Use the technique of tree beating to collect invertebrates from the branches of an oak. Identify the groups to which the animals belong with a simple invertebrate key. Try to work out simple food chains or use the BBC web site to make it easier www.bbc.co.ukgcsebitesizebiology
Look at the leafy branches of an oak tree and find the different kinds of gall. Keep an oak apple in a ventilated jar, wait and watch for the insect to emerge.
Look at specimens of lichens, mosses and liverworts and consider how they are adapted to life in the branches of the oak.
Look at the distribution of a named epiphyte on a tree and get students to propose hypotheses to explain and then investigate the distribution.
Look at succession in a woodland floor as the seasons progress from spring to summer.
Investigate the distribution of plants such as Dog's Mercury using transect and quadrat frame techniques. Consider the different modes of nutrition of epiphytes, saprophytes and parasites and get students to research the part played by named species in food chains and webs.