One in six UK species threatened with extinction – here’s what we could lose (plus how to save them)

Spread the love
Water voles are endangered mammals in the British Isles.
Ben Andrew/RSPB

Richard Gregory, UCL

The UK is considered one of the most nature-depleted countries in the world. This is not surprising given its history of early industrialisation and agricultural intensification.

These islands have lost species and unique habitats have shrunk to tiny remnants. Nearly every landscape and view has transformed.

What is more surprising is that over the last 50 years or so, from when scientists started to collect information about biodiversity systematically, there has been no let-up in that downward slide.

More than 750 assessed species have declined by 19% on average since monitoring began in 1970. The losses continue despite the heroic efforts of many passionate people and organisations. Today, out of over 10,000 species assessed, 16% (1,500, or one in six) are threatened with extinction.

That is the sobering conclusion of the latest state of nature report, compiled by experts from over 60 of the top research and conservation organisations in the UK, using the latest and most accurate information about biodiversity on land, in freshwater, around the coast and in the ocean.

The evidence that species and habitats are being lost is clear. And yet, as the report shows, there has never been a better understanding of the state of nature and, importantly, what is needed to fix it.

Nature continues to decline

Everyone depends on nature for the things it provides for free: so-called ecosystem services like healthy food, materials, clean air and water. You could add human wellbeing, physical and mental health – and for many, inspiration, solace and joy.

There is cause to protect nature because it aligns with our values, from the moral responsibility we feel to future generations to the intrinsic worth we know nature has. These are all good reasons, but self-preservation is compelling.

The new report presents evidence on how and why nature is changing in the UK and in its four constituent countries. To do this, the authors analysed three measures: species abundance (the number of individuals), species distribution (the proportion of sites occupied) and national extinction risk.

These measures have been assessed for hundreds – and in some cases thousands – of species native to the UK. Our new findings are in line with previous reports (2013, 2016, 2019) in pointing to a pattern of continued biodiversity loss.

An orange and brown patterned butterfly among wildflowers.
The threatened marsh fritillary butterfly.
Patrick Cashman/RSPB

The new report’s key findings include:

  • The distributions of almost 5,000 invertebrate species have on average shrunk by 13% since 1970. Strong declines were seen in insect groups that perform key ecosystem functions, including pollinators (18% decrease) and pest controllers (34% decrease).
  • The distributions of 54% of flowering plant species and 59% of bryophytes (mosses and liverworts) have decreased across Britain since 1970. By comparison, only 15% and 26% of these groups have increased respectively.
  • The abundance of 13 species of seabird has fallen by an average of 24% in the UK since 1986. But these results pre-date an ongoing outbreak of Highly Pathogenic Avian Influenza, which has killed thousands of seabirds, some belonging to populations constituting the bulk of an entire species.
  • Roughly 2% of species (151) once found in the UK have disappeared. These include the great auk, Kentish plover, Norfolk damselfly, burbot and large copper butterfly.

The report shows that climate change – which is predominantly caused by burning fossil fuels – is among the biggest threats to wildlife in all ecosystems. The intensive way in which land is managed for farming (with the loss of hedgerows, farm ponds and scruffy margins and the increasing use of pesticides and fertilisers, as well as changes in crops and cropping patterns) is also a major driver of biodiversity loss, and contributes to climate change.

At sea, unsustainable fishing practices are a major factor. Added to these pressures on wildlife are invasive species, pollution and for some, such as birds of prey, persecution.

Solving all of these problems will involve several actions that can be joined up to support each other. This must be swift and extensive to be effective.

The report establishes what is known about the success or failure of conservation efforts. Fortunately, there are many success stories. Species like natterjack toads, Duke of Burgundy butterflies, bitterns, and large marsh grasshoppers have all benefited from bespoke conservation projects and are bouncing back.

A toad.
Natterjack toads cling on in a handful of shallow coastal pools.
Andy Hay/RSPB

Cairngorms Connect is the UK’s largest habitat restoration project, covering 60,000 hectares in the Scottish national park. It aims to restore native woodland, peatlands and rivers over the next 200 years. This is the scale at which conservationists need to operate in order to reverse nature’s decline.

Recovery by 2050?

It is only through the collective efforts of thousands of people, most of them volunteers, that we can report on the state of nature with such clarity and breadth. Without their enthusiasm, commitment and skill, we’d only have a sketchy understanding of how the environment is changing, and whether conservation efforts are making a difference.

The 2023 state of nature report is timely given the recent adoption of global targets to recover nature. The Convention on Biological Diversity’s new global framework, signed by nearly 200 countries in December 2022, aims to maintain, enhance, restore and expand ecosystems, reduce the number of species threatened with extinction and increase the abundance of native species by 2030, putting nature on a path to recovery by 2050.

A farm field margin covered in wildflowers.
Restoring meadows on farmland could benefit pollinating insects.

To halt and reverse biodiversity loss in the UK, efforts to conserve and restore species and habitats must ramp up. But the underlying drivers of this loss must be addressed too, especially those attached to our food system.

That means making food production more sustainable and nature-friendly on land and at sea, and adjusting our diets to cut demand for products that drive the loss of nature, such as meat.

Nature-based solutions to climate change, such as restoring and protecting carbon-absorbing forests and wetlands in river catchments, or restoring coastal habitats, can also boost biodiversity if well designed (think saving two birds with one tree).

We have never had a better understanding of the state of nature and what is needed to fix it. Now we need action.

Imagine weekly climate newsletter

Don’t have time to read about climate change as much as you’d like?

Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 20,000+ readers who’ve subscribed so far.The Conversation

Richard Gregory, Honorary Professor of Genetics, Evolution & Environment, UCL

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Continue ReadingOne in six UK species threatened with extinction – here’s what we could lose (plus how to save them)

Children born today will see literally thousands of animals disappear in their lifetime, as global food webs collapse

Spread the love

Frida Lannerstrom/Unsplash, CC BY

Corey J. A. Bradshaw, Flinders University and Giovanni Strona, University of Helsinki

Climate change is one of the main drivers of species loss globally. We know more plants and animals will die as heatwaves, bushfires, droughts and other natural disasters worsen.

But to date, science has vastly underestimated the true toll climate change and habitat destruction will have on biodiversity. That’s because it has largely neglected to consider the extent of “co-extinctions”: when species go extinct because other species on which they depend die out.

Our new research shows 10% of land animals could disappear from particular geographic areas by 2050, and almost 30% by 2100. This is more than double previous predictions. It means children born today who live to their 70s will witness literally thousands of animals disappear in their lifetime, from lizards and frogs to iconic mammals such as elephants and koalas.

But if we manage to dramatically reduce carbon emissions globally, we could save thousands of species from local extinction this century alone.

Ravages of drought will only worsen in coming decades.
CJA Bradshaw

An extinction crisis unfolding

Every species depends on others in some way. So when a species dies out, the repercussions can ripple through an ecosystem.

For example, consider what happens when a species goes extinct due to a disturbance such as habitat loss. This is known as a “primary” extinction. It can then mean a predator loses its prey, a parasite loses its host or a flowering plant loses its pollinators.

A real-life example of a co-extinction that could occur soon is the potential loss of the critically endangered mountain pygmy possum (Burramys parvus) in Australia. Drought, habitat loss, and other pressures have caused the rapid decline of its primary prey, the bogong moth (Agrotis infusa).

All species are connected in food webs. The spider shown here is an elongated St. Andrews cross spider Argiope protensa from Calperum Reserve, South Australia.
CJA Bradshaw

Research suggests co-extinction was a main driver of past extinctions, including the five previous mass extinction events going back many hundreds of millions of years.

But until now, scientists have not been able to interconnect species at a global scale to estimate how many co-extinctions will occur under projected climate and land-use change. Our research aimed to close that information gap.

The unprecedented bushfires of 2019/2020 on Kangaroo Island killed thousands of individuals in many different wildlife populations.
CJA Bradshaw

The fate of wildlife

Using one of Europe’s fastest supercomputers, we built a massive virtual Earth of interconnected food-web networks. We then applied scenarios of projected climate change and land-use degradation such as deforestation, to predict biodiversity loss across the planet.

Our virtual Earths included more than 15,000 food webs that we used to predict the interconnected fate of species to the end of the 21st Century.

Our models applied three scenarios of projected climate change based on future pathways of global carbon emissions. This includes the high-emissions, business-as-usual scenario that predicts a mean global temperature increase of 2.4℃ by 2050, and 4.4℃ by 2100.

If this scenario becomes reality, ecosystems on land worldwide will lose 10% of current animal diversity by 2050, on average. The figure rises to 27% by 2100.

Adding co-extinctions into the mix causes a 34% higher loss of biodiversity overall than just considering primary extinctions. This is why previous predictions have been too optimistic.

Worse still is the fate of the most vulnerable species in those networks. For species highest in food chains (omnivores and carnivores), the loss of biodiversity due to co-extinctions is a whopping 184% higher than that due to primary extinctions.

Without enough prey, predators like this African lion, will perish.
CJA Bradshaw

We also predict that the greatest relative biodiversity losses will occur in areas with the highest number of species already – a case of the rich losing their riches the fastest.

These are mainly in areas recognised as “biodiversity hotspots” — 36 highly threatened areas of the Earth containing the most unique species, such as Southwest Australia and South Africa’s Cape Floristic region. This is because the erosion of species-rich food webs makes biological communities more susceptible to future shocks.

Tropical forest is the main ecosystem found in many biodiversity hotspots worldwide.

We also detected that these networks of interacting species themselves will change. We used a measure of “connectance”, which refers to the density of network connections. Higher connectance generally means the species in a food web have more links to others, thereby making the entire network more resilient.

Connectance, we learnt, will decline between 18% and 34% by the end of this century in the worst-case climate scenario.

This reduction in connectance was also driven by the loss of some key species occupying the most important positions in their local networks. These could be top predators such as wolves or lions keeping plant eaters in check, or an abundant insect eaten by many different insectivores.

When such highly connected species go extinct, it makes the network even less resilient to disturbance, thereby driving even more loss of species than would otherwise have occurred under a natural ecological regime. This phenomenon illustrates the unprecedented challenges biodiversity faces today.

Adieu, koala?
CJA Bradshaw

Can we minimise the threat?

As the United Nations Biodiversity Conference winds up this week in Montreal, Canada, governments are trying to agree on a new set of global actions to halt and reverse nature loss.

It follows the recent COP27 climate change summit in Egypt, where the resulting agreement was inadequate to deal with the global climate crisis.

We hope our findings will, in future, help governments identify which policies will lead to fewer extinctions.

For example, if we manage to achieve a lower carbon-emissions pathway that limits global warming to less than 3℃ by the end of this century, we could limit biodiversity loss to “only” 13%. This would translate into saving thousands of species from disappearing.

Clearly, humanity has so far underestimated its true impacts on the diversity of life on Earth. Without major changes, we stand to lose much of what sustains our planet.The Conversation

Corey J. A. Bradshaw, Matthew Flinders Professor of Global Ecology and Models Theme Leader for the ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders University and Giovanni Strona, Doctoral program supervisor, University of Helsinki

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Continue ReadingChildren born today will see literally thousands of animals disappear in their lifetime, as global food webs collapse