Showcasing our reserves part two - guest post from Patrick Cashman

In the second post showcasing our reserves, Patrick Cashman talks about how nature can recover, given a helping hand...

Collectively, RSPB nature reserves make a significant contribution to preserving some of the UK’s best natural sites, habitats and landscapes. 

However, as seminal documents like the State of Nature report remind us, nature is in deep trouble and much of our natural heritage has been worn away, rather like a threadbare carpet. In some areas you can, thankfully, still determine the pattern, so protecting and enhancing what remains is a clear priority.

Putting it back

But in areas where the pattern has worn away completely, you have to start putting it back. When recreating lost landscapes, this means managing the land not for what you have today, but what you’d like tomorrow. In other words you have to start again.

In 2005, the RSPB bought an arable farm at Winterbourne Downs, in Wiltshire, on which to recreate chalk grassland. Where there was once a blanket of cereal crops, we wanted to see a carpet of wild flowers.

The reserve lies between Porton Down and Salisbury Plain, the largest remaining expanses of chalk grassland in the UK, and it is intended to be a stepping stone to enable species to move through the landscape.

We’ve harvested seed from Salisbury Plain and other chalk grassland sites to convert cereal fields into chalk grassland. It’s worked really well and there are now beautiful meadows, buzzing with insects and gloriously colourful with flowers.

The flatness of the heavily-tilled former arable fields meant that the micro-climatic conditions across the site were too similar, inhibiting variety.

For example, butterflies can be very sensitive to small changes in temperature so creating varied conditions would give the reserve lots of options for butterflies throughout the day and the season. Creating variety is also one of the ways we can help make sites resilient to climate change.

To solve this problem we came up with the idea of big butterfly banks. Working with Butterfly Conservation we designed and built two large curved banks, formed from the underlying chalk, snaking across the site, providing areas which would warm up throughout day.

A blizzard of butterflies

The bare chalk on the banks has also made great conditions for specialist chalk-grassland plants. You can read more about how the banks work in our Winterbourne Downs showcase.

It really came home to me that the banks were working when we were looking at them on the hottest day of the year so far. The main insect activity had moved to the cooler shadier area, the opposite of what I see on a typical British summer day!

It’s been a good year for butterflies at Winterbourne Downs, especially small tortoiseshells and the chequerboard marbled whites.

The most notable sight has been the blizzard of hundreds of small blue butterflies on the wing, a target chalk grassland specialist and Britain’s smallest resident butterfly, with some now over two kilometres away from their original colony and many using the new big banks.

On one of our “Bug hunt and meadow safari” public events we discovered an even more significant species: a six-belted clearwing. This harmless and nationally-scarce moth, with its ‘clear’ wings, mimics a bee.

Orchids have really benefited from our management and several varieties have been increasing in number and spreading across the reserve.

This year we were really pleased to find 70 pyramidal orchids and six fragrant orchids on areas of relict grassland, and green-winged and common-spotted orchids on fields that were under cultivation just a few years ago.

Finally, we manage Winterbourne Downs for the stone-curlew as well as chalk grassland habitat. Since we have been managing the reserve, stone-curlew numbers have increased from zero and we now have five pairs regularly nesting.

Nature has amazing powers of recovery when you give it a helping hand.