly distributed
• Weak relationship between individuals
Give an example of a mechanical, chemical and aposematic defense for prey.
Mechanical - porcupine spikes
Chemical - skunks
Aposematic - poison dart frog
Can species evolve to keep up with environmental change? Why or not why?
Yes, species can evolve to keep up with environmental change, but whether they do so successfully depends on several factors, including the speed of change, the species’ generation time, and the amount of genetic variation present in the population.
Give examples of what aspects of climate drive global scale weather patterns? How is this different than what drives regional weather patterns?
– Latitude and sunlight
– Air circulation and precipitation
These are typically a larger scale - looking at things like solar radiation and wind patterns/trades. Regional would be on a smaller scale such as seasonality, bodies of water, etc.
Give a specific example of a biotic factor that causes a uniform dispersion pattern.
Biotic factors – if a species can live there, can it
tolerate the biotic interactions?
Answers can vary based on example but it should be centered around intense competition.
What level of disturbance can increase species diversity, and why?
Intermediate
At low disturbance, competitive species can exclude species and reduce diversity
At high disturbance, many species can’t persist in the environment
Intermediate disturbance hypothesis: intermediate disturbance allows for the highest species diversity
What should you not do to minimize your
ecological footprint?
• Eat more red meat
• Drive/fly more
• Increase energy use in home
• Hot water laundry
• More heat/AC
• Do not use energy efficient lighting
• Do not follow recycling guidelines
• Use more plastic
• Do not support & participate in conservation efforts
• Be unaware of issues in your state
Why is understanding ecological concepts useful?
Food supply
– Agriculture production (soil fertility, insect pollination, pest control)
– Global fisheries: a major source of the world’s protein needs
Fresh water supply
Pharmaceuticals and other beneficial biological molecules
Disease/pathogen spread
Cleansing of atmosphere (CO2 , toxic particles)
Recreational and aesthetic pleasure, and physical, mental, and spiritual wellbeing
How do things like toxic waste influence population density?
Toxic waste influences population density primarily by making certain areas less desirable—or even dangerous—for people to live in.
Health Risks: Areas with high levels of toxic waste often pose serious health risks (e.g., cancer, respiratory issues, birth defects), which can lead residents to move away or deter new residents from settling. Chronic exposure can lead to higher mortality rates or reduced fertility, indirectly reducing population density over time.
Environmental Degradation: Polluted soil, water, and air reduce the quality of life and can destroy local ecosystems, making the area less livable.
What is the difference between primary and secondary succession, with examples? Which is more dangerous?
Primary succession: colonization of new environment
without –removes- soil (volcano eruption, glacier
retreat)
• Occurs over a long period of time
• Fast growing species and high dispersers get there first;
facilitation occurs to improve soil fertility, stability, pH
• Slower growing, competitive species then establish
Secondary succession: occurs after existing community cleared after disturbance that left the soil intact
• Occurs over a shorter period of time (compared to primary)
• Examples: deforestation, fire
What does ecological footprint have to do with water pollution and habitat loss?
An ecological footprint measures the environmental impact of human activities—how much land, water, and other natural resources we use to sustain our lifestyles. It directly connects to water pollution and habitat loss because these are two major ways our resource use affects ecosystems.
Polluted water harms aquatic life, disrupts ecosystems, and affects human health.
Species lose the homes and resources they need to survive, leading to population declines and extinctions.
Why would it be important to know the land distribution in relation to climate? Use the example of mountains or bodies of water.
Typically climate and land distribution have a relationship with one another - for example, for mountains because of the airflow over the mountains it is typically warm & wet on windward side; cool & dry leeward side. Bodies of water generally buffer temperature on land and increase rainfall.
Provide a specific example of how predation can impact population density.
Answers may vary but note it should be centered around that predation impacts population density by keeping certain populations in check - certain species could be more sparse in some areas with more predators, et.
Give a brief overview of the phosphorous cycle.
Weathering of Rocks
Phosphate-containing rocks gradually break down through weathering, releasing phosphate ions (PO₄³⁻) into the soil and water.
Absorption by Plants
Plants take up phosphate from the soil to build DNA, RNA, ATP, and cell membranes.
Transfer Through Food Webs
Animals get phosphorus by eating plants or other animals. It moves through the ecosystem via consumption.
Decomposition
When organisms die or excrete waste, decomposers return phosphorus to the soil or sediments.
Sedimentation and Uplift
In aquatic systems, phosphorus can settle into sediments. Over long geological timescales, these sediments may be uplifted into rock, restarting the cycle.
How can human activities, like using fertilizers, disrupt the natural nitrogen cycle and affect ecosystems?
Synthetic fertilizers add large amounts of nitrogen to soil. When more nitrogen is applied than plants can use, excess nitrogen runs off into waterways, causing eutrophication, algal blooms, and oxygen depletion, which harm aquatic life and land ecosystems by first targeting the primary producers and move up the chain to consumers.