The felling of trees and scrub is a contentious issue on nature reserves; whether it be plantation pine to restore heathlands or willows and alder on a wetland. Since time immemorial people have had an affinity for trees as they have provided us with shelter, fuel and myriad other benefits.
Nowadays trees are quite rightly appreciated for their aesthetic qualities and their recreational value when they gang together to form woodlands. That they produce oxygen and remove atmospheric carbon is also a notable boon.
Quite apart from the above, trees provide food and homes for our wildlife, so naturally the sight of them being felled in the name of nature conservation can appear somewhat paradoxical.
There are several reasons why we carry out scrub and tree management on Radipole and Lodmoor but chief among them is to preserve reedbeds. The arrival of willows and alder in a reedbed sound the first chimes of their death knell as trees represent ‘successional’ vegetation. Reedbeds by their very nature dry out as each year new stems grow then die back, which over time accumulates as an organic layer - added to by silt deposited by floods. The dryer it gets the better the conditions become for scrub which, if left, hastens the drying through their thirsty roots and leaf drop.
Between 1973 and 1987 scrub cover on Radipole increased from 1ha to 5.5ha due to the processes listed above and who knows what that figure would have risen to if left unchecked?
Reedbeds are a priority habitat because the vast majority of our once vast reedy wetlands have disappeared over the past 200 years due to drainage and reclamation, primarily for agriculture, or have gone unmanaged and become overwhelmed by scrub.
Scrub clearance added to reed cutting and raised summer water levels are, in effect, a means of holding back the sands of time which is of enormous importance to the species of bird, mammal, reptile, amphibian and invertebrate that depend on reed partially or entirely for their survival.
Our policy however, is not of all out tree eradication. We manage scrub along the reed margins and have isolated patches of low scrub within dry reed which is of importance to harvest mice and provides singing perches for Cetti’s and sedge warbler, reed bunting and stone chat. Additionally we have extensive willow carr at the top of Radipole and a diverse thorny copse known as the Secret Garden, which add to the varied mosaic of habitats and add to the biodiversity of the reserve.
Above: As well as degrading reedbeds scrub can act as a predator perch - bad news for fellows like the bearded tit (below) and reed warbler (bottom).
Last Sunday witnessed the inaugural Big Litter Pick at Radipole Lake with staff and volunteers bagging up 50 large bin bags of general rubbish over four productive hours. Added to this tally were two bicycles, various wheels, helmets, a body board, a tent and a safe.
The day was part of the Wild about Weymouth and Portland (WAWAP) initiative, a new partnership project run by the Royal Society for the Protection of Birds, Dorset Wildlife Trust, Natural England, Weymouth and Portland Borough Council, (who kindly collected and disposed of the piles of rubbish) and Dorset County Council. One of WAWAP project goals is to encourage local people and visitors to learn about and enjoy the rich natural environment of the borough.
Among those who helped out for two hours was the Deputy Mayor of Weymouth and Portland Council Graham Winter, who said: “I’m very happy to show my support for this beautiful reserve, which is one of the jewels of the borough.”
As well as being unsightly and potentially polluting, certain items can pose specific danger to our wildlife; for example, the sticky remnants within drinks cans is appealing to mice (harvest, wood and others) which crawl in and become trapped and must suffer an agonising, slow death.
It is proposed that the event will be the first of many which it is hoped can be rolled out into the wider borough. We are all hugely grateful to those who pitched in and helped.
Sorry for the lack of blog action of late; we have been hampered by an IT issue that I can't pretend to understand at all. I hope the following cheery news will make amends...
Last Friday, when stealing my way through dense reedy scrub to access some alders earmarked for the chop, (scrub is cyclically removed from our reedbeds – no need to go into that now) I made a very interesting and historic discovery.
Sallow root plate with (at least partially) excavated burrows amongst the roots.
Amongst the reed and sedge was small and otherwise unprepossessing multi-stemmed sallow with a slightly raised root plate – nothing to get the heart racing there you may think. Sedge and reeds encircling the trunk were flattened as they were along a number of well worn paths towards the river. Another path stretched through the vegetation in the opposite direction towards a pool 50 or so yards away.
An otter path.
The area screamed otter from the outset a fact only confirmed by the presence of large spraints of varying vintages dotting the root system and lending the air a heady fragrence of jasmine - the telltale scent of a good otter spraint.
A typical spraint marking the 'property'. Close examination reveals fish scales and bones - and they really do smell sweetly of Jasmine.
Whether the root plate conceals an underground holt, or just makes a communal ‘couch’ I couldn’t say – I just rattled off these pictures then hastily exited, not wishing to be intrusive.
Interestingly the main trunk of the tree was riddled with holes from the burrowing larvae of lunar hornet clearwing moths, and several of which had been opened up by something intent on consuming the tasty nutritious grubs. All the otterologists I have thus far consulted have not been aware of such activity from otters but I wouldn’t put it past the inquisitive chaps given their keen sense of smell and powerful jaws.
The above clearly showing lunar hornet burrows several of which have been gnawed... but by whom?!
For pictures and more information on clearwing moths click here:
http://ukmoths.org.uk/show.php?bf=371
We received this picture from Rik Nicholls which shows one of our bitterns testing out the path around the buddleia loop. It was taken during the cold snap over Christmas when there were up to 5 Bittern present on the reserve. The structure in the background is the viewing shelter which is usually where you would look for bitterns. I wonder if anyone was in the shelter when the photo was taken?
Since the cold Bitterns have become much less obvious but yesterday evening we held a guided walk to look for them. Everyone had their fingers crossed and it worked! The whole group got great views of 2 Bittern and another was seen whilst we were all looking the other way.
Staff and volunteers in the Visitor Centre have fielded a few queries in recent days about a male pochard (pictured below) with a facial abnormality. Rather than the typical coppery chestnut this individual's head had a muddy colouration - and for good reason...
Ailing pochard? Photograph by Edward Flatters.
Someone offered that it was losing feathers or suffering from a fungal infection. Happily for the pochard and for the concerned visitors the bird was suffering from nothing worse than a mud splattered face. Pochard are diving ducks and grub around in the substrate for tasty morsels - if you watch closely a plume of silt often billows up from the lake bed when they dive. In places Radipole silt is claggy and occasionally they will surface resembling a duck that has just copped a mud pie full in the fizzog.
For comparison below is a male pochard in its fully preened, buffed and blow dried finery. A handsome fellow indeed.