Category Archives: Biodiversity

Global effects of land-use intensity on pollinator biodiversity: a new study just published

Humans affect the land on which they live in many different ways, and this in turn influences local biodiversity. Sometimes this has positive effects on local wildlife: consider the diversity of birds to be found in well-managed suburban gardens, for example. But often the effect is negative, especially when the land is intensively managed or habitats are destroyed, for example via deforestation or urban development.

This is not a new phenomenon – according to a recent study, most of the habitable parts of the planet have been shaped by humans for at least 12,000 years (see Ellis et al. 2021). What is new, however, is the scale and the speed with which land-use is changing, which are far greater than they have been historically. An important question is the extent to which this change in land-use intensity is affecting pollinator diversity in different parts of the world. Over the past 18 months I’ve been collaborating on a project led by Joe Millard (as part of his PhD) and Tim Newbold which uses the Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (PREDICTS) database to address that very question.

A paper from that collaboration is published today in the journal Nature Communications; it’s open access and can be downloaded by following this link.

The study was global in scale and used data from 12,170 sites to assess the affect of land-use intensity on 4502 pollinating species. The findings are really fascinating; highlights include:

In comparison to natural vegetation, low levels of land-use intensity can have a positive effect on the diversity of pollinators.
For most land categories, greater intensity of land-use results in significant reductions in diversity and abundance of pollinators, however. For example, for urban sites there’s a 43% drop in number of species and a drop in 62% pollinator abundance from the least to the most intensive urban sites.
On cropland, strong negative responses of pollinators to increasing intensity are only found in tropical areas, although different taxonomic groups vary in their responses.
The latter finding is especially concerning given that: (i) most pollinator diversity is found in the tropics; (ii) the majority of tropical crops are insect pollinated; and (3) tropical agriculture is becoming increasingly intensive and land use is likely to rapidly change in the coming decades.

The full reference for the study, with all authors, is:

Millard, J., Outhwaite, C.L., Kinnersley, R., Freeman, R., Gregory, R.D., Adedoja, O., Gavini, S., Kioko, E., Kuhlmann, M., Ollerton, J., Ren, Z.-X. & Newbold, T. (2021) Global effects of land-use intensity on local pollinator biodiversity. Nature Communications 12, 2902. https://doi.org/10.1038/s41467-021-23228-3

Natural Capital, Ecosystem Services, and Nature-Based Solutions: an analogy with books

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The terms ‘Natural Capital’, ‘Ecosystem Services’, and ‘Nature-Based Solutions’ seem to generate one of two emotions in some people: confusion and irritation. Confusion stems from not appreciating that these are different, though closely related, concepts, as I will show below. Irritation often is the result of seeing ecosystem ‘valuation’ as a neo-liberal plot to somehow ‘sell-off nature’. I’ve discussed this irritation in the past – see this old post for instance about ‘How do we value nature?‘ – so I’m not going to dwell on it: some people see the advantage of using these concepts, others don’t. And that’s fine. But I will touch briefly on the confusion aspect because it pertains to a discussion on Twitter this morning that was stimulated by this tweet from Prof. James Bullock, in which he saw the three concepts as re-packaging on the same ideas under different (and confusing) names.

James and I have been friends for a long time, and there’s things we agree on and things we disagree on. And that’s also fine. But as I pointed out in my response to the tweet, I think that these concepts are different, and that they logically flow together. To me, Ecosystem Services are the benefits to society provided by Natural Capital. Nature-Based Solutions are strategies or schemes for targeting Natural Capital creation or enhancement (e.g. flood meadows or woodland) to provide Ecosystem Services (e.g. flood management or carbon storage).

The analogy that I used (which a few people seemed to appreciate) is that this is the difference between books, what we learn from books, and decisions on how to produce more books.

Since the publication of Pollinators & Pollination: Nature and Society, books have been on my mind a lot 🙂

As always, your comments are encouraged.

A spectacular new plant has been named to honour a colleague: meet Ceropegia heidukiae!

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Finding organisms that have not previously been described by scientists is not unusual; every year, hundreds of ‘new’ species enter the taxonomic literature, a testament to how little we still understand about the Earth’s biodiversity. The majority of these species are insects, because that’s the most diverse group of organisms on the planet. But new species of plants and fungi also turn up regularly: for example in 2020, botanists and mycologists at Kew named 156, including some from Britain.

So although discovering undescribed species is not uncommon, any field biologist will tell you that it’s an exciting moment to spot something that you’re never seen before and which could turn out to be new. That was certainly the case when my colleague Dr Annemarie Heiduk’s attention was drawn to a South African plant that was clearly something special. As Anne said to me this week:

‘I will never ever forget the very moment when I spotted it and immediately knew it was something no-one has ever seen before. And I was so lucky to find it in flower. I cannot describe how beautiful it looked sticking out of the surrounding grass vegetation. It is certainly one of a kind and I really know how lucky I was to have found it. Not once did it ever cross my mind that I will discover a novel Ceropegia species, let alone one that is so distinct!’

So it was that last year Anne discovered the plant that was to be named in her honour: Ceropegia heidukiae. The species has been described by David Styles and Ulrich Meve in the journal Phytotaxa (from where the image above was taken). There’s also an account of the species on the Pollination Research Lab blog, with further photographs and information about the plant.

Anne has been honoured in this way not just because she discovered the plant, but also because, to quote the paper, she:

‘is a pollination ecologist who with her research on the floral chemistry and deceptive pollination strategies of Ceropegia trap flowers has acquired recognition as an expert in this field’

Anne tells me that she has already collected pollinator and floral scent data for this new species, so we can look forward to seeing that published in the near future. I described the fascinating pollination ecology of Ceropegia, including some of Anne’s earlier work, in my recent book. This is a genus of plants that has intrigued me since I first saw photographs of them and started growing them as a teenager, 40 years ago. Since then I’ve published several papers about their pollination strategies, and how they compare with the family Apocynaceae as a whole: see the following links for some examples:

https://jeffollerton.co.uk/2017/09/03/fly-pollination-in-the-trap-flower-genus-ceropegia-a-new-study-just-published/

https://jeffollerton.co.uk/2018/08/21/the-evolution-of-pollination-systems-in-one-of-the-largest-plant-families-a-new-study-just-published-download-it-for-free/

So, a big congratulations to Anne, and to David and Ulrich – it’s an amazing plant! I wonder what else is still waiting to be discovered in the stunning grasslands of South Africa?

Houseplants & Happiness: join me at the LEAF Houseplant Festival – 30th & 31st May!

New article just published: ‘Pollinators and pollination: myths, misunderstandings and much more to discover’

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My first (and hopefully not my last) article for the magazine British Wildlife has just appeared in the April issue. Entitled ‘Pollinators and pollination: myths, misunderstandings and much more to discover’ you can get a preview here: https://www.britishwildlife.com/article/volume-32-number-5-page-316-323

The article focuses on some of the myths and misunderstandings that I dealt with in my book Pollinators & Pollination: Nature and Society. It also points out that, even in a place like Britain with a long tradition of natural history study, there’s still much for the patient observer to discover. If you’re interested in a PDF, drop me a line via the Contact page.

Protecting British Pollinators event TOMORROW – 25th March

Pollinators are allies in the fight against climate change: a new commentary just published in New Scientist

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Over the past few months I’ve been thinking a lot about the relationship between the “Climate Emergency” (CE) and the “Ecological Emergency” (EE), and how they overlap considerably in terms of causes and solutions, but that the priorities of the CE often trump those of the EE. One of the outcomes of this has been a commentary that’s been published in New Scientist this week. It’s free to access – here’s the link:

https://www.newscientist.com/article/mg24933260-100-pollinators-are-our-secret-weapon-in-the-fight-against-global-warming/

It’s extracted from a much longer article that discusses the role of pollinators in relation to climate change. Hopefully that will be published in the not too distant future.

The other thing that’s happened this week is that, in my role as Visiting Professor of Biodiversity at the University of Northampton, I was asked to take part in a webinar that’s one of a series being produced in support of the Levelling Up Goals. The LUGs, modelled on the UN’s Sustainable Development Goals (SDGs) have cross-party support in Parliament and aim to bring economic prosperity to those parts of the country that have lagged behind in recent decades. The “Green Economy” is seen as central to this.

The webinar was recorded and you can view it here: https://www.fit-for-purpose.org/engage/how-to-level-up-harness-the-energy-transition

It was interesting and I learned quite a bit, for example about how the government is investing the state pension pot in sustainable energy projects. The format of the webinar, however, with the chair asking individuals a question and each of us responding, was a little frustrating as there was no real opportunity to counter statements being made, particularly by the MP for Hexham.

Yesterday Karin and I had out first COVID-19 vaccination; today we both feel a little under the weather, but it will pass. It’s certainly better than the alternative!

First, do no harm! The fundamental rule of creating pollinator habitat that you need to know

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I had an interesting conversation with a landscape architect on Wednesday who was asking for some advice about creating urban habitat for pollinators. The plan was to strip turf from under the trees in a city greenspace in order to put in some flowering plants as nectar and pollen sources. I often get asked about this, not only by landscape architects, but by professional gardeners, park committees, local residents groups, and so forth. My initial advice, following the Greek physician Hippocrates, is always the same:

“First, do no harm.”

Hippocrates was of course speaking to doctors and saying: before you intervene in a patient’s health, make sure you are not making things worse for them.

So what do I mean by this? Why is it relevant to pollinators?

Well, in the case of the discussion from earlier this week, the team had no idea if there were ground nesting bees such as Andrena spp. in the area where they planned to strip the turf. Stripping the turf would likely have destroyed any nests, or at least prevented the bees from emerging, particularly if a thick mulch was applied to the area. There were also suggestions of using glyphosate to kill off the grass, though I certainly advised against it: by coincidence a meta-analysis by Lucas Battisti and colleagues was published this week showing categorically that glyphosate is toxic to bees. Imagine spraying it over an area that has a colony of one of the ground-nesting solitary species? Or where queen bumblebees might be hibernating? Queen Bombus spp. often hibernate close to the base of trees – see D.V. Alford’s classic 1969 study of bumblebee hibernation.

It’s not only pollinators that could be harmed by starting work without appropriate surveys: even unpromising-looking municipal grassland, for example in parks, can harbour a significant diversity of plants that are being suppressed by too-frequent mowing. Mow less often and they will flower, producing nectar and pollen for pollinators, then later seeds for birds.

Sometimes you can do more by doing less.

One of the things that I stress in my book Pollinators & Pollination: Nature and Society, is that habitat creation for pollinators is about much more than just planting wild flower meadows and putting up some bee hotels. It needs forethought about what is on a site already, and what may be destroyed by the proposed actions. There also needs to be a consideration of the wider landscape context in which the proposed site is situated, and whether it is providing some of the other things that pollinators need to complete their life cycles each year. The diagram above is from my book and I refer to it as the “Requirements of Pollinators Triangle”. Because pollinators are so diverse in their natural histories, no one site can hope to provide everything that they all need. However there are some general principles that I present in the book.

If you’d like to know more about any of this, or need advice, or to enquire about the training that I offer, please do get in touch via my Contact page.

Online talks and training: here’s a selection of what I offer

How old are the flowering plants? A new study aims to reconcile the fossil and DNA evidence – but what does it mean for pollinators?

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Yesterday I was contacted by a journalist to give a comment on a paper that’s just been published in Nature Ecology and Evolution:

Silvestro, D., Bacon, C.D., Ding, W. et al. (2021) Fossil data support a pre-Cretaceous origin of flowering plants. Nature Ecology and Evolution https://doi.org/10.1038/s41559-020-01387-8

I was happy to do so as it adds a fascinating twist to a long-standing interest of mine: when did the angiosperms evolve and what role did pollinators play in that evolution?

In the end they didn’t use the text that I sent back to them, so I thought that I’d share it on the blog:

The evolution of the angiosperms was arguably one of the most significant events in the history of life on Earth, but the timing of the origin of this group of plants remains a hotly debated topic, with conflicting evidence coming from the fossil record and molecular biology. This important new study has developed a novel statistical approach to reconcile these two lines of evidence, and comes down firmly on the side of the molecular evidence to conclude that angiosperms originated much earlier than the fossil record suggests. This will be sure to stir up further debate that can only be resolved by finding well preserved and accurately interpreted fossils of an appropriate age. In the future I would like to see Silvestro et al.’s technique applied to the major groups of pollinators such as bees and wasps (Hymenoptera) and butterflies and moths (Lepidoptera) where there is likewise a discrepancy between what the fossils and DNA are telling us. Pollinators have had a profound influence on angiosperm evolution and we might expect a close correlation between the origin and subsequent diversification of these different groups of organisms. This would certainly support the findings from Silvestro et al.’s study. It’s an exciting time for researchers in this field: a world without flowers and pollinators would look very different