THE discovery of human excrement and hypodermic needles has prompted the Yorkshire Dales National Park Authority to issue a clean-up plea.

It says the main litter hotspots are in Wharfedale.

Phil Richards, area ranger for Lower Wharfedale, said: "We have been finding everything from disposable tents and food wrappers to human excrement and hypodermic syringes.

"At Lower Grass Wood, near Grassington, illegal campers have caused significant problems by cutting down trees for fire wood, burning gates and footpath signposts and also leaving vast amounts of rubbish.

"Apart from the problems of having to remove the rubbish, it also has an impact on the wildlife and the landscape, and it's not very nice for other people to see."

Now the national park is urging visitors to take their rubbish home with them and not leave it for others to pick up.

Grass Wood, which is owned and managed by the Woodland Trust - the UK's leading woodland conservation charity - has been a target for illegal camping for some time.

Now the trust and its partners - the national park authority, Grassington Angling Club and the parish council - are looking at various ways to halt the problem, including planting hawthorn at some of the illegal camping areas.

Mr Richards added: "The vast majority of visitors to the national park treat the area with respect, but a minority treat the countryside with total disregard.

"They spoil the very thing they come to enjoy and they have no consideration for others.

"It is not uncommon to remove between 10 and 20 bags of rubbish after a sunny weekend, including beer bottles, cans and disposable barbecues.

"In addition, fires that are started also pose a threat to the woodland and its habitat, especially as the weather warms up and the groundcover gets drier and drier.

"Our message to everyone who comes to this beautiful landscape is that the national park is a special area for all to enjoy and, in order for it to remain so, please treat it with the respect it so much deserves. Leave no trace of your visit when you go."

Woodland Trust spokesman Alistair Nash added: "Woodland fires can cause devastation, with loss of trees, plants and wildlife.

"A fire can spread very quickly, putting people's lives at risk.

"We ask people to be vigilant and take care when enjoying the countryside."