Energy flow

Energy flow through an ecosystem begins with the?

Sun

What does a food chain start with?

Producer

What does a typical food chain look like?

Producer → primary consumer (herbivore) → secondary consumer (carnivore/omnivore) → tertiary consumers → quaternary consumers

Food chains consists of

different tropic levels

Food web is?

A combination of food chains that integrate to form a network

(some organisms can feed off each other e.g. bird eats mosquito, mosquito feeds on birds)

What happens if a food web is more complex?

Ecosystem will be more stable since a shift in any organism population numbers would not adversely affect the other organisms in the ecosystem.

What are some factors that can affect ecosystems that can affect populations and communities or habitats?

Disease outbreaks

Introduction of new animals and plants into the habitat

Human activities (deforestation and overfishing)

Ultimately, all life forms from all trophic levels would?

all trophic levels will be decomposed by decomposers

Why is this important?

For nutrient cycling, and for dead organic matter to be broken down into inorganic molecules that plants can use

How is energy lost?

Loss is through conversion into other forms of energy, such as heat, sound, and processes such as respiration, inefficient or wasteful digestion (excretion) movement, reproduction etc

On average, how much energy is transferred?

10% of the energy is captured and used by the organism in the next trophic level.

Describe non-cyclic

Flow of energy is non-cyclic in nature which means energy at the top will not move back down the trophic levels or jump down to the producers.

What types of ecological pyramids are there?

Pyramid of numbers (population)

Pyramid of biomass

Pyramid of energy

Why would some pyramids be inverted?

Only number pyramids will be inverted. E.g. tree → insects. As one tree is very big, we do not need a lot of trees to support insects.

What is ecological balance?

Condition of dynamic balance within an ecosystem in which the SPECIES AND DIVERSITY REMAIN IN A STABLE STATE.

why is it important?

Ensure continued survival of organisms.

How do we determine if one animal is a autotroph?

Uses light energy, carbon dioxide and water to produce glucose during photosynthesis

In an ecosystem, which trophic level typically has the largest population? Explain.

Trophic level 1, as only 10% of the energy is captured and used by the organisms in the next trophic level (as a lot of it is lost through various processes). Since autotrophs are at the beginning of the food chain, there would be lesser and lesser energy to support the number of primary, secondary and tertiary consumers in the next few trophic levels (so there will be fewer organisms that can be supported)

How to reduce population of pests (in the case of rats) without affecting the rest of the ecosystem?

Introduce rat traps that limit population without exterminating the population. This allows the ecosystem to be sustainable as there still would be rats for the predators.

(why? cz u can control amount of rats trapped)