Heaven for insects as autumn revives the Heath’s vitality

Blackberries on Hampstead Heath. Picture: Polly Hancock (Image: Archant)

The end of the growing season also provides us with delightful displays of fruits, standing dead stems, seeds and seed heads. These are vital food sources for wintering birds and small mammals.

Many invertebrates will feed on these dead plants and seeds, with many also seeking a winter refuge in the hollow stems.

Dead stems tend to remain drier and less prone to rot causing fungi than if they were lying on the wet soil. Being physically hard also provides a defence against predators and the unforgiving elements.

A wide range of common and often overlooked plant species on the Heath are critical in these overwintering strategies, including those ubiquitous thistles, teasels, knapweeds and blackberry bushes.

As autumn begins on Hampstead Heath, fallen wood can house insects over the winter months. Picture: Polly Hancock (Image: Archant)

Biologically the Heath is an incredibly dynamic place.

If no conservation management were to occur, most of the site would quickly revert to woodland and the character of the landscape would gradually be lost through this process – known as natural succession.

A lack of continuity of these varied habitats would also eventually lead to a decline in overall species diversity.

It would prove impossible to remove the annual growth from each individual plant and tree each year, so through sympathetic, judicious, and targeted management, we aim to ensure the Heath retains a balanced mosaic of open grassland, woodland, heathland and wetland.

This inevitably means much of the conservation work involves clearing plant material. We are mindful of the importance of micro-habitats, and as a result we use this surplus material to create habitat piles.

We try to leave piles elevated, and placed in dappled shade (so they are neither baked by the sun nor too damp) and we carefully stack and cut them to leave open stem ends for invertebrates.

Often, these habitat piles are misleadingly referred to as “dead wood”.

In fact, when correctly placed, the dead wood really becomes alive once again as it is colonised by birds, small mammals, invertebrates and fungi.