TV botanist and green campaigner Professor David Bellamy will be among the key speakers at a big environmental conference in North Yorkshire.

This year's Association of National Park Authorities' Conference is being hosted by the Yorkshire Dales. It is taking the theme of the "enterprising environment".

About 300 delegates from the country's 11 national parks are taking part in the conference. Other speakers at the event in Skipton include Environment Minister Chris Mullin.

The theme has been designed to test how far park authorities can push the limits of their economic and social duty to local communities, while pursuing the national park purposes of conserving, enhancing and promoting their special qualities.

The association's general secretary, Professor Ian Mercer, said: "We will be looking at the role national park authorities can play in being better agents for change in remote rural environments and communities, and how we can help deliver thriving and vibrant areas for visitors and residents."