̽��ֱ�� of Cambridge - Ecosystem

Lack of evidence hampers progress on corporate-led ecosystem restoration

jg533 — Fri, 08 Sep 2023 07:47:52 +0000

An international team of scientists has analysed publicly available sustainability reports released by 100 of the world’s largest companies and found that despite many businesses claiming to actively rebuild damaged ecosystems, very little is known about what is actually being achieved.

Efforts to rebuild degraded environments are vital for achieving global biodiversity targets, and corporate-led projects offer huge potential to restore damaged and lost ecosystems around the globe.

But the study reveals that over 90 percent of corporate-led restoration projects fail to report a single ecological outcome. Around 80 percent of projects do not reveal how much money is invested in restoration, and a third fail to even state the area of habitat that they aim to restore.

̽��ֱ��United Nations has launched a Decade on Ecosystem Restoration, and in recent years businesses around the world have collectively pledged to plant billions of trees, hundreds of thousands of corals and tens of thousands of mangroves. Around two thirds of the top 100 largest global corporations undertake ecosystem restoration.

̽��ֱ��study is published in the journal Science.

“Ultimately, if big businesses are going to contribute effectively to the UN Decade on Ecosystem Restoration, there needs to be transparency and consistency in reporting,” said Professor Rachael Garrett, Moran Professor of Conservation and Development at the ̽��ֱ�� of Cambridge Conservation Research Institute, and a co-author of the report.

She added: “This is in the interest of the businesses themselves, who stand to gain from demonstrating to their customers, shareholders, employees and the wider public that they are making meaningful impacts with their declared restoration efforts.

“ ̽��ֱ��world’s largest corporations have the potential to lift ecosystem restoration efforts to an unprecedented scale. But their involvement has to be managed with proper evidence and accountability, to make sure the outcomes are beneficial and fair for everyone.”

Many countries require businesses to conduct Environmental Impact Assessments (EIAs) to quantify and reduce their environmental damage, and other private-sector initiatives also encourage companies to measure and disclose their biodiversity impacts. However, the study finds that current guidelines and legal frameworks around ecosystem restoration are inadequate, and are not yet resulting in appropriate reporting by businesses.

̽��ֱ��researchers are calling for more transparency around the reporting of corporate-led ecosystem restoration projects, and for reporting to be more consistently centred around scientific principles that determine ecosystem restoration success.

“Restoring degraded ecosystems is an urgent challenge for this decade, and big businesses have the potential to play a vital role,” said Dr Tim Lamont at Lancaster ̽��ֱ��, lead author of the study.

He added: "With their size, resources and logistics expertise, they could help deliver the large-scale restoration we need in many places. But at the moment there is very little transparency, which makes it hard for anyone to assess if projects are delivering benefits for ecosystems or people.

“When a business says it has planted thousands of trees to restore habitat and soak up carbon – how do we know if this has been delivered, if the trees will survive, and if it has resulted in a functioning ecosystem that benefits biodiversity and people? In many cases, we’ve found that the evidence provided by large corporations to support their claims is insufficient.”

̽��ֱ��researchers say new improved reporting guidelines around ecosystem restoration should:

Recommend that companies clearly differentiate between restoration activities that merely mitigate the negative environmental impacts of a business’ operations from those that aim to provide wider climate, biodiversity and social justice outcomes.
Recommend a principle-based approach, drawing from conservation science, for planning and reporting, so that restoration projects in a range of different contexts can all maintain high standards across core areas.
Ensure corporations engage with and empower local stakeholders to co-design restoration projects from the outset.

Reference

Lamont, T, et al: 'Hold big business to task on ecosystem restoration: corporate reporting must embrace holistic principles from restoration science.' Sept 2023, Science. DOI: 10.1126/science.adh2610

Adapted from a press release by Lancaster ̽��ֱ��.

A near total lack of transparency is making it impossible to assess the quality of corporate-led ecosystem restoration projects, a new study finds.

̽��ֱ��world’s largest corporations have the potential to lift ecosystem restoration efforts to an unprecedented scale. But their involvement has to be managed with proper evidence and accountability, to make sure the outcomes are beneficial and fair for everyone.

Rachael Garrett

Tim Lamont

Degraded coral reef 'rubblefield' in Indonesia

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Cambridge researchers lead policy briefing on Nature-based Solutions for the climate and biodiversity crises

Anonymous — Fri, 30 Apr 2021 13:38:29 +0000

Nature-based Solutions (NbS) – solutions to societal challenges that involve working with nature – are such a solution. Examples include tree planting to sequester atmospheric carbon and restoring coastal habitats to mitigate floods.

Now, a group of researchers led by Professor David Coomes and Rogelio Luque-Lora from the ̽��ֱ�� of Cambridge Conservation Research Institute, have published a policy briefing outlining the underlying concepts of NbS as well a list of strategies and policy recommendations to take NbS to their full potential, in advance of the United Nations Climate Change Conference which will be held in Glasgow later this year.

̽��ֱ��briefing has been produced in association with the COP26 Universities Network, a group of UK-based universities and research institutes, including the ̽��ֱ�� of Cambridge and Cambridge Zero.

As explained by the authors, Nature-based Solutions can deliver both climate change mitigation and adaptation. Mitigation involves reducing the degree of climate change: planting trees to absorb carbon dioxide, for example. Adaptation is about reducing communities’ exposure and vulnerability to the negative effects of climate change, by providing flood protection, for example. And by enhancing biodiversity, NbS can also boost the resilience of ecosystems to changing climate conditions.

Nature-based Solutions often work by protecting existing ecosystems, which prevents further release of carbon into the atmosphere and safeguards the biological diversity attached to those ecosystems. They can also work by restoring habitats which have previously been degraded, improving the ability of these habitats to sequester carbon and host biodiversity. Both these strategies also have the potential to enhance the provision of ecosystem services, including water filtration and soil retention.

Other strategies include the sustainable management of working landscapes, such as agricultural land, and the creation of new habitats. ̽��ֱ��latter has also been referred to as ‘green engineering’ or ‘green infrastructure’, and can contribute to societal adaptation to climate change by cooling and cleaning the air in cities and providing physical and mental health benefits.

In the UK, NbS can support job creation and livelihoods, and can play a key role in ‘building back better’ after COVID-19 and can be more cost-effectively deployed than non-NbS approaches to mitigation and adaptation.

There is also scope for the UK use its presidency of COP26 to promote effective and fair NbS across the globe. In this context, the authors recommends that the UK promotes a broad range of NbS that go beyond the present emphasis on tree planting. In fact, while the authors acknowledge that commercial forestry plantations can be necessary to meet societal demand for timber and wood pulp, they caution that the promotion of afforestation with non-native species can have detrimental effects on biodiversity, for example when they replace species-rich grassland ecosystems. They can also lead to the release of carbon into the atmosphere, if carbon-rich habitats such as peatland are replaced by the shallower soils of plantations.

̽��ֱ��authors warn, too, that NbS can never be a substitute to the urgent and thorough decarbonisation of the economy. NbS can only contribute to meeting international climate targets if they act as a complement to the main task of transitioning away from fossil fuels. There is a risk that NbS could be used to justify ‘business as usual’, by conveying the illusion that emissions are being compensated for by deploying NbS.

NbS are most effective when they are strategically deployed to minimise trade-offs and deliver simultaneous wins. For example, restoring upland peat in the UK can help to protect communities from flooding and soil erosion while also storing carbon, providing recreational space and natural habitat for wildlife with negligible loss of agricultural potential on the national scale. In contrast, replacing highly productive agricultural land with natural habitats could make the UK more dependent on food imports.

Also, crucially, local communities must be involved in every stage of the planning and implementation processes. This is essential to ensure that local people do not overwhelmingly bear any costs associated with NbS, that they receive a just share of the benefits, and that they support the projects in the medium and long terms.

“I am excited by the opportunities that COP26 will provide to make the most of the potential of NbS to deliver climate change mitigation while benefitting biodiversity and livelihoods,” said Coomes.

Adapted from a story published on the UCCRI website.

As societies face the triple challenge of avoiding the worst effects of climate change, protecting remaining biodiversity and improving human wellbeing, there are calls to end siloed thinking and design solutions that address these problems simultaneously.

Rob Barnes under licence from AGEDI

Mangrove ready to be planted

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Ecosystems Overload

fpjl2 — Tue, 10 Dec 2019 09:48:57 +0000

We are laying waste to the biosphere. If we're serious about saving millions of species, then it's our own that must change how it thinks about, lives off and values the planet it inhabits.

Illuminating the hidden kingdom of the truffle

lw355 — Mon, 12 Feb 2018 11:00:12 +0000

“A unique aroma, a combination of newly plowed soil, fall rain, burrowing earthworms and the pungent memory of lost youth and old love affairs,” wrote the late American food writer Josh Ozersky about truffles.

His sensual words echo the almost hedonistic regard with which truffles are held, and go some way to explaining a price tag of around £1,700 per kilo for rarer species like the Périgord black truffle, and predictions that global sales of truffles will reach several billion GBP annually in the next decades.

Yet very little is known about the biology and ecology of these unassuming-looking fungi that grow naturally in connection with the fine root systems of trees.

Now, with the help of a well-experienced ‘truffle dog’ called Lucy and the Cambridge ̽��ֱ�� Botanic Garden, researchers from Cambridge’s Department of Geography have begun a ‘natural’ experiment to study the seasonal changes and productivity of the Burgundy truffle.

More common than the Périgord black truffle and the rarer-still white Alba truffle, Burgundy truffles are found across Europe and the eastern part of England, including in the 40-acre Botanic Garden planted by Charles Darwin’s mentor Professor John Stevens Henslow in 1846.

“We really don’t know much about the life of a truffle,” explains Professor Ulf Büntgen who, with PhD student Elisabeth Johnson, hopes to discover how, when and where truffles grow and mature, how their spores are dispersed and by which animals, and how their lifecycle is affected by changing environmental conditions, including climate.

“Truffles are remarkable organisms and interesting ambassadors for our fascinating but fragile soil ecosystems, which are considered one of the last big frontiers in science,” says Johnson. “Being able to delve into the mysteries of one of their enigmatic inhabitants is thrilling, especially since they are directly linked to above-ground biodiversity through their partnership with trees – it’s a meeting of two worlds.”

“ ̽��ֱ��beauty of using the Garden for this kind of research is that we have over 8,000 plant species and we’ve been here for 170 years. ̽��ֱ��trees have had lots of time to establish connections with truffles,” adds Professor Beverley Glover, Director of the Garden.

Truffles live in symbiotic partnership with a host tree – the plant delivers sugars and the fungi provide nutrients. However, as soon as the truffle is unearthed, the truffle’s ecosystem, including its mutualistic partnership, is destroyed.

“No-one has succeeded in creating the necessary complexity of real-world conditions in a normal lab to understand the below-ground lifecycle of the truffle,” explains Büntgen. “ ̽��ֱ��Cambridge ̽��ֱ�� Botanic Garden is an almost perfect living laboratory, potentially allowing us a glimpse into the life cycle and community structures of truffles across time and space. It is an immense privilege to be able to carry out this kind of research at this historic site.”

̽��ֱ��Garden was founded to support the ̽��ֱ��’s teaching and research, which it still does today. “What’s exciting about this project for the Garden team are the many ‘firsts’,” says Glover. “It’s the first time we’ve looked at the truffles below our trees, the first time we’ve had a dog involved in research, and as far as we know it’s the first time in the world that anyone has looked at which species of tree these truffles can grow on.”

One area of interest to the researchers is the possibility of climate-induced range shifts in the habitats of truffles. Büntgen’s previous research looked at why yields of the Périgord truffle in Spain, France and Italy have been in decline since the mid-1970s. His work using tree rings as a read-out for the effect of climate on growth showed that falling Mediterranean truffle harvests coincided both with drier summers and reduced growth of Spanish oaks.

In another recent study, Büntgen described the first cultivation of Périgord black truffles in the UK, suggesting that black truffles are able to grow far outside their native habitat.

“Ecological range shifts can have implications for rural tourism, regional agriculture and global prices,” he adds. “We hope that new understanding of the hidden life of the Burgundy truffle will help us to understand the environmental drivers of the growth and maturation of other members of this remarkable family.”

̽��ֱ��results from the long-term Botanic Garden experiment will be combined with a larger study of around 30 sites in Switzerland, Germany and Spain.

Lucy will be vital to the success of the project. Büntgen trained his family pet in just four days. Given the chance, she would happily search the undergrowth for many hours simply for the pleasure of finding, digging up and wolfing down one of these nutty-smelling delicacies.

“You never train a dog to smell a truffle – they smell everything. You just train the connection. Lucy is a hunting dog that likes food – she’d harvest for six hours in a row if we let her. Without a dog like Lucy you simply don’t know where to dig.”

Once Lucy has found a truffle, the researchers move in quickly, before she has the chance to snaffle the luxury. As she happily eats her own reward, Büntgen and Johnson take measurements, recording aspects of the truffle and its environment, including its host tree, before removing it for further analysis.

Meanwhile Johnson has decided not to eat truffles for the duration of her PhD: “I find them far too fascinating to eat. Discovering truffles as living beings in our complex ecosystems as a whole gives me immense delight. When not removing them in the name of science, we try to leave their habitat relatively undisturbed to understand how they interact with wildlife and how they unfold new living networks within the deeply fascinating and little-understood world below our feet.”

All truffles unearthed at the Botanic Garden are for research purposes.

Truffles are one of the world’s most expensive ingredients, and also one of the most mysterious. Now, with the help of a 170-year-old ‘living laboratory’, and a dog called Lucy, researchers hope to unearth new understanding of the secret life of these underground delicacies.

Truffles are remarkable organisms and interesting ambassadors for our fascinating but fragile soil ecosystems

Elizabeth Johnson

Illuminating the hidden kingdom of the truffle

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Birds learn from each other’s ‘disgust’, enabling insects to evolve bright colours

fpjl2 — Mon, 18 Dec 2017 16:01:33 +0000

Many animals have evolved to stand out. Bright colours may be easy to spot, but they warn predators off by signalling toxicity or foul taste.

Yet if every individual predator has to eat colourful prey to learn this unappetising lesson, it’s a puzzle how conspicuous colours had the chance to evolve as a defensive strategy.

Now, a new study using the great tit species as a “model predator” has shown that if one bird observes another being repulsed by a new type of prey, then both birds learn the lesson to stay away.

By filming a great tit having a terrible dining experience with conspicuous prey, then showing it on a television to other tits before tracking their meal selection, researchers found that birds acquired a better idea of which prey to avoid: those that stand out.

̽��ֱ��team behind the study, published in the journal Nature Ecology & Evolution, say the ability of great tits to learn what to avoid through observing others is an example of “social transmission” of information.

̽��ֱ��scientists scaled up data from their experiments through mathematical modelling to reveal a tipping point: where social transmission has occurred sufficiently in a predator species for its potential prey to stand a better chance with bright colours over camouflage.

“Our study demonstrates that the social behaviour of predators needs to be considered to understand the evolution of their prey,” said lead author Dr Rose Thorogood, from the ̽��ֱ�� of Cambridge’s Department of Zoology.

“Without social transmission taking place in predator species such as great tits, it becomes extremely difficult for conspicuously coloured prey to outlast and outcompete alternative prey, even if they are distasteful or toxic.

“There is mounting evidence that learning by observing others occurs throughout the animal kingdom. Species ranging from fruit flies to trout can learn about food using social transmission.

“We suspect our findings apply over a wide range of predators and prey. Social information may have evolutionary consequences right across ecological communities.”

Thorogood (also based at the Helsinki Institute of Life Science) and colleagues from the ̽��ֱ�� of Jyväskylä and ̽��ֱ�� of Zürich captured wild great tits in the Finnish winter. At Konnevesi Research Station, they trained the birds to open white paper packages with pieces of almond inside as artificial prey.

̽��ֱ��birds were given access to aviaries covered in white paper dotted with small black crosses. These crosses were also marked on some of the paper packages: the camouflaged prey.

One bird was filmed unwrapping a package stamped with a square instead of a cross: the conspicuous prey. As such, its contents were unpalatable – an almond soaked with bitter-tasting fluid.

̽��ֱ��bird’s reaction was played on a TV in front of some great tits but not others (a control group). When foraging in the cross-covered aviaries containing both cross and square packages, the birds exposed to the video were quicker to select their first item, and 32% less likely to choose the ‘conspicuous’ square prey.

“Just as we might learn to avoid certain foods by seeing a facial expression of disgust, observing another individual headshake and wipe its beak encouraged the great tits to avoid that type of prey,” said Thorogood.

“By modelling the social spread of information from our experimental data, we worked out that predator avoidance of more vividly conspicuous species would become enough for them to survive, spread, and evolve.”

Great tits – a close relation of North America’s chickadee – make a good study species as they are “generalist insectivores” that forage in flocks, and are known to spread other forms of information through observation.

Famously, species of tit learned how to pierce milk bottle lids and siphon the cream during the middle of last century – a phenomenon that spread rapidly through flocks across the UK.

Something great tits don’t eat, however, is a seven-spotted ladybird. “One of the most common ladybird species is bright red, and goes untouched by great tits. Other insects that are camouflaged, such as the brown larch ladybird or green winter moth caterpillar, are fed on by great tits and their young,” said Thorogood.

“ ̽��ֱ��seven-spotted ladybird is so easy to see that if every predator had to eat one before they discovered its foul taste, it would have struggled to survive and reproduce.

“We think it may be the social information of their unpalatable nature spreading through predator species such as great tits that makes the paradox of conspicuous insects such as seven-spotted ladybirds possible.”

A new study of TV-watching great tits reveals how they learn through observation. Social interactions within a predator species can have “evolutionary consequences” for potential prey – such as the conspicuous warning colours of insects like ladybirds.

We suspect our findings apply over a wide range of predators and prey. Social information may have evolutionary consequences right across ecological communities

Rose Thorogood

Per Tillmann

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Biggest library of bat sounds compiled to track biodiversity

jeh98 — Thu, 14 Apr 2016 11:41:21 +0000

An international team led by scientists from the ̽��ֱ�� of Cambridge, ̽��ֱ�� College London (UCL), and the Zoological Society of London (ZSL), developed the reference call library and a new way of classifying calls to accurately and quickly identify and differentiate bat species.

̽��ֱ��researchers say the method can be used to monitor biodiversity change and complete information on bat species distributions in remote and understudied regions in Mexico. It could also be expanded for use in other areas across the Neotropics, which incorporates South and Central America, and the Caribbean Islands and Florida.

It is the first time automatic classification for bat calls has been attempted for a large variety of species, most of them previously noted as hard to identify acoustically.

“Audio surveys are increasingly used to monitor biodiversity change, and bats are especially useful for this as they are an important indicator species, contributing significantly to ecosystems as pollinators, seed dispersers and suppressors of insect populations,” explains lead author Dr Veronica Zamora-Gutierrez, from the ̽��ֱ�� of Cambridge Conservation Research Institute and UCL.

“By tracking the sounds they use to explore their surroundings, we can characterise the bat communities in different regions in the long term and gauge the impact of rapid environmental change.”

“Before now it was tricky to do as many bat species have very similar calls and differ in how well they can be detected. We overcame this by using machine learning algorithms together with information about hierarchies to automatically identify different bat species.”

For the study, published today in Methods in Ecology and Evolution, the researchers ventured into some of the most dangerous areas of Mexico, primarily the northern deserts, to collect 4,685 calls from 1,378 individual bats from 59 of the over 130 species occurring in Mexico.

Most of the areas hadn’t been sampled before and the data collected, along with additional information from collaborators, provides calls for over half of the species and all of the families of bats in Mexico.

Co-author, Professor Kate Jones, UCL and ZSL, said: “We’ve shown it is possible to reliably and rapidly identify bats in mega-diverse areas, such as Mexico, and we hope this encourages uptake of this method to monitor biodiversity changes in other biodiversity hotspot areas such as South America.”

“Our ability to readily map ecological communities is imperative for understanding the impact of the Anthropocene and implementing effective conservation measures.”

̽��ֱ��team now plan on developing a citizen science monitoring programme for Mexican bats to collect further information on bat calls. They will also develop more robust tools for bat identification using the Bat Detective website which will allow them to refine the machine learning algorithms used by the software.

̽��ֱ��study also involved researchers from the IPN CIIDIR Durango (Mexico), Universidad Veracruzana (Mexico), Western ̽��ֱ�� (Canada), ̽��ֱ�� of Bristol, ̽��ֱ�� of Ulm (Germany), Smithsonian Tropical Research Institute (Panama), Ernst-Moritz-Arndt ̽��ֱ�� (Germany), ̽��ֱ�� College Dublin and ̽��ֱ�� of Warwick. It was kindly funded by CONACYT, Cambridge Commonwealth European and International Trust, ̽��ֱ��Rufford Foundation, American Society of Mammalogists, Bat Conservation International, Idea Wild, ̽��ֱ��Whitmore Trust and Engineering and Physical Sciences Research Council (EPSRC).

Adapted from a ̽��ֱ�� College London press release.

Inset image: ̽��ֱ��western yellow bat (Lasiurus xanthinus) is a species of vesper bat found in Mexico and the south-western United States (UCL/ZSL).

Researchers have compiled the largest known library of bat calls to identify and conserve rare species in Mexico – a country which is home to many of the world’s bats and has one of the highest rates of species extinction and habitat loss.

Bats are especially useful for monitoring biodiversity change as they are an important indicator species, contributing significantly to ecosystems

Veronica Zamora-Gutierrez

Noel Reynolds

Bat

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

What's the point of midges - and how do you stop them biting?

amb206 — Wed, 26 Aug 2015 08:00:00 +0000

Scroll to the end of the article to listen to the podcast.

Dr Henry Disney (Department of Zoology) has been fascinated by insects since he was four years old. His career has taken him all over the world. Despite losing 75% of his sight in 2012, Disney walks every day to his lab, where use of the latest imaging and magnifying technology enables him to continue his research. Below, Disney answers questions about the tiny insects that can, during summer months, turn a camping holiday on the beautiful west coast of Scotland into a nightmare.

What are midges?

Midges are classified as Diptera – which comes from the Greek for two wings. Diptera fall into three main groups: higher flies, middle flies and lower flies. Midges, like mosquitoes, fall into the lower group, which are the most ancient. They are typified by long antennae which have many segments. Some Diptera are enormously important as a threat to human health: they include many species in which the females suck blood and, in many parts of the world, transmit diseases such as yellow fever and malaria.

What is the life cycle of a midge?

̽��ֱ��speed at which midges reproduce is temperature dependent. In the UK, you might get two or three generations a year. In the hot and steamy environment of Cameroon, where I’ve worked as a medical entomologist, you might see a new generation emerging every three weeks. Adult females lay their eggs in the water or on the margins of water. ̽��ֱ��eggs hatch into free-living larvae which go through several moults before they pupate. ̽��ֱ��adult emerges and sits on its empty case for a moment to open its wings before buzzing off.

When are midges most visible?

Midges are easiest to spot when groups of them dance in mid-air. What you’re seeing are the males saying to the females: here we are, where are you? They give off a signal that's partly smell and partly sound. If you watch really carefully, you might see a pair of midges dropping out of the group to mate. Midges swarm near an object such as a branch which gives them a point of reference. Sometimes they gather in such numbers that they make huge towers. So many midges once swarmed on Salisbury Cathedral that the fire brigade was called; it looked as if the spire was swathed in smoke.

How many species of midge are there?

In the UK, alone there are more than 500 species of non-biting midges and more than 150 species of biting midges. Identification of the species is primarily based on details of the male genitalia examined under a microscope. Increasingly this is supplemented by the use of DNA ‘barcodes’.

Why do midges bite?

Only the females bite. They need a protein-rich meal of fresh blood in order to mature their eggs. Both the males and the females rely on sugar meals for energy for flight but the females need more than this to ensure the next generation. Female midges feed on the blood of birds as well as mammals. Each species has its own preferred choice of host.

What is the midge's place in the ecosystem?

Meniscus midges live at the point where air and water meet – a zone known as the surface film. It’s a habitat that supports a whole community of plants and animals, many of them still unexplored. Some minute organisms spend their lives within the surface film; others, like meniscus midges, spend their larval lives feeding on it.

̽��ֱ��boundary where air and water connect is rich in resources. ̽��ֱ��larvae of non-biting midges feed on algae and bacteria, filtering micro-organisms out of the water, but some are predators. ̽��ֱ��larvae of phantom midges live in the open water and prey on water fleas and small larvae. Adult midges are eaten by all kinds of things - from spiders to swallows. ̽��ֱ��larvae are eaten by fish, dragonfly larvae, water beetles and other predators.

What can midges tell us about the environment?

̽��ֱ��apparent boundary between air and water of ponds and other bodies of water is masked by a layer of lipoprotein leached from organic materials. Within this ‘membrane’ live all kinds of microorganisms – bacteria and so on. Some of it drops in from above and some of it rises up from below. Hundreds of species depend on the ‘membrane’ for food as well as on the prey that inhabits it. Changes to the structure and content of this membrane will affect all these species.

Research has shown that midges are some of the most sensitive indicators of pollution in water. ̽��ֱ��presence of some species is a sign of a healthy water course with normal oxygen levels; their absence is a sign of lower oxygen levels and can point to pollution. Water authorities sample the numbers and species of midges present in a water course above and below a discharge – for example from a sewage treatment plant – to monitor contamination of the water by organic matter.

Oil, and detergents used to disperse oil, also alter the character of the surface layer – and will have a negative effect on species such as meniscus midge larvae that depend on this delicately balanced habitat.

What more is there to learn about midges?

Some insects have economic and medical importance. For example, there's a huge body of literature devoted to mosquitoes. Anything that bites and transmits disease is likely to attract research funding. A Scandinavian team showed that midge bites could lead to a mild fever but its effects were short-lived and quickly alleviated. Although midges are known as ‘Scotland's secret weapon’, there is no need to worry about being bitten leading to serious problems. However, biting midges have been implicated in transmitting a disease of livestock. In hot climates, midges are known to spread both African Horse Sickness and Blue Tongue virus.

There is still much to learn about midges and novel biological methods of control, that avoid the use of pesticides, for those species posing problems.

How did you get interested in insects?

I was always fascinated by natural history. When I was around four, I disappeared and everyone was out looking for me. I was found sitting among some cabbages watching a caterpillar. An aunt hugely encouraged me and left me a small legacy with which I bought my first microscope. I'm still using it more some 50 years later. My career has been immensely varied - I've worked in medical entomology in Belize and Cameroon. Since my move to Cambridge, I’m occasionally asked to report on specimens from forensic cases - including some involving infamous crimes – as well as pest problems and medical cases. I’ve authored, and contributed to, several books and written hundreds of papers. I’m never bored.

̽��ֱ��most important question of all: how do you keep midges at bay if you have to work in areas where they are rife?

̽��ֱ��most effective solution for people working outdoors is to wear a loose net over-garment with a hood, impregnated with DEET, over one's normal clothing. This lasts longer than applying DEET to one's skin or normal clothing. We used to test these against alternatives when running the annual field course at my field centre in Yorkshire for the London School of Hygiene and Tropical Medicine.

Next in the Cambridge Animal Alphabet: N is for an animal that won't win any beauty contests, but can live for 30 years and may be able to help in the development of new therapies for chronic pain.

Have you missed the series so far? Catch up on Medium here.

Inset images: Adult Dixella in side view (from British Dixidae (Meniscus Midges) and Thaumaleidae (Trickle Midges) by Henry Disney, published by the Freshwater Biological Association); Dorsal view of adult Dixa BM, BL, median and lateral bands on the scutum (from British Dixidae (Meniscus Midges) and Thaumaleidae (Trickle Midges) by Henry Disney, published by the Freshwater Biological Association).

Home page banner image: A chironomid midge. Credit: S Rae

The Cambridge Animal Alphabet series celebrates Cambridge's connections with animals through literature, art, science and society. Here, M is for Midge as we talk to eminent ecologist Dr Henry Disney about his lifelong interest in Diptera.

When I was four, I disappeared and was found sitting among some cabbages watching a caterpillar

Henry Disney

From British Dixidae (Meniscus Midges) and Thaumaleidae (Trickle Midges) published by the Freshwater Biological Association

Dorsal view of adult Dixa BM, BL, median and lateral bands on the scutum

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Does it help conservation to put a price on nature?

sc604 — Thu, 30 Oct 2014 18:00:00 +0000

Putting a price on the services which a particular ecosystem provides may encourage the adoption of greener policies, but it may come at the price of biodiversity conservation. Writing today (30 October) in the journal Science, Professor Bill Adams of the ̽��ֱ��’s Department of Geography argues that assigning a quantitative value to nature does not automatically lead to the conservation of biodiversity, and may in fact contribute to species loss and conflict.

While assigning a monetary value to the benefits of an ecosystem can be an essential tool in the environmental planning process, unequal access to those benefits, particularly where there are differences in wealth and power, can lead to poor trade-offs being made, both for the ecosystem itself and those who rely on it.

“Putting a price on what nature provides is not in itself a conservation measure,” said Adams. “There is a risk that traditional conservation strategies oriented toward biodiversity may not be effective at protecting the economic benefits of an ecosystem, and vice-versa.”

For example, when stream channels in the US state of Maryland were re-engineered to provide a means of natural flood control, it ended up causing the loss of trees which had been growing next to the water and were unable to adapt to their new, drier environment.

̽��ֱ��ways in which we depend on our natural environment are increasingly expressed as ‘ecosystem services’, or the range of benefits we get from nature for free. These benefits include the provision of food and clean water, erosion control and carbon storage. Quantifying the value of nature in this way is meant to allow policymakers to consider the potential economic and social impacts of altering a particular habitat.

This approach does sometimes lead to win-win scenarios, where the value of ecosystem services is dependent upon a high level of biodiversity. One example is in the coffee plantations of Costa Rica, where the retention of forest habitat in areas around the plantations doubled the amount of pest control of coffee berry borer beetle provided by birds, which benefitted the coffee farmers while protecting biodiversity.

However, consideration of ecosystem services when making decisions does not automatically lead to retention of biodiversity. “In many cases, trade-offs are made,” said Adams.

Several factors cause tension between biodiversity conservation and ecosystem services. One problem is that the biological and physical processes that guarantee the supply of specific ecosystem services may be different from those that support valued species. An ecosystem that is managed to deliver particular services may not support particular elements of biodiversity.

A second problem is that there are often no markets for some vital services, such as soil formation and nutrient cycling, and while payment schemes can be created to create market-like structures, the value assigned to ecosystem services depends on market prices, which are subject to change.

A third problem arises from the institutional and political processes linking economic benefits from ecosystems and human wellbeing. “Unequal access to benefits, for example where there are differences in wealth and power among stakeholders, can lead to trade-offs being made, with negative impacts for the ecosystem itself and those who rely on it,” Adams comments “It’s not enough to identify the net benefits of ecosystem services; it also matters who gets them.”

For example, in Nepal, research has shown that forests managed by the local community, rather than by the state, yielded benefits of clean water, tourism and harvested wild goods. However, these forests restricted poorer people’s access to forest-derived products, creating hardship, illegal use and impacts on other areas.

“In a world run according to economic arguments, the survival of biotic diversity will depend on its price,” said Adams. “Sometimes economics will favour conservation and sometimes it won’t. But conservationists need to plan for both outcomes.”

Assigning an economic value to the benefits which nature provides might not always promote the conservation of biodiversity, and in some cases may lead to species loss and conflict, argues a ̽��ֱ�� of Cambridge researcher.

There is a risk that traditional conservation strategies oriented toward biodiversity may not be effective at protecting the economic benefits of an ecosystem, and vice-versa

Bill Adams

Oliver Whiteside via flickr

Mountain forest mist

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