How to reverse global wildlife declines by 2050


Wouter Taljaard/Shutterstock

Michael Obersteiner, University of Oxford; David Leclère, International Institute for Applied Systems Analysis (IIASA), and Piero Visconti, International Institute for Applied Systems Analysis (IIASA)

Species are going extinct at an unprecedented rate. Wildlife populations have fallen by more than two-thirds over the last 50 years, according to a new report from the World Wildlife Fund. The sharpest declines have occurred throughout the world’s rivers and lakes, where freshwater wildlife has plummeted by 84% since 1970 – about 4% per year.

But why should we care? Because the health of nature is intimately linked to the health of humans. The emergence of new infectious diseases like COVID-19 tend to be related to the destruction of forests and wilderness. Healthy ecosystems are the foundation of today’s global economies and societies, and the ones we aspire to build. As more and more species are drawn towards extinction, the very life support systems on which civilisation depends are eroded.

Even for hard-nosed observers like the World Economic Forum, biodiversity loss is a disturbing threat with few parallels. Of the nine greatest threats to the world ranked by the organisation, six relate to the ongoing destruction of nature.

A digger tears down trees in a Malaysian rainforest.
New infectious diseases tend to emerge in places at the forefront of environmental destruction.
Rich Carey/Shutterstock

Economic systems and lifestyles which take the world’s generous stocks of natural resources for granted will need to be abandoned, but resisting the catastrophic declines of wildlife that have occurred over the last few decades might seem hopeless. For the first time, we’ve completed a science-based assessment to figure out how to slow and even reverse these trends.

Our new paper in Nature featured the work of 60 co-authors and built on efforts steered by the Intergovernmental Panel on Biodiversity and Ecosystem Services. We considered ambitious targets for rescuing global biodiversity trends and produced pathways for the international community to follow that could allow us to meet these goals.




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Bending the curve

The targets of the UN Convention on Biological Diversity call for global trends of terrestrial wildlife to stop declining and start recovering by 2050 or earlier. Changes in how land is used – from pristine forest to cropland or pasture – rank among the greatest threats to biodiversity on land worldwide. So what are the necessary conditions for biodiversity to recover during the 21st century while still supporting growing and affluent human societies?

Two key areas of action stand out from the rest. First, there must be renewed ambition from the world’s governments to establish large-scale conservation areas, placed in the most valuable hotspots for biodiversity worldwide, such as small islands with species found nowhere else. These reserves, in which wildlife will live and roam freely, will need to cover at least 40% of the world’s land surface to help bend the curve from decline to recovery for species and entire ecosystems.

The location of these areas, and how well they are managed, is often more important than how big they are. Habitat restoration and conservation efforts need to be targeted where they are needed most – for species and habitats on the verge of extinction.

A downward sloping line showing wildlife declines splits into three alternative trajectories, where biodiversity increases, plateaus and crashes by 2050.
The next 30 years will prove pivotal for Earth’s biodiversity.
Leclère et al. (2020), Author provided

Second, we must transform our food systems to produce more on less land. If every farmer on Earth used the best available farming practices, only half of the total area of cropland would be needed to feed the world. There are lots of other inefficiencies that could be ironed out too, by reducing the amount of waste produced during transport and food processing, for example. Society at large can help in this effort by shifting towards healthier and more sustainable diets, and reducing food waste.

This should happen alongside efforts to restore degraded land, such as farmland that’s becoming unproductive as a result of soil erosion, and land that’s no longer needed as agriculture becomes more efficient and diets shift. This could return 8% of the world’s land to nature by 2050. It will be necessary to plan how the remaining land is used, to balance food production and other uses with the conservation of wild spaces.

Without a similar level of ambition for reducing greenhouse gas emissions, climate change will ensure the world’s wildlife fares badly this century. Only a comprehensive set of policy measures that transform our relationship with the land and rapidly scale down pollution can build the necessary momentum. Our report concludes that transformative changes in our food systems and how we plan and use land will have the biggest benefits for biodiversity.

But the benefits wouldn’t end there. While giving back to nature, these measures would simultaneously slow climate change, reduce pressure on water, limit nitrogen pollution in the world’s waterways and boost human health. When the world works together to halt and eventually reverse biodiversity loss, it’s not only wildlife that will thrive.The Conversation

Michael Obersteiner, Director, Environmental Change Institute, University of Oxford; David Leclère, Researcher in Ecosystem Services and Management (ESM) Program, International Institute for Applied Systems Analysis (IIASA), and Piero Visconti, Research Scholar, Ecosystem Services and Management Programme, International Institute for Applied Systems Analysis (IIASA)

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

We accidentally found a whole new genus of Australian daisies. You’ve probably seen them on your bushwalks



Alexander Schmidt-Lebuhn, Author provided

Alexander Schmidt-Lebuhn, CSIRO and Ben Gooden, CSIRO

When it comes to new botanical discoveries, one might imagine it’s done by trudging around a remote tropical rainforest. Certainly, that does still happen. But sometimes seemingly familiar plants close to home hold unexpected surprises.

We recently discovered a new genus of Australian daisies, which we’ve named Scapisenecio. And we did so on the computer screen, during what was meant to be a routine analysis to test a biocontrol agent against a noxious weed originally from South Africa.




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The term “genus” refers to groups of different, though closely related, species of flora and fauna. For example, there are more than 100 species of roses under the Rosa genus, and brushtail possums are members of the Trichosurus genus.

This accidental discovery shows how much is still to be learned about the natural history of Australia. Scapisenecio is a new genus, but thousands of visitors to the Australian Alps see one of its species flowering each summer. If this species was still misunderstood, surely similar surprises are still out there waiting for us.

How it began

It all started with a biocontrol researcher asking a plant systematist, who looks at the evolutionary history of plants, to help figure out the closest Australian native relatives of the weed, Cape ivy (Delairea odorata).

Cape ivy leaves covering a tree stump
Cape ivy is destructive to agriculture and native plants.
Murray Fagg/Australian Plant Image Index, Author provided

Weeds like Cape ivy cause major damage to agriculture in Australia, displace native vegetation and require extensive management. Biological control (biocontrol) is one way to reduce their impact. This means taking advantage of insects or fungi that attack a weed, generally after introducing them from the weed’s home range.

A well-known Australian example is the introduction of the Cactoblastis moth in 1926 to control prickly pear in Queensland and New South Wales. Even today it continues to keep that weed in check.




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To minimise the risk of selecting a biocontrol agent that will damage native flora, ornamental plants or crops, it’s tested carefully against a list of species of varying degrees of relatedness to the target weed.

Authorities will approve the release of a biocontrol agent only if scientists can show it’s highly specific to the weed. Assembling a list of species to test therefore requires us to understand the evolutionary relationships of the target weed to other plant species.

If such relationships are poorly understood, we might fail to test groups of species that are closely related to the target.

Missing data

Our target weed Cape ivy is a climbing daisy that has become invasive in temperate forests and coastal woodlands throughout south-eastern Australia. One of us, Ben Gooden, is researching the potential use of Digitivalva delaireae — a stem-boring moth — for its biocontrol.

We tried to design a test list, but could not find up-to-date information on Cape ivy’s relatives. We already knew it is related to the large groundsel genus Senecio, but we didn’t know how closely. And no genetic data existed for many Australian native species of Senecio.

So, we set out to solve this problem together.

First, we assembled already-published DNA sequences for as many Senecio species and relatives as we could find, and then generated sequences for an additional 32 native Australian species.

We then united all these genetic data into a comprehensive phylogenetic analysis. “Phylogenetics” infers the evolutionary relatedness of organisms to each other.

Hidden in the evolutionary tree

The resulting “evolutionary tree” showed many of the native Senecio species where we expected them to be. More importantly, however, it showed us that Cape ivy is actually quite distantly related to Senecio.

To our surprise, the analysis also placed several Australian species traditionally belonging to the Senecio genus far outside of it, indicating they didn’t belong to Senecio at all and needed to be renamed.

Simplified phylogenetic tree
Simplified phylogenetic tree of the daisy tribe Senecioneae showing the evolutionary distance between Senecio, Cape ivy, and the new genus. Unlabelled branches indicate other lineages of the same tribe.
Alexander Schmidt-Lebuhn, Author provided

The most interesting group of not-actually-Senecio are five species with leaf rosettes and one (or rarely, a few) flowerheads carried on distinctive stalks.

They’re all restricted to alpine or subalpine areas of south-eastern Australia, and all except one are found only in Tasmania. They turned out to be so unrelated, and so distinct from any other named plant genera, that they have to be recognised as a genus in its own right.

Introducing Scapisenecio

We have now named this new genus as Scapisenecio, after the long flower stalks (scapes) characterising the plants.

The most widespread and common species is Scaposenecio pectinatus, commonly known as the alpine groundsel, which is a familiar sight to hikers and bushwalkers in the Australian mainland alps and the central highlands of Tasmania.

Close-up of a single yellow daisy
Species belonging to this genus are a common sight to alpine hikers.
Alexander Schmidt-Lebuhn, Author provided

Apart from the excitement of finding a previously undescribed, distinctive genus, these results were also directly relevant to the original purpose of our work: informing a plant list to test possible biocontrol agents.

The traditional misclassification of these species would have misled us about their true relationships. Our new genetic data now allow us to test biocontrol agents on an appropriate sample of species, to minimise risks to our native flora.

It is not often we find that a new, unexpected lineage of plants has existed all along, right in front of us.




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The Conversation


Alexander Schmidt-Lebuhn, Research Scientist, CSIRO and Ben Gooden, Plant ecologist, CSIRO

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