Ryan, we investigated this.
If you want to leave a caravan on site permanently you need to apply for a Caravan Site Licence, no matter where it is and that is granted under planning permission. Otherwise there'd be caravans lying around all over wherever people fancied living.
Your arguments could be a) you want to live there or b) you want to run a holiday site and the planners would probably not let you do either.
Even with the 28 day leisure rule you can't leave it there permanently without a Caravan Site Licence even though you'd only use it for no more than 28 days, if you see what I mean. If you're not there, then it can't be there. You'd not get away with saying you were just 'storing' it on your property either becasue you can only do that on a private main residence.
You may be able to keep it on there for 'forestry' purposes, but again it can't be there all year round and even then unless you are there working enough to justify it and your wood is large enough to justify it then they will make you shift it.
Remember the planner's MANTRA - "no-one is allowed to live in the woods".
I have a small caravan on our site and the planners have said it must be gone by later in the year, I even had to send through a forest management plan and details of a FC meeting I had before they'd give an inch.
Fair enough really, it's a wood not a caravan park, and a caravan looks out of place even though it's well hidden. I'll take it off for the winter, but I'll need to make the case again next year and show that I achived what I said I needed it for if I want it back on site - but it's so much hassle I don't think I'll bother.
I might just dig a hobbit style burrow deep in the trees.
Just joined and I'm posting a lot, must look like a right know it all!