Land, water and bees – don’t take us for granted Bees in the ecosystem

Animal pollinators are needed for about three- quarters of global food crop species. One in three mouthfuls of our diet depends on pollination by bees. Cereals, such as wheat, rice, maize and millet, are wind-pollinated. Cereal staple foods (making up about two-thirds of global crop production) are not dependent on bees. Bees as pollinators

Bees in the ecosystem If bees were to disappear from the surface of the Earth, it would be hard to grow strawberries, courgettes, peaches, brazil nuts, watermelons… So bees and other pollinators are important for our food security. Without bees our diet would be boring and less healthy. Bees are an important part of the whole ecosystem, and not just for humans.

Ecosystems include food webs Food webs show the transfer of energy between living things – ‘who eats whom’ in a particular habitat. Sunlight energy is used by plants to make more plant material in a process called photosynthesis. Plants are known as producers. The energy in the plant material is passed onto the animals that eat it. They are called consumers.

Ecosystems include food webs Two groups of living things decompose (break down) dead material in a habitat:  bacteria  fungi. The substances produced by the action of decomposers are recycled into the soil, then by the plants that grow in the soil and then by the consumers that eat the plants.

Bees in food webs Bees are an important food source for some birds and for many types of spider and insect. In North America, black bears eat both bees and their honey. Photo: Stieber/Shutterstock.com

Bees in food webs Ecosystems are delicately balanced. If bees disappear, the balance will be disturbed. One change in a food web, such as the loss or reduction in numbers of an organism, causes other changes elsewhere. If bee numbers fall, the animals that eat them will have to find a new food source. This will cause more competition for resources.

Food webs rose fruit fly honey- bee cater- pillar aphid (green -fly) lady- bird spider thrush Photos: Wellcome Trust / Wellcome Images; Stieber/Shutterstock.com; Erni/fotolia.com; Studiotouch/fotolia.com; Fedorov Oleksiy/Shutterstock.com; kernel/fotolia.com; v_ridjin/fotolia.com; TwilightArtPictures/fotolia.com

Food webs What do you think would happen in this food web if all the honeybees in an area died out? And what would happen if…  a new bird of prey eats thrushes?  pesticides wipe out aphids?  a disease kills roses?

Hedgerow food web Think of plants and animals you might find in a hedgerow at the edge of a field. Research this if you need to. Construct a simple food web to show the interdependence of at least four organisms in the hedgerow. Remember to use arrows to show the transfer of energy. Swap your food web with your neighbour. Do you agree with what they have put into their food web?

Hedgerow food web On the food web you have been handed, identify and label:  primary consumer  producer  secondary consumer  predator  prey. Return it to your neighbour for them to check. As a whole class, you could then combine your examples into a large food web for a hedgerow.

Links to video Bees’ Needs (DEFRA)