Varieties of Leaves

Leaves are the powerhouses of the hedgerow ecosystem, fixing the energy that everything depends on.  Although many are superficially similar, each species of plant has distinctive leaves reflecting their different evolutionary histories and the ecological pressures that have driven their evolution.

The identification of hedgerow shrubs and trees and other plants growing in a hedgerow provides an excellent starting point for the development of some basic plant identification skills.  Students quickly gain confidence and satisfaction from learning to identify the common plants that dominate our landscape, and can be encouraged to  develop the skills needed to observe organisms more closely to pick out key features.

Leaves may all look the same to start with but easily recognised differences between them allow most hedgerow plants to be identified to species.  Guides such as those available through SAPS or in the AIDGAP series are invaluable in pointing out the features that separate species from one another.  It is also possible to identify winter twigs to species, so that hedgerow field work can take place at any time of the year.

The number of shrubs that make up a hedge is an important attribute of the hedgerow and has been used in the past to distinguish older from newer hedgerows. Older hedgerows were thought to gain woody species at the rate of one per century, but recent planting schemes have encouraged the planting of new hedges with a high diversity of native shrubs and trees, so diversity is now no longer a reliable guide to age. It is, however, likely that a more diverse hedge will house a greater diversity of invertebrates and other animals – certainly something worth investigating with an enthusiastic class.