On Thursday 15th September at the Victoria Hall in Tisbury High Street, starting at 19:30, we shall hear from Dr Ed Treasure of Wessex Archaeology who will talk to us on "Rewilding Archaeology".
A moment’s silence will be held at the start of the meeting as a mark of respect for the late Queen Elizabeth ll.
If you haven't already signed up to the talk and want to come, please let us know via the Contact form. We can also send out Zoom links for those who prefer to stay at home. Guests are welcome for £2 per ticket.
We have an update to our Talks listing with Dr. Ed Treasure of Wessex Archaeology, Salisbury sharing his specialist work in the analysis of environmental evidence.
Rewilding is a form of ecosystem management that has arisen out of our need to conserve biodiversity and work towards a more sustainable future. It refers to the repair or restoration of ecosystem services through the introduction, or rather re-introduction, of selected species and allowing nature to take its course.
Rewilding is not without controversy – how do we define appropriate restoration baselines? What species should we conserve, which should we remove and which should we reintroduce? What timescale are we working with and how big should our projects be? How do we establish appropriate management strategies? How effective can rewilding be in human dominated landscapes that have been shaped by millennia of farming?
This talk will show how archaeological and palaeoecological datasets can be used to inform rewilding processes and conservation management. Archaeologists, and researchers in related areas, can provide unique long-term perspectives on changes to the environment, and crucially provide information on factors which have shaped present-day biodiversity patterns – we can place conservation management practices within a wider historical and ecological framework, by understanding the relationship between past vegetation changes and human impacts on past environments.
If you haven't already signed up to the talk at the Victoria Hall, Tisbury and want to come, please either reply to the Treasurer's email sent out on 28th August or let us know via the Contact form. We can also send out Zoom links for those who prefer to stay at home. Guests welcome for £2 per ticket.
We have made a change to the listing for the 20th October 2022 talk due to diary conflicts and we are pleased to welcome back Leif Bersweden with a talk called "Where the Wild Flowers Grow: my botanical journey through Britain and Ireland".
Leif Bersweden (who talked to us in 2018 about his search for all the orchids native to these islands) will tell us about his latest botanical adventure as he botanised his way through another calendar year, the joy he finds in engaging with nature, the importance of plants for our climate and our unbelievable botanical diversity.
We look forward to hearing Peter Thompson's talk on the "Bats along the River Nadder" at a later date.
Dr. Peter Inness from the Meteorology Department of Reading University opened this fascinating talk, the last in our 2021/22 series of indoor meetings, with two images of the same patch of woodland near his Oxfordshire home taken two years apart to the day. In the first, the forest floor was carpeted with bluebells; in the second merely a green carpet with a few unopened bluebell buds visible. This was one of several illustrations he used to show how short term changes in weather can impact the natural world, as he sought to distinguish this variability from longer term trends.
In her recent PhD thesis a student at Reading had used data collected by volunteers across the British Isles (recorded on the Natures Calendar website managed by the Woodland Trust) to show that across the UK the mean first flower date for bluebells was 1st of May in 2013, but 8th April in 2017, fully three weeks earlier.
Dr Inness was able to explain this difference reflected short term climate impacts, rather than long term trends. Data for bluebell first-flowering dates and temperature records for January to April in successive years show that bluebell flowering dates respond to the weather and temperature conditions during March, February and January, as the plant stems emerge and the flower buds form, rather than during the flowering period itself. And, though invertebrates react rather more rapidly than plants, similar analyses for the first appearance of orange tip butterflies and for blue tits nesting reached similar conclusions.
In 2021, by contrast, hawthorn blossom appeared a whole month later than normal, reflecting an abnormally frosty April.
Looking at longer term trends and the impact of climate change, however, Dr Inness referred to the paper published recently by the Royal Society. This used records on 406 plant species, some dating from as far back as the 18th century, to show a marked shift that took place in the 1980s. Plants are now emerging on average a whole month earlier each year than seventy years ago.
He showed projections prepared by the Meteorological office to indicate that by 2050, in every other year we will experience summer temperatures similar to those we experienced in the very hot year of 2018. And, unless significant reductions in greenhouse gas emissions are achieved globally, these temperatures will be the annual norm by the end of the century. And he also showed projected rainfall maps clearly showing that our winters will be wetter and summers dryer, and warned that individual rainfall events will be 29% stronger. A new UK record for of 316mm rain in a 24 hour period, set as recently as 2009, was surpassed again only six years later in 2015 with a new record of 341mm. All of which suggests that nationally there are considerable tasks and costs ahead to prepare reservoirs and infrastructure to be able to cope.
From a wildlife perspective these climate trends are complex and deeply concerning. Dr Inness gave as examples the likely impact on the relatively shallow root systems of beech trees, less well adapted to cope with summer drought conditions than deeper rooted oaks. And the impact on populations of birds such as swallows whose northerly migrations are triggered by seasonal changes in daylight hours. They may arrive at European destinations too late to feed their young on invertebrates maturing earlier as a result of warmer Spring conditions.
Troubling as these issues are, the talk was hugely valuable and timely, providing us all with deeper insight into the impact weather and climate have on the natural world around us.
by Richard Budden
Dr Peter Inness, a lecturer in the Meteorology Department of Reading University, is coming to give us a talk at the Victoria Hall, Tisbury this coming Thursday at 7:30pm. Please note that we had thought it would be earlier due to travel arrangements, but Pete is able to start at our usual time of 7:30pm.
As the author of "Teach yourself weather" and series editor for a new series of academic textbooks on Weather and Climate Science for Wiley-Blackwell, Pete will have plenty of knowledge to share.
If you haven't already signed up to the talk and want to come, please let us know via the Contact form. We can also send out Zoom links for those who prefer to stay at home. Guests welcome for £2 per ticket.
Slugs and snails have a true champion in Imogen Cavadino, an entomologist who is carrying out research for the RHS. We were treated to a wealth of information with up-close-and-personal photography of these oft-maligned creatures.
Slugs evolved from snails as they simplified their coiled shells and diverged into different families. There’s even such a thing as a semi-slug, one that can’t retract into the shell it carries on top. Some slug species still have a visible pale mantle under the surface, marking their vestigial shell which serves as storage for calcium salts.
The majority of snails have shells which coil to the right, developing asymmetrically via torsion, so that both their respiratory pore and anus end up on the right side of their heads. They are so dependent on moisture that if deprived, they can create an epiphragm to seal themselves in and succumb to a dormant state. Quick to revive if the conditions improve, Imogen told us that a snail was once stuck on a postcard as an exhibit in the British Museum (before they knew about their dormancy behaviour) and stunned everyone by making an escape.
For a researcher, the slime colour can be useful for identifying the species. Slugs produce two types of mucus for defence and movement. We heard that the netted field slug (deroceras reticulatum - above on the left) is the most harmful to our agricultural activities, making a feast of root vegetables in the autumn, but the cellar slugs (Limacus sp. - on the right) feed on rotting material, fungi, lichens and algae and are therefore blameless.
The Royal Horticultural Society (RHS) has been campaigning, with Imogen heavily involved with their media activity, to dispel the myths that all slugs are enemies of the gardener. The last big slug survey was done in the 1940s and the RHS’ recent research has been aided by a formal survey conducted by 60 chosen participants around the country, who performed scheduled slug counts, with the glorious total of 21,000 slugs collected and identified in one year.
They discovered that non-native species were becoming more dominant, no doubt hitching rides on plants from other countries. New varieties are also being discovered, like the ghost slug (Selenochlamys ysbryda - above centre) with no eyes, first identified in Wales in 2014.
Finally, that all important question – how do you euthanise a slug? Obviously, only the types which are eating your veg – please identify them first! The most ethical way is to put them in a sealed container and place in the freezer. Or if you are wanting to maintain their colours for identification purposes, you can drown them in carbonated spring water.
On a more positive note, the RHS welcomes recordings from anyone who wants to get involved. You will find information from Imogen on our Wildlife Recording page, about helping to record slug and snail activity.
At 7:30 pm this coming Thursday in the Victoria Hall, Imogen Cavadino is coming to share her knowledge about slugs and snails.
Imogen is an entomologist currently carrying out research funded by the Royal Horticultural Society (RHS) to help in identifying their species, and to discover which ones are responsible for damaging plants, whether in gardens, on farmland or in the wild.
She aims to inform pest management strategies so that only those slugs and snails that are actually damaging plants are targeted, reducing control costs as well as potential harm to other wildlife.
Mark Elliott of the Devon Wildlife Trust gave a fascinating talk to the Society’s February meeting on the reintroduction of beavers into the UK, based on his experience as leader of the Trust’s project on the River Otter in south Devon.
As he explained, beavers are a species native to Britain that were hunted to extinction roughly 400 years ago. As they are no longer regarded as ‘ordinarily resident’ they can only be released into the countryside with a licence; but things are changing now, as a result of the success of the Devon trials. Last August DEFRA confirmed that the River Otters trial had been sufficiently successful for the beavers to stay indefinitely, and support will now be provided for similar managed projects elsewhere.
This outcome could not have been foreseen at the start of the Devon programme back in 2015. Mark showed us how these semi-aquatic rodents had interacted with the environment on the Otter, showing how the population had grown and migrated along the river catchment over the period since then. From two founding family groups the number had grown to around 13 territories in 2019.
At the outset Mark dispelled the popular misconception beavers eat fish; they are strict vegetarians. And he showed the results of work carried out by the Universities of Exeter and Southampton to measure the beaver’s impacts on fish and other wildlife. The increased variety of habitats that result from the beavers’ dams (that periodically get washed away and then rebuilt) have led to enhanced fish populations of all types and sizes, and the wetlands that result are ideal breeding and feeding grounds for frogs and for wildfowl.
The water storage capacity of the river catchment has increased, and water quality downstream has improved, with lower levels of sediment, nitrogen and phosphorus downstream of the beavers than in the upstream input, and an increase in the concentration of dissolved carbon.
He didn’t disguise occasional problems that have resulted from damage to crops of sweetcorn and flooding of adjacent grazing land, but showed how these can be managed effectively.
Overall the experience in Devon is that the beavers are popular and, if the initial introduction is managed wisely, can exist alongside the human population to provide benefits to our environment.
You can read more about the Devon beaver population and Mark Elliott’s ongoing work by visiting: www.devonwildlifetrust.org/what-we-do/our-projects/river-otter-beaver-trial
Our 40th Annual General Meeting starts at 7:00pm in the Victoria Hall, Tisbury. All are welcome to attend.
The talk starts at 7:30pm. If you haven't already signed up to the talk and want to come, please let us know via the Contact form. We can also send out Zoom links for those who prefer to stay at home. Guests welcome for £2 per ticket.
Our speaker, Mark Elliott heads the project being carried on by Devon Wildlife Trust on the River Otter that has led beaver conservation in the UK for more than ten years.
He will be able to describe their work, what we have learned as a result about this amazing animal, how they can benefit us and the landscape around us, and how we can manage potential conflicts with land owners and residents.
Photo credit: Eurasian beaver (Castor fiber). Per Harald Olsen, CC BY-SA 3.0 via Wikimedia Commons
Bob Gibbons gave us a marvellous talk last week, illustrated with his own spectacular photographs of some of the fascinating species found in Purbeck. Explaining that a great percentage of the area is subject to national and international designations because of the habitats and wildlife found there, he suggested that it is possibly the most wildlife rich area in the UK if not Europe.
The appellation “Island” is thought to have come from earlier times when the marshes of the Piddle and Frome valleys to the northwest combined with Poole harbour to partially cut the area off.
Of particular value is the way the mosaic of habitats grade into each other over large areas without hard boundaries. Another factor which explains the great diversity of species is the poor quality of the soil – either inherently poor podzols of the heaths or the chalk and limestone soils which have been impoverished by centuries of grazing. These poor soils made agriculture difficult which held back development as did the “Island’s” status as a hunting forest and this allowed wildlife to survive into the present era.
As a result of an unusually complex underlying geology the area holds many habitats within a relatively small area: heaths, bogs, chalk downs, limestone grassland, Poole Harbour and its islands, commons, coastal cliffs, and dunes. The only thing in short supply is natural broad-leafed woodland.
Another crucial reason for Purbeck’s uniqueness is its position in the centre of our south coast where it enjoys lots of sunshine. It is as sunny as areas further east and warms up in spring as quickly as areas further to west. This seems to result in it being in a “sweet spot” which has produced an amazing assemblage of species, including many on the edge of their range. As a result, in Purbeck you may find species more usually seen in Cornwall alongside others more usually seen in Sussex, and it is a stronghold for many species, particularly insects.
I suspect many who enjoyed Bob’s talk and photos will be planning a visit to Purbeck this summer. The Society is planning a trip to Tyneham in July.
Photo: Barn owl
The headers display photos taken by our members. Do get in touch via the Contact Form if you'd like to submit a photo for selection.