Short-term postdoc wanted!

Post-doctoral research assistant wanted for Farm-Ecos project (Farming and Natural Resources: Measures for Ecological Sustainability)

Farm-Ecos is a Department of Agriculture, Food and the Marine funded, interdisciplinary project, which aims to identify and outline the evidence base for novel, cost-effective measures to protect and enhance farmland biodiversity. The project started in June 2017 and is a collaboration between Teagasc, NUIG, GMIT, TCD and DCU. The project has conducted on-farm assessments of habitat quantity and quality and of indicator species diversity across a range of farming intensities in Sligo and Wexford.

We are seeking a short-term (8 month) post-doctoral research assistant (PDRA) to join this team, based in the research group of Jane Stout in the School of Natural Sciences, Trinity College Dublin, but working closely with the whole Farm-Ecos team. The PDRA will:

  • Use plant and insect data collected on farms in Wexford and Sligo to test and refine score cards for assessing biodiversity on farmland
  • Incorporate best-practice and knowledge from other projects (e.g. EIP projects on results-based payments) and finalise score cards and rapid assessment cards into tools for future use
  • Develop a framework for policy recommendations from Farm-Ecos
  • Write policy notes, scientific papers, blogs and media posts to disseminate Farm-Ecos outputs.

Key skills

Essential:

  • PhD in ecology, agro-ecology, entomology, farmland ecosystem services or similar
  • Proven ability to work in a team and to communicate effectively with other team members – the position will involve collaborative data sharing, analysis and writing
  • Good quantitative and statistical skills
  • Excellent written communication skills to prepare clear and precise documents and reports

Desirable:

  • Knowledge and interest in farmland pollinators, natural enemies, and/or ecosystem services
  • Understanding of agri-environmental policies, CAP, farmland biodiversity assessment
  • Languages skills – must be fluent in English

Salary: This appointment will be made at point 1 of the PDRA scale from the Irish Universities Association Researcher Salary Scales i.e. €38,632 per annum (gross) for 8 months, from 1st October 2020.

To apply: please send letter of application, outlining suitability for the post, and a CV including the names and contact details of two referees, to Jane Stout stoutj@tcd.ie before 28th September 2020. Interviews will be conducted 29th September (via Zoom).

For further information contact Jane Stout (stoutj@tcd.ie)

Download pdf of this advert below

Science by bicycle

Science is a long process…this newly published research article, in the journal Agriculture, Ecosystems, and the Environment, is the culmination of nearly two years of writing a grant proposal with my advisors (Profs Jane Stout and Yvonne Buckley), two years of hard field work, and then two years of writing, revising, and resubmitting the manuscript. Nonetheless, after all that, I must say I am proud of this particular piece of science. The manuscript itself is long, with many detailed statistical tests, and involves several independent datasets that I collected over my two years in Dublin.

Herbicide-exposed plot at RTE, featuring the bike that carried me more than 15,000 km during this study, the watering cans I used to carry ~3,000 liters of water per week, and the fancy fences RTE built for me.

Our experiment was designed to determine whether small concentrations of fertiliser and herbicide had any effects on the growth of ruderal plants and the insects that visit their flowers. We chose the species in the study (Cirsium vulgare, Hypochaeris radicata, Filipendula ulmaria, Epilobium hirsutum, Origanum vulgare, Plantago lanceolata, and Phacelia tanacetifolia) based on their prevalence in Irish agricultural systems. I hand-collected individuals of the plants from a conservation area near Kilkenny (thanks Hannah!) in the springs of 2017 and 2018.

The Riverfield, a conservation area near Kilkenny, managed by Hannah Hamilton, where I collected the plants for the research project.

Our data show that even exposure to tiny amounts of fertiliser and herbicide change the growth of these plants, and the visitation of their pollinating insects. Mostly, these results conform to hypotheses: plants exposed to tiny amounts of fertiliser grow taller and have longer leaves, while plants exposed to herbicide are shorter and have shorter leaves. Interestingly, there is no difference in the size of the floral display, which means that plants exposed to a little fertiliser have fewer flowers per individual (but at a much taller height), while herbicide exposed plants have more flowers per individual (but at a much shorter height). Plants exposed to herbicide also had a lower visitation rate per unit floral area, meaning that the flowers were on average less preferred by flower-visiting insects.

I obsessively collected so much data for this study, including a completely independent greenhouse experiment, that I plan to publish several more papers from it, so stay tuned!

One of the challenges of this dataset was the sheer number of zeroes. For collection data in the study, more than 50% of my five-minute observations yielded zero visitors. That’s a lot of time starting at flowers with no insects (85.75 hours to be exact), and a great deal many more samples where only one insect visited. This led me to describe the study to anyone who would listen as “Zen and the art of pollinator watching.”

Gorgeous Eristalis hoverfly on cat’s ears (Hypochaeris radicata).

What the manuscript doesn’t include is the process of learning to live in a new country (Ireland), figuring out the name of the store where I could buy their entire stock of watering cans (Woodie’s), begging people to let me put these weird garden plots on their land, navigating the windy streets of Dublin on my bicycle (without getting killed or shouted at, preferably), or surviving the particularly muddy times where I could never seem to get clean and dry.

I did the math at the end of the 2018 field season and learned that I had been cycling an average of 160 miles per week to visit all of my plots repeatedly, and hand-carrying an average of 3000 liters of water to water and treat my plots in two 10 liter watering cans per site. Across the 2 years of the study, I actually cycled more than 15,000 km (9,320 mi), the vast majority of which was in urban Dublin, round and round to my sites.

Would I recommend field work by bicycle to young scientists? Not exactly! Cycling limits the weight and volume of equipment you can carry, and it is more time consuming than simply driving. But science by bicycle seemed to be the most feasible option for me in Dublin (which is, after all, very cyclable), given time and financial constraints, and I think it worked for the purposes of this study.

Covered in mud to my armpits in spring ‘18.

Bredagh and my favourite collaborator, Pushkin at UCD Rosemount. (photos courtesy of my ancient flip phone)

As detailed by the lengthy acknowledgements in the manuscript, this work would not have been possible without the help of many people. In particular, I want to thank all of the sites that allowed my to have my plots on their land and tolerated me showing up repeatedly to sample and water them: Raidió Teilifís Éireann, Riverview Nature School, Gas Networks Ireland, Trinity College Dublin, University College Dublin and the Lamb Clarke Irish Historical Apple Collection at Rosemount Environmental Research Station, the Marino Institute, and the Airfield Estate. Also thanks to all the people who facilitated my work at these sites: Dr. W. Deasy, B. Moran, Dr. K. McAdoo, T. Bannon, C. van der Kamp, R. Hession, C. Bennett, E. Kavanagh, C. Fogarty, S. Austin, M. Burke, R. Judge, S. Waldren, E. Bird, and M. McCann. Thanks also to my coauthors and everyone in the Stout lab and all the technical assistance at TCD: S. Palumbo, A. Flaherty, J. Stone, S. McNamee, B. Malone, O. Fenton, D. OHuallachain, J. Finn, J. Zimmerman, J. Parnell, and S. Hodge. I can’t thank those who helped me with identifications enough: U. Fitzpatrick, T. Murray, M. Speight, M. Smith, B. Nelson, and S, Falk. Finally, thanks to Hannah Hamilton for feeding me enough to keep me alive, helping me to find valuable research sites, and generally being such a great friend.

And I have to say thanks to Ireland for being my home for two years. I absolutely loved learning as much as I could about you in my short time there. Stay beautiful!

Funding for this study was provided by a Marie Skłodowska-Curie Independent Fellowship [grant number FOMN-705287] to LR, JS, and YB.

About the author: Dr Laura Russo was a Post-doctoral Research Fellow in the Plant-Animal Interactions group at Trinity College Dublin from early 2017 to early 2019. She is now an Assistant Professor in Ecology & Evolutionary Biology at the University of Tennessee.

Is it either sugar or pollinators? Why can’t we have both?

In this post, PhD student, Elena Zioga reflects on the decision by the French government to allow neonicotinoid use, in the same week as she published her first paper on pesticide residues in nectar and pollen…

I decided to take few weeks off work, but my research cannot let me go as things are happening. My review paper on pesticide residues in plant pollen and nectar is now published online and I am very happy to share it with the rest of the world (read more here).

However, my joy is highly contained by the sad news that came out on Thursday, 6 August, when the French Agricultural Ministry announced their decision on lifting the ban on neonicotinoid insecticides used as seed treatment for the sugar beet cultivation.

The neonicotinoid compounds clothianidin, imidacloprid and thiamethoxam were being used in the EU as sugar beet seed coatings in order to control the aphid (Myzus persicae) population on the crop and prevent the Beet Yellows Virus transmission (1). According to the estimates by professionals, taken up by the ministerial press release, this disease can cause yield reductions of up to 30% to 50% (2). Thus, the French government acceded to the requests of the sugar beet growers who believe that there is no other viable alternative to neonicotinoids against the aphids. Hence, in addition to the promise of compensation and the launch of a research effort of 5 million euros, the French government announced a “legislative amendment” allowing “for the 2021 campaign and if necessary the two following campaigns at most” exemptions allowing the use of seeds coated with neonicotinoid insecticides, assuring that these exemptions will only concern sugar beet (2).

elena sugar beet article
Pesticide-treated seeds (from https://www.fwi.co.uk/arable/crop-management/disease-management/neonic-seed-treatment-ban-means-sugar-beet ©Tim Scrivener).

In France, the 2016 biodiversity law banned the neonicotinoid insecticides as of September 2018 (3). On December 2018, the EU banned the use of these compounds on flowering and outdoors growing crops (4). “These bans are essential to fight against the massive decline of bee colonies and wild pollinators“, said the Ministry of Agriculture and Food, in an August 2018 statement (5). Back then, that decision was supported by voluminous data on the negative impacts of these compounds on pollinators. What has changed two years later? How is it possible to neglect all the past research and go back to zero? How is it possible, from being a leader in the fight against the pollinator killing neonicotinoids in Europe, that France has apparently become a stooge for the agrochemical and industrial agriculture lobbies? In my opinion, this is an unacceptable setback showing that governments, in an effort to keep their voters happy, might sometimes take decisions that are detrimental for the environment.

I am simply wondering why that same French government who decided to ban the neonicotinoid use two years ago is taking the exact opposite decision now, and with a potential three year plan of application! In their defense, they argued that since sugar beet is harvested before flowering in the field, it would not attract pollinators and the use of neonicotinoids in seed coating on this crop would therefore have no adverse consequence on the bees. It was also argued that usually the sugar beet crop is followed by straw cereals, which are not attractive to pollinating insects. In addition, there were reassurances that there will not be any flowering crops planted the following seasons. Are these sufficient arguments to support this setback?

From my point of view, NO, and here is why:

The exposure of bees and other pollinators to neonicotinoids is mainly through wild flowers. A 2015 study clearly showed that the pollen of wild plants growing in the margins of the seed treated crops was highly contaminated with neonicotinoids, and the honey bees were bringing this pollen back to their hives (6). Moreover, neonicotinoid compounds and their metabolites can be very persistent in the soil (with typical half-lives estimated to be of the order 15-300 days) exhibiting a potential for accumulation in soil following repeated applications (7). Neonicotinoids can be found long after their use has ceased both in the cultivated soils and in plants growing there in subsequent years, thus exposing pollinators to a significant risk (8). A 2020 study evaluating the consequences of the 2013 EU moratorium restricting the use of three neonicotinoid insecticides (clothianidin, imidacloprid and thiamethoxam) by monitoring winter oilseed rape crops for five years following the European moratorium (from 2014 to 2018), concluded: “the three neonicotinoids concerned could be detected in the samples taken. In particular, imidacloprid was detected each year, in total in 43% of the samples analyzed, without a decreasing trend over the years but with a strong inter-annual variation” (9).

Substances applied in soils and as seed treatments may be considered low risk for honey bees (Apis mellifera), which do not collect soil material. However, for other wild bee species (e.g. bumble bees and solitary bees) this may be a rather important route of exposure (10). The majority of wild bee species spend a significant time of their life span in the soil as they may built their nest underground, or even use soil material in order to construct their nests (11, 12). A 2019 study, found that “chronic exposure to nesting substrates contaminated with neonicotinoids may represent an important route of exposure that could have considerable physiological and ecological consequences for bees and plant-pollinator interactions” (13), while a study of 2020 claimed that “native bee richness in non-target field margins may be negatively affected by the use of neonicotinoid seed treatments in agroecosystems” (14).

These data clearly show that a possible exemption for the use of neonicotinoids on sugar beet seeds would have serious consequences for the pollinator communities on and around the seed treated fields, by contaminating the environment around these fields with neonicotinoids and thus posing a hazard to pollinators. Going back to planting neonicotinoid-treated sugar beet seeds should not be considered as a temporary solution for limiting the spread of the Beet Yellows Virus, but as contributing to permanent and constant ecological destruction. There were several reasons that triggered the neonicotinoid ban two years ago, the same reasons that are still in effect nowadays. The only change is the addition of more scientific evidence supporting the damaging effects of neonicotinoids to pollinators.

I consider that the French government must therefore not grant an exemption for the use of neonicotinoids and should instead invest more in research towards finding another solution to preventing the spread of the Beet Yellows Virus. This is the only way to keep both the high yields in sugar production and the pollinators safe!

References

(1) Neonicotinoids in sugar beet cultivation in Central and Northern Europe: Efficacy and environmental impact of neonicotinoid seed treatments and alternative measures. Hauer et al. J. Crop Prot. 2018, 93, 132-142. https://doi.org/10.1016/j.cropro.2016.11.034.

(2) https://agriculture.gouv.fr/filiere-betterave-sucre-plan-de-soutien-gouvernemental-pour-faire-face-la-crise-de-la-jaunisse.

(3) https://www.gouvernement.fr/en/a-biodiversity-agency-for-a-new-relationship-between-humankind-and-nature#:~:text=The%20Law%20of%208%20August,environment%20and%20quality%20of%20life.

(4) https://ec.europa.eu/food/plant/pesticides/approval_active_substances/approval_renewal/neonicotinoids_en.

(5) https://agriculture.gouv.fr/entree-en-vigueur-de-linterdiction-des-neonicotinoides-le-1er-septembre.

(6) Neonicotinoid Residues in Wildflowers, a Potential Route of Chronic Exposure for Bees. Botías et al. Environ. Sci. Technol. 2015, 49, 21, 12731-12740. https://pubs.acs.org/doi/abs/10.1021/acs.est.5b03459.

(7) Quantification of Imidacloprid Uptake in Maize Crops. Bonmatin et al. J. Agric. Food Chem. 2005, 53, 5336-5341. https://pubs.acs.org/doi/10.1021/jf0479362.

(8) Neonicotinoids, bee disorders and the sustainability of pollinator Services. Van der Sluijs et al. Curr. Opin. Env. Sust. 2013, 5, 293-305. https://doi.org/10.1016/j.cosust.2013.05.007.

(9) Neonicotinoid-induced mortality risk for bees foraging on oilseed rape nectar persists despite EU moratorium. Wintermantel et al. Sci. Total Environ. 2020, 704, 135400. https://doi.org/10.1016/j.scitotenv.2019.135400.

(10) Pesticide Exposure Assessment Paradigm for Stingless Bees. Cham et al. Environ. Entomol. 2019, 48, 36-48. https://doi.org/10.1093/ee/nvy137.

(11) Workshop on Pesticide Exposure Assessment Paradigm for Non-Apis Bees: Foundation and Summaries. Boyle et al. Environ. Entomol. 2019, 48, 4-11. https://doi.org/10.1093/ee/nvy103.

(12) Pesticide Exposure Assessment Paradigm for Solitary Bees. Sgolastra et al. Environ. Entomol. 2019, 48, 22-35. https://doi.org/10.1093/ee/nvy105.

(13) Chronic contact with realistic soil concentrations of imidacloprid affects the mass, immature development speed, and adult longevity of solitary bees. Anderson and Harmon-Threatt. Sci. Rep. 2019, 9, 3724. https://doi.org/10.1038/s41598-019-40031-9.

(14) Reduced species richness of native bees in field margins associated with neonicotinoid concentrations in non-target soils. Main et al. Agric. Ecosyst. Environ. 2020, 287, 106693. https://doi.org/10.1016/j.agee.2019.106693.

 

About the Author: Elena Zioga is a PhD student on the PROTECTS project

Conducting and publishing my first systematic literature review – A unique experience

PROTECTS project PhD student Elena Zioga reflects on her experiences publishing her first paper…

To begin with, YAY, excitement all over the place!!!

Frankly, when I started my research quest back in September 2018, I was not thinking that it would end up being a paper for publication. It started as a literature review, in order to set up the basis for my PhD research on characterizing pesticide residues in floral resources for bees. Upon discussions with the rest of the members of the project in which I am involved (PROTECTS), we decided that there was a need for establishing the existing knowledge in terms of the pesticide residues ever found in pollen and nectar collected from plants. We wanted to know which compounds have been evaluated until now, and what their exact concentrations in pollen and nectar were. This knowledge would be very helpful for the risk assessment studies for pollinators. Soon, we discovered that instead of finding an answer to that specific question, we could also identify major knowledge gaps in the area; gaps that had to be highlighted.

There was a need for not only recording what was already known in the field, but also identifying the major gaps by summarizing results from a diverse inter-disciplinary research combining the research areas of bee biology, ecotoxicology, botany and chemistry. Setting up a basis not only for my PhD thesis, but also for future residue studies requested for a Reliable, Quantifiable and Reproducible systematic literature review. Hence, with my supervisor Jane Stout (Trinity College Dublin) and co-supervisor Blanaid White (Dublin City University), we started working towards that. One of the most important steps of this process was the beginning of the literature search and making sure that our question was clear and specific, in a way that our search terms over the various databases were well identified and established. Lesson learnt – During this stage, EVERYTHING need to be recorded, or everything will be forgotten. Try to keep notes of how, when and why you did things, as you will soon need this information regardless using it or not.

Since I had a 50 year period of interest, and given the technological advance during all these years I had come across studies with various methods of chemical analysis. As there were not many studies on the topic, I was trying to include as many as possible, but in the meantime I had to critically evaluate whether the studies contained the information we needed and in a form that could be further processed in our analysis. Lesson learnt – Critical thinking, Strike 1.

Once the studies relevant to our research question were identified, we were ready to proceed with the extraction of the data of interest. This is the stage where Excel was our best friend. As such, it supported us and was there for us, but also did not hesitate to ‘slap’ right in the face when wrong decisions were made. Lesson learnt – Excel is wise, take full advantage of its opportunities, Critical thinking, Strike 2. Make sure you name your columns in a strategical way and then fill the rows with all the essential information provided by the studies of interest. Keep in mind you research question, as this is the best guide during his stage.

When the data are collected in an excel layout they can be easily quantified. This is where I got to explore them and tried to see how and if they could be further analyzed in order to get more information out of them. Given the limited amount, the nature and the knowledge gaps of the residue studies, we could not perform a meta-analysis. However, the data indicated that we could go a bit beyond of just reporting the major gaps and the median values of the compounds found in pollen and nectar. That was when Dr Ruth Kelly, who was a Postdoc in our lab at the time, came to the rescue, joined our paper and offered her valuable information and skills on stats. It turned out that even though we were restricted to few compounds (neonicotinoid insecticides), we could identify a positive relationship between their residues found in pollen and nectar of plants. This is very important as it means that for those compounds, we could use the concentrations found in pollen to predict those in nectar. Taking into account how difficult nectar collection is and that it is slightly easier to collect pollen, this would facilitate future residue studies. Also, this could imply that this relationship may apply to more compounds belonging to other chemical groups (e.g. herbicides, fungicides and other non neonicotinoid insecticides), pointing out new roads for research. Lesson learnt – Listen to your data!

Once we got the results from the data analysis, all I needed to do was to think of the best way to present them to the rest of the scientific community. I tried to create a story that would make sense to other people, keep them interested while reading the article and potentially positively influence the future research of some of them. All was going great until we reached to a point where I was asked to reduce the size of my discussion part as I had written too much… For example, a discussion of 10 pages is a discussion good for a thesis, but can be tiring for a paper – very true. Managing to reduce that to six pages was a great challenge for me. Lesson learnt – Critical thinking, Strike 3.

While writing this paper, there were times I reached what seemed to be a dead end or this crucial spot were decisions had to be made. This is when my supervisors and/or co-authors of the paper came as my saviors and gave the solutions to all my problems. Lesson learnt – It is OKAY to not being able to answer to some questions. Remember we are here to learn. Discuss about your thoughts and worries with people that are more experienced, and are willing to help you.

To me, a paper is always a team effort. The better the teamwork, the better the outcome. From the contribution of the co-authors, to the discussions with the people of your research project, from the discussions with the rest of your lab members to the comments of the reviewers, every single person adds a small or a larger stone to it. A big ‘THANK YOU’ to my co-authors, to all the PROTECTS’ group that is so supportive and especially to Dara Stanley (University College Dublin) who triggered us in starting this paper, to the rest of the plant-insect interactions lab members for the fruitful discussions, and to all those who contributed in making this paper ready to be published!

Lesson learnt – Good things can happen through good collaborations!

In case you are interested in reading the full paper entitled ‘Plant protection product residues in plant pollen and nectar: a review of current knowledge’, here is the link:

https://doi.org/10.1016/j.envres.2020.109873.

Elena graphical abstract
Graphical abstract summarizing the paper

You may follow the general updates on our research through our project’s twitter account @ProtectsProject and my personal account @ZioElena.

For an excellent guide on how to conduct a systematic quantitative literature review visit the following link: https://www.griffith.edu.au/griffith-sciences/school-environment-science/research/systematic-quantitative-literature-review.

 

 

 

Monitoring habitats? The simplest approach is not always the best

From billabongs to vernal ponds and from wadis to turloughs, seasonal wetlands occur all over the world and are home to vulnerable freshwater species. According to the most recent World Wildlife Fund Living Planet Report, freshwater ecosystems are suffering more severe losses than terrestrial or marine ecosystems, with population abundance declining by 83% between 1970 and 2014. Effective monitoring is a crucial element of biodiversity conservation, and a small change, widening the taxonomic range of indicator species used in habitat assessments, could make a big difference for freshwater biota.

Seasonal wetlands experience frequent disturbance, which can interfere with the effectiveness of indicator species in habitat monitoring. In our paper, we showed that the simplest monitoring approach can yield misleading results.

ADelaney_Slack

Biodiversity, the set of organisms living on earth in all their variety, is in crisis.  International organizations such as the IPBES, FAO and leading scientists have repeatedly sounded the alarm, pointing out that the range and abundance of life forms are decreasing rapidly, and that we may lose the multiple benefits derived from nature, including pollination.

To combat biodiversity loss, conservation measures have been put in place around the world, and the European Union Habitats Directive is one such measure. The Habitats Directive aims to conserve over 230 selected natural habitats which occur in 28 countries in Europe through a network of protected areas. As with any good conservation program, a monitoring system is in place to assess its effectiveness, and in 2019, the status of protected European habitats was reported. The scale of the work is enormous, and a detailed inventory of all species and environmental variables affecting each habitat would be prohibitively expensive and time-consuming. Using selected species as proxies or indicators of overall habitat condition offers a more achievable means of assessment and this approach is incorporated into the Habitats Directive.

The use of indicator species exploits a trend for patterns of diversity or species composition across multiple taxa to coincide. We call this cross-congruence, and it enables us to infer the conservation status of a habitat by assessing a small number of key species. However, cross-congruence is weaker in habitats which have experienced human disturbance, and little is known about diversity patterns in habitats which are characterized by regular natural disturbances. A disturbance is likely to reduce cross-congruence if different taxa respond differently to a change or if they exploit different resources in a habitat. If diversity or composition of different taxa using the same habitat does not coincide, then using indicator species could lead to misleading habitat assessments. Indicator species are widely used in conservation assessment, and so this is an issue that could affect protected habitats around the world.

We aimed to test whether diversity patterns across different taxa were consistent in a habitat characterized by frequent natural disturbance, and whether a habitat assessment reliant on plants as indicator species reflected the provision of resources for organisms with contrasting habitat requirements. We focused on dune slacks: isolated freshwater wetlands occurring between the ridges in coastal sand dunes. They were an ideal model habitat because they are protected under the EU Habitats Directive, and so in many cases experience low human disturbance, but they flood in winter and dry out in summer, leading to regular natural disturbance. Because dune slacks can be small, we surveyed two small-bodied invertebrates which have been recommended as indicator species in the past (snails and water beetles) and compared their diversity and composition to that of plants, which are generally used as indicator species for the habitats protected under the EU Habitats Directive.

ADelaney_beetle-700x525
A water beetle in a slack at Kincasslagh, Co. Donegal, Ireland. Image courtesy Aoife Delaney

Plants, snails, and water beetles have shown cross-congruence in pond systems elsewhere, but they have contrasting environmental requirements, so they may respond differently to flooding and desiccation. We also carried out a habitat assessment based on the methods used in the EU habitat assessments for Irish dune slacks, which incorporates plants as indicator species.

We found no evidence that the species richness or diversity of snails, water beetles and plants were correlated in dune slacks, and nor could the composition of plant species be used to predict the likely suite of beetles or snails at a site. No significant difference could be detected between the diversity or composition of snails or water beetle species at sites that passed and failed the habitat assessment.

In this case, cross-congruence between plants, snails and water beetles was not observed and a habitat assessment based on indicator species from a single taxonomic group, plants, failed to deliver information on the snail and water beetle species in dune slacks.

The contrasting biological requirements of the three species groups has probably led them to respond differently to disturbance. For example, six sites failed to flood during the year of survey, even though it was a wetter year than average, and three of these passed the habitat assessment. The water table may have risen sufficiently close to the surface to support the typical wetland plants, but flooding is vital for aquatic snails and beetles to persist, and the failure of a site to flood will dramatically change the snail and water beetle assemblages present in any year when flooding does not occur. Drying out is a major threat for dune slacks in the EU and it is of concern that the current conservation assessment methods are not adequate to detect sites which are at risk, as the damage may be permanent by the time the plant composition has changed.

The habitat assessment is intended to identify sites which contain habitat of good quality and those which require interventions to improve their habitat quality. We found ten species listed as vulnerable on the Irish Red Lists for snails and water beetles in sites that failed the habitat assessment, and they could be lost if management aimed at restoring the plant community is put in place. Because the diversity of plants, snails and water beetles in dune slacks are not congruent, the current habitat assessment methods put them in danger of misguided conservation interventions that could have a negative effect on biodiversity.

This might seem to be bad news, but there is a potential solution: selecting indicator species from taxa with contrasting biological requirements is likely to make the assessment more robust and reliable.

These findings are described in the article entitled Principles of cross congruence do not apply in naturally disturbed dune slack habitats: Implications for conservation monitoring, published in the journal Ecological Indicators.

A previous version of this article was originally posted on Science Trends

About the author: Dr Aoife Delaney completed a PhD in dune slack ecohydrology, supervised by Drs. Jane Stout and Catherine Coxon at Trinity College Dublin