Ecology - Energy Transfer and Flow Notes
Energy Transfer and Flow
Energy Transfer
Producers (Autotrophs)
- Energy originates from the sun.
- Producers, also known as autotrophs, are organisms that create energy-rich compounds like glucose through photosynthesis.
- Examples of producers include plants, certain bacteria species, and algae.
Energy From the Sun
- Photosynthesis is the process of converting carbon dioxide (CO2) and water (H2O) into sugars (glucose) and oxygen using sunlight.
- The basic photosynthesis equation involves light energy, carbon dioxide, and water, resulting in oxygen.
Life Without Light
- Some organisms inhabit deep-sea hydrothermal vents.
- Continental shelf average width = 50 miles (varies from a few to 900 miles).
- Continental slope average depth 12,500 feet.
Life Without Light
- Chemosynthesis uses chemical energy to produce carbohydrates from carbon dioxide (CO_2), hydrogen sulfide, and oxygen.
- Chemosynthetic bacteria prevent oceans from becoming toxic.
- They create a microbial mat.
- Grazers like snails, limpets, and scale worms eat the mat, and predators consume the grazers.
Consumers (Heterotrophs)
- Consumers, or heterotrophs, cannot produce their own food.
- They rely on other organisms for energy and nutrients.
Types of Consumers
- Carnivores kill and eat other animals (e.g., snakes, tigers, coyotes, hawks).
- Scavengers consume carcasses (e.g., turkey vulture).
Types of Consumers
- Herbivores eat plants (e.g., cows, caterpillars, deer).
- Omnivores consume both plants and animals (e.g., humans, bears, pigs).
Other Types of Consumers
- Decomposers chemically break down organic matter (dead plants and animals) and feed on it.
- They produce detritus, which consists of small pieces of decaying plant and animal remains.
- Decomposers play an important role in nutrient cycling back into the soil, water, and air.
- Examples of decomposers are bacteria and fungi.
Other Types of Consumers
- Decomposers produce detritus, which consists of small pieces of decaying plant and animal remains.
- Detritivores feed on detritus (remains of dead organic material).
- Examples of detritivores are earthworms, mites, and snails.
Detritivores in Aquatic Food Webs
- Often called "bottom-feeders."
- Examples include crustaceans like crabs and lobsters, and echinoderms like sea stars or sea cucumbers.
Energy
- Sunlight is the primary source of energy for most living things.
- Producers (Plants) use sunlight to make food.
- Consumers like the black-tailed prairie dog (herbivore) eat seeds and grass.
- Other consumers like coyotes (carnivore), hawks and badgers eat prairie dogs.
Energy
- A turkey vulture (scavenger) may consume leftovers.
- Decomposers like bacteria and fungi break down any prairie dog remains.
Energy Flow
Food Chain
- A food chain is a diagram illustrating how energy flows from one organism to another.
- Primary producer → Herbivore → Carnivore.
- Example: Algae → Flagfish → Largemouth bass → Anhinga → Alligator.
Food Web
- A food web is a diagram that shows the feeding interactions between organisms in an ecosystem.
- It illustrates the transfer of energy within an ecosystem when one organism consumes another.
Food Chains Within Food Webs
- Each path through a food web is a food chain.
- A food web links all food chains in an ecosystem together.
Food Chains Within Food Webs
- Example: Grassland Ecosystem
- Several food chains can be identified, involving grasses, grains, carrots, grasshoppers, mice, rabbits, birds, owls, and foxes.
Keystone Species
- A keystone species' population change causes dramatic changes in the structure of a community and ecosystem.
- Examples: sea otters, sharks, elephants.
Keystone Species
Why do sharks matter?
