Category: Ecosystems

Heatwave kills ‘a third’ of spectacled fruit bats in Australia

Heatwave kills ‘a third’ of spectacled fruit bats in Australia

By Georgina Wade

Researchers from Western Sydney University have concluded that about 23,000 spectacled flying foxes, also known as spectacled fruit bats, died in a two-day heatwave in Northern Australia. Temperatures exceeded 42° C on 26 and 27 November, causing the bats to topple from trees into backyards, swimming pools and other locations. As rescuer David White put it, “it was totally depressing”.

And while the numbers already seem astronomical, they may not entirely representative of the devastation as some settlements were not included in the count. In fact, lead researcher Dr. Justin Welbergen believes the deaths could be as high as 30,000 deaths. He also sees the spectacled fruit bats as a “canary in the coal mine for climate change” because the events raise concerns regarding the fate of animals with more secretive and secluded lifestyles.

Experts have long been concerned about the survival of the spectacled flying foxes. Prior to November, government-backed statistics had estimated that only 75,000 spectacled flying foxes resided in Australia.

Mass deaths amongst the flying foxes used to be attributed to cyclones, but regularly occurring heatwaves have become a bigger, more formidable risk. National Flying Fox Programme Chairman, David Wescott, believes this is a major cause for concern, “it’s been a massive population decline for a species that isn’t under a great deal of pressure outside of these weather events,” he explains.

And the heat is not showing any signs of cooling down anytime soon. Just last week, Sydney experienced its hottest day since 1939 with temperatures reaching 47.3° C, resulting in rescuers working around the clock to save a number of koalas, birds and possums.

Nursing possums with burnt paws caused by hot roads and rehydrating birds that have fallen out of the sky are only some of the tasks rescuers are facing. Because, like the spectacled flying foxes, these native animals are particularly vulnerable to heat stress.

Kristie Harris, Office Manager for the New South Wales Wildlife Information, Rescue and Education Services (Wires) says responses like this are necessary as animals continue to succumb to heat extremes. “Any time we have any type of heat event, we know we’re going to have a lot of animals in need,” Harris said.


Cover photo from Max Pixel (public domain).
Arctic reindeer numbers decreasing due to climate change

Arctic reindeer numbers decreasing due to climate change

By Georgina Wade

A new report from the American Geophysical Research Union (AGU) finds that the population of caribou in the Arctic has crashed by more than half in the last two decades, falling from 5 million to around 2.1 million animals.

The findings reveal that changes in weather patterns and vegetation are making the Arctic tundra a much less hospitable place for the species. And while reindeer and caribou are the same species (caribou were never domesticated and tend to be much bigger), it’s the wild caribou herds in northern Canada and Alaska that are faring the worst. To date, herds have shrunk by more than 90 percent,a decline so drastic that “that recovery isn’t in sight”, the 2018 NOAA Arctic Report Card stated.

Prof Howard Epstein, an environmental scientist from the University of Virginia and one of the many scientists involved in the research behind the Arctic Report Card, warned that warming in the region shows no signs of abating. “We see increased drought in some areas due to climate warming, and the warming itself leads to a change in vegetation.”

Increases in the number of insects are also a problem. “If it’s warm and windy, the insects are oppressive, and these animals spend so much energy either getting the insects off of them or finding places where they can hide from insects,” Epstein explained.

And while carbon emissions can be reduced at a global scale in an attempt to limit the temperature increase and save the species, the growing pile of evidence suggests warming in the Arctic will continue. Additionally, scientists at AGU have revealed that East Antarctica’s glaciers have begun to “wake up” and show a response to the warming. NASA says that it has detected the first signs of significant melting in a swathe of glaciers in East Antarctica, adding to the mounting evidence of unprecedented climate-driven change at the top and bottom of the planet and signifying the opening of the “world’s freezer”.


Cover photo by Marcus Löfvenberg on Unsplash
Once eradicated mosquito-related diseases may return to Europe thanks to climate change

Once eradicated mosquito-related diseases may return to Europe thanks to climate change

By Will Bugler

Diseases including malaria, yellow fever, zika virus and dengue fever could return to Europe, according to the largest ever study of the mosquito evolutionary tree. The study investigates mosquito evolution over the last 195 million years and suggests that climate change today could provide favourable conditions for mosquito-borne diseases to spread in areas where they had been previously eradicated.

The research from the Milner Centre for Evolution at the University of Bath, University of York and China Agricultural University, shows that the rate at which new species of mosquitos evolve generally increases when levels of atmospheric carbon dioxide are higher. This is a concern because the greater the number of mosquito species, the more potential exists for new ways of transmitting disease, and perhaps for new variants of those diseases.

“It is important to look at the evolution of the mosquito against climate change because mosquitoes are responsive to CO2 levels” explained Dr Katie Davis, from the University of York’s Department of Biology, “Atmospheric CO2 levels are currently rising due to changes in the environment that are connected to human activity, so what does this mean for the mosquito and human health?

“Despite some uncertainties, we can now show that mosquito species are able to evolve and adapt to climate change in high numbers. With increased speciation, however, comes the added risk of disease increase and the return of certain diseases in countries that had eradicated them or never experienced them before.”

Chufei Tang, formerly at the Milner Centre for Evolution and now at the China Agricultural University, said “The rising atmospheric CO2 has been proven to influence various kinds of organisms, but this is the first time such impact has been found on insects.”

More research is needed to understand what climate change means for the future of the mosquito and the work will contribute to further discussions about the value of the mosquito to the ecosystem and how to manage the diseases they carry.


Tang et al (2018) “Elevated atmospheric CO2 promoted speciation in mosquitoes (Diptera, Culicidae)” is published in Communications Biology, DOI: 10.1038/s42003-018-0191-7. Click here to access the study.

Cover photo by U.S. Air Force/Nicholas J. De La Peña (public domain)
Biodiversity is plummeting, humanity needs a radical response

Biodiversity is plummeting, humanity needs a radical response

By Will Bugler

The scariest thing about Halloween this year? Digesting the findings of the World Wildlife Fund’s (WWF) most recent 2018 Living Planet report. The report shows that in the 40 short years between 1970 and 2014, more than 4,000 species of mammal, bird, fish reptile and amphibian are in decline. The average rate of decline of the species in the study? 60 percent. This astonishing loss of biodiversity presents a grave threat to human prosperity. The loss of wildlife and the ecosystems that support it will undermine any attempt to mitigate or adapt to climate change.

WWF’s report lists many factors for the decline, noting that just 25% of land on the planet has not been severely damaged by human activity. It also warns that this is likely to drop to just 10 percent by 2050 due to pollution, disease and climate change. The report was particularly striking in its timing, coming just weeks after the Intergovernmental Panel on Climate Change’s recent report on climate change, which warned of the impacts that the world faces at 1.5 degrees of warming. The impacts included wiping out almost all of the world’s coral reefs and altering other fragile habitats and ecosystems.

These two reports together show that significant and far reaching change is necessary in order to protect the vital systems that we rely on to grow food, access fresh water, and power our lives. They also clearly imply that only a holistic approach to climate change adaptation will be effective in safeguarding human systems in the coming decades.

Broadly speaking, the purpose of adapting to climate change is to safeguard lives and livelihoods of people in the face of considerable changes to the climate system; many of which are now inevitable. This goal becomes impossible if we are unable to protect the ecosystems that support life. These may seem like straightforward statements of the obvious, however this does have implications for the way we respond to climate change.

Decision making on climate adaptation should be part of a much broader approach to socio-ecological protection. When making decisions about how best to adapt to climate related impacts such as flooding for example, a narrow, impact-specific approach might be to identify the threat (an overflowing river) and then come up with a cost-effective way to reduce the risk it poses to people and property (a flood barrier perhaps). Congratulations you have successfully reduced the risk of flooding – but have you increased the overall resilience of the people and the environment?

The flood barrier might have diverted the flood risk further downstream leading to flooding of a fragile ecosystem or farmland. It may have cut off vulnerable populations from accessing the market to sell their goods or reduced access to the river for fishermen, or it may provide a perverse incentive for people to build houses and property behind the barrier, increasing the potential impact of a future, more severe flood event.

Finding solutions to climate change that build long-term resilience, requires decisions that are taken in line with a coherent, systemic approach to strengthening ecosystems and protecting the lives of the most vulnerable people. Decisions that reduce climate risk or indeed cut carbon emission at the expense of either people or the environment are self-defeating.

Download the full WWF Living Planet Report by clicking here.


Cover photo by Thomas Kelley on Unsplash
Japanese cherry blossoms make early appearance: Extreme weather to blame

Japanese cherry blossoms make early appearance: Extreme weather to blame

By Georgina Wade

The annual cherry blossom bloom in Japan signals the arrival of spring. Typically occurring in early April, the event brings flocks of tourist to the region looking to experience the floral embodiment of Japan’s most deep-rooted cultural and philosophical beliefs. But never has there been a widespread cherry blossom show put on in the fall – until now. Weathernews received more than 350 reports of early blossoms.

But, what is causing this premature fall bloom? According to the Hiroyuki Wada, an arborist with the Flower Association of Japan, cherry blossom buds develop during summer but usually don’t bloom until because of a plant hormone the leaves release to slow plant growth in preparation for the winter. However, Japan was hit by both Typhoon Jebi and Typhoon Trami in September, which carried powerful winds and salty seawater, forcing trees to shed leaves before the hormone could be released, and with the additional warm air from the South, the trees were ‘tricked’ to blossom.

Category 5 Typhoon Jebi was the strongest storm to hit Japan since 1993, killing 17 people with insured losses estimated at between 2.3 and 4.5 billion USD. A few weeks later, Typhoon Trami followed suit leaving dozens injured and hundreds of thousands of homes without power. Warm air brought about by the typhoons was quickly masked by cooler conditions during the storms’ aftermath, prompting a combination of changeable weather that mimicked spring.

Although it’s clear that this year’s storm season is to blame, the premature cherry blossoming trend has been ongoing for some time. For over 1,000 years, the flowering of Japan’s cherry trees has been chronicled in the city of Kyoto. But bloom dates have shifted radically earlier in recent decades, signalling that the region is warming.

Yasuyuki Ano, a professor of environmental sciences at Osaka Prefecture University, assembled a data set that compiles blossom-flowering dates in Kyoto starting from 800 A.D. Prior to 1850, flowering dates were fairly stable.

But from 1850 to present day, the flowering period has only surged forward at the rate of about one week per century. With warmer March temperatures typically signifying an earlier bloom, scientists believe the earlier bloom dates are directly linked with rising regional temperatures. Both Kyoto’s cherry tree flowering and temperature data suggest that its climate is the warmest it has been in at least a millennium.

The buds that opened now will not be blossoming again in coming spring. Despite this early blooming, experts do not believe this event will disrupt the timing or magnificence of the bloom next spring.


Cover photo by Sora Sagano on Unsplash.
Protecting wetlands helps communities reduce damage from hurricanes and storms

Protecting wetlands helps communities reduce damage from hurricanes and storms

By Siddharth Narayan, University of California, Santa Cruz and Michael Beck, University of California, Santa Cruz

2017 was the worst year on record for hurricane damage in Texas, Florida and the Caribbean from Harvey, Irma and Maria. We had hoped for a reprieve this year, but less than a month after Hurricane Florence devastated communities across the Carolinas, Hurricane Michael has struck Florida.

Coastlines are being developed rapidly and intensely in the United States and worldwide. The population of central and south Florida, for example, has grown by 6 million since 1990. Many of these cities and towns face the brunt of damage from hurricanes. In addition, rapid coastal development is destroying natural ecosystems like marshes, mangroves, oyster reefs and coral reefs – resources that help protect us from catastrophes.

In a unique partnership funded by Lloyd’s of London, we worked with colleagues in academia, environmental organizations and the insurance industry to calculate the financial benefits that coastal wetlands provide by reducing storm surge damages from hurricanes. Our study, published in 2017, found that this function is enormously valuable to local communities. It offers new evidence that protecting natural ecosystems is an effective way to reduce risks from coastal storms and flooding.

Coastal wetlands and flood damage reduction: A collaboration between academia, conservation and the risk industry.

The economic value of flood protection from wetlands

Although there is broad understanding that wetlands can protect coastlines, researchers have not explicitly measured how and where these benefits translate into dollar values in terms of reduced risks to people and property. To answer this question, our group worked with experts who understand risk best: insurers and risk modelers.

Using the industry’s storm surge models, we compared the flooding and property damages that occurred with wetlands present during Hurricane Sandy to the damages that would have occurred if these wetlands were lost. First we compared the extent and severity of flooding during Sandy to the flooding that would have happened in a scenario where all coastal wetlands were lost. Then, using high-resolution data on assets in the flooded locations, we measured the property damages for both simulations. The difference in damages – with wetlands and without – gave us an estimate of damages avoided due to the presence of these ecosystems.

Our paper shows that during Hurricane Sandy in 2012, coastal wetlands prevented more than US$625 million in direct property damages by buffering coasts against its storm surge. Across 12 coastal states from Maine to North Carolina, wetlands and marshes reduced damages by an average of 11 percent.

These benefits varied widely by location at the local and state level. In Maryland, wetlands reduced damages by 30 percent. In highly urban areas like New York and New Jersey, they provided hundreds of millions of dollars in flood protection.

Wetland benefits for flood damage reduction during Sandy (redder areas benefited more from having wetlands). Narayan et al., Nature Scientific Reports 7, 9463 (2017)., CC BY

Wetlands reduced damages in most locations, but not everywhere. In some parts of North Carolina and the Chesapeake Bay, wetlands redirected the surge in ways that protected properties directly behind them, but caused greater flooding to other properties, mainly in front of the marshes. Just as we would not build in front of a seawall or a levee, it is important to be aware of the impacts of building near wetlands.

Wetlands reduce flood losses from storms every year, not just during single catastrophic events. We examined the effects of marshes across 2,000 storms in Barnegat Bay, New Jersey. These marshes reduced flood losses annually by an average of 16 percent, and up to 70 percent in some locations.

Reductions in annual flood losses to properties that have a marsh in front (blue) versus properties that have lost the marshes in front (orange). Narayan et al., Nature Scientific Reports 7, 9463 (2017)., CC BY

In related research, our team has also shown that coastal ecosystems can be highly cost-effective for risk reduction and adaptation along the U.S. Gulf Coast, particularly as part of a portfolio of green (natural) and gray (engineered) solutions.

Reducing risk through conservation

Our research shows that we can measure the reduction in flood risks that coastal ecosystems provide. This is a central concern for the risk and insurance industry and for coastal managers. We have shown that these risk reduction benefits are significant, and that there is a strong case for conserving and protecting our coastal ecosystems.

The next step is to use these benefits to create incentives for wetland conservation and restoration. Homeowners and municipalities could receive reductions on insurance premiums for managing wetlands. Post-storm spending should include more support for this natural infrastructure. And new financial tools such as resilience bonds, which provide incentives for investing in measures that reduce risk, could support wetland restoration efforts too.

Improving long-term resilience

The dense vegetation and shallow waters within wetlands can slow the advance of storm surge and dissipate wave energy. USACE

Increasingly, communities are also beginning to consider ways to improve long-term resilience as they assess their recovery options.

There is often a strong desire to return to the status quo after a disaster. More often than not, this means rebuilding seawalls and concrete barriers. But these structures are expensive, will need constant upgrades as as sea levels rise, and can damage coastal ecosystems.

Even after suffering years of damage, Florida’s mangrove wetlands and coral reefs play crucial roles in protecting the state from hurricane surges and waves. And yet, over the last six decades urban development has eliminated half of Florida’s historic mangrove habitat. Losses are still occurring across the state from the Keys to Tampa Bay and Miami.

Protecting and nurturing these natural first lines of defense could help Florida homeowners reduce property damage during future storms. In the past two years our team has worked with the private sector and government agencies to help translate these risk reduction benefits into action for rebuilding natural defenses.

Across the United States, the Caribbean and Southeast Asia, coastal communities face a crucial question: Can they rebuild in ways that make them better prepared for the next storm, while also conserving the natural resources that make these locations so valuable? Our work shows that the answer is yes.


This is an updated version of an article originally published on Sept. 25, 2017.The Conversation Siddharth Narayan, Postdoctoral Fellow, Coastal Flood Risk, University of California, Santa Cruz and Michael Beck, Research professor, University of California, Santa Cruz. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cover photo by NPS Everglades/Flickr (public domain)
Australian ecosystems crippling under weight of climate change

Australian ecosystems crippling under weight of climate change

By Georgina Wade

­­Ecosystems across Australia are on the brink of collapse under climate change. Research published in Nature Climate Change analysing the interaction of gradual climate trends and extreme weather events since the turn of the century describes a series of sudden and catastrophic ecosystem shifts that have occurred recently across Australia.

Amongst the most notable tragedies, a mass mortality of corals on the Great Barrier Reef occurred in 2016 after 30% of the reef’s corals died in a relentless nine-month marine heatwave with an additional 20% bleached to death in 2017. And with Australia’s average sea temperature having increased by about 1°C since the start of the 19th century and continuing to climb, the remaining corals face the same fate.

Australia is one of the most climatically variable places in the world. In a study from Environmental Research Letters, Australia showed the highest inter-annual variability of any continent and also showed the highest biome-level variability of any continent for tropical forest, temperature broadleaf forest, and tropical savannas and grasslands.

And despite being a highly populous region involving numerous activities that transform the natural landscape, Australia retains large tracts of near-pristine natural systems.

Many of these regions are iconic, providing benefits to the tourism industry and sustaining outdoor activities while providing precious ecological services. In spite of this, the stress of climate change and extreme weather events is causing environmental alterations in these valuable ecosystems.

The research examined several ecosystems across Australia that have experienced catastrophic changes in the last decade and found that undisturbed systems are not necessarily more resilient to climate change.

Describing a combination of “presses” and “pulses” in which gradual climate change can be thought of as an ongoing “press” on which the “pulse” of extreme events is now superimposed, the case studies provide a range of examples in which both can interact to push an ecosystem to a “tipping point”.

The difficulty in foreseeing the timing and severity of extreme weather events makes predicting ecosystem collapses essentially impossible. Additionally, the cost of targeted interventions can be exorbitant.

Between the uncertainty and associated costs, interventions are difficult to implement and might even require controversial methods like assisted colonisation. Ecosystem management will not only require high policy and philosophy fluidity, but decisions will increasingly need to be made faster and potentially without fully understanding ecological and evolutionary consequences.


Harris, R.M.B et al. (2018). Biological responses to the press and pulse of climate trends and extreme events. Nature Climate Change, Vol. 8, pages 579–587 (2018).

Cover photo Wikimedia Commons (CC BY-SA 3.0): Bleached branching coral (foreground) and normal branching coral (background). Keppel Islands, Great Barrier Reef.
Arctic ice depends on half a degree of heat

Arctic ice depends on half a degree of heat

By Tim Radford

Half a degree Celsius doesn’t sound like much, but for the Arctic ice it could make a world of difference.

Two separate studies have calculated what it would take to keep the Arctic ice frozen through the summer months – and thus preserve the precious polar ecosystem and help contain further global warming.

It’s simple: fulfil the promises that 195 nations made in Paris in 2015, and keep global warming to “well below 2°C” and ideally at 1.5°C by the year 2100.

That extra half a degree makes a huge difference. At a maximum global average warming of 2°C above the norm for most of human history, the Arctic could become technically ice-free once every three to five years.

Reduce carbon dioxide emissions even further, take greater steps to conserve forests and keep the global temperature at the 1.5° C maximum rise, and the chances are that the Arctic seaways will open only about one summer in 40 years.

Glaciologists consider the Arctic “ice-free” when there are only a million square kilometres of floe left. It has yet to happen. But the sea ice has become noticeably thinner, and smaller in surface area, over the last 40 years.

“The good news is that the sea has a quick response time and could theoretically recover if we brought down global temperatures . . . though  other ecosystems could see permanent negative impacts from ice loss”

For more than two decades, meteorologists and oceanographers have repeatedly warned that runaway global warming, as a consequence of ever-greater combustion of fossil fuels, could bring about an ice-free polar ocean by about 2050.

Sea ice is part of the climate machine. It reflects solar radiation and keeps the ocean cool. It provides a surface on which Arctic seals can haul out, and on which polar bears can feed.

But the catch is that, although the world’s nations almost unanimously voted in Paris to contain global warming, the pledges made at the time were nowhere near ambitious enough.

Since the Paris meeting global warming has accelerated, and one group has warned that the 1.5°C limit could be exceeded by 2026. Many researchers think that the political decisions of the next decade will be vital.

Clear benefits

Researchers already know that the 1.5°C target will deliver palpable rewards: it will make a huge difference, for instance, to sea levels, grain harvests and global fish catches.

US and Canadian climate scientists set out to see what difference half a degree would make to the Arctic. They worked with different climate simulations to reach roughly the same conclusion, in two papers in the journal Nature Climate Change.

The Canadian team calculated that at 2°C, ice-free conditions would happen every five years; at 1.5°C, the hazard would drop to one in 40 years; at 3°C, permanent ice-free summers would be likely. A second study from the US backed up the premise.

“I didn’t expect to find that half a degree Celsius would make a big difference, but it really does,” said Alexandra Jahn, of the University of Colorado at Boulder.

Higher costs

“At 1.5°C half the time we stay within our current summer sea ice regime, whereas if we reach two degrees of warming, the summer sea ice will always be below what we have experienced in recent decades.”

Higher levels of warming would impose higher costs: 4°C of warming would deliver a high probability of an ocean free of ice for three months every summer by 2050, and five months a year by 2100.

“The good news is that the sea has a quick response time and could theoretically recover if we brought down global temperatures at any point in the future,” Dr Jahn said.

“In the meantime, though, other ecosystems could see permanent negative impacts from ice loss, and those can’t necessarily bounce back.”


This article was originally published on Climate News Network and can be accessed here.

Cover photo by Anders Jildén on Unsplash.
How will climate change affect Arctic caribou and reindeer?

How will climate change affect Arctic caribou and reindeer?

By Conor Mallory, University of Alberta

This spring, I spent close to two weeks flying over central Nunavut, peering out the window of a small plane at the rolling tundra below, looking for and counting caribou to monitor their numbers.

The Qamanirjuaq barren-ground herd were arriving on their tundra calving grounds to give birth after migrating from winter ranges in the boreal forest. At times caribou dotted the landscape all the way to the horizon.

The terrain here is relatively pristine. There are few communities or developments. Due to the remoteness of the herd’s habitat, it is, in some ways, hard to imagine that human activities — whether climate change or industrial disturbance — could ever be of much concern to them.

And yet, we know that human activity and disturbance provide the most imminent threat to the persistence of many caribou and reindeer populations. (Reindeer and caribou are the same species, Rangifer tarandus, but have different English names in North America and Eurasia. Of course, the species has many names in different languages across the world, such as tuktu in Inuktitut.)

A complicated problem

Just how this iconic Arctic species will be affected in a warming climate remains unclear. Current predictions suggest that the climate will continue to change for decades into the future, regardless of the mitigation actions we take.

Caribou and reindeer have tremendous socioeconomic value in the north, and if we want to maintain sustainable caribou harvesting and husbandry in the future, we must understand how they will respond to environmental change.

My colleagues and I reviewed hundreds of scientific papers that studied caribou and reindeer from Alaska to Nunavut to Russia. By the end, we produced a complete picture of how climate change may affect the caribou and reindeer species, based on current knowledge.

We found that it’s challenging to make general predictions. The species has a circumpolar distribution and inhabits a variety of ecosystems, both similar and distinct. How different populations will respond to varying effects of climate change in this diverse range of systems is complex.

Summer effects

In many regions, climate change is causing longer and warmer summers. In the context of caribou, which live in colder regions, this typically means longer growing seasons and better access to nutritious plants throughout the summer months.

But plants are not the only part of the ecosystem affected by longer and warmer summers. Parasitic flies, particularly warble flies and botflies, torment caribou during the summer months. These insects aren’t just looking for blood like mosquitoes and black flies — they’re trying to lay their eggs on a caribou’s skin or in its nose.

As you can likely imagine, caribou want no part of this. They will spend hours running to escape these parasites, which means they spend less time feeding.

For a given region or herd, will increased plant growth or increase insect harassment have more of an effect on caribou?

We’re already seeing some of these effects play out. In Svalbard, Norway, warmer summers have been generally positive for caribou, as better plant growth has led to heavier animals in the fall. But in Arctic North America, more green growth has been associated with declines in caribou populations, possibly due to the northward expansion of less nutritious shrubs.

Research has shown that insects have been trouble for caribou in Arctic Finland. There, warmer weather brought more insects that harassed caribou calves, which led to less weight gain and more calf deaths.

Winter effects

Winter warming produces similarly complex effects. Climate change is predicted to increase the frequency of winter icing. Icing is usually caused by rain-on-snow or thaw-freeze events, and presents a real problem for caribou.

During the winter caribou dig in the snow to get to food underneath. Icing events trap food beneath an impenetrable layer of ice. These events have led to mass starvation of Arctic caribou and reindeer in the past.

On the other hand, longer autumns and earlier springs shorten the winter period of food scarcity. This should benefit caribou, but the net effect will depend on the balance of these changes in a given region.

These are just some of the wide-ranging potential implications of climate change for Arctic caribou and reindeer. They may also shift their ranges northward and alter their migratory behaviour in response to climate change, or begin sharing their lands with new or increased competitor species such as moose and white-tailed deer.

Importance of caribou and reindeer

Caribou and reindeer provide incredible value throughout the circumpolar world. In ecological terms, they are the most abundant large terrestrial herbivore. They have important grazing effects on plant communities and support predator populations.

The ecological importance of caribou means that changes to caribou and reindeer populations affect many other organisms, including wolves, Arctic shrubs and lichens.

They also have huge socioeconomic value. One report conservatively suggests that three herds in northern Canada provide the equivalent of $20 million dollars annually in food alone. Semi-domesticated reindeer similarly contribute huge value to those who herd them, including the Saami people of Finland, Russia, Norway and Sweden.

If there is a silver lining to this, it’s that we know caribou and reindeer live in a wide variety of environments and ecosystems — and this may provide them with some resilience.

But we don’t know if their ability to adapt is sufficiently agile to respond to the ongoing rapid environmental change in the north.

The ConversationScientists like myself need to work together with wildlife managers and harvesters to unravel the complexity of responses to environmental change. This information will be key to making decisions about caribou going forward.


Conor Mallory, PhD Student, University of Alberta. This article was originally published on The Conversation. Read the original article.

Cover photo by Christopher Michel (CC BY 2.0): Svalbard reindeer.
Reducing flood risk with the help of ecosystems

Reducing flood risk with the help of ecosystems

By Caroline Fouvet

While Houston is still reeling from the impacts of Hurricane Harvey, it appears that one of the city’s main vulnerabilities were its vast impervious surfaces. Concrete, asphalt and various types of surface materials prevent the absorption of water into the soil, and when gallons of rain pour down on urban areas, drainage systems get saturated. Ecosystems could make a substantial contribution to flood risk reduction and enhance urban resilience.

In the case of Hurricane Sandy, a study demonstrated that the presence of marsh wetlands avoided $625 million in direct flood damages across 12 states, as coastal wetlands reduced flood heights. This illustrates that ecosystems can greatly contribute to flood prevention, in particular for low-lying cities. There are different types of ecosystems that can increase cities’ resilience to flooding. However, many of these ecosystems are threatened by human activity, and initiatives are currently being implemented to mainstream their use and strengthen the resilience of low-lying and coastal cities.

Wetlands are diverse and can be found at different locations. For instance, marshes, areas of grassy vegetation and peaty soil, are common in floodplains while tidal wetlands, characterised by reeds, mangroves and mudflats, are located at river mouths. Forested wetlands and ponds are additional wetland types that can absorb large amounts of water runoff and help regulate overland floods. Besides, other forms of ecosystems, such as coral reefs, play an important role in protecting low-lying urban areas. They provide natural barriers against wave energy, an essential aspect to consider when it comes to storm surges and rising sea levels, and act against coastal erosion. Consequently, protecting those ecosystems is essential to leverage the potential flood protection they provide. Wetlands are currently threatened by manmade activities such as new build-up or pasture areas that convert them into non-wetland zones, pollution emanating from untreated wastewater and vegetation clearing. These decrease the wetlands’ capacity to hold back and absorb water.

There currently exist several initiatives that focus on protecting and using those ecosystems against floods. In Bangladesh for example, an initiative funded by the Least Developed Country Fund, focuses on coastal afforestation as a way to increase community resilience. Part of the project is dedicated to planting protective and productive vegetation, including mangroves, to protect communities’ livelihoods from extreme weather events and sea level rise.

The insurance industry is also interested in ecosystems’ capacity to act against flooding. During an event on environmental protection held at the United Nations Office for Disaster Risk Reduction (UNISDR), insurers acknowledged that investments in natural solutions played an important role in risk reduction. Representatives of academia, conservancy institutions and insurers also teamed up to release a study on wetlands’ contribution to reducing floods in the US and included those ecosystems in flood models. Although wetlands are rarely considered in flood risk assessments, the study demonstrated that in high risk areas in New Jersey for instance, “marshes reduce risks to property by as much as 70%” showing the immense impact ecosystems could have on flood risk if managed properly.


Cover photo: U.S. Marine Corps photo by Lance Cpl. Niles Lee/Released (public domain). Marines unload supplies to assist families in Orange, Texas, Sept. 3, 2017. The Marines assisted the Red Cross by transporting supplies from the Red Cross warehouse to families in Orange, Texas, affected by Hurricane Harvey.