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Five years have elapsed since the translocation of a population of the dingy skipper Erynnis tages was completed at Summit Colliery in Kirkby-in-Ashfield, Nottinghamshire. Monitoring has indicated that the project has succeeded way beyond expectations and has provided the population with a long-term future in the local area and numbers are such that expansion into new habitats beyond the existing range will very likely occur in the future.

Following demolition of the Summit headstock and colliery infrastructure, the site was left untouched for many years and in that time the botanical and invertebrate interest had developed sufficiently to meet the criteria to be designated as a Local Wildlife Site. The designation of the site created a problem, because the site was previously allocated by the local authority, following the demolition, as employment land. Following cessation of coal mining, the site was returned to Welbeck Estates who were seeking to re-develop the site to provide employment opportunities in the local area.

Survey of the site in support of a planning application, confirmed the botanical interest of the site with a variety of grassland species including common spotted orchid Dactylorhiza fuchsii and bee orchid Ophrys apifera. Invertebrates surveys revealed the presence of a range of butterfly species including a small population of dingy skipper, which is uncommon in Nottinghamshire. Consultees including Nottinghamshire Wildlife Trust (NWT) objected to the development, because of the site’s designation and the potential impact on biodiversity.

Baker Consultants were commissioned by Welbeck Estates to negotiate with the relevant stakeholders such as NWT to resolve the issue and to provide a long-term sustainable solution that would protect botanical diversity, maintain the conservation status of dingy skipper and enable re-development of the site.

The solution was based on the premise that not all of the site was of botanical and/or invertebrate interest and alternative land with low ecological value was available in the local area to modify and create bespoke habitat for butterflies and plants. Detailed method statements were prepared and the consultees were satisfied that the solution was sustainable and compliant with local and national planning policies for biodiversity.

Baker Consultants in-house ecologists had the necessary expertise to prepare land to create species-rich grasslands within the Summit Colliery site and on a nearby former colliery spoil tip, which had been part-cleared of immature plantation woodland (a mix of Swedish whitebeam Sorbus intermedia , Scots pine Pinus sylvestris and grey alder Alnus incana). The grasslands were created using translocated materials including orchid-rich turf with the remaining areas being hydro-seeded with a grassland seed-mix containing larval and adult food plants for the butterfly species recorded on the site.

New off-site butterfly bank

The translocation of dingy skipper larvae and the creation of specific habitat was carried out by Mike Slater (Chairman of the Warwickshire Branch of Butterfly Conservation). Mike was invited to help, because of his expertise with habitat creation for dingy skipper, specifically the creation of butterfly banks. Mike surveyed the site, identified locations containing the larvae, supervised the creation of the butterfly banks and the translocation of the turf containing the larvae. The turfs were carefully positioned into the butterfly banks and the banks were modified at the micro-scale to provide the exacting conditions required by dingy skipper eggs and larvae.

The care and attention to detail has proved to be worthwhile. The translocated grasslands and hydro-seeded grasslands are thriving and the few losses of plant species has been restricted to non-native garden plants. Monitoring of the dingy skipper populations provided encouraging results from the outset and the results of the 2016 monitoring indicated a minimum population size increase of 350% in the created habitats when compared to the baseline in the original habitats. The final monitoring in 2018 of adult butterflies only, indicated that the increase in population size has been sustained.

 

Translocated and sown species-rich grassland at Summit Colliery

Half of the former Summit Colliery site has been developed with two areas allocated for biodiversity that will continue to be managed for plants and butterflies. The off-site land is connected to a larger area of Local Wildlife Site grassland that also supports dingy skipper; all of which will be sustainably managed.

The expertise provided by Butterfly Conservation and willingness of Welbeck Estates, supported by Baker Consultants enabled a sustainable long-term solution to be developed that is compliant with planning policy.

 

 Hydro-seeded off-site grassland

 

A review of evidence published in the Journal of Ecology (as recently reported by BBC News,) has concluded that the ash tree is likely to be wiped out in Europe. A fungal disease known as ash-dieback (or Chalara) and the spread of an invasive beetle (the emerald ash borer) are killing off ash trees across Europe; although the beetle has not yet reached UK shores. It is believed that the impact of ash-dieback could mirror that of Dutch elm disease, which largely wiped out elm trees in the 1980s.

UK woodland by Carlos Abrahams, Technical Director

UK woodland by Carlos Abrahams, Technical Director

Ash-dieback

Ash-dieback is caused by the fungus Hymenoscyphus fraxineus, which kills the leaves, then the branches, trunk and eventually the whole tree. It is believed to have the potential to destroy 95% of ash trees in the UK. 

Ash dieback was first seen in Eastern Europe in 1992 and now affects more than 2 million square kilometres across Europe. Since being first identified in England in 2012 in a consignment of imported infected trees, it has since spread from Norfolk and Suffolk to South Wales.

The emerald ash borer

The emerald ash borer is a bright green beetle native to Asia. The beetle hasn’t yet reached the UK, but is currently spreading west from Moscow at a rate of 25 miles (41 km) a year. It is thought to have reached Sweden. Although the adult beetles feed on ash trees, they cause little damage. It is their larvae that kill ash trees, by boring under the bark into the wood.

The impact

If ash trees are wiped out in the UK, research from the Journal of Ecology indicates that the UK countryside will be changed forever. Ash is the second most common woodland tree in the UK, second only to the oak, and our towns and cities have 2.2 million ash trees in and around them. Furthermore, loss of ash trees won’t just change our landscape, but will have a severe impact on biodiversity. There are 1,000 species associated with ash or ash woodland, including 12 types of bird, 55 mammals and 239 invertebrates.

Our view

This is a highly complex issue, and we at Baker Consultants keenly follow research developments, such as that in the Journal of Ecology. Harnessing our collective decades of botany experience, our view is that ash will no doubt significantly decline, but that UK extinction is unlikely if the disease follows the usual epidemiology route. This is partly because in Northern Europe many of the ash tree populations are of a very narrow gene pool owing to decimation during the two World Wars and planting of replacements. In the UK, we have a wider gene pool of ash, which increases the likelihood of resistance of certain types of ash to ash-dieback. For this reason, some botanists, including ours, think that UK native ash has a better chance of survival than European strains due to this genetic diversity.  However, many of the imported strains of ash that have been planted in the UK will likely rapidly succumb to ash-dieback. 

Following on from this, one of the big debates in the forestry and conservation communities is what to plant in place of ash? We may have to create more mixed woodlands to give fauna and epiphytic flora (a plant that grows on another plant upon which it depends for mechanical support but not for nutrients e.g. ferns or moss) any chance of survival. Also, non-native sycamore trees are often controlled in woods where ash and sycamore co-exist. Given the potential implications of ash-dieback, should this policy of sycamore control be relaxed?

These are questions we need to consider as individual ecologists and as an industry.

As The Guardian reported, this January saw the announcement that wild beavers living on the River Otter in Devon would be allowed to remain, providing they are ‘proven free of disease and of Eurasian origin’. This is a potentially historic decision, as it is thought that beavers became extinct in the UK at the end of the 17th Century.

Update as of March 2015: The wild beavers have now been released back into the River Otter after being confirmed disease free.

Beavers are considered a keystone species due to their beneficial impact on biodiversity. As John Lister-Kaye, director of the Aigas Field Centre, describes it, “Beavers shift everything, tirelessly, instinctively, creatively. That’s why ecologists call them a ‘keystone species’. By doing their own thing, they create habitats and opportunities for just about everything else”.

Beaver by Aigas Field Centre

Photo by Aigas Field Centre

A nine-year study of essentially wild beavers carried out at the Aigas Field Centre found that, when measured against adjacent wetlands the beavers had not utilised, biodiversity had expanded by a factor of four.

As well as this benefit for wildlife, the wetlands created and restored by beavers can trap sediments, reduce pollution and slow water flows through a river catchment. This can help improve water quality and reduce flooding downstream, helping sustainable management of the water cycle and benefiting human communities in nearby areas.

The Devon beavers are not alone in the UK, as there could currently be around 300 wild beavers, including those in an official beaver trial in Knapdale, Argyllshire and the beavers ‘unofficially’ living wild on the River Tay, Perthshire. However, aside from the Devon beavers, no decision has been made regarding the future of beavers in the UK.