New strategy gets to the root of Scotland's biodiversity crisis

Genetic diversity – differences within a particular population, species, variety or breed due to variations in their DNA – is vital in ensuring flora and fauna can adapt and survive the existential threats of new diseases, as well as environmental and climate change. 

One of the three components of biodiversity, along with species and habitats, the importance of genetic conservation was recognised in the goals of COP15, held in Montreal in December last year.

The ‘Scottish Biodiversity Strategy to 2045: tackling the nature emergency’, meanwhile, notes that, of 26 key species selected for assessment, a review found four at risk of severe genetic problems. In a bold mission statement, the strategy sets a vision for no loss of diversity within species between now and 2045. 

Against this backdrop, and at a time of increasing pressures brought by the twin biodiversity and climate crises, ecologist Jeanette Hall is working hard to ensure genetic diversity is maintained as an essential part of conserving nature in Scotland.

As woodlands advisor for NatureScot, Jeanette naturally focuses first on trees.

NatureScot's Jeanette Hall

“We have trees that are particularly distinctive to Scotland and we want to preserve their Scottish distinctiveness,” she notes, “however, because we are facing climate and other environmental changes, and some trees are threatened by disease, one of the main things we want to do is enable natural selection – so where those trees are able to adapt to change, they’re best able to do so.”

The importance of genetic diversity for adaptation to changing conditions can be illustrated by the threat posed by ash dieback. This disease can result in a 90% mortality rate. Despite this, some trees have levels of resistance, and this has been shown to be under strong genetic control. 

“In the case of something like ash dieback, there is a lot of genetic variation,” Jeanette explains. “This means some trees are much more likely to die than others. It’s not an individual gene; there’s a whole load of genes. So you can’t just say this gene is important then breed all the trees to have that gene. 

“There are lots of different genes that contribute to the tree’s ability to deal with the disease and the environment’s a really important factor as well. 

“What we need to do is to provide an environment where trees can reproduce, enabling natural selection to operate so the young trees are given the best opportunity to survive. 

“Those that are most resistant to the disease will go forward to form the future population. Often, one of the most important things to do is manage grazing, which is a major threat to regeneration, particularly because deer and sheep find ash trees especially tasty, which prevents seedlings growing into saplings and then mature trees. 

“So that’s not about protecting a particular genetic variation; it’s more about making sure there’s enough regeneration for natural selection to operate and ensure there are trees that are more able to cope with the disease.”

NatureScot is carrying out groundbreaking  genetic conservation work to increase the Highland populations of great crested newt

Another species that’s a prime focus of NatureScot’s recent work is the great crested newt, which is native to the Scottish Highlands.

These amphibians are genetically unique, having ably adapted to past climate change events, but with so few populations NatureScot teamed up with local people to protect them. 

The organisation also liaised with farmers, who understand genetic diversity and how it affects resistance to disease, drought and the importance of avoiding inbreeding. It reports having been able to increase the number of newt populations in the Highlands by 25%.

While such work is necessarily localised, the impact of NatureScot’s genetic conservation work is much more far-reaching.

“The work we do on the ground will have the most impact here in Scotland but we’re also doing a lot of work on the global stage,” notes Jeanette.

“For example, we were part of the national delegation at the recent biodiversity COP in Montreal. Scottish scientists, including NatureScot staff, played a leading role in developing international indicators of genetic diversity.

"Our approaches were incorporated in the Convention on Biological Diversity’s plan for 2030, so it’s fair to say we are helping to put together the proposals for how genetic conservation should take place worldwide. The actual work we do on the ground can operate as an example for how others might put genetic conservation into practice in their own countries. 

“We’ve also developed ways of evaluating the impact of our genetic conservation, which will help other countries to think about how best to report on it.”

In fact, Scotland was the first country to report at a national level on genetic diversity of wild species. Scientists at Royal Botanic Garden Edinburgh, Edinburgh University and NatureScot are currently investigating methods of updating and expanding this work to ensure it is of most benefit to conservationists and policymakers.

“One of the most important things Scotland has done is to produce a scorecard, which enables us to report on genetic conservation,” says Jeanette. “That’s really important because if you’re undertaking conservation, with policies or incentives for people to do particular things, you want to know that it’s working: that requires monitoring. 

“The scorecard we’ve developed means any country, whatever species they have, however abundant those are, can evaluate how well they’re doing in terms of genetic conservation. 

“That scorecard was developed in Scotland but it’s been adopted by the Convention on Biological Diversity (CBD) as a useful way for any nation or region to measure genetic diversity.”

With genetic conservation one of the headline goals at the CBD’s recent conference in Montreal, it’s evident the mission does not stop at national borders. Working collaboratively with partners around the world enables learning from each other and sharing what works and what doesn’t. 

Jeanette notes: “NatureScot is working with scientists worldwide to develop ways of carrying out and measuring genetic conservation work and actually understanding the impact of that work. So there’s a lot of European and, indeed, global collaboration going on to develop our approaches.”
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Conservation ensures future generations won’t pine for the past

TO Scots environmental pioneer and philosopher John Muir the ‘Big Tree’ was nature’s forest masterpiece and the greatest of living things.

Today it’s widely recognised the greatness of trees often very much depends on their genetic conservation. 

Different populations of the same species will adapt to survive and thrive in their peculiar local conditions. 

Beinn Eighe – the UK’s first site designated for the genetic conservation of ancient Caledonian pinewood

Here in Scotland, the Scots pine has evolved to deal effectively with harsh, cold winters and hotter summers in the east of the country. Pines in the west, however, are better able to put up with the milder and damper conditions.

On a more global scale, there is a well-developed gene conservation programme for trees, with a network of Gene Conservation Units (GCU) recognised by the European Forest Genetic Resources Programme (EUFORGEN). 

The GCUs are, in effect, mapped areas of forest or woodland where dynamic gene conservation is one of the primary management targets for one or more tree species. 

A major element of this vital work involves encouraging the production of new seedlings and saplings. 

NatureScot’s Beinn Eighe National Nature Reserve in Wester Ross was designated as the UK’s first GCU in 2019. This was in recognition of the distinctiveness of its famous ancient Caledonian pinewoods, including elders fondly known as ‘granny pines’. 

Since then five more GCUs have been registered in Scotland and NatureScot recently published a report proposing a further 98 units. 

Some of these areas are privately owned but others are already active nature reserves belonging to NatureScot.

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Genetic diversity is the natural way forward

IT’S a common, if understandable, misconception that genetic conservation is a practice managed under strictly controlled conditions by white-coated technicians in labs. 

In fact, this work can be carried out in Scotland’s remote wilderness amidst ancient forests and among wild animal populations. 

This work is classed as ‘in situ’ – or onsite –  and its aim is to maintain genetic diversity by allowing natural processes to take place.

In situ conservation doesn’t necessarily aim to preserve particular genetic traits or unique variants, although it may do, but ensure natural selection can continue to operate, enabling populations to adapt to changing environments. 

Habitat loss and fragmentation can also cause loss of diversity. This can lead to inbreeding and reduce the ability of species to adapt to change, so genetic conservation often involves expanding and connecting habitats. 

This was the case when working in situ with the Highland great crested newt, where a network of ponds was created, closely connected by the type of habitat that newts can easily move through.

‘Ex situ’ genetic conservation work, meanwhile, can happen in places as diverse as botanical gardens and zoos and may involve collections of reproductive material, such as the Millennium Seed Bank, home to 39,000 species of the world’s seeds, or the Svalbard Seed Vault. This underground research facility, is flood, bomb and radiation proof – evidence of how important genetic conservation is to the planet

Ex situ conservation is also often carried out in response to a serious threat and includes well-publicised reintroduction programmes, such as white-tailed and golden eagles in Scotland. 

Often in situ and ex situ genetic conservation work is carried out simultaneously but, ultimately, both are vital if the planet’s flora and fauna is to thrive.