Friday, 26 April 2013

Winter Hymnal

Well the warmth of the breeze and the sounds of the cuckoo are heralds that spring is upon us – better late than never – but before I talk about our springtime work, let me update you on some of the stuff we’ve been doing over the winter.
Winter is of course prime tree felling and scrub clearance time.  Flora and fauna are hibernating below ground and nature lies dormant, making it the ideal time to do any habitat alteration or restoration that may be needed.
We completed a range of projects throughout the winter, all with the help of our countryside volunteers who unfailingly, unflinchingly (well, some flinching when knee deep in icy water) toiled through the snow, wind and rain to get the job done.
In the Long Lash field at Mottisfont we cleared overgrown wet meadow ditches that are a vital habitat for our Biodiversity Action Plan Priority species, the Southern Damselfly.  Up to 25% of the global population of Southern Damselflies occurs in the UK and it is classed as a category 3 Rare species on the Red Data Book list.  These damselflies require the shallow and slow flowing water of wet meadow ditches and streams in order to breed and their numbers have been dramatically reduced in the past by cessation of grazing (grazing animals help keep the water courses open), water abstraction and loss  due to agriculture and forestry practices and nutrient enrichment from agricultural land.
Our work in Long Lash consisted of clearing the overgrown rushes and reeds from alternating 20m sections of bank to halfway across the ditch.  The vegetation was beginning to overgrow the ditches, which results in silt build up and then more vegetation taking root – eventually stopping the flow of water and filling in the ditch.  By clearing alternating sections it meant we allowed the water flow to remain steady and yet left plenty of bankside vegetation for other creatures that thrive here such as water voles.  Cattle will graze the field in order to help keep the ditches open.   After spending snowy winter days in waders in these ditches, I hope the Damselflies reap the benefits!
One of the Long Lash ditches with alternating 20m reed clearance - thats a nice water flow!

Another task we tackled over winter was enhancing and creating wide rides in our woodlands in order to benefit butterfly species as well as contributing to the overall biodiversity of the woodland.  Following a Woodland Management Plan and under the guidance of Geoff our trusty Butterfly Conservation Trust volunteer, we cleared scrub, felled certain trees and swiped out undergrowth to maintain and extend linear rides throughout the woodlands of the estate.  By clearing out some of the undergrowth and canopy of woodland, you allow sun to reach the woodland floor and a resulting carpet of wild flowers and other flora bursts from the soil, where they have lain dormant under the shadow of the canopy.  These sunny, floral rides allow butterflies and other insects to meander through the woodland feasting on light and nectar and so helps spread the range of a species and join up connecting habitats where such species may be found.  An example is that there are Pearl Bordered Fritillaries very near to our woodland estate and such ride work may help tempt them into our woodland.
The rides also benefit other woodland creatures such as our various bat species – the Barbestelle bats use the rides as flight corridors en route to their feeding grounds on the River Test.

One of the rides we opened up in Winter - and check out the explosion of Bluebell foliage!

We have been fighting the good fight against invasive Cherry Laurel and Rhododendron Ponticum by felling the plants, burning them on the spot and chemically treating the stumps to prevent regrowth.  These plants are majorly invasive and incredibly voracious once they take hold in a habitat, as they have nothing to keep them in check – no disease that affects them and no native plant that shades them out.   They grow and spread very quickly via a suckering technique; if you were to cut a stump it would resprout and if you cut a branch and left it lying on the ground it would take root itself and grow another plant.  They shade out all the native flora they grow up around, creating a dead and bare undercanopy that has no wildlife value as no native flora is able to grow and the associated animal species such as caterpillars and Dormice cannot survive without them.   Rhododendron has also been found to carry and spread Phytophthora Ramoran, which causes Sudden Oak Death and is a threat to our native tree species.
Whilst we have won the battle in clearing it from some areas of our woodland this winter, we have yet to win the war and wipe it out completely.  However  Tony, one of our volunteers, is currently mapping all the laurel and rhodi on the estate in order to fix a battle plan for the coming winter….

Now most of us enjoy a cool glass of Gin and Tonic every now and then, and this was in our minds as we carried out clearance work around our Juniper trees on Stockbridge down over the winter.  Juniper is one of only three conifer tree species that are native to Britain (the other 2 being Yew and Scots Pine) and it was one of the first trees to colonise Britain after the last Ice Age (no I don’t mean last winter).  However these days it is having a harder time to survive due to various reasons.  Firstly it is the Giant Panda of the tree world; it isn’t very good at reproducing as it is a dioecious species; meaning it has male and female trees (like Holly and Ash) and as the two sexes could grow distances apart from each other it makes successful pollination more difficult.   Trees have to be at least 8 years old to be mature enough to reproduce and once a seed is produced as berries on the female trees, they take 2 summers to ripen (during which birds will scoff some), up to 2 years to germinate in the ground (while insects and voles have a good gobble at them) and when a seedling does manage to sprout (for which they need bare soil as they are very easily shaded out by grasses) they are prone to being chewed by small mammals.  And if they by some miracle do get beyond infanthood and become a mature Juniper tree they are again at risk of being shaded out by much quicker growing scrub like privet, thorn and Dog wood.
Our Juniper trees on Stockbridge Down are all of a mature age and have been overtaken by scrubby growth that is rapidly shading them out and will kill them off without intervention.  Therefore we have spent time clearing out the privet and thorn by hand – obtaining impressive blackthorn bruising along the way – and I have also been going in amongst the trees with the tractor and swipe creating a ‘halo’ effect around them and free-ing them to the light.  (A swipe is a machine that consists of some heavy chains that spin round at high speed and essentially cut through anything at the ground level, brilliant for clearing scrub up to a certain size)  We have to be wary of clearing too much scrub too quickly from around the Juniper as they can get light shock if they are suddenly open to the light and the elements and this can cause bush collapse.  We have made a fantastic start this winter and I will be monitoring the area to see the effects and continuing the work next winter. (By the way, PlantLife is a fantastic resource to look up for info about Juniper if you want to know more).
Some of our Juniper trees enjoying the sun after our clearance work - this whole area was thorn and privet scrub before.

So there we have it.  A winters worth of work and I haven’t even mentioned the hedgerow restoration, tree planting, coppicing, log processing, scrub clearance on Stockbridge…. The list goes on and I don’t think people’s attention spans will hold for it all.
But if you’re walking through our woods or across Stockbridge Down then keep an eye open for the winter works we’ve done and the result they are having – nature is finally waking up.

No comments:

Post a Comment