Noticed your comment about Monks Wood and culling issues.
The BDS have been involved with a long term study at Wytham woods - the resulting data has been of great interest to those who may need to justify/plan deer control - especially relating to Muntjac/Fallow probs.
The following links will give you a chunks of ammunition in formulating and referencing the need for control of Deer numbers in woodland. Highlights the detrimental effects of unchecked deer access on other animals/flora that a Wildlife trust may be trying to encourage in a balanced biotope.
Contact Stephen for info - very authoratative! firstname.lastname@example.org
Now, the Woodland Trust's viewpoint on deer - NOTE that venison income is NOT a factor they consider, likewise, they do NOT allow sporting shooting - so any mention of paying clients is not likely to be in your interest!!
Put the two loads of info together - you should be able to forward a watertight case for management, while allowing the Trustees to cover their collective backs in authorizing action!