A excellent lecture by Prof Brian Legg and Tim Wright of the Heartwood Monitoring Group on the evolution of Hertfordshire's 'new' forest attracted a capacity audience of 90 at Welwyn Civic Centre. For those who missed the Gerald Salisbury Memorial Lecture, a video of the presentations can now be viewed on YouTube.

Tim and Brian not only talked about the remarkable volunteer effort organised by the Woodland Trust that has seen 600,000 native trees and shrubs planted on former arable land near Sandridge, but also a fine selection of the flora and fauna that have been identified there.

Systematic recording tells its own fascinating story of the impact on wildlife as former fields have morphed into wildflower meadows and grasslands. Where planted with saplings, the grassland is –  after 14 years –  gradually turning into woodland as the trees grow.

Butterflies regularly now found at Heartwood range from the smallest UK species, the Small Blue, to the largest, the Purple Emperor. The grassland areas are a stronghold for Red-listed Skylarks. Summer-visiting Willow Warblers, by no means common elsewhere in Hertfordshire, are nesting in the new woodland in significant numbers. Four areas of ancient woodland on the 347-hectare site are home to spectacular native Bluebells and may also house a winter roost of Barbastelle bats.

A final message from the lecture is that while the past 14 years of Heartwood monitoring have witnessed impressive changes, its transformation is far from complete and can be expected to continue for decades to come.

The lecture was jointly organised by HNHS and Welwyn Natural History Society. Warm thanks go to Brian, Tim, and everyone who helped make the event a success.