Walking across chalk grassland high in the Chilterns, I stop to enjoy the haze of fresh green leaves on distant hedgerows, and a bright yellow brimstone butterfly flutters past me. Thanks to the April showers, spring has finally arrived!

Local wildlife sites I am visiting one of the hidden treasures of Oxfordshire, a Local Wildlife Site where some of Britain’s rarest species can still thrive. The chalk grassland of the Chilterns is a species-rich habitat renowned for delicate wild flowers such as gentians and harebells, and where marbled white and small blue butterflies flit across the short turf. Since the Second World War, 80 per cent of this unique habitat has been destroyed due to intensive farming, mismanagement and development pressure, and this threatens the vulnerable wildlife that depend on these grassland areas for their survival.

There are almost 400 Local Wildlife Sites dotted across the county, which together account for more than 5,500ha of countryside.

Although not a statutory designation like the legally protected Sites of Special Scientific Interest (SSSIs), they are often of comparable quality and represent some of Oxfordshire’s most pristine and important natural habitats, many of them recognised through UK Biodiversity Action Plans.

They include ancient beech woodlands, Thames-side meadows and Cotswold limestone grassland, but few people are aware they exist. Most Local Wildlife Sites are privately owned with little or no public access although some, like Farmoor Reservoir, can be enjoyed by everyone. I may be biased, but these diverse and often secret wildlife havens are, in my opinion, collectively some of the most important sites for wildlife conservation in Britain.

Thanks to landowners The Oxfordshire Local Wildlife Sites Project was set up with the aim of protecting and restoring Oxfordshire’s vulnerable Local Wildlife Sites and, through a process of survey and assessment, to identify the best quality sites for wildlife. And it is the landowners in Oxfordshire who we have to thank for the current state of our Local Wildlife Sites. Without careful and sensitive management, valuable and often fragile habitats such as Magdalen College’s water meadows, where this week you’re likely to see the snake’s-head fritillaries in full flower, would not be here at all.

Sadly, however, there is always a risk of Local Wildlife Sites becoming neglected. Changes in ownership or the way land is managed (or not managed) can have adverse impacts on these areas. It’s my job to visit landowners offering advice and support to help ensure the long-term future of all the remaining sites by recommending suitable management techniques such as creating nectar blocks of wild arable flowers for butterflies and moths, which in turn benefit local bat populations.

Landscape scale Protecting specific sites is one thing, but wildlife does not recognise boundary lines on a map, and the importance of landscape-scale conservation is becoming more apparent. Local Wildlife Sites are fundamental in supporting legally protected areas to form vital links across the county and beyond, creating a national network of habitats.

And that’s why I’ve been walking on a sun-soaked Chiltern hillside, discussing the best management options for a site which supports some of the UK’s most endangered wildflowers.

Gazing across the landscape below me, it strikes me again how important sites like this are. It may be relatively small but it provides a crucial wildlife refuge, and together with other such sites, helps species to spread further afield. To find out more about the Berks, Bucks & Oxon Wildlife Trust visit www.bbowt.org.uk/what-we-do