Friday, 5 June 2015

Apping and assessing air pollution using lichens!

CEH released a new mobile phone app today. It gives everyone a way of assessing nitrogen pollution in their local area.



For those that don’t know lichens look like this!


The app is based on a field guide developed by CEH staff and our partners last year


Unlike most of our previous apps, such as iRecord Butterflies and iRecord Ladybirds, the Lichen app isn’t for wildlife recording, rather it’s a tool for assessing the status of nitrogen in your area by surveying lichen on trees. By identifying the presence or absence of nine nitrogen sensitive and eight non-sensitive lichens on tree trunks and branches you can get an estimate of how polluted your area is.

Lichens on a tree trunk – © Ian Leith/Centre for Ecology & Hydrology


Full guidance can be found in the app but basically to get going you need to Identify five oak or five birch trees (not a mixture of the two) in your local area.
  • Trees should be single stemmed (standard) with a straight trunk, and greater than 40 cm in girth. 
  • There also needs to be some accessible branches.
Following the instructions in the app you then identify the lichens growing on the East, West, South of the tree trunks, and then some of the tree branches. You might need to use a hand lens to help with ID as some lichen features are very small!


Here's where you need to sample lichens on your trees.



All the details are then recorded using the App:



And if you have any problems identifying your lichens there’s a handy ID guide built into the App with lots of photos:



Once all the info is complete, you click on the ‘Results’ button. The app works out your lichen indicator score (LIS) and the NAQI score (Nitrogen Air Quality Index).


That’s it! More information on the Lichen App can be found in a news story on our website.

Wednesday, 27 May 2015

Managing the world’s water – sharing good practice

Dr Harry Dixon reports from the World Water Congress in Edinburgh

This week CEH organised a Special Session at the International Water Resources Association’s (IWRA) World Water Congress. The Congress is the Association’s 15th global gathering and this year it is being held in the shadow of Edinburgh Castle, reflecting the Scottish Government’s drive to grow the water sector under its HydroNation agenda.

At CEH, we host the UK Committee for Nation and International Hydrology (UKCNIH). This Committee, chaired by Professor Alan Jenkins, provides a forum for UK government departments, agencies, research bodies, professional societies and universities to discuss current issues and priorities related to freshwater research. The aim is to better coordinate UK engagement in national and international hydrological research.

Speakers in the special session on international catchment management science
and application at the World Water Congress XV.

Central to the Committee’s activities are the UK’s activities related to the International Hydrological Programme of UNESCO , for which CEH leads engagement on behalf of the Department for International Development (DFID), and involvement in the water related activities of the World Meteorological Organization (WMO), for which Alan Jenkins is the UK Hydrological Adviser.

On behalf of the UKCNIH we convened a session at the World Water Congress to bring together a range of experts from both the UK and overseas involved in catchment management science. The aim was to discuss both the scientific and implementation challenges related to catchment based approaches to water management.

The Session was kicked off by Mark Williams, Scottish Water’s Head of Environmental Science and Regulation, who provided a very interesting set of examples of issues the water industry are faced with when tacking urban pollution. Next, David Harley, Water and Land Manager at the Scottish Environment Protection Agency, provided a local perspective outlining the regulatory challenges related to the development of River Basin Management Plans and in particular the issue around rural defuse pollution.

The Congress is, as the name suggests an international gathering with around 900 delegates from across the work attending. One key aim of our Session was to discuss the role of international science programmes in relation to improving catchment management and one very interesting examples in this area came from Prof David Harper (University of Leicester and long-standing member of the UKCNIH) who provided an overview of his work on the Lake Naivasha basin in Kenya. David outlined his research on the ecohydrology of the basin, an area which provides 40% of all cut flowers that are sold in EU supermarkets.



In addition to UK researchers and practitioners, we were very pleased to be joined by representatives of both UNESCO and WMO to give a UN perspective on the future direction for global science in this area and ideas on how the world community can improve catchment management. Dr Blanca E JimĂ©nez Cisneros is the Secretary of the International Hydrological Programme (IHP) and UNESCO’s Director of Water Sciences. Blanca’s presentation set out the global challenges related to water security and the ways in which the IHP aims to provide a framework for global water science, policy development and education. Giacomo Teruggi from WMO detailed their activities under the Hydrology and Water Resources Programme and gave an interesting overview of the Associated Programme on Flood Management – a joint initiative by the WMO and Global Water Partnership to advocate the concept of Integrated Flood Management.

To bring the different ideas together, Prof Bob Ferrier (James Hutton Institute and member of CEH’s Science Development Group ) rose to the challenge of summarising the current issues and challenges in relation to catchment science and posed some thought provoking ideas. Following Bob’s presentation, Alan Jenkins adopted the role of David Dimbleby to host a Question Time style panel session with all our speakers to explore the issues further. The panel and audience discussed a range of questions covering: the key scientific questions to which catchment managers need answers; the challenge of mobilising individuals and organisations in relation to adaptation; and how to stimulate greater community engagement in managing the freshwater environment.

The Session generated some interesting discussions and highlighted the difficult challenges faced by the global community to improve catchment management. However, it also highlighted some great examples of UK scientists and practitioners rising to these challenges to deliver integrated catchment management approaches both in this country and overseas.

It is clear that as hydrologists we have an important role to play in developing water management in this area and that by working through organisations such as UNESCO and WMO we can ensure we learn from others internationally and that the good practices we have in the UK are shared around the world.

Dr Harry Dixon

Dr Harry Dixon is a Senior Hydrologist at CEH and the Secretary of the UK Committee for National and International Hydrology. He works closely with Prof Alan Jenkins to provide the Committee’s Secretariat and CEH’s leadership of UK engagement in international science programmes of WMO and UNESCO.

Related links


World Water Congress XV Special Session 4 outline of speakers 

World Water Congress XV

UK Committee for National and International Hydrology

Staff page of Prof Alan Jenkins, CEH

Staff page of Dr Harry Dixon, CEH


Wednesday, 20 May 2015

A decade of recording harlequin ladybirds in the UK

Dr Helen Roy of CEH is among the scientists behind the UK Ladybird Survey which, thanks to the help of the public, has monitored the rapid spread of the non-native harlequin ladybird in the UK from its first confirmed appearance in 2004. Coinciding with a new paper in Ecological Entomology, Helen looks back at ten years of harlequin ladybird recording.

"The harlequin ladybird (Harmonia axyridis), heralded as “the most invasive ladybird on Earth”, was first recorded in the UK in October 2004. Within a few months the online Harlequin Ladybird Survey was launched as part of the wider UK Ladybird Survey. Over the last decade, tens of thousands of people have contributed their sightings of this invasive non-native ladybird (and other species of ladybird) to the UK Ladybird Survey.

"The result - a unique dataset tracking the invasion of a non-native species from the moment of arrival.

Harlequin ladybird (Photo: Ken Dolbear)

Today (20 May 2015) we celebrate the contributions of these inspiring volunteer recorders through the publication of a paper describing advances in understanding of the ecology of the harlequin ladybird in the UK. The paper builds on a paper published in the same journal in 2006 which made predictions about the impact of the harlequin.

There have been many exciting discoveries over the years and some rather bleak messages too. Much of the research on this species would have been impossible without the volunteer recorders. We have learnt so many lessons from these ladybirds.

Highlights include:


  • The UK Ladybird Survey dataset highlighted that seven out of eight native species of ladybird were declining and this was strongly linked to the arrival of the harlequin ladybird.
  • We have also explored the way in which the colour patterns of harlequin ladybirds, their association with different habitats and plants within these habitats, their reproductive behaviour, their flight patterns and so much more has influenced the spread of this species.
  • The harlequin ladybird has been shown to be more resistant to parasites than other ladybirds.
  • We have shared the dataset with other scientists across the UK and around the world and enjoyed comparing our findings with others who are studying the harlequin ladybird across Europe, South Africa, North and South America and Asia.
  • The role of citizen scientists in this research has been inspiring and we have enjoyed sharing experiences with other citizen scientists and their projects to develop a citizen science.
  • The number of new arrivals is increasing year on year and the number of records of H. axyridis received by the UK Ladybird Survey demonstrates the critical role that people can play in non-native species surveillance.
  • The commitment of people to recording harlequin ladybirds encouraged the development of a recording system for other non-native species which is being used as an early warning tool for the Asian hornet and other species that are on the horizon. The demand for scientific evidence to underpin our understanding of the impacts of invasive non-native species on other wildlife continues to be high.



The next ten years


So what about the next ten years? We still have so much to learn about the harlequin ladybird and its interactions with other species. To date much of the research has looked at predation and we need to examine the importance of competition between harlequin ladybirds and other species, and our understanding of the resilience of the networks of species with which the harlequin ladybird intermingles. We are also asking people to tell us about the natural enemies (mainly parasites) of ladybirds as they observe them interacting with harlequin ladybirds and other species. It is possible that some of these incredible parasites will adapt to using the harlequin ladybird as a host – evolution in action!

Collaboration and working in partnership is so important and we have been delighted to have so many opportunities to work with so many people and organizations over the last ten years. We want to thank everyone who has contributed – it has been a privilege to work with you all. We hope that people will continue to be part of the UK Ladybird Survey. The smartphone app, iRecord Ladybirds, ensures that it is extremely easy to record sightings of all ladybirds. An incredible 12000 records have already been contributed through the app.

"So, if you see a ladybird, please record your sighting. Every record counts!"


Dr Helen Roy

Ten years of invasion: Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in Britain. 2015. Helen E Roy and Peter M J Brown. Ecological Entomology.

CEH News:  Ten years of invasion -  a decade of recording harlequin ladybirds

UK Ladybird Survey: Recording ladybirds

Monday, 18 May 2015

Fascination of Plants Day 2015

CEH scientists were among those taking part in an event at Harcourt Arboretum in Oxfordshire this weekend staged as part of the worldwide Fascination of Plants Day 2015. Insect interactions with different plants and wildflowers were high on the agenda as our experts led guided walks, answered questions and revealed the contents of a moth trap set up for the event.

Moth and butterfly ecologist Dr Marc Botham began proceedings when he opened the moth trap to fascinated onlookers.


Dr Marc Botham (kneeling) opened a moth trap at the event

Although Marc himself was a little disappointed with the number and variety of species caught during a cooler than average May night, there were still plenty to keep the crowd interested, with poplar hawk moths particularly numerous. 


Many of the people got to hold some of the still docile moths for the first time and see up close the amazing colours and markings.



Next up was the first of the day's ladybirds walks, led by entomologist Dr Helen Roy, who taught some of the younger participants the art of using a sweep net and showed them how to input their discoveries into the Ladybird Survey app.


A number of pine ladybirds were found on both pine and hawthorn trees in the woodland. On a day when ladybirds were actually quite scarce, 14-spot and 7-spot ladybirds were also spotted by some of the more eagle-eyed participants.


Dr Oli Pescott, a botanist at CEH, led plant and wildflower walks during the day. As well as pointing out much of what was in bloom around the arboretum, Oli revealed fascinating facts, identification tips, similarities between species and the importance of different plants for insect interactions.

The cuckooflower or Lady's smock (Cardamine pratensis), a primary
larval food plant of the Orange tip butterfly

Comparing characteristics of thyme-leaved speedwell (left) and
germander speedwell.

Dog's mercury (Mercurialis perennis) - don't eat it! A
woodland plant which is highly poisonous.

This is the third international Fascination of Plants Day. Events are being held worldwide with the aim of getting people enthused by plants and their importance for the environment, food production, agriculture, as well as the sustainable production of goods such as timber, chemicals, pharmaceuticals etc.


As well as CEH, other organisations taking part at the Harcourt Arboretum event included the University of Oxford, the Wildlife Trusts, the Thames Valley Environmental Records Centre, and the RSPB.

Paulette Burns

Further information


Marc, Oli and Helen all work closely with the Biological Records Centre within CEH.

Fascination of Plants Day 2015 official website

Tuesday, 14 April 2015

CEH science at EGU 2015

CEH scientists are among those presenting research updates to the European Geosciences Union General Assembly in Vienna this week (12-17 April 2015). The meeting brings together scientists from all over the world to discuss aspects of Earth, planetary and space sciences.

Abstracts of oral and poster presentations led by CEH scientists and students can be found below:
Additionally, Dr Eiko Nemitz is a convenor of two sessions on Biosphere-atmosphere exchanges while Bob Moore is convening a PICO session on hydrological forecasting.

On Thursday, Prof Christel Prudhomme is one of the panel of experts taking part in the Young Hydrologic Society's session on Meet the expert in hydrology - The mystery of evaporation.

Good luck to everyone taking part!


Dr Paul Scholefield is one of the CEH scientists presenting at EGU2015 this week:

Below, poster presentation by Christine Braban and colleagues in the Natural Hazards session on Atmosphere emissions from volcanoes and their dispersion:

Effusive Eruption Modelling project: Assessing UK impacts of trace species and sulphur deposition

EGU 2015 is taking place at the Austria Center Vienna. Photo: CC BY-SA 3.0 BambooBeast

Related links


European Geosciences Union General Assembly 2015

CEH Biosphere-Atmosphere Interactions science area

CEH Natural Hazards science area


Friday, 27 March 2015

What ails our horse chestnut trees and can we save them?

A guest blog from pupils of La Sainte Union School, Camden, London.

Dr Michael Pocock, an ecologist at CEH, is one of the scientists behind Conker Tree Science. Thanks to a Royal Society partnership grant, he recently shared some of his knowledge and skills with students at a school in London.
One pupil’s scientific drawing of the tiny leaf-miner larva

Michael writes, “Over the past few months I have been visiting Dr Pari Collis and her pupils at La Sainte Union school in Camden, London as part of a Royal Society partnership grant. Based on my experience with Conker Tree Science, I helped the girls begin a project on the horse-chestnut leaf miner, but with their teacher they took it so much further than I thought they would.

"Not only did they undertake careful ecological studies, but they also covered biochemistry and environmental ethics, mixed with a little bit of German, maths and art! My final visit to the school was last week when they gave an excellent presentation of their project in front of an audience of teachers and parents.
"It has been a privilege to work with Dr Collis and the girls over the past year and share moments of scientific discovery and excitement with them. I would highly recommend using the Royal Society partnership grants for any scientist to link with a local secondary school."

The pupils at La Sainte Union school have written up their project and submitted it for peer review at the Young Scientists Journal. Below is an abridged version of their full article:


"Horse chestnut trees are ornamental trees and were largely planted for their attractive shape and beautiful flowers which make them really desirable in parks and village greens. We noticed that there was extensive early browning of the horse chestnut trees in our school grounds, which we found was caused by the horse-chestnut leaf-miner, Cameraria ohridella. Both the horse chestnut tree and the Cameraria ohridella are invasive species but we consider the moths to be pests because they harm the trees that we chose to plant.

We worked in groups to visually estimate the number of horse chestnut leaf miner in one tree. We counted the number of the leaf miners in a small section of the tree and then scaled up to estimate that there were 250,000 – 500,000 leaf miners per tree.

Making careful observations of  horse-chestnut leaves
The common horse chestnut Aesculus hippocastanum is very susceptible to infestation by the leaf miner, but we found that the red-flowering hybrid (Aesculus x carnea) is very resistant. The mass of the red flowered horse chestnut tree leaves was approximately twice that of the white flowered trees (0.02 compared to 0.01 g per cm2). The caterpillars seem unable to feed successfully on these leaves.

We wanted to find out if anything could be done to stop the moths. We investigated the following possibilities of control:

  • Natural predators (parasitoid wasp and blue tit);
  • Pheromone traps that attract and kill male moths;
  • Collecting and burning or burying fallen leaves in autumn to destroy the overwintering pupae.

Natural pest controllers: Leaves from an infected horse chestnut tree were collected and stored in zip-lock bags for two weeks on a cool and dark shelf. We then recorded the number of adult Cameraria ohridella moths and parasitoid pest controllers. There were 171 wasps altogether (19% of the total) which means 171 horse chestnut tree leaf miner larvae were killed by the larvae of the parasitic wasps.

Pupils ready for the big sweep to 
collect fallen horse chestnut leaves

Blue tits have discovered that horse chestnut trees are absolutely loaded with caterpillars. Caterpillars are an important food source for blue tits, which feed them to their young. If blue tits were to start eating a substantial amount of the caterpillars it would help the horse chestnut tree. We examined the leaves for v-shaped tears as evidence of ‘bird attack’ and found 0 to 57 bird attacks per leaf.

Pheromone traps: The main component of the sex attractant (pheromone) released by the females of the horse chestnut leaf miner has been identified as E,Z-8,10-Tetradecadienal12. We used pheromone traps to catch male moths which reduces mating and therefore egg laying. We weighed the content of the trap and estimated that 30,000 moths had been captured over a period of two months. This is about a tenth of the number we had estimated on each tree in July after the 1st generation.

Clearing leaf litter: Early in the season (July), we noticed that the browning of the leaves is more prominent at the base of the tree. This is consistent with the moths emerging from the fallen leaves and spreading upwards first to the lower leaves. We collected fallen leaves from under the horse chestnut tree and found an average of 100 pupae per leaf. If we estimate that there could be at least 100 fallen leaves in the vicinity of the tree, then 10,000 moths could emerge. If half of these are females, which lay 30 eggs each, we could expect 150,000 moths at the end of the first generation and 2,250,000 eggs at the end of the second generation. In reality the number will be smaller because not all pupae, moths or eggs will survive. Nonetheless the number of potential moths is formidable bearing in mind that the calculation is based on just 100 leaves.

It may be time for the UK to follow Berlin’s example where there is a programme encouraging everyone to take part in raking up and clearing every single horse chestnut tree leaf. It is considered to be every citizen’s civic duty to participate in the clearing of the leaves. Involving the community in this way may have many social benefits encouraging social interaction, interest and responsibility for the environment."

Michael Pocock and several of the students
By: Tito A, Ursula A, Elisabeth A, Sharon B, Ariane F, Grace G, Catriona G, Zoe H, Oghogho I, Dea L, Mia O, Lara R, Hannah S and Ellie T (La Sainte Union School, London).

Dr Pari Collis is the science teacher at La Sainte Union school who invited Michael to visit and she concludes:  We really enjoyed working with Dr Michael Pocock.  Michael’s enthusiasm was absolutely infectious and it kept everyone on board. The girls did outdoor science, learnt how to be observant and use scientific method.  They improved their communication skills, worked as a team and showed commitment to the project. Under Dr Pocock’s guidance they also learnt to read original scientific papers for themselves. Most importantly they took an interest in their surroundings, seeing them in a different light, and in particular have become extremely fond of horse chestnut trees and conkers.  They discussed the project and shared their enthusiasm with their friends and family. It has been a great pleasure to have worked with Michael and to share and discuss our findings with him.  

Additional information

Michael has also recently written about his life in science for Catalyst magazine, which is produced to inspire secondary school pupils about science.

Royal Society Partnership Grants

Conker Tree Science

Staff page of Dr Michael Pocock

Thursday, 12 March 2015

Retirement beckons for voice of UK hydrological reporting

As many of our regular readers will know, the UK hydrological summary is a monthly update from scientists within the Centre for Ecology & Hydrology working with colleagues from the British Geological Survey. Every month, under the National Hydrological Monitoring Programme, they collate, quality check and analyse various data with regard to river flows, reservoirs and groundwater, placing them in historical context and identifying hydrological trends. The team produces regular updates and occasional reports into events such as the summer floods of 2007 and the recent 2010-2012 drought to flood transformation.

For several decades, a mainstay of the NHMP has been our own Terry Marsh, leader of the programme since 1982. This month, March 2015, is Terry's last before retirement so it is fitting that he authored the summary issued this month (analysing water resources in February 2015), bringing the total he has authored to an incredible 286. This "special souvenir edition" contains a tribute to Terry from his colleagues.

So, download the latest summary (PDF) and, after taking in the assessment of the UK's hydrological conditions, browse to page 3 for a tribute to Terry Marsh, the eloquent voice of UK hydrological reporting over the last three decades. As Terry is always one for a turn of phrase, it is certainly an appropriately written tribute. Although as colleagues note, it’s perhaps ironic that Terry signs off with a month notable for its normality!

A word cloud based on hydrological summaries authored by Terry Marsh

Related links


Staff page of Terry Marsh, CEH

National Hydrological Monitoring Programme

Hydrological Summaries of the UK

Blog posts relating to the National Hydrological Monitoring Programme