Food web and Energy transfer
Introduction:
1. Definition:
• Food web - A food web is a network of many connected food chains that shows how energy and nutrients move between organisms in an ecosystem.
• Energy flow - Energy flow is the movement energy from that sun to producers and then through different organisms as they eat and are eaten.
Why are they needed?
Food web:
• Food webs show how all organisms in a ecosystem are connected.
• They help explain who depends on whom for food.
• They make the ecosystem stable - if one species disappears, others still have different food source.
• They show the balance between producers, consumers, and decomposers.
Energy transfer:
• Every organism need energy to live, grow, move and reproduce.
• Energy transfer explain how energy moves from the sun » plants » animals » decomposers.
2. Producers as the source of energy:
1. Definition:
• Producers are organisms, like plants and algae, that make their own food using sunlight, and provide the starting energy for all other organisms in à food chain or food web.
2. What do they do?
• They make their own food through photosynthesis.
• They capture energy from the sun and turn it into chemical energy (glucose).
• They provide food and oxygen for other living organisms.
• They support the entire ecosystem.
Consumers and their role:
1. Definition:
• Consumers are organisms that cannot make their own food and must eat other plants and animals to get energy. The depend directly or indirectly on producers for their survival.
2. Directly VS Indirectly
Directly:
• This means the consumer eats the producer itself.
• Example: À cow eats grass.
• The energy goes straight from the plant to the animal.
Indirectly:
• This means the consumers eats other animal that already ate the producer.
• Example: À lion eats à zebra and the zebra eats the grass.
• The energy goes plant » zebra » lion, so, the lion gets the plants energy.
Decomposers and the Nutrient cycle:
1. Definition:
• Decomposers are organisms that break down dead plants, dead animals, and waste materials into simple substances that return to the soil.
2. Why do we need Decomposers? • They break down dead plants, animals, and waste so the environment doesn’t fill up with the dead materials.
3. What is the nutrients cycle?
• The nutrient cycle is the continued movement and recycling of nutrients (like:- nitrogen, carbon and minerals) through Decomposers.
4. How does the nutrient cycle work? • Minerals like phosphorus and nitrogen are already present in the ground.
• Through the plants root, plants take in nutrients and use then to grow.
• Animals get nutrients by eating. Herbivorous eats plants, Carnivorous eats other animals, this passes nutrients through the food chain.
• Waste and death return the minerals, when plants or animals die, or when animals produce waste, those materials contain nutrients.
• Decomposers break everything down. Bacteria and fungi break down dead materials into simple substances.
• Nutrients go back in the soil, the broken down nutrients return to the soil, ready for plants to use again.