Thursday, March 18, 2010

Ride-Side Sallows

Please stand in silence for the lovely sallows that lined the main ride
of Straits Inclosure, Alice Holt Forest. I counted and graded them last
June, when there were 210 individual sallow bushes, including 127 large
broad-leaved bushes. Last July these bushes hosted a spectacular flight
of iris.

There are now only 61 bushes.

The Forestry Commission needs to resurface this ride to enable it to
support heavy vehicles necessary for extracting timber from the far end
of the wood. The job had been on the cards for several years. The ride
was cut out in 1987 and the new bare edges formed an excellent seed bed
for sallow germination. Many sallows established themselves in the
ditch, which in theory needed cleaning out.

I had discussions with the FC Head Forester about this issue a few years
ago, and felt we had agreed a reasonable compromise, but that
(excellent) forester moved on and no further communication took place,
despite my offers and the fact that the FC office at Alice Holt was
fully aware of the significance of these bushes, the number of Purple
Emperor enthusiasts visiting the wood, and my work. To be fully honest,
though, iris functions within a dynamic matrix that encompasses at least
the whole of Alice Holt, so it is hard for us to be too precious about
one particular part of the matrix at any particular point in time.

The really sad thing is that few of the retained bushes are suitable for
iris, most are on the sunny north side (south-facing) and nearly all
have been over-exposed, whereas the butterfly clearly favours shaded
bushes. Also, most of the 61 have been high pruned and / or are very
spindly. Some people may feel that their retention smacks of tokenism.


Several other tall sallows were removed last autumn, during
sensitively-conducted thinning works in the far end of the wood. We can
assume that other bushes will be removed or damaged during the current
thinning works. Lying on heavy Gault Clay, this is not an easy wood for
timber extraction.

In effect, please do not expect to see iris in any numbers in Straits
Inclosure for at least another ten years. This year they will be very
scarce there.

I've been dealing with the FC at Alice Holt over the issue of ride-side
sallow management since the autumn of 1976 and have made precisely no
progress with them on this matter whatsoever, and neither has any other
body.

From the FC's point of view, the ride-side shrub zone hinders access to
the crop and overhanging bushes present health & safety issues (to
contractors, staff and visitors, especially cyclists and horse riders).
But the real issue is that sallows colonise bare ground, and the only
bare ground that appears in many modern woods is along the ditches. The
challenge is really to re-set this ride edge shrub zone, crucial to
iris, camilla, betulae, etc, back off the ride. To this end three small
bays were cut out along the Straits main ride in the autumn of 2007, and
a few sallow seedlings are appearing there.

Meanwhile, anyone wanting some iris larvae - for whatever purpose -
should search the buds and forks of the lying cut sallows along the
Straits main ride, especially along the shady southern side. Help
yourself.

We need to produce some clear succinct guidance on the management of
sallows for Purple Emperors (and much other - I hate the word but I'll
use it here - biodiversity). Indeed, this is something we can develop
through this website - whether anyone will listen is a different matter,
but at least we can aim to provide accurate information.

In despair,
Matthew

1 comment:

julian.dowding said...

This is outrageous. I picked up the thread on Pete's UK butterflies site which is running an article on the subject and may be worth a view for those that haven't seen it yet. This is dreadful for everyone concerned particularly after the thefts which came earlier.
Fingers crossed for some progress on both fronts.
Julian