Sunday, 12 January 2014

Ancient Woodlands and Biodiversity Offsetting: what do BSBI members think?

Sanicle Sanicula europaea
Image: I. Denholm
Lots of coverage in the media recently about ancient woodlands, but here at BSBI we like to take an objective look at the evidence.

So what is it about ancient woodlands in particular that has caused both the Woodland Trust and 38 degrees to launch petitions to protect them?

Well, it’s not just about the trees - Miles King makes that point very well here

Any botanist who has carried out Local Wildlife Site surveys for a Wildlife Trust or Local Authority will have entered a wood with a checklist of Ancient Woodland Indicator plants. 

Toothwort Lathraea squamaria
Image: I. Denholm
These lists were the brainchild of George Peterken and Francis Rose, and tell you which plants to look out for in order to find out if the site meets the criteria to be designated as a Local Wildlife Site. 

Ancient Woodland Indicator lists vary according to region, but are likely to include such plants as Toothwort Lathraea squamaria, Herb-Paris Paris quadrifolia and Sanicle Sanicula europaea

Grime et al. (1988) point out that Sanicle “is long-lived, with a half-life of between 59 and 360 years (Inghe & Tamm, 1985). Thus, [it] may live for as long as the trees above it”. 

Image: I. Denholm
This certainly doesn’t mean that all ancient woodlands are teeming with interesting wildflowers, or that all secondary woodland is species-poor – far from it! 

But regarding Bluebells, Grime et al. point out that “In some lowland areas... the species is largely restricted to ancient woodland (Rackham, 1980) and may therefore be declining”. 

If you’d like to know more about ancient woodlands, the works of Prof Oliver Rackham - a BSBI member since 1980 - should be your first port of call. 

In The History of the Countryside (1986), he says “Our historic woods are not mere isolated relics of antiquity, but belong to an unbroken tradition extending through the Middle Ages back to the beginnings of civilization and beyond.”    


Herb-Paris Paris quadrifolia
Image: K. Walker
BSBI President Ian Denholm said “these proposals from the Government conflict with their stated commitment to act on the findings of the recent ‘State of Nature’ report, which documented alarming declines in species (including flowering plants, mammals, birds and insects) that are habitat specialists, dependent on the retention and correct management of long-established tracts of woodland.  I would encourage BSBI members to look at these campaigns and consider adding their support.”

The 38 degrees petition calls on Owen Patterson to “Please stop the proposal under ‘Biodiversity Offsetting’ to allow the destruction of our Ancient Woodlands for building”. 

The Woodland Trust petition is addressed to the Prime Minister, copying in Forestry Minister Dan Rogerson. It begins “I want to see better protection for ancient woodland” and goes on to suggest some options for how to achieve this. It closes by calling for “an open, constructive discussion on these options”.

References:
Grime, J.P., Hodgson, J.G. & Hunt, R. 1988. Comparative Plant Ecology: a functional approach to common British species. London: Unwin Hyman
Rackham, O.1986. The history of the countryside. London: J.M. Dent