Category Archives: Biodiversity

Tight But Loose – just what is “biodiversity”?

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Fleet photo 1

Ever since I set up the Biodiversity Blog in 2012 I’ve had it in mind to write a post asking the question “Just what is “biodiversity”?”, but have never quite got round to it, there’s been too many other interesting and important things to write about on here!  This week over at the Dynamic Ecology blog Brian McGill has beaten me to it with a really interesting post entitled:  Biodiversity and pizza – an extended analogy leading to a call for a more multidimensional treatment of nature.

I’m not entirely sure that the pizza analogy works, it’s a little tortuous, but none the less the post is provocative and interesting, and has generated a lot of comments.  I strongly recommend it.

In the interests of recycling, and because the readership of my blog only overlaps partially with that of Dynamic Ecology, thought I’d restate a few things that I brought up in the comments to Brian’s post (but this certainly won’t substitute for going over and reading it yourself”.

One of the questions that Brian asks is:  “Is biodiversity a useful term or has it outlived its usefulness?”  It’ll come as no surprise to readers that I like the word “biodiversity”: I used it for the title of my blog and for my professorship, because it captures a lot about what I value in the natural world, and because it’s a term that I’ve (professionally speaking) grown up with. To my mind it is an umbrella term that can mean different things to different people; some see this as a disadvantage but I think that, as long as we qualify precisely what we are referring to, using “biodiversity” in a loose way is not a problem. Perhaps an appropriate analogy is with politics: if someone describes themselves as a “conservative” or a “socialist” or a “liberal”, those terms cover huge internal variation and political scope, but it’s not a problem because it broadly describes the beliefs of that individual.

As an instance of when “biodiversity” may not be a useful concept for nature conservation, Brian gives an example of salt marsh, often areas with rather low species diversity, as being of low priority for conservation because they are poor in “biodiversity”.  But this ignores the fact that all of the “official” definitions of biodiversity explicitly include diversity of habitats/communities/ecosystems/biomes in a defined geographical area.  For example the United Nations Convention on Biological Diversity defines it as:

“the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.” [my emphasis]

Thus destroying an area of salt marsh may indeed result in few species being lost, but it would be a significant loss of biodiversity at that higher level of community/ecosystem, if a region has only salt marsh, woodland and grassland in it: in essence you’ve lost one third of your biodiversity because you’ve lost one third of your habitats.

Something that’s occurred to me over the last couple of days of reading comments and thinking about the questions that Brian posed is that “nature” and “biodiversity” are not actually synonymous at all. When people say they like “being in nature” or they “value contact with nature”, what they are usually saying is that they enjoy landscapes, seascapes, changes in the weather, being out of doors, etc., things which are not strictly part of what we understand as “biodiversity”.

Likewise, “protecting the environment” includes a whole set of non-biodiversity related questions and actions such as air and water quality, wastes management, sustainable use of resources, etc., much of which may not directly affect biodiversity at all.

“Biodiversity” has a specific meaning, as the definition above shows, even though that meaning can be broadly defined. Which sounds like a contradiction, but it’s not – and brought to mind the title of the Led Zeppelin fanzine: “Tight But Loose”*.  Biodiversity as a concept and as a field of research and action involves so many different types of stakeholder (ecologist, botanist, zoologist, artist, conservationist, activist) that (as I said) it provides a useful (loose) umbrella.  Problems only occur when people use different tight definitions and talk past one another.

The other aspect to Brian’s post is around the pros and cons of valuing ecosystem services, which is a much bigger argument in some ways, and I’m going to point readers to two blog posts, one recently from Steve Heard which I think is a very nice, concrete example that captures a lot of the uncertainties that Brian describes:

https://scientistseessquirrel.wordpress.com/2015/08/04/invasions-beauty-and-ecosystem-services-a-conundrum/

The second is one of mine from last July related to the value of valuing nature, which was prompted by the Costanza et al. update paper:

https://jeffollerton.wordpress.com/2014/07/27/how-do-we-value-nature/

These are fascinating discussions that will run and run, I have no doubt.

 

*I’m fond of bringing musical examples into these blog posts 🙂

 

Protecting an ecosystem service: approaches to understanding and mitigating threats to wild insect pollinators

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Bee on apple blossom 2 - 1st May 2015Back in April 2015 I attended a two day meeting at Imperial College’s Silwood Park campus to discuss initial project ideas to address evidence gaps in the recent National Pollinator Strategy.  I mentioned the meeting in passing in a post at the time concerned with whether biodiversity scientists should also be campaigners, but didn’t say a lot about what conclusions we came to and what the next steps would be because at the time I was unclear on both of those counts: it was a very wide ranging meeting with a lot of participants coming at the question of pollinator conservation from different perspectives.  As well as academics there were representatives from the agrochemical industry, government research organisations, and  the National Farmers Union.

During summer 2015 one of the conveners of the meeting, Dr Richard Gill, herded cats organised colleagues, pulled together all of the text and ideas that were generated, and took on the task of seeing a summary of the meeting through from initial draft to publication.  It was a monumental effort, involving 27 authors and 86 manuscript pages, and Richard did a sterling job.  Entitled “Protecting an ecosystem service: approaches to understanding and mitigating threats to wild insect pollinators” it will appear as a chapter in the next volume of Advances in Ecological Research, which should be published later this month.

The abstract and contents for the chapter are below; if anyone wants a copy of the full chapter, please let me know.

Abstract

Insect pollination constitutes an ecosystem service of global importance, providing significant economic and aesthetic benefits as well as cultural value to human society, alongside vital ecological processes in terrestrial ecosystems. It is therefore important to understand how insect pollinator populations and communities respond to rapidly changing environments if we are to maintain healthy and effective pollinator services. This paper considers the importance of conserving pollinator diversity to maintain a suite of functional traits to provide a diverse set of pollinator services. We explore how we can better understand and mitigate the factors that threaten insect pollinator richness, placing our discussion within the context of populations in predominantly agricultural landscapes in addition to urban environments. We highlight a selection of important evidence gaps, with a number of complementary research steps that can be taken to better understand: i) the stability of pollinator communities in different landscapes in order to provide diverse pollinator services; ii) how we can study the drivers of population change to mitigate the effects and support stable sources of pollinator services; and, iii) how we can manage habitats in complex landscapes to support insect pollinators and provide sustainable pollinator services for the
future. We advocate a collaborative effort to gain higher quality abundance data to understand the stability of pollinator populations and predict future trends. In addition, for effective mitigation strategies to be adopted, researchers need to conduct rigorous field- testing of outcomes under different landscape settings, acknowledge the needs of end-users when developing research proposals and consider effective methods of knowledge transfer to ensure effective uptake of actions.

Contents
1. Importance of Insect Pollination
1.1 Providing an Ecosystem Service
1.2 Brief Introduction to Pollination Ecology and the Importance of Wild
Pollinators
2. Major Threats to the Pollination Service Provided by Insects
3. Steps in the Right Direction to Protect Insect Pollinator Services: Policy Actions
4. Understanding and Mitigating Specific Threats to Wild Insect Pollinators to Protect Pollinator Services
4.1 Understanding the Stability of Insect Pollinator Communities
4.2 Using Molecular Approaches to Monitor Insect Pollinators
4.3 How Do Parasites Shape Wild Insect Pollinator Populations?
4.4 Understanding Insect Pollinator Population Responses to Resource Availability
4.5 Engineering Flowering Field Margins as Habitats to Attract Insect Pollinators
4.6 How Might We Improve the Wider Countryside to Support Insect Pollinators
4.7 Insect Pollinators in Urban Areas
5. Considerations When Developing Future Research and Mitigation Strategies
Acknowledgements
Appendix
References

Biodiversity Blog – 2015 in review

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The WordPress.com stats helper monkeys prepared a 2015 annual report for this blog.

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 39,000 times in 2015. If it were a concert at Sydney Opera House, it would take about 14 sold-out performances for that many people to see it.

Click here to see the complete report.

Six Kingdoms for Christmas: the cultural biodiversity of a winter festival

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Since beginning this blog in 2012 I’ve traditionally posted one or two Christmas-themed items around this time of year, including a piece on “Thanking the pollinators for Christmas” and a true story from 2013, “A Christmas vignette“.  The role of pollinators in producing much of the traditional Christmas fare has subsequently been picked up by others (last year the University of Bristol, this year a blog from Trinity College Dublin) so I’ve decided to break with tradition and consider the ways in which biodiversity (both wild and farmed, though the latter of course originated as the former) adds to the cultural experience of Christmas through its traditions and rituals.

In this regard I’m coming at the topic as a north-European agnostic who values Christmas as an opportunity to relax and unwind at the darkest, coldest* part of the year, rather than as a Christian.  And because I’m a British scientist much of what I say relates to British customs, though I’ve tried to include non-British examples where I’m aware of them – feel free to let me know about examples I’ve missed by commenting below.

I’ve decided to structure this post taxonomically and focus on a Six Kingdom Classification** of life on Earth as that’s been the theme of my first year undergraduate teaching since October.  Four of the six Kingdoms can be dealt with fairly quickly as their significance to Christmas is marginal or non-existent.  The two “bacterial” Kingdoms (Archaea and Eubacteria) contribute little to Christmas other than providing much of the gut flora that’s going to help us digest our Christmas dinner. Important but not specifically festive.  Likewise the protists and algae (Kingdom Protoctista) add nothing specific to Christmas unless there are traditions associated with seaweed of which I am unaware.

The other three Kingdoms are the ones where cultural biodiversity associations are more apparent.  The Kingdom Fungi (yeasts, mushrooms and moulds) provides us with several Christmas traditions including (in Germany) hanging mushrooms on the Christmas tree for good luck, and in parts of Scandinavia hanging strings of dried mushrooms around the house as decorations and as a source of winter food.  There is also the association between the red-and-white colour scheme of fly agaric magic mushrooms (Amanita muscaria) and the robes of Santa Claus, though I’ve seen that idea debunked in a few places and it appears that the “traditional” interpretation of Santa’s suit originated in the USA in the 19th century.

The Kingdom Animalia (both invertebrates and vertebrates) affords us a host of cultural connections to Christmas.  Birds include the turkey (Meleagris gallopavo) which in times past were famously walked to London from Norfolk; the domestic goose (Anser anser domesticus); and much of the song Twelve Days of Christmas refers to birds, including the turtle dove (Streptopelia turtur) one of the UK’s most declining and threatened bird species.  Mammals we associate with Christmas include of course reindeer (Rangifer tarandus) pulling Santa’s sleigh, led by the nasally-advantaged Rudolph, but also domesticated farm animals.  For example in Denmark in osme households it’s more traditional to eat pork (Sus scrofa domesticus) for Christmas dinner than goose.

Staying with the vertebrates, in our house it’s traditional to have smoked salmon (Salmo salar) with scrambled eggs for breakfast on Christmas Day, and (again in Denmark) sild (Clupea harengus) is also traditionally served as a starter, but I don’t know of other fish traditions.  Likewise I’m unaware of any invertebrates that are specifically associated with Christmas, though there have been recent reports of sustainably-sourced lobsters (Homarus americanus and H. gammarus)  becoming “traditional” in Europe.  There are also some local traditions such as honey bees singing in their hives on Christmas Eve.

The last of the Six Kingdoms is the Plantae, which, whilst the least taxonomically diverse, provides us with a wealth of cultural associations to Christmas.  These traditionally include evergreen plants that have been used to decorate homes, probably since the earliest pagan Yuletide festivals, such as: Christmas trees (various conifers in the genera Picea, Abies and Pinus); European ivy (Hedera helix); holly (Ilex aquifolium); and mistletoe (Viscum album).  However such traditions evolve and adapt to local needs and availability of plants.  For example in North and South America other genera of conifers not found in europe, such as Pseudotsuga and  Araucaria, may be used as Christmas trees***.  Likewise the absence of European mistletoe in North America means that people have adopted native mistletoes in the related genus Phoradendron for decorating and snogging traditions.  Over at her blog, ecologist Manu Saunders has recently discussed how native Australian species can substitute European plants for Christmas decorations.

The final example from the Plantae is the poinsettia (Euphorbia pulcherrima) which I’ve pictured above.  In many ways this is an unusual plant to have such a strong cultural association with Christmas: it’s a mildly toxic species of spurge from tropical Mexico that was introduced to North America in the 19th century, then subsequently to Europe.  However its festive connotations date back to the earliest period of Spanish colonisation in the 16th century, so it’s older than some of the other Christmasy traditions I’ve discussed.

Of course biodiversity is about more than just species and taxonomic diversity, it also encompasses the diversity of habitats in which that life is found.  Here too we see strong influences of the natural world on the culture of Christmas, including festive scenes of snow-bound boreal conifer forest.  As our planet warms, however, that might be a view that is found only on Christmas cards and old movies, rather than directly experienced*.

And on that sobering note, I wish all of my readers and restful and biodiverse holiday: have a great Christmas everyone!

 

*Ha!  It’s looking to be the warmest December on record, and at times has felt more like early summer than mid-winter.

**I’m aware that there are other Kingdom-level classifications out there which could be used, but the Six Kingdom approach is a good starting point.

***Closer to home, colleagues in the office adjacent to mine have adorned their large weeping fig (Ficus benjamina) with home-made Christmas decorations.  Looks good.

Biodiversity lost and found: extinct island birds and living African dragonflies

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Two newly published studies have caught my eye this week as exemplifying two important aspects of biodiversity research: describing new species and understanding which species we’ve recently lost due to human activities.

Researchers working in the Macaronesian islands of the Azores and Madeira have described five new species of endemic water rails (genus Rallus) that are thought to have gone extinct within the period when humans colonised the islands.  One species may even have hung on into historic times.  All of the species were either flightless or had reduced capacity for flying, making them vulnerable to over-exploitation by humans.  That’s a common phenomenon on oceanic islands, with the dodo being the archetypical example.

What’s particularly remarkable is that these five new species increases the known recent diversity of the genus Rallus by about one third!  The reference for the paper, and a link to the pdf, is:

Alcover et al. (2015) Five new extinct species of rails (Aves: Gruiformes: Rallidae) from the Macaronesian Islands (North Atlantic Ocean) Zootaxa 4057: 151–190

The second paper is a mass-naming of 60 (!) new African dragonfly and damselfly species by a team led by KD Dijkstra, a Dutch entomologist whose work I’ve mentioned previously.  I had the pleasure of teaching with KD on a Tropical Biology Association field course in Tanzania a few years ago and his knowledge of African natural history is astounding.

To put these 60 new species into context, it increases the known diversity of African dragonflies and damselflies by almost 10%.  The reference and a link to the paper follows:

Dijkstra et al. (2015) Sixty new dragonfly and damselfly species from Africa (Odonata). Odonatologica 44: 447-678

Finding appropriate names for all of these insect species has required a degree of ingenuity from the authors and a quote from the paper demonstrates how memorable and creative some of them are:

“The Peace Sprite Pseudagrion pacale was discovered on the Moa River near Sierra Leone’s diamond capital Kenema. Twenty years earlier villagers trapped between rebel and government forces on opposite banks drowned in these tranquil waters. Two years later Kenema became the national epicentre of the Ebola outbreak…… The horntail Tragogomphus grogonfla evokes a Liberian pronunciation of ‘dragonfly’, the sparklewing Umma gumma a classic Pink Floyd album…… and the claspertail Onychogomphus undecim simply its date of discovery, 11/11/11.”

One of the things that I’ve tried to impress upon my final year undergraduate students this term during our Monday morning biodiversity seminars is just how little we still don’t understand about life on our planet.  Discoveries of new species are a regular occurrence, and for most we know nothing about their life histories or their interactions with other species (the aspect of biodiversity that particularly interests me).  In other cases (as with the Macaronesian water rails) the species were gone before we knew that they even existed.  I wish that I could be sure that this won’t happen in the future, but it will, until we (and the future generations that we are teaching) do something to address the problems of habitat destruction and inappropriate exploitation of biodiversity.

8 things I learned from the Parliamentary Pollinators Update seminar – UPDATED

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POST event December 2015

As I advertised a couple of weeks ago, last Wednesday I was in London to take part in a Pollinators Update seminar at the Houses of Parliament organised by the Parliamentary Office for Science and Technology (POST).  It was a very interesting event and good to catch up with some of the latest ideas about pollinators and their conservation.  However it’s been a busy week since then and I’ve not had time to post a full account of the seminar, which was attended by over 40 people.  So I’ve decided to write a brief summary of eight things I learned that day from my fellow speakers* and from the day in general; in some cases I’ve linked to the original sources where available:

1.  About 46% of Europe’s bumblebees have declining populations (see the European Red List for Bees that I highlighted in an earlier post)

2.  Around 2% of the world’s bee species do 80% of the crop pollination (Kleijn et al. (2015) Nature Communications)

3.  Pollinators other than bees perform 39% of the flower visits to crops (Rader et al. (2015) Proceedings of the National Academy of Sciences)

4.  By 2100 the Red-tailed Bumblebee (Bombus lapidarius), one of the commonest species in Europe, may be extinct across most of the continent due to climate change (Rasmont et al. (2015) Climatic Risk and Distribution Atlas of European Bumblebees)

5.  Only 6.6% of Entry Level Stewardship agreements by farmers across England included plans to grow nectar- and pollen-rich flower mixes.

6.  Criticism of laboratory studies of the effects of neonicotinoid pesticides are just as illogical as criticisms of field studies: both have their limitations and advantages, and both are needed.

7.  A panel of four experts on pollinators and pollination will largely agree about the answers to most questions an audience asks.

8.  A Westminster seminar such as this will attract very few MPs if it clashes with an important debate in the House of Commons, in this case about future military action in Syria.

UPDATE: here’s a number 9 suggested by Simon Potts: we all strongly support and encourage the setup of an All Party Parliamentary Group on “Pollinators” not just “honeybees” or “bees”.

 

*With thanks to my fellow panelists Simon Potts, Claire Carvell and Richard Gill, and to Kirsten Miller and the POST team for organising the event, and for the photograph of the panel in action.

 

Virtual Conference on Ecology and Climate Change

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Following on from what seemed to be a quite popular Virtual Conference on Pollinators, Pollination and Flowers I thought I’d mark this week’s Paris talks on tackling climate change with a second  “virtual conference” on the topic of climate change and how it may affect (and be affected by) natural and agricultural ecological systems.

This is a great set of talks* with some very thought-provoking ideas.  Hope you enjoy them.

Douglas Sheil  (Norwegian University of Life Sciences)

Do forests attract rain?

 

Hans Joosten (University of Griefswald)

For peat’s sake – bogs and climate change

 

Nicola Di Cosmo (Institute for Advanced Study)

Climate, conflict, and historical method

 

Ben Beard (NCEZID Centers for Disease Control)

Climate change, ecology, and disease emergence

 

Jennifer Cartwright and Bill Wolfe (USGS Tennessee Water Science Center)

Climate-sensitive, insular ecosystems of the Southeast U.S.

 

Nabil Nemer (American University of Beirut)

Are changes in insect patterns in the Lebanese Mountains evidence of climate change?

 

Lini Wollenberg (University of Vermont)

Climate Change Mitigation on Agriculture-Forest Landscapes

 

Tim Benton (University of Leeds)

Food and the future: climate and resilience

 

Feel free to discuss the talks in the comments section and to post links to other talks on the same topic.

 

*I’m assuming that, as all of these videos are in the public domain, none of the presenters or copyright owners objects to them being presented here.  If you do, please get in touch and I’ll remove it.

Butterflies and pesticides – a new study and a smoking gun

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Gatekeeper cropped P1010472

Following hot on the trail of the raft of recent papers that I highlighted on the blog last week comes a new study by Andre Gilburn and colleagues entitled “Are neonicotinoid pesticides driving declines of widespread butterflies?“.  The paper is open access and published in the journal PeerJ which encourages post-publication comments and review of the work.  I see that Tom Oliver of the Centre for Ecology and Hydrology has started the ball rolling with a couple of questions, and hopefully more will follow, with responses from the authors.

The paper focuses on the fact that between 2000 and 2009 there was a 58% decline in butterfly abundance on farmed land in the UK despite a doubling of spending on conservation in the UK over the same period, much of it on agri-environmental schemes on that very same farmed land.

Using a statistical modelling approach the authors conclude that the introduction of neonicotinoid pesticides in the mid-1990s is strongly implicated as a likely driver of those declines.  My immediate question on reading the paper was: “What were the trends like before the mid-1990s, and did the rate of decline change significantly after that period?”

The authors don’t directly answer the question but it seems to me to be quite an important one to answer because abrupt changes in rates of decline in the abundance and diversity of species can be linked to broader changes in, for example, land management and agricultural practices, as we showed recently for bee and wasp extinctions in Britain.

So I looked for the data that would tell me whether the trend had changed and found what I needed in the UK Butterfly Monitoring Scheme annual report for 2014.  Here’s a screen grab of Figure 3 from the report:

Butterfly abundance indices - November 2015

I’ve marked the point at which neonicotinoid pesticides were starting to be widely used in UK farming with a black line.  As you can clearly see this is also roughly the point at which the abundance of the 24 “Species of the wider countryside” begins to trend downwards.  In comparison, the 26 “Habitat specialists” show much less of a change, and in fact their initial decline was much earlier (in the 1970s-80s), possibly in response to loss of species rich grassland and ancient woodland.

Of course I’m just eyeballing the data and it needs to be tested statistically to see if there really is a break point in the trend at the mid-1990s, but this ought to be possible for anyone with access to the full data set.  Even if this is shown to be the case it’s all correlative (as Gilburn and colleagues acknowledge) and proving causation is difficult.  Nonetheless it looks to me like there’s an interesting smoking gun here that deserves further study.

Pollinators seminar at the Houses of Parliament – 2nd December

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Skipper on ragwort - cropped

The Parliamentary Office of Science and Technology (POST) has organised a “Pollinators Update” afternoon seminar in London on Wednesday 2nd December, to discuss recent developments in pollinator conservation research. I’ve been asked to give a 15 minute presentation on the pollinator extinctions research we published in Science last year.

The full programme will be:

 

  • 2.30pm Sarah Newton MP, Chair’s Welcome
  • 2.40pm Presentations
  • Professor Simon Potts (Professor of Biodiversity and Ecosystem Services) – Reading University
  • Professor Jeff Ollerton (Professor of Biodiversity) University of Northampton
  • Dr Claire Carvell – NERC Centre for Ecology and Hydrology
  • Dr Richard Gill – Imperial College London
  • 3.40pm Discussion
  • 3.55pm Chair’s closing remarks
  • 4.00pm Refreshments

 

The seminar is free to attend but you need to book a place: see the POST website for details.

Pesticides and pollinators: some new studies and contrasting conclusions

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Bee on apple blossom - 1st May 2015

The question of whether or not neonicotinoid pesticides are negatively impacting agricultural pollinator abundance, diversity and behaviour continues to focus the minds of researchers. It’s an issue that has been almost constantly in the news since the earliest suggestions that these pesticides were harming pollinators. These concerns have led to temporary EU restrictions on the use of these chemicals, a decision that was partially over turned this year in the UK.

The past two months has seen the publication of at least five papers on the topic, two of them this week alone.  In this post I want to highlight those papers and provide some commentary.

The first two studies have shown that neonicotinoid pesticides can affect pollinator behaviour, and specifically the memories of both honey bees and bumblebees:

Wright et al. “Low doses of neonicotinoid pesticides in food rewards impair short-term olfactory memory in foraging-age honeybees”

Stanley et al. “Bumblebee learning and memory is impaired by chronic exposure to a neonicotinoid pesticide“.

Subtle behavioural changes such as those documented here are not generally assessed in standard toxicological safety assessments for pesticides, which are mainly focused on whether or not the chemicals kill non-target animals, and at what dosage.  But for plant-pollinator interactions (including agricultural pollination) such changes in pollinator behaviour could be crucial to the effectiveness of the pollinators.  How crucial?  Well up until today we didn’t know; but with the publication of another paper by Stanley and colleagues we now have evidence that the sub-lethal effects on pollinator behaviour can actually translate into an effect on pollination of apple crops:

Stanley et al. “Neonicotinoid pesticide exposure impairs crop pollination services provided by bumblebees“.

The study is the first one to my knowledge that tests the effects of field-relevant doses of pesticides on pollinator performance and subsequent pollination services in a commercial farm crop, and adds some valuable hard data to an already heated debate.  The story, embargoed until this evening, has already been picked up by media, including the BBC News website.

To summarise the study: using artificial bumblebee colonies and caged apple trees Stanley and colleagues implemented an experiment in which they tested the effect of two different levels of exposure to a neonicotinoid pesticide on pollinator behaviour and subsequent pollination services to the fruit trees. They found a clear effect of exposure to the higher level of pesticide, resulting in a change in bee behaviour and a subsequent reduction in apple quality.

By way of a contrast, another study this week has focused on the lethal effects of these pesticides.  Henry et al. “Reconciling laboratory and field assessments of neonicotinoid toxicity to honeybees” has shown that although the chemicals are lethal to individual honey bees, the overall impact of the loss of the bees is buffered by the fact that the colonies can simply produce more worker bees to compensate for the losses.  This is interesting but needs to be judged in the context of the fact that honey bees are very unusual and atypical compared to most other pollinators, and indeed most other bees.  They produce very, very large colonies with a unique social structure, and so this compensation might be expected.  These caveats were echoed by some of the scientists asked to comment on the study in media stories such as the one on the BBC News website.

Finally, Godfray et al. have updated their earlier review of the environmental effects of these pesticides with “A restatement of recent advances in the natural science evidence base concerning neonicotinoid insecticides and insect pollinators“.  Given the rate at which new studies are coming out, it won’t be long before a second restatement is required!

Where does this leave the whole debate around pesticides?  Still with firmly entrenched views on both sides I would have imagined.  No doubt the debate will run and run.

Meanwhile, important as it is, the focus on pesticides is in danger of over-shadowing other really interesting studies that might affect how we manage our agro-ecosystems in the UK.  For example, I’d completely missed a paper from the end of September by Pywell et al. entitled “Wildlife-friendly farming increases crop yield: evidence for ecological intensification“.  As far as I can judge from the Altmetric information for the paper, so too had the media: it received no coverage on any of the usual outlets.  But this is important stuff that deserves wider publicity: it’s going to take more than a ban on pesticides to recover some of the biodiversity (at both a species and a habitat level) that we’ve lost due to intensive farming over the last 100 years or so.