Introduction to food web and ecosystem ecology

Question 1

What is a food web?

Answer 1

• a simplified way to show the connections between different species in an ecosystem based on who eats whom. It illustrates the flow of energy and nutrients through various organisms, indicating who eats whom in a community
  -consists of producers, comsumers, and decomposers
• Arrows in the food web show the direction of energy flow, indicating who is being consumed by whom. It provides a simplified visual representation of the relationships and interactions between different species in an ecosystem.

Question 2

What are the different components of a food web? Create a food web found in the Hamilton area.

Answer 2

Producers:

Definition: Organisms that produce their own food through photosynthesis or chemosynthesis.
Examples: Plants, algae, and some bacteria.
Primary Consumers (Herbivores):

Definition: Organisms that consume producers (plants) for their energy and nutrients.
Examples: Herbivorous animals such as rabbits, deer, and insects.
Secondary Consumers (Carnivores):

Definition: Organisms that feed on primary consumers (herbivores) for energy.
Examples: Carnivorous animals such as snakes, birds of prey, and spiders.
Tertiary Consumers (Top Predators):

Definition: Organisms that consume secondary consumers.
Examples: Apex predators like lions, sharks, and eagles.
Decomposers:

Definition: Organisms that break down dead organic matter, returning nutrients to the soil or water.
Examples: Bacteria, fungi, and scavengers like vultures and certain insects.
Scavengers:

Definition: Animals that consume the carcasses of dead animals.
Examples: Vultures, hyenas, and some species of beetles.
Detritivores:

Definition: Organisms that feed on detritus, which includes decomposing plant and animal matter.
Examples: Earthworms, some insects, and crustaceans.
Consumers of Different Trophic Levels:

Definition: Different levels of consumers in the food web, organized into trophic levels (e.g., primary consumers, secondary consumers).
Examples: Herbivores, carnivores, and omnivores, each occupying a specific trophic level.
Parasites and Parasitoids:

Definition: Organisms that live on or in a host organism, obtaining nutrients from the host.
Examples: Parasitic worms, ticks, and parasitoid wasps.
Mutualists:

Definition: Species that engage in mutualistic relationships, where both partners benefit.
Examples: Pollinators (bees, butterflies) and plants, where the plant provides food, and the pollinator aids in reproduction.

Question 3

How does energy move between trophic levels? Why is it so inefficient?

Answer 3

• energy transper between trophic levels on average is only 10%
• from top of trophic pyramid to botton, number of indivduals and ecological efficiency decreases
• most energy lost to heat

Question 4

What is an ecosystem? Why is it a useful perspective to study ecological systems?

Answer 4

• and ecosystem is a complex, interconnected community of living organisms (biotic factors) interacting with their physical environment (abiotic factors). It encompasses the relationships and exchanges of energy, nutrients, and materials within a defined geographic area
• Studying ecological systems is useful because it helps us understand how living organisms interact with their environment, providing insights into the delicate balance of nature. This perspective is crucial for making informed decisions about environmental conservation, resource management, and sustainable practices, ensuring the well-being of ecosystems and the services they provide to humans.

Question 5

Why is delineating ecosystems arbitrary? What considerations need to be made when delineating an ecosystem?

Answer 5

• Delineating ecosystems is somewhat arbitrary because nature doesn’t have clear-cut borders. Ecosystems are interconnected and change over time, making it challenging to define precise boundaries. When delineating ecosystems, we must consider factors like scale, environmental conditions, species interactions, human influence, historical factors, and the specific goals of ecosystem management.

Question 6

List multiple ways particles can move in between compartments of an ecosystem.

Answer 6

• atmopsheric deposition
• release of gasses, aerosols - - biological release, widfires, etc
• decay, mineralization,
• weathering solubilization
  -formation of secondary minerals
  SEE DIAGRAM

Question 7

Outline how and why an individual human can be described using an ecosystem model.

Answer 7

• can look at energy consumption and waste elimination
• can look at inputs and outputs
• can analyze internal systems and bacteria
• show interconnectedness with surrounding
• ndividuals are dynamic, adapting and changing over time based on experiences and circumstances
• dependant on reasources
• Individuals influence their surroundings through actions, while external factors impact personal choices and well-being.
• Recognizes the adaptive capacity of individuals, mirroring the resilience and flexibility observed in natural ecosystems.

Question 8

what is bioaccumulation

Answer 8

• the buildup of a chemical in an organism through biocencentration and food inputs

Question 9

what is bioconcentration

Answer 9

• the equilibrium distribution within an organism and the concentration of the chemical in the environment
• results from a balance between passive absorption of a chemical in an organism though the gills or skin and the elimination of that chemical through excretion

Question 10

what is biomagnification

Answer 10

• the relative increase of environmental chemicals in the tissues of organisms with hierarchical increases in a food chain. it takes into accoutn bioconcentration and bioaccumulation

Question 11

what is a box model

Answer 11

• simplified hiersitic model that identifies input and outputs into a system.
• Combining boxes creates biogeochemical cycles