大象传媒

Alan Titchmarsh is in Ireland, contemplating Britain's first plant life. Lichens, for example, are made up of two distinct organisms: a funga and an alga that depend on each other for their survival. The alga provides food for the fungus and the fungus provides shelter for the alga which means they do not need soil to grow and that rocks can nurture life. In more sheltered spots where there is just enough soil for them to cling to, more complex plants were able to take hold like the spiny burnett rose and the hardy geranium that is the bloody cranesbill. As these first plants died they decayed and began to enrich what little soil there was. More seeds would then grow in and gradually plant colonisation gained momentum.