Author Archives: Matt Williams

Climate change and land use are lethal one-two punch for protected areas

Scientists from Macquarie University in Sydney, Australia have authored a new paper that shows that terrestrial protected areas (PAs) around the world are hit by two major threats: climate change and land-use change. While areas may be able to withstand one of them, the two of them combined are overwhelming.

Image credits: Stefan Cosma.

Climate change has already been found to be impacting biodiversity and ecosystems in a number of ways. These include changes in species distribution, declining coral reef production, and affecting 1 in 5 threatened or near-threatened species. Some estimates suggest that up to 8% of species are predicted to become extinct from climate change.

Land-use change, on the other hand, is also one of the leading threats to biodiversity currently. Agriculture and logging in particular destroy habitat for wildlife in many of the most biodiverse regions of the world.

On their own, both issues are major concerns for conservation but can be managed. Together, their combined impacts may spell disaster for the species of Earth if action is not taken. This new study shows that the two threats may work synergistically to undermine the effectiveness of PAs and threaten progress on species conservation goals.

protected area
Image from Phys.org

The researchers compared the rate of climate change and land-use change to characteristics of PAs such as species diversity and location. They used this data to project what kind of changes PAs will experience in the coming decades and how this might affect their functioning.

Two key findings from this study are that:

  • 27% of PAs around the world are in areas that will experience high rates of climate change and land use change by 2050 – areas that the paper terms “high-risk zones”
  • Land use change and climate change will collectively challenge efforts of biodiversity conservation

The authors of the paper reaffirm the need for conservation targets to consider all the factors that make a PA effective. These include “improved governance, targeted interventions and clear management plans”. Additionally, they state the need for PAs to utilize principles of climate change adaptation to maintain their effectiveness into the future.

The authors also recommend “ambitious climate change mitigation that exploits synergies with land-use systems”. But what could something like this entail?

A study from 2019 found that a number of different practices can have large benefits to both climate change mitigation and/or adaptation as well as combatting land degradation – without requiring any land-use changes. Some of these practices include:

  • Improved cropland management;
  • Improved forest management;
  • Increased soil organic carbon content;
  • Increased food productivity;
  • Dietary change;
  • Reducing food loss and waste.

Importantly, however, in terms of climate change mitigation, the number one focus in the coming decades must be on keeping fossil fuels in the ground.

The study was published in the journal Nature Climate Change.

Extinct megafauna were “engineers” that shaped Central and South American ecosystems

Megafauna comprises large, often charismatic animals. They’re usually the first thing that comes to mind when we think of wildlife conservation. Think elephants, rhinos, giant pandas, and tigers.

There is also an abundance of extinct megafauna in the fossil record, such as mammoths, sabre-toothed cats, and dire wolves. Extinct megafauna is not just a fascinating insight into the past– their existence shapes aspects of current ecosystems in interesting ways. For instance, a new study has found evidence that extinct megafauna were important drivers of ecosystem geography in Central and South America.

Megafauna ecology

Glyptodon is an example of extinct South American fauna – a relative of the armadillos. Credits: Pavel Riha / The Conversation.

Modern megafauna animals are often described as ecosystem engineers and keystone species for the important role they have in shaping their surrounding environment. Elephants, for example, are the largest land animals in the world, with the males weighing in at up to 7 tons. They shape their environment in a number of significant ways, including maintaining grasslands and spreading plant seeds. While different megafauna animals have different impacts on the environment, they all play an important role. So, how did animals that lived in the past affect their environment?

This new study sheds some light on that question.

What the new research found

The paper focuses on the Neotropical realm — consisting of tropical Central America and all of South America. The researchers wanted to know how much of the variability in plant traits and ecosystem geography could be explained by extinct megafauna – defined by the authors as extinct mammalian herbivores weighing over 50kg. What they found was that “extinct megafauna left a significant imprint on current ecosystem biogeography”.

The authors found that many of the plant traits that they studied were significantly influenced by the presence of megafauna. These plant traits included wood density, spines on the leaves for defence, leaf size, and more. These findings mean that extinct megafauna ecology is an incredibly important component to understanding plant evolution – one which has been “largely neglected in the ecological literature” according to the authors.

They also found that – like modern elephants – extinct megafauna also likely had a role in maintaining grasslands. They discuss how the extinction events of megafauna may have played a significant role in the shift from grassland to forest ecosystem that have occurred in South America, and state that “megafauna extinctions could largely explain the current prevalence of forests in the continent”.

The paper was published in Nature Communications on 10 January 2022.

Marine Protected Areas: An update on the research

Marine protected areas (MPAs) are areas of seas, oceans or estuaries that are managed and regulated for a number of different purposes. Usually, for biodiversity conservation, as they limit or disallow fishing and aquaculture activities within the boundaries of the MPA. Here, we will go through some of the more recent research surrounding MPAs. We will look at some non-material benefits of MPAs, how they can be designed to maximize their effectiveness, and what they mean for the wellbeing of the local communities they impact.

From Ocean Health Index

A quick review of marine protected areas (MPAs)

Here is some of what was already known about MPAs prior to these studies:

From the National Marine Protected Areas Centre

Study 1: Evidence for cultural ecosystem services from MPAs

There are many types of services provided by ecosystems that benefit human welfare. Protected areas are a strategy to maintain these services for our own wellbeing – and some of those services protected by MPAs are listed above. However, one type of ecosystem service that had not been studied comprehensively are cultural ecosystem services (CES’s).

CES’s are non-material benefits provided to society by ecosystems – which can include recreation, aesthetic enjoyment, and mental health benefits. They are thus much harder to quantify than some other ecosystem services such as the production or regulation of nutrients. Many research and knowledge gaps still remain.

With this in mind, researchers from the University of Aberdeen in the UK compared the CES’s delivered by MPAs compared to non-protected control sites. Using social media sampling, they noted several key findings:

  • People take and upload to social media more photos from inside MPAs than in non-MPA sites
  • Photos taken from inside MPAs tend to be more nature and wildlife focused than those taken in control sites
  • Photos taken from inside MPAs are more popular and described more positively than photos from control sites

The conclusion that the authors draw from these findings is that people ”preferentially visited MPAs to experience nature and wildlife” and that “MPAs deliver added CES’s”. Thus, in addition to the practical and environmental benefits provided by MPAs, there is now evidence that they may also provide mental health and recreational benefits to visitors and tourists.

Graphical abstract of the study

The study was published in the journal One Earth.

Study 2: How to design an effective MPA

Not all MPAs are created equal – some perform better than others. Scientists from Tel Aviv University in 2021 conducted a meta-analysis using data from 27 no-take MPAs around the world to identify what factors drive this variation in MPA quality.

Specifically, the researchers analysed ‘edge effects’. These are ecological – often human-caused – stressors in the surroundings of a protected area that can degrade the environment within its borders. Terrestrial edge effects have been well studied before, but this paper fills a knowledge gap by empirically demonstrating the existence of marine edge effects as well.

The study found that edge effects affecting MPAs largely result from fishing activities – both illegal and legal. Edge effects can extend up to 1km within the borders of no-take MPAs, and MPAs that are smaller than 10km2 (which are the majority of MPAs) tend to show a particularly large edge-effect area.

The findings of this research demonstrate that the biomass within MPAs is around half of what it would be if it weren’t for edge effects. Taking action to lessen these edge effects therefore, is vital to improving the effectiveness of MPAs and achieving conservation goals.

Importantly, the authors note that MPAs that have buffer zones surrounding their no-take areas do not show edge effects. What this means for biodiversity goals is that no-take areas cannot allow unregulated fishing immediately outside their borders. Rather, regulations for fishing need to be enforced for the surrounding areas to protect the no-take area from edge effects.

The authors studied 27 MPAs around the world

The authors recommend that for MPAs to maximise their effectiveness, 3 relatively simple considerations should be implemented in their design:

  1. A size larger than 10km2,
  2. A precautionary buffer at least 1km wide around the borders of the no-take zone, and
  3. A circular design – this reduces the border areas (and thus the potential for edge effects) to a minimum

The study was published in the journal Nature Ecology & Evolution

Study 3: MPAs and human wellbeing

Environmental and conservation goals must be implemented with human wellbeing as a priority – particularly for the local communities around PA’s. In 2019, a team of international scientists conducted a comprehensive review of 118 peer-reviewed articles surrounding the research on MPA impacts on human wellbeing. Wellbeing aspects that were analysed included mainly economic and governance factors. This meant that there was a relative lack of study on social, health, and cultural factors of wellbeing.

They found that MPAs overall had a mix of positive and negative outcomes, though there were more reported positive than negative outcomes. Around half of wellbeing outcomes were reported to be positive and one-third were reported to be negative. The remainder noted no change either way.

The authors also analysed the factors that contributed to positive wellbeing outcomes from MPAs – which included:

  • No-take MPAs
  • Well enforced MPAs
  • Old MPAs
  • MPAs with single zones rather than multiple zones

In general, there tended to be overlap between the factors that make MPAs ecologically effective and those that promote positive human wellbeing. This is yet another reason to prioritise PA quality and not just focus on area-based targets.

Overall, the authors concluded that MPAs certainly have the potential to enhance both biodiversity conservation and human wellbeing. However, currently, many reported impacts of MPAs on humans are negative, prompting more efforts to design our conservation efforts around benefiting both people and nature.

Graphic summary of the review paper

The study was published in the journal Nature Sustainability.

MPAs are a vital tool to combat biodiversity loss and climate change. This new research shows that they can also provide CES benefits, how they can be spatially designed to maximise their effectiveness, and that they can improve human well-being if they are designed and managed properly.

We need to protect 50% of the planet — but even that’s not enough

Image credits: Lingchor.

Protected areas are advocated for by scientists and conservationists alike because of their clear environmental benefits. Due to the constant expansion of our species, environments and ecosystems are under more and more pressure, and having safe havens like these protected areas is essential for the wellbeing of our planet.

Primarily, protected areas protect biodiversity and ecosystems while also often functioning as natural climate solutions. Protected areas also come with a host of benefits for goals beyond environmentalism. These include social and financial benefits for residents within protected areas and safeguarding against the emergence of new zoonotic diseases. Simply put, protected areas are not just good for the planet — they’re good for us as well.

Currently, around 15% of Earth’s land surface (and around 7% of Earth’s ocean surface) is protected. There is therefore a long way to go before we reach the 50% protection goal.

However, in urging our governments to reach this 50% target, some scientists have warned us there is a risk that we can get so caught up in the quantity of protected land and seas that we don’t also consider how effective those protected areas are in the first place. But before we talk about the quality of protected areas, let’s talk a bit about quantity.

Where does this 50% figure come from anyway?

Prominent voices that are calling for half the Earth to be protected include the aptly named Half-Earth Project based on the book written by E. O. Wilson, as well as Nature Needs Half, an international organization that advocates for half of the planet to be protected by 2030. Their choice of 50% of the Earth, however, is not an arbitrary one, but one that is supported by science.

The Global Safety Net is a tool developed by a team of scientists that combines a number of different data layers and spatial information to estimate how much of Earth’s terrestrial environment needs to be protected to attain three specific goals. Those goals were 1) biodiversity conservation, 2) enhancing carbon storage, and 3) connecting natural habitats through wildlife and climate corridors.

The researchers found that using this framework, a total of 50.4% of terrestrial land should be conserved to “reverse further biodiversity loss, prevent CO2 emissions from land conversion, and enhance natural carbon removal”. Interestingly, these results concur with prior calls to protect half the planet.

This data also found that, globally, there is significant overlap between the land that needs to be protected for conservation and Indigenous lands. The authors of the paper write that by enforcing and protecting Indigenous land rights, we can combine biodiversity and climate goals with social justice and human rights. They emphasize that “with regard to indigenous peoples, the Global Safety Net reaffirms their role as essential guardians of nature”.

Biodiversity inside and outside protected areas
From The Guardian

Why it can be detrimental to only look at the numbers

Scientists are absolutely right in saying we should aim to protect half the planet. But there’s more to it than that. An equally important consideration is how effective those protected areas are at achieving their stated goals.

Worryingly, some scientists estimate the true quantity of protected land is much lower than the official 15% when effectiveness is considered. One paper found that “after adjusting for effectiveness, only 6.5%—rather than 15.7%—of the world’s forests are protected”. Importantly, the authors caution their readers against assuming that protected areas will completely eliminate deforestation within their boundaries. On average, they found that protected areas only reduced deforestation by 41%.

Another team of scientists analyzed over 50,000 protected areas in forests around the world and their impact from 2000-2015. A major finding from their paper was that a third of protected areas did not contribute to preventing forest loss. In addition, the areas that were effective only prevented around 30% of forest loss. The authors call for improving the effectiveness of existing protected areas in addition to expanding protected area networks.

Finally, a team of researchers recently authored a paper that analyzed protected areas established between 2000 and 2012 and found that significantly more amounts of deforestation could be avoided if existing protected areas were made more effective — this was despite the authors stating that protected areas already reduce deforestation by 72%. This is a notably higher effectiveness than is stated by those other papers – perhaps because the team analyzed only protected areas that were established relatively recently. Multiple papers have found that newer protected areas tend to be on average more effective than older ones.

So how can we make protected areas more effective then?

One of the most important considerations is that protected areas tend to prevent more deforestation in areas where deforestation is higher. However, it is still important to protect lands currently at low risk of degradation. In that way, future forest loss can be prevented before it becomes a significant problem.

Indirectly, other attributes of a country can predict how effective or ineffective the protected areas within that nation will be. Countries that have higher human development, higher GDP per capita, better governance, and lower agricultural activity tend to host more effective protected areas than countries with lower human development and GDP per capita, lower government effectiveness, and higher levels of agriculture.

Finally, as mentioned before, there is a huge amount of overlap between potential land for protection and Indigenous land. Engaging with, and granting property rights and legal recognition to, Indigenous people is a cost-effective way to protect forests while also addressing a human rights issue at the same time.  

What all of this data shows us is that the conversation surrounding environmental protection needs to be considered in a broader context, and take into consideration economic, political, and social justice concerns. And it is an issue that is far too complex for its success to be measured by a single number.

The fascinating (and very real) story of the dire wolf

Artistic reconstruction of a dire wolf.

You may have seen them in Game of Thrones, but dire wolves (Canis dirus) were very much real creatures. The species roamed North America (and much less commonly, South America and Asia) during the Late Pleistocene for tens of thousands of years until it went extinct around 10,000 years ago, along with many other emblematic megafauna like the wooly mammoths or the saber-toothed cats.

It has since become an iconic prehistoric wildlife symbol and one of the most well-known extinct creatures from recent evolutionary history. Here are some things you may not have known about this extraordinary animal.

How is a dire wolf different from modern grey wolves?

The dire wolf was very similar in appearance to the grey wolf (Canis lupus), with the primary difference being that dire wolves were bulkier. Although their skeletal dimensions were very similar, the dire wolf was significantly heavier than the grey wolf. Paleontologists from Xavier University, Ohio estimated an average body mass of 60-68kg for the dire wolf, over 20 kg heavier than the grey wolf and making it the largest species of the subfamily Caninae.

Size comparison between a dire wolf and a human.

Also unlike grey wolves, dire wolf fossil samples have rarely been found in high latitudes above 42°N, suggesting they were less fond of the cold. It is not yet known why the species was restricted the range this way, but proposed explanations include temperature and climate as well as prey availability. After the extinction of the dire wolves, grey wolves were able to move south into mid-continent North American territory, suggesting that competition with the dire wolves may have been restricting them to northern territories for thousands of years.

They last had a common ancestor with modern grey wolves 5.7 million years ago

Despite their name and similarity, dire wolves are actually less closely related to grey wolves than some other members of the canine family, such as the African wild dog and the Dhole. Researchers in 2021 used the DNA from five dire wolf samples that were dated from 12,900 to more than 50,000 years ago to determine the evolutionary history of the species. They found that dire wolves split from all other living canids around 5.7 million years ago.

Evolutionary history of the dire wolf and other canids – image and data from Perri et al 2021

ZME Science has previously reported on how this is likely an example of convergent evolution in action, showcasing how two evolutionarily distinct species can become superficially similar if they occupy similar ecological niches.

They likely did not compete for prey with sabretooth cats, despite what was once thought

In a 2019 study that analyzed fossils from Rancho La Brea in California, researchers found a substantial difference in the ecology of canid and felid predators. Specifically, the dire wolf was found to hunt in open environments, while saber-tooth cats such as Smilodon consumed prey from closed environments, suggesting that there was little competition between these two animals for prey.

The same researchers also analyzed tooth surfaces and found that their tooth complexity was very similar to the African wild dogs and extant coyotes. Consistent with prior research published in 2007, this suggests that dire wolves were adapted for both hunting live prey as well as scavenging carcasses.

The dire wolves and saber-toothed cats likely also displayed very different modes of hunting, analogous to modern dogs and cats. Dire wolves, similar to grey wolves, were pursuit predators with limbs adapted for fast running, while saber-toothed cats were likely ambush predators as modern big cats are as well.

They had the strongest bite force quotient of any placental mammal

It is not only its size and massive carnassial (shearing) teeth that made the dire wolf a formidable predator of its time. It also had an incredibly strong bite force – over twice as strong as the sabretooth cat (when body weight is controlled for).

Research published in 2005 showed that, after adjusting for body mass, the dire wolf outcompeted all other placental mammals in bite force, at 163 newtons/kilogram of body weight – compared to the grey wolf at 136. This incredible amount of force was likely due in large part to the large temporalis muscles on the side of its head.

However, several marsupial carnivores scored higher for bite force per body mass. Priscileo roskellyae and Thylacoleo carnifex are extinct marsupial lions from Australia that hold the record for all-time strongest mammalian bite force adjusted for body mass, while the Tasmanian devil has the highest bite force for body weight ratio of any living carnivorous mammal.

Comparisons of bite force quotients in mammalian predators – data from Wroe et al 2005

Dire wolves went extinct around 10,000 years ago – probably because its prey disappeared

The dire wolf relied on large herbivorous mammals to sustain itself – these included horses, giant sloths, and giant bison. During the extinction event, many of these larger mammals went extinct in what is known as the Late Pleistocene megafaunal extinction event. It is thought that the dire wolf was not able to survive on the smaller herbivores that survived the extinction event, whereas other smaller canids such as the grey wolf were able to.

In fact, new research has determined that a diet shift away from horses and towards moose and caribou was likely a key factor in grey wolves surviving the extinction event that saw the end of the dire wolves. Indeed, these prey species tend to be found in higher latitudes where grey wolves were typically present but dire wolves were rare, so it is possible that the distribution of these prey species may have been one reason why the grey wolves survived when dire wolves did not. However, this is only speculation and will require more research to conclude with any degree of certainty.

Dire wolves remain one of the iconic Pleistocene creatures, living alongside the early humans and fascinating our imagination for t thousands of years. As research continues to come in, we will no doubt learn even more about these wolves and the environment they lived in.