Ecosystems

Ecosystem

A community of plants, animals and their surrounding physical environment including soil, rainwater and sunlight

What are the biotic parts of an ecosystem

The living things:

• plants

• animals

• bacteria/fungi

What are the abiotic parts of an ecosystem

The non-living things:

• climate

• water

• soil

What is the interrelationships present within a natural ecosystem

The interrelationships link together the biotic and abiotic parts of the ecosystem:

Physical linkages- ‘animals eating the plant’

Chemicals linkages- ‘mild acids in rainwater speed up the decay of dead leaves

Decomposers

Break down dead organic matter, releasing the nutrients into the soil

Producers

Green plants that use photosynthesis and take nutrients from the soil using their roots

Consumers

Primary consumers are plant-eating animals that eat the producers

Secondary consumers are meat-eating animals that feed on herbivores

Tertiary/quaternary consumers hunt and eat other carnivores in the ecosystems

What is a food chain and why is energy loss (by 10%)?

Food chain- direct transfer of energy between organisms in an ecosystem

Energy is lost along the chain because there are parts of plants/ animals that are not eaten. Energy is lost because hunters use a lot of kinetic energy chasing their prey, which is time consuming

Nutrient cycling

Nutrients are foods that are used by plants and animals as they grow. Two main sources: rainwater, washing chemicals out of the atmosphere/ weathering of rocks, releasing chemicals into the soil.

Litter (dead organic matter)

Nutrients are dissolved in rainfall or stored in dead or waste matter as litter. Nutrients in the leaf litter will run off in rainwater, and other will decompose and released into the soil

Soil

Nutrients from the litter are added to the nutrients released from weathered rock. Some of these nutrients will be washed out of the soil (leaching) or taken up by plants through roots

Biomass (energy from plants and animals)

Nutrients in plants are stored in biomass and can be passed through food chains when eaten by consumers

Distribution of global ecosystems

The distribution of global ecosystems is based on the climate , especially the temperature and rainfall; determines which plants and animals can survive in the region