Now is a key time for the UK's plantations on ancient woodland sites (PAWS) as the timber crops on many of them are reaching maturity and planting and management decisions made now will determine whether or not they retain remnant characteristics of ancient native woodland, an event run by the Woodland Trust, Tilhill Forestry and the Forestry Stewardship Council heard earlier this month.
At Cleobury Coppice, a 50ha privately owned wood in south Shropshire, Woodland Trust ancient woodland restoration project officer Jeremy Evans explained that owners and managers can seek certification for woodlands that bring together economic, environmental and social objectives, and that these need not be in conflict.
Evans, one of 20 advisers covering the trust's priority areas for ancient woodland conservation in the UK, said: "We are looking for four types of features - flora, archaeology, dead wood and the population of trees themselves."
Woodland specialist flora such as spring bulbs provide evidence of continuity and "can spread out again as conditions in the stand change", he explained. "Archaeology" tends to be subtle remnants of former boundary banks or saw pits - "something ancient woodlands are richer in than other land uses", said Evans. "They may only be lumps and bumps in the ground but it's worth putting on the map because it's a link to the past and it shows the wood had a purpose. By marking it, you are saying: 'Please don't drive over this bit.'" More systematically, an aerial LIDAR survey "can give a topographical image of the forest floor", he added.
Dead wood "is key and can be very biologically active in terms of epiphytic growth, though it's not all of equal value", he said. The mix of remnant tree species is also telling. "Native limes, dogwoods and guelder rose are ancient woodland indicators - they aren't often introduced into woodlands."
Tilhill Forestry senior area forestry manager Paul Manley, who has recently taken over management of Cleobury Coppice, said: "This is the wood's first crop of trees, which are 55-60 years old. Before that we know little about it." It has a five-yearly thinning plan with two more cycles to go but still contains pre-plantation oaks "that are a good seed source and like the birches are site-typical - they want to grow here", said Evans.
An adjoining woodland from which western red cedar and western hemlock have already been cleared "is already showing an excellent response", though there has been some conifer regeneration, he added. "The best option is to take these out in one go, otherwise the opportunities created by the change in stand conditions are taken by them."
Evans acknowledged that "deer are a problem, even for the flora" but questioned the merit of kick-starting native tree regrowth on such a site by planting protected saplings. "There are some places where we have spent years with acorns and tubes and got nowhere."
In one area that is "all plantation", there is little specialist flora other than "scraps" of wood sorrel and violet, he pointed out. "Some woodland types aren't teeming with it. If it's not abundant, give the trees a thin and see what the response is." The response of the woodland flora to an unexpected mature windblown spruce "lets you see what would happen if you thinned", he added.
Elsewhere at an adjacent overmature Christmas tree stand, Evans said: "Quite often there just aren't any features. Some stands just wipe out any remnants." In more meagre areas, rather than care for the occasional self-seeded native "your time and money are better spent where there are better-quality features". On the wood's only true ancient tree, he advised: "Put your management resources into important features such as this." Even a wholly dead oak remnant elsewhere "is an important feature and worth keeping, but needs shade to maintain its fungal population".
A windblown goat willow, while not particularly old, "is the only mature one in the wood" and given its potential as habitat for willow and marsh tits "is something I would highlight". Even tree stumps are "better left in place to maintain connectivity with the soil", he added. "I wouldn't flag up one, but a cluster of them I would put in the report."
The wood is among some 220,000ha of certified woodland, including tens of thousands of hectares of PAWS, managed by Tilhill Forestry, explained certification manager Ewan McIntosh. "The quality and management varies dramatically. That's something we are working on. Managers only have so much time so we want to know which are the best ones. In some we won't achieve anything - there are PAWS with Rhododendron ponticum that would take millions of pounds to address."
Discussing an impromptu mountain bike track, he added: "Most Tilhill forests have some level of public access. Recreational activities can't have a negative effect on the rest of the woodland and you have to be able to demonstrate that. If you allow it, it has to be managed and insured. Trying to police it or prevent it gets the wrong response."
Certification - Access to markets and demonstrating best practice
Forest Stewardship Council (FSC) UK forest standards manager Owen Davies gave three reasons to get a woodland certified.
"Commercially, you may want access to a market that demands it, or to get a premium for your wood - though demand varies massively around the country. You may not be a professional forester but want to know you are doing the right thing. Or you may want to demonstrate to third parties that you are employing best practice," he said.
FSC's UK forest management standard is based on UKWAS (the UK Woodland Assurance Standard), a voluntary standard developed by industry and conservation bodies. The current version (UKWAS 3.1) was agreed in March 2012. A simplified UKWAS 4 "is expected to be endorsed by the end of the year".
This simply calls on owners and managers to identify and evaluate features and threats, and prioritise actions "based on threat level". Davies pointed out: "UKWAS doesn't say 'restore PAWS', but you have a duty to retain features."