Posted: 29/01/2014 at 08:01
From it's shape and the fact that it's flowering at the moment I suspect that the cherry may be the lovely Prunus subhirtilla autumnalis - there are pink and white versions. http://www.crocus.co.uk/plants/_/prunus--subhirtella-autumnalis-rosea/classid.4651/ - an ornamental rather than a fruiting variety and absolutely gorgeous. Frequently used as a specimen tree in a lawn.
I agree with Welsh Onion that the red-leaved tree looks more like something ornamental rather than an orchard variety.
Not sure about the third 'pear' tree.
What is certain is that Bob is absolutely right - clear the land around them, feed and mulch and give them a chance to recover from being starved - if things don't improve in a couple of years then it may be time to replace them. Photos of blossom may help us with identification later in the year