I don't know if there is any legal distinction between the two but you might get away with just using Woodland - this may be considered scondary to a Forest. You might also be able to use the word 'Copse' which is used in the UK to describe a small area of trees surrounded by, and often fenced off from, an field.


Woodland

Ecologically, a woodland is an area covered in trees, differentiated from a forest. In these terms, a forest has a largely closed canopy – the branches and foliage of trees interlock overhead to provide extensive and nearly continuous shade. A woodland, on the other hand, allows sunlight to penetrate between the trees, limiting shade. Woodlands may support an understory of shrubs and herbaceous plants (often including grasses). Woodlands may form a transition to shrublands under drier conditions.

Woodland is used in British woodland management to mean any smaller area covered in trees, however dense. (Forest is usually used in the British Isles only for more extensive wooded areas, again however dense – and also including Royal forests, which may not be wooded at all). The term Ancient Woodland is used in British nature conservation to refer to any wooded land established for a very long period (equivalent to the American term old growth forest).

COPSE
A copse is an English term for a small lowland woodland. It is often used as a part of a place name, for example Borthwood Copse on the Isle of Wight, or Moor Copse near Tidmarsh.

The term is derived from the similar and linked word coppice. Most woodlands which have copse as a part of their name were probably coppiced once, but this does not mean that the practice continues today, as it was once a lot more popular than it is now. As coppicing was mostly practiced in lowland England, this is the area where use of the word is most common.

However, the word has entered the language as a term simply meaning a small woodland, and perhaps implying some rustic overtones, and so it is occasionally given to new woodlands or applied to areas which have no connection with coppicing.



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Note added at 12 hrs (2009-02-11 09:49:10 GMT)
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BTW: This is how it would be used in the area where I live:
However, the word has entered the language as a term simply meaning a small woodland, and perhaps implying some rustic overtones, and so it is occasionally given to new woodlands or applied to areas which have no connection with coppicing.