The wooded area of Vann Lake is a particularly fine example of ancient woodland on Weald Clay surrounding an 8 acre lake and is a designated a Site of Special Scientific Interest.
The origins and date of the lake and dam are unclear. The most likely theory is that in the 18th century the reservoir was built to power a proposed linen mill that was never built.
Several different habitats can be found at Vann Lake including both wet and dry woodland and open water. Around the lake alder trees dominate the damp areas and oak the drier parts, with lime, birch, ash, hazel and beech interspersed between. The site is rich in invertebrates. Other typical woodland butterflies found here include the purple emperor, white admiral and silver-washed fritillary.
In total about 110 bird species have been recorded at the reserve.
Away from the lake the woodland ground flora is particularly rich, supporting a large number of interesting flowering plants: bluebell, snowdrops, primroses and a number of orchids such as the early purple, common spotted and greater butterfly orchid.
Vann Lake is one of the best sites in the country for fungi and the reserve has been studied in detail by mycologists from Kew since 1971. During that time a number of endangered species have been recorded, as well as many new species to Britain and one new to science. To date in excess of 770 fungi species have been identified.
Like much of the woodland in Surrey active management has declined since the 1940s although the Trust is now working in many areas of the woodland to being them back into a traditional hazel coppice regime. This involves coppicing the existing hazel, removing some of the ash and birch and replanting with hazel.
See other images of Vann Lake and Candy's Copse Reserve