Tag Archives: Conservation

Is there really a “battle for the soul of biodiversity” going on at IPBES? UPDATED x 3

Carved demon

No.  But perhaps I should give some context to both question and answer…

The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) describes itself as “the intergovernmental body which assesses the state of biodiversity and of the ecosystem services it provides to society, in response to requests from decision makers”.   Sounds a little dry, I agree, but in fact IPBES is the most exciting and innovative international environmental body to have emerged in recent years.  Exciting because its remit is specifically to assess how society is affecting global biodiversity in toto, but also its value to humans.  Innovative because it’s a broad church that is trying to bring together the knowledge and expertise of both natural and social scientists, practitioners, indigenous peoples, and stakeholders of all kinds. This broad approach is something which some other international bodies have not, traditionally, been so keen to adopt.

IPBES has its critics who see it as superfluous in that its mission overlaps too much with that of organisations such as the Convention on Biological Diversity, the Ecosystem Services Partnership, and the United Nations Environment Programme.  However I certainly think that there’s room for such an organisation.  We need as many voices as possible shouting about how important these issues are, at all levels of society, from the work of local conservation volunteers and the People’s Walk for Wildlife upwards to the highest levels of international governance.  So I’m a supporter of what IPBES is trying to do; perhaps I’m biased but I was especially impressed by the fact that the first major output of IPBES was a badly needed Assessment Report on Pollinators, Pollination and Food Production for which I acted as an expert peer reviewer over its two iterations.  I’ve written posts about this a couple of times – see for example this one.

In recent weeks, however, there’s been some reports of in-fighting within IPBES, and between IPBES and other organisations, that science journalists have seen as being a major war of ideas.  It culminated in Nature publishing a piece entitled “The battle for the soul of biodiversity“, backed up by an editorial suggesting that “the global body for biodiversity science and policy must heal rifts“.

The crux of the perceived disagreements centre on terminology and concepts as much as anything, and specifically the notion of ‘ecosystem services’ versus ‘nature’s contributions to people”.  These seem to me to be saying much the same thing using different words, and I have to say that I was shocked when I read those articles and wondered what the hell was going on: was IPBES really falling apart before it had even managed to firmly establish itself (remember it only launched in 2013)?  Or was this just journalistic hyperbole of the kind that serves no real purpose other than to increase sales and page views?

I have no inside track to IPBES’s workings so I kept an eye on developments.  I was delighted, therefore, to see the 19th September issue of Nature publish four letters from IPBES insiders and experts from other organisations.  All of these, plus the articles I linked to above, are open access.

The first letter is from Jasper Montana of Sheffield University pointing out that “ideas need time to mature” and that “debates are grist to the mill of innovation for environmental governance”.  In other words, IPBES is a young organisation and the sorts of terminology being used are far from mature: terms such as “ecosystem services” and “natural capital” are at most a few decades old.  Clearly there is an urgency in building governance systems that can effectively conserve biodiversity, but debates around the best terms to use will not hinder that process.

The second letter from Bernardo Strassburg in Brazil entitled “honour guidelines that reconcile world views” pointed out that IPBES’s own guide to such concepts notes that the ecosystem services approach is just one of several, all perfectly valid, ways of viewing the relationships between people and nature, and of seeing people as part of nature.

The next letter is from IPBES chair Sir Bob Watson assuring us that “squabbles don’t obscure the bigger picture” and that a diversity of opinions and ideas is one of IPBES’s strengths.  It’s worth noting here that the original model for IPBES was the IPCC (Intergovernmental Panel on Climate Change) which has in the past been criticised for not allowing a diversity of opinions among contributors to its reports.  You can’t please all the people all of the time, and clearly not Nature journalists….

Finally Rudolf de Groot, chair of the Ecosystem Services Partnership, plus colleagues Pavan Sukhdev & Mark Gough, argued that “sparring makes us strong” and write the most critical of the four letters, stating that they “strongly object to the tone and content” of the original article.  They assure us that the Ecosystem Services Partnership and IPBES are not in competition and that there is mutual respect for different opinions and concepts.  Furthermore “both organizations…stand united against biodiversity loss and ecosystem degradation…. Irrespective of the terminology used, our community is undivided in our knowledge that we fundamentally depend on nature in countless ways.”

So there you have it.  The Nature article and editorial were, in my opinion and those of the letter writers, over the top, exaggerating debates and disagreements that, whilst certainly real, do not endanger IPBES nor its mission.  I urge you to read the original articles then the letters, and make up your own mind.  Comments welcome as always.

UPDATE 1:  Just after I tweeted this post the Natural Capital Coalition added it to the bottom of a tweet thread that they had started when the original articles were published.  I confess that I missed these first time round but the thread adds extra detail to why the articles were misleading.  Well worth reading – here’s the start of the thread:

 

UPDATE 2:  It seems Nature is happy to continue the exchange of views following the article; the current issue of the journal contains another letter (once again open access), this time from Jim Harris (Cranfield University) and Janne S. Kotiah (University of Jyväskylä, Finland) pointing out that “the debate around which framework to use to value biodiversity could stem from the relatively recent coining and adoption of the concept of nature’s contribution to people (NCP).  Google Scholar returns only 19 hits for NCP and nearly 100,000 for ecosystem services, mainly because the latter has been in use for much longer“.

They go on to say (as all the correspondents on this article have) that they see no reason why the two worldviews of NCP and ecosystem services are irreconcilable. NCP seems new and different because it’s unfamiliar jargon   All of this reminded me of one of my first posts on this blog – “Business and biodiversity: oil and water?” which documented an event that I attended in London called “Biodiversity & ecosystem services: new collaboration opportunities for academics with businesses” .  It’s worth quoting what I said with regard to jargon within the field:

“In the workshop I attended there was some discussion as to whether technical language such as “biodiversity”, “natural capital” and “ecosystem services” (which one contributor referred to as “eco-babble”) deters senior business managers from engaging with nature conservation. I pointed out that words and phrases such as “email”, “internet” and “world wide web” were not so very long ago similarly considered to be technical jargon but are now part of our every day language.”

I still stand by this: technical language is only a barrier to engagement if people do not take the time to understand the jargon.  And jargon can become everyday language very swiftly.

UPDATE 3: This issue rolls on and Nature is still allowing commentary.  Just before Christmas Jonathan Davies and Peter Stoett wrote on behalf of the authors of the biodiversity section of the newest Global Environment Outlook (GEO-6) from UNEP  (due March 2019) that “Biodiversity loss is dire, don’t get distracted“.

 

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Filed under Biodiversity, Ecosystem services, IPBES, Pollination

British phenological records indicate high diversity and extinction rates among late-summer-flying pollinators – a recently published study

Balfour et al Figure 1

Natural history records of plant flowering and pollinator foraging, much of them collected by well informed amateurs, have huge scientific importance. One of the values of such records to ecology is that it allows us to document where these species occur in space and when they are active in time. This can be done at a range of spatial and temporal scales, but large-scale patterns (for example at a country level) are, I think, especially useful because they provide scientific evidence that can inform national conservation strategies.

During 2017 I collaborated with a young early career researcher at the University of Sussex, Dr Nick Balfour, on an analysis of the phenologies of British pollinators and insect pollinated plants.  That study was recently published (see citation below) and I think that the results are fascinating.

Nick did most of the leg work on this, which involved assessing more than one million records that document the activity times of aculeate wasps, bees, butterflies and hoverflies held in the databases by three of the UK’s main insect recording organisations, the Bees, Wasps and Ants Recording Society (BWARS), the UK Butterfly Monitoring Scheme (UKBMS) and the Hoverfly Recording Scheme (HRS).  Information on flowering times was taken from a standard British flora (Clapham et al. 1990 – Flora of the British Isles. Cambridge University Press).

As well as looking at annual flight periods and flowering trends for these organisms we also focused on pollinator and plant species that were endangered or extinct. Here are some headline results and thoughts on what the work shows:

  • About two-thirds (62%) of pollinator species peak in their flight times in the late summer (July and August), though there was some variation between the different groups – see the figure from the paper above).  Particularly noticeable was the double peak of the bees, with the first peak denoting the activity of many early-emerging solitary bees, such as species of the genus Andrena, whilst the second peak is other solitary bees plus of course the bumblebees which by that time have built up their colonies.
  • A rather fixed phenological pattern with respect to different types of plants was also apparent, which I was not expecting at all: insect pollinated trees tend to flower first, followed by shrubs, then herbaceous species (again, refer to the figure above). This might be because larger plants such as trees and shrubs can store more resources from the previous year that will give them a head start in flowering the following year, but that idea needs testing.
  • Putting those first two points together, what it means is that trees tend to be pollinated by those earlier emerging bees and hoverflies, whereas the herbs are mainly pollinated by species that are active later.
  • When looking at the extinct and endangered pollinators, the large majority of them (83%) were species with a peak flight times in the late summer, a much larger proportion than would be expected given that 62% of all species are active at that time. However this was mainly influenced by extinct bee species and the same pattern was not observed in other groups.
  • The obvious explanation for that last point is that historical changes in land use have led to a dramatic reduction in late summer flowering herbaceous species and the subsequent loss of floral resources has been highly detrimental to those bees. But intriguingly no such pattern was apparent for the endangered pollinators and clearly there are complex reasons why pollinators should become rare or extinct, a point that I have discussed previously on the blog.
  • The lack of late summer flowering resources for pollinators is a contentious issue however as plant conservation groups have in the past recommend that meadows and road verges are cut in late summer to maximise plant species richness.  Mowing road verges once or twice a year certainly benefits plant diversity, as this recent review by Jakobsson et al. (2018) demonstrates.  But there’s very little data available that assesses how timing of cutting can affect pollinators.  The only study that I know of (and if I’ve missed any, please let me know) that has considered this is the PhD work of one of my former students, Dr Sam Tarrant who looked at pollinators and plants on restored landfill sites compared to nearby nature reserves.  In a paper that we published in the journal Restoration Ecology in 2012 we showed that on restored landfill sites the abundance of pollinators in autumn surveys (conducted September-October) was just as high as for summer surveys.  On nature reserves, which are routinely cut from mid-July onward, this was not the case.

Here’s the full citation of Nick’s study with a link to the publisher’s website, and a copy of the abstract is below.  If anyone wants a PDF, drop me a line:

Balfour, N., Ollerton, J., Castellanos, M.C., Ratnieks, F.L.W. (2018) British phenological records indicate high diversity and extinction rates among late-summer-flying pollinators. Biological Conservation 222: 278-283

Abstract:

The long-term decline of wild and managed insect pollinators is a threat to both agricultural output and biodiversity, and has been linked to decreasing floral resources. Further insight into the temporal relationships of pollinators and their flowering partners is required to inform conservation efforts. Here we examined the
phenology of British: (i) pollinator activity; (ii) insect-pollinated plant flowering; and (iii) extinct and endangered pollinator and plant species. Over 1 million records were collated from the historical databases of three British insect monitoring organisations, a global biodiversity database and an authoritative text covering the national flora. Almost two-thirds (62%) of pollinator species have peak flight observations during late-summer
(July and August). This was the case across three of the groups studied: aculeate wasps (71% of species), bees (60%), and butterflies (72%), the exception being hoverflies (49%). When species geographical range (a proxy for abundance) was accounted for, a clear late-summer peak was clear across all groups. By contrast, there is marked temporal partitioning in the flowering of the major plant groups: insect-pollinated tree species blossoming predominantly during May (74%), shrubs in June (69%), and herbs in July (83%). There was a positive correlation between the number of pollinator species on the wing and the richness of both flowering insect pollinated herbs and trees/shrubs species, per calendar month. In addition, significantly greater extinctions occurred in late-summer-flying pollinator species than expected (83% of extinct species vs. 62% of all species). This trend was driven primarily by bee extinctions (80% vs. 60%) and was not apparent in other groups. We contend that this is principally due to declines in late-summer resource supplies, which are almost entirely provisioned by herbs, a consequence of historical land-use change. We hypothesize that the seasonality of interspecific competition and the blooming of trees and mass-flowering crops may have partially buffered spring flying pollinators from the impacts of historical change.

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Filed under Bees, Biodiversity, Butterflies, Hoverflies, Macroecology, Pollination, Wasps

Hunting the Chequered Skipper: an encounter with England’s latest species reintroduction project

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If you have been following recent conservation news on social media you’ll know that this week was an important one for invertebrates.  The Chequered Skipper, a butterfly last seen in England in 1976, has been reintroduced to the country as part of the Back From the Brink initiative.  The Chequered Skipper project is led by Butterfly Conservation and a team travelled to a site in Belgium earlier in the week where about 40 skippers were captured.  These insects were transported back to the UK where they were held overnight in mesh cages at a secret location in order to acclimatise them, then released into the wild.  The release was filmed as part of next week’s BBC Springwatch series – look out for it.

The exact location of the reintroduction is secret.  However I can tell you that it’s occurred in the Rockingham Forest area of north Northamptonshire, in habitat that (over the past couple of years) has been managed specifically for this reintroduction, in order to create a network of sites across which the species could disperse in the future.  This area was the last stronghold of the species in England prior to its extirpation.  No one knows why it went extinct here, but hung on and did well in Scotland, but it may relate to climate: 1976, as many of the middle-aged will remember, was a very hot, dry summer, and this butterfly likes it warm and humid.

Yesterday I had the privilege of seeing this reintroduction first hand when I visited the site with my colleague Dr Duncan McCollin.  Duncan and I are supervising a PhD student, Jamie Wildman, along with Prof. Tom Brereton, Head of Monitoring at Butterfly Conservation (BC), and the University of Northampton’s Visiting Professor in Conservation Science.  Jamie’s project will focus on understanding the habitat requirements for Chequered Skipper, and monitoring the success of the reintroduction.  I’m also hoping that it might be possible for Jamie to assess the role of this species as a pollinator of the plants it visits.  Butterflies as pollinators is a very under-researched area.

Here’s a shot of the Four Mus-skipper-teers* just before we set off to help BC volunteers to locate the skippers and record their behaviour:

Four Mouse-skipper-teers 2018-05-26 11.10.19.jpg

 

The day started unpromisingly.  It was cool and overcast, and little was flying except some hardy Common Carder Bees.  But around lunchtime things began to warm up and gradually the sun broke through and we started to see flying Lepidoptera that we excitedly chased, only to be disappointed by yet another Mother Shipton or Silver Y.  But no skippers.

As we encountered some of the BC volunteers who were also tracking the insects we were told that we had “just missed one” or that they “saw one down that ride, we marked the spot”.  One volunteer wanted to show me a photo of a Chequered Skipper that he’d just taken “so I could get my eye in”.  I politely refused; I wanted to see the real thing and didn’t want to jinx it with a digital preview.

Finally, our efforts were rewarded and we found the first skipper of several we later encountered.  The image at the head of this post is that butterfly, a sight that has not been seen in England in more than 40 years.  An exciting and privileged encounter.  The county Butterfly Recorder, David James (on the right in this next shot), is ecstatic that the reintroduction has occurred “on his patch” but also nervous at the responsibility it represents:

Skipper crew 2018-05-26 13.15.06

Later we spent time helping Jamie follow a female skipper who was showing egg-laying behaviour, moving slowly for short distances along a shrubby edge, occasionally nectaring on Bugle, and diving deep into the vegetation to (we hope) oviposit on grass leaves:

 

Skipper watching 2018-05-26 15.10.18

Although I’ve over-cropped this next image of the skipper on Bugle, I thought I’d leave it as I like the different textures and patterns, and the slightly blurry ambience:

Skipper nectaring 2018-05-26 13.06.08

The primary aim of Butterfly Conservation’s project is to return a small part of England’s lost biological heritage.  But it’s about more than just the Chequered Skipper.  It’s also about understanding how managing a network of sites for this flagship species can benefit other organisms.  The wide woodland rides that have been created are packed with plant species, amongst them at least five grasses that could be used as caterpillar food sources for the skippers, plus more than 20 nectar sources were flowering that they (and other flower visiting insects) could use.  Those other insects were plentiful too: over the day I spotted five species of bumblebees, several different day flying moths, lots of Dark-edged Bee Flies, and a few different solitary bees and syrphids flies.  We heard calling cuckoos, and four different warblers: chiffchaffs, garden warbler, whitethroats, and blackcaps.  Red kites (another incredibly successful species reintroduction) floated overhead skimming the treetops as they their cried to one another.

Rockingham Forest is a lovely part of Northamptonshire, well worth a visit.  The Chequered Skipper will be a wonderful addition to its biodiversity.  Of course there are no guarantees that the reintroduction part of the project will be a success, but if it isn’t it won’t be because of a lack of commitment from the people involved.  If the population does become established then in the future the location will be made public and butterfly enthusiasts will be able to come and pay homage to one of the few butterflies with a pub named after it.

 

*You get the puns you deserve on this blog…..

 

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Filed under Bees, Biodiversity, Birds, Butterflies, Pollination, University of Northampton

Plant-pollinator networks in the tropics: a new review just published.

P1080615

As an ecologist who has carried out field work in the temperate zone (UK), the subtropics (Tenerife and South Africa) and the tropics (parts of South America, Africa and Australia)  I’ve always found the idea that the study of ecology can be divided into “tropical” and “non-tropical” a bit odd.  It’s as if the way that the natural world works somehow changes at about 23 degrees north or south of the equator, making things “different” around the equator.  The tropics are a very special, diverse place, it’s true, but so are many places outside the tropics.

With this in mind I was pleased when I was asked by some of my Brazilian colleagues to contribute to a chapter in a new book entitled Ecological Networks in the Tropics. It was an opportunity to review what is known about plant-pollinator networks in the tropics and the ways in which they are very similar to such networks at lower latitudes. Here’s the details of the chapter, followed by the abstract.  If anyone wants a copy please drop me an email:

Vizentin-Bugoni J, PKM Maruyama, CS Souza, J Ollerton, AR Rech, M Sazima. (2018) Plant-pollinator networks in the tropics: a review. pp 73-91 In Dáttilo W & V. Rico-Gray. Ecological networks in the Tropics. Springer.

Abstract:

Most tropical plants rely on animals for pollination, thus engaging in complex interaction networks. Here, we present a global overview of pollination networks and point out research gaps and emerging differences between tropical and non-tropical areas. Our review highlights an uneven global distribution of studies biased towards non-tropical areas. Moreover, within the tropics, there is a bias towards the Neotropical region where partial networks represent 70.1% of the published studies. Additionally, most networks sampled so far (95.6%) were assembled by inferring interactions by surveying plants (a phytocentric approach). These biases may limit accurate global comparisons of the structure and dynamics of tropical and non-tropical pollination networks. Noteworthy differences of tropical networks (in comparison to the non-tropical ones) include higher species richness which, in turn, promotes lower connectance but higher modularity due to both the higher diversity as well as the integration of more vertebrate pollinators. These interaction patterns are influenced by several ecological, evolutionary, and historical processes, and also sampling artifacts. We propose a neutral–niche continuum model for interactions in pollination systems. This is, arguably, supported by evidence that a high diversity of functional traits promotes greater importance of niche-based processes (i.e., forbidden links caused by morphological mismatching and phenological non-overlap) in determining which interactions occur, rather than random chance of encounter based on abundances (neutrality). We conclude by discussing the possible existence and direction of a latitudinal gradient of specialization in pollination networks.

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Filed under Bees, Biodiversity, Biogeography, Macroecology, Mutualism, Pollination

Local and regional specialization in plant–pollinator networks: a new study just published

Euphorbia canariensis pollinators 2016-04-29 17 58 00

A fundamental feature of the natural world is that no species exists in isolation: all organisms interact with other organisms during their lives. These interactions take many forms and the outcome varies with the type of interactions. For example predator-prey interactions are clearly negative for the prey species, but positive for the predator. Other interactions result in positive outcomes for both species, including relationships between pollinators such as bees, birds and flies, and the flowers that they pollinate. An important feature of such interactions is how specialized or generalized it is; that is, how many different pollinators are actually involved in pollinating a particular type of flower, or how many types of flower does a specific pollinator visits.

In a newly published study, I have collaborated with colleagues from Denmark and Brazil to assess how local specialization (within a community) relates to regional specialization (across communities) using two separate data sets from the Brazilian rupestrian grasslands and Canary Island/North African succulent scrub vegetation.

Here’s the citation with a link to the paper (drop me a line if you can’t access it and need a PDF):

Carstensen, D.W., Trøjelsgaard, K., Ollerton, J. and Morellato, L.P.C. (2017) Local and regional specialization in plant–pollinator networks. Oikos (in press) doi:10.1111/oik.04436

The abstract is as follows:

“Specialization of species is often studied in ecology but its quantification and meaning is disputed. More recently, ecological network analysis has been widely used as a tool to quantify specialization, but here its true meaning is also debated. However, irrespective of the tool used, the geographic scale at which specialization is measured remains central. Consequently, we use data sets of plant–pollinator networks from Brazil and the Canary Islands to explore specialization at local and regional scales. We ask how local specialization of a species is related to its regional specialization, and whether or not species tend to interact with a non-random set of partners in local communities. Local and regional specialization were strongly correlated around the 1:1 line, indicating that species conserve their specialization levels across spatial scales. Furthermore, most plants and pollinators also showed link conservatism repeatedly across local communities, and thus seem to be constrained in their fundamental niche. However, some species are more constrained than others, indicating true specialists. We argue that several geographically separated populations should be evaluated in order to provide a robust evaluation of species specialization.”

This is what those two different habitats look like:

If you would like more information on plant-pollinator networks, including details of an edible game for Christmas (!), follow this link to the standingoutinmyfield blog.

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Filed under Bees, Biodiversity, Biogeography, Brazil, Macroecology, Mutualism, Pollination, Tenerife

How many trees are there in Amazonia: two recent studies reached very different conclusions – UPDATED

The region of South America that we know as “Amazonia” has arguably the greatest biological diversity of any part of the planet, certainly as far as plants are concerned.  In some places the number of tree species per hectare exceeds 400, an order of magnitude greater than the number for the whole of the British Isles.  However estimating the total number of even the described plant species in this vast area has proven controversial, as two recent studies exemplify.  The first study was by ter Steege et al. (2016) and entitled “The discovery of the Amazonian tree flora with an updated checklist of all known tree taxa“, whilst the second is from just last month: Cardoso et al. (2017) “Amazon plant diversity revealed by a taxonomically verified species list“.  Both of them are open access so click on the links if you want to read the full studies.

One might expect that two such studies focused on Amazonia, both using vouchered herbarium records, would reach broadly similar conclusions as to the number of tree species in the region.  Not a bit of it: ter Steege et al. (2016) report 11,676 species, whilst Cardoso et al. (2017) say that the figure is 6,727.  That’s almost a two-fold difference!  Why the discrepancy?  Inspired by an initial tweet by University of Glasgow taxonomist Roderic Page, I downloaded the data from both studies and looked at it closely.

Here’s a scatter plot of the number of tree species per plant family reported by both studies:

Amazon tree diversity

 

The red line shows where we would expect the data points to lie if both studies had reported the same number of tree species per family.  Clearly few families lie on this line and most are above it as we might expect: as I’ve said, ter Steege et al. (2016) concluded that there were far more tree species overall and this is reflected at the family level.  Note that I’ve graphed this using a log scale and what might seem to be small differences are actually very large indeed.

Although the findings from two studies are highly correlated (diverse families are diverse in both studies, ditto families with low diversity) the actual level of that species richness is very different.  For example, in the Annonaceae, ter Steege et al. report  480 species, Cardoso et al. report 388; in the Clusiaceae the figures are 247 versus 135.  Other families are excluded from one data set or the other: ter Steege et al. reckon there 7 species of trees in the Dilleniaceae whereas Cardoso et al. cite zero.  Here’s a link to the data set if you want to explore further.  

So what’s going on here?  Why do two studies with similar aims, published about 12 months apart, come to such different conclusions.  As far as I can see there are three reasons for this.

First of all, the studies used slightly different taxonomies when it came to considering families and species.  So for example, Cardoso et al. recognise the family Peraceae which ter Steege et al. do not.  Although I haven’t done it, I’m sure that if one were to dig down to the species level there would be differences in which species were accepted and which were considered synonyms.

Secondly, the exact definition of what constitutes a “tree” varies between botanists, and the non-botanists who are no doubt responsible for some of the plant collections: some consider anything to be woody and tall-ish to be a “tree”, others have more strict definitions.  Notes about growth form taken in the field consequently get included in herbarium databases and may be inaccurate, especially for the uncommon species that have rarely been seen in the field.

The final reason, and the one that seems to be responsible for most of the discrepancy, is the definition of what constitutes “Amazonia”.  In the first study ter Steege et al. defined it as including the “forests and savannahs of the Amazon basin and Guiana Shield”.  In contrast Cardoso et al. considered only “lowland Amazon rain forests”.  That’s a big difference as there’s lot of savannah in this region, as well as other habitat types.  When we did field work in Guyana some years ago we could travel very quickly between savannah and rainforest.  It was clear to us that there is a range of trees that are restricted to one habitat or another, including species of Dilleniaceae (mentioned above) that are savannah specialists (hence the family’s exclusion from the Cardoso et al. study).

Now neither of these studies is “wrong” in the sense of being inaccurate or misguided: both are great studies involving a huge effort on the part of the authors.  But the limitations and definitions of geography and taxonomy that I’ve highlighted do mean that they need to be treated as rather different and not directly comparable.

So how many tree species are there in Amazonia?  If we consider just the rainforest then it’s 6,727 (Cardoso et al. 2017).  If we consider all habitats in the region, including rainforest plus savannah etc., then the figure is 11,676 species (ter Steege et al. 2016).  One of the implications of this is that the non-rainforest “Amazonian” habitats collectively contain 4949 tree species.  Thus a large proportion of the diversity of the region is in habitats, such as savannah, which are less of a focus for conservation efforts and not as well known to the general public, but are at least as threatened by agriculture and mining as rainforest.

Thanks to Roderic Page for initially highlighting this on Twitter, and Sandy Knapp for discussion.

UPDATE:  In retrospect my conclusion above regarding the proportion of trees in non-lowland rainforest habitats was much too high, as a couple of commenters have noted below.  It’s worth reading what they have to say, and my responses.  It’s likely that the taxonomic differences between the two studies are at least as great as the geographical ones, but then taxonomic opinions vary hugely.  Just serves to emphasise what a controversial and problematic question this is!

 

 

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Plant-pollinator networks, the time dimension, and conservation: a new study just published

Biella network

After rather a long gestation period, involving much re-analysis and rewriting, we’ve finally published Paolo Biella’s research from his Master’s thesis.  It’s a really neat plant-pollinator network study from mid-elevation grasslands in Italy’s Northern Apennine.  In it we have considered the way in which such networks could be analysed in relation to plant phenology (i.e. the timing of when they flower) rather than arbitrary time slices (e.g. months, weeks).  We have also discussed how this approach may inform conservation strategies in grasslands such as these.  The full citation with a link is:

Biella, P., Ollerton, J., Barcella, M. & Assini, S. (2017) Network analysis of phenological units to detect important species in plant-pollinator assemblages: can it inform conservation strategies?  Community Ecology 18: 1-10 

I’m happy to send a PDF to anyone who is interested in seeing the full study.

Here’s the abstract:

Conservation of species is often focused either only on those that are endangered, or on maximising the number recorded on species lists. However, species share space and time with others, thus interacting and building frameworks of relationships that can be unravelled by community-level network analysis. It is these relationships that ultimately drive ecosystem function via the transfer of energy and nutrients. However interactions are rarely considered in conservation planning. Network analysis can be used to detect key species (“hubs”) that play an important role in cohesiveness of networks. We applied this approach to plant-pollinator communities on two montane Northern Apennine grasslands, paying special attention to the modules and the identity of hubs. We performed season-wide sampling and then focused the network analyses on time units consistent with plant phenology. After testing for significance of modules, only some modules were found to be significantly segregated from others. Thus, networks were organized around a structured core of modules with a set of companion species that were not organized into compartments. Using a network approach we obtained a list of important plant and pollinator species, including three Network Hubs of utmost importance, and other hubs of particular biogeographical interest. By having a lot of links and high partner diversity, hubs should convey stability to networks. Due to their role in the networks, taking into account such key species when considering the management of sites could help to preserve the greatest number of interactions and thus support many other species.

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The Biodiversity Impact of Waterside Campus: an interim report on the bird surveys

bird-gains-and-losses

In previous posts I’ve discussed the work that we are doing monitoring the effects of building a large, new campus for the University of Northampton (see: Monitoring the biodiversity impact of the new Waterside Campus and a video I did of a talk about this project).  We have finally got round to writing an an interim report on the bird surveys we have been conducting (2014-2016), repeating the initial baseline surveys that were carried out in 2012-13.  The executive summary is below and you can download a PDF of the full report here.

As you will see it’s a mixed picture, with some losses and some gains of species, but we are broadly optimistic that the planned landscaping and habitat creation will have a positive effect come the 2018 opening date of Waterside Campus.  It’s important to note that studies such as this which follow up initial ecological surveys and assess the subsequent impact over time are extremely rare as there is no statutory obligation to do so.

Winter surveys will begin shortly and I will report back late next year, time willing.  Any questions or comments, please let me know.

 

Executive summary

  • Surveys of winter and spring bird diversity are being carried out to assess the effects of construction activities and habitat creation on local biodiversity at the University of Northampton’s new Waterside Campus.

 

  • These results are compared to pre-construction baseline surveys in winter 2012-13 and spring 2013, undertaken as part of the ecological impact assessment of the site.

 

  • Results after two repeat sets of surveys (winter 2014-15 and 2015-16; spring 2015 and 2016) are presented, with birds grouped into RSPB Green, Amber and Red categories.

 

  • Winter bird diversity has dropped from 41 species to 31 species; more Red and Amber listed birds have been lost than Green listed species.

 

  • Spring bird diversity has dropped from 40 to 36 species; more Green and Amber listed birds were lost, but the number of Red listed species increased slightly.

 

  • As well as losing species the site has gained birds that were not recorded in the baseline surveys, including Green-listed Coot and Treecreeper, the Amber-listed Stock dove, and the Red-listed House sparrow.

 

  • In addition, most of the “missing” birds are known to occur at sites 500m to 1000m from Waterside and could return following the end of construction and appropriate habitat creation.

 

  • Surveys will continue until after Waterside Campus opens in 2018, and analyses will be undertaken to tease out how these changes in bird numbers are related to changes to both the local and regional environments.

 

  • Outputs from this project so far include two conference presentations and two final year dissertations (one completed and one planned). At least one peer-reviewed research paper is anticipated.

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Filed under Biodiversity, Birds, Nene Valley NIA, University of Northampton, Urban biodiversity

Managing for Pollinators – a special issue of the Natural Areas Journal

Inula at Ravensthorpe 20160710_145426The October issue of the Natural Areas Journal is a special one devoted to the topic of “Managing for Pollinators”.  All of the papers have a North American focus but I think that they will be of general interest to anyone, anywhere in the world, who is concerned with how best to manage habitats for pollinators.  Here’s the contents page of the issue, copied and pasted from the site; I’m not sure if the full text links will work if you or your institution does not have full text access, but you should at least be able to view the abstracts:

Editorial: Pollinators are in Our Nature Full Access

Introduction by USFS Chief Tidwell – Pollinators and Pollination open access

pg(s) 361–361

Citation : Full Text : PDF (227 KB)

National Seed Strategy: Restoring Pollinator Habitat Begins with the Right Seed in the Right Place at the Right Time Full Access

Peggy Olwell and Lindsey Riibe
pg(s) 363–365

Citation : Full Text : PDF (1479 KB)

Hummingbird Conservation in Mexico: The Natural Protected Areas System Full Access

M.C. Arizmendi, H. Berlanga, C. Rodríguez-Flores, V. Vargas-Canales, L. Montes-Leyva and R. Lira
pg(s) 366–376

Abstract & References : Full Text : PDF (1302 KB)

Floral Guilds of Bees in Sagebrush Steppe: Comparing Bee Usage of Wildflowers Available for Postfire Restoration Full Access

James H. Cane and Byron Love
pg(s) 377–391

Abstract & References : Full Text : PDF (1500 KB)

The Role of Floral Density in Determining Bee Foraging Behavior: A Natural Experiment Full Access

Bethanne Bruninga-Socolar, Elizabeth E. Crone and Rachael Winfree
pg(s) 392–399

Abstract & References : Full Text : PDF (1219 KB)

Common Methods for Tallgrass Prairie Restoration and Their Potential Effects on Bee Diversity Full Access

Alexandra Harmon-Threatt and Kristen Chin
pg(s) 400–411

Abstract & References : Full Text : PDF (300 KB)

Status, Threats and Conservation Recommendations for Wild Bumble Bees (Bombus spp.) in Ontario, Canada: A Review for Policymakers and Practitioners Full Access

Sheila R. Colla
pg(s) 412–426

Abstract & References : Full Text : PDF (420 KB)

Conserving Pollinators in North American Forests: A Review Full Access

James L. Hanula, Michael D. Ulyshen and Scott Horn
pg(s) 427–439

Abstract & References : Full Text : PDF (1711 KB)

Dispersal Limitation, Climate Change, and Practical Tools for Butterfly Conservation in Intensively Used Landscapes Full Access

Laura E. Coristine, Peter Soroye, Rosana Nobre Soares, Cassandra Robillard and Jeremy T. Kerr
pg(s) 440–452

Abstract & References : Full Text : PDF (4647 KB) : Supplementary Materials

Revised State Wildlife Action Plans Offer New Opportunities for Pollinator Conservation in the USA Full Access

Jonathan R. Mawdsley and Mark Humpert
pg(s) 453–457

Abstract & References : Full Text : PDF (249 KB)

Diet Overlap of Mammalian Herbivores and Native Bees: Implications for Managing Co-occurring Grazers and Pollinators Full Access

Sandra J. DeBano, Samantha M. Roof, Mary M. Rowland and Lauren A. Smith
pg(s) 458–477

Abstract & References : Full Text : PDF (1537 KB)

The Role of Honey Bees as Pollinators in Natural Areas Full Access

Clare E. Aslan, Christina T. Liang, Ben Galindo, Hill Kimberly and Walter Topete
pg(s) 478–488

Abstract & References : Full Text : PDF (467 KB)

Food Chain Restoration for Pollinators: Regional Habitat Recovery Strategies Involving Protected Areas of the Southwest Full Access

Steve Buckley and Gary Paul Nabhan
pg(s) 489–497

Abstract & References : Full Text : PDF (732 KB)

Forbs: Foundation for Restoration of Monarch Butterflies, other Pollinators, and Greater Sage-Grouse in the Western United States Full Access

R. Kasten Dumroese, Tara Luna, Jeremiah R. Pinto and Thomas D. Landis
pg(s) 499–511

Abstract & References : Full Text : PDF (1716 KB)

Using Pollinator Seed Mixes in Landscape Restoration Boosts Bee Visitation and Reproduction in the Rare Local Endemic Santa Susana Tarweed,Deinandra minthornii Full Access

Mary B. Galea, Victoria Wojcik and Christopher Dunn
pg(s) 512–522

Abstract & References : Full Text : PDF (2880 KB)

Save Our Bats, Save Our Tequila: Industry and Science Join Forces to Help Bats and Agaves Full Access

Roberto-Emiliano Trejo-Salazar, Luis E. Eguiarte, David Suro-Piñera and Rodrigo A. Medellin
pg(s) 523–530

Abstract & References : Full Text : PDF (463 KB)

The Importance of Phenological Diversity in Seed Mixes for Pollinator Restoration Full Access

Kayri Havens and Pati Vitt
pg(s) 531–537

Abstract & References : Full Text : PDF (2208 KB) : Supplementary Materials

Stewardship in Action Full Access

Sarah Riehl
pg(s) 538–541

Citation : Full Text : PDF (595 KB)

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The macroecology of animal versus wind pollination – a new study just published

In collaboration with colleagues in Brazil, Denmark, and elsewhere in the UK, we’ve just published a new research paper which looks at the global spatial distribution of wind and animal pollinated plant species, and the underlying historical and contemporary ecological causes of that distribution.  It’s a study that builds on my “How many flowering plants are animal pollinated?” paper in Oikos, and has been a long time in its gestation.  We’re very excited by its findings and plan to develop this project in the future.

As a bonus we made the cover of the journal with the amazing image below!  Big thanks to Pedro Viana and Jesper Sonne for the photos.

Here’s the citation with a link to the publisher’s website; the abstract is below.  If anyone wants a PDF copy, please ask.

Rech AR, Dalsgaard B, Sandel B, Sonne J, Svenning J-C, Holmes N & Ollerton J (2016) The macroecology of animal versus wind pollination: ecological factors are more important than historical climate stability. Plant Ecology & Diversity 9: 253-262

 

Abstract:

Background: The relative frequency of wind- and animal-pollinated plants are non-randomly distributed across the globe and numerous hypotheses have been raised for the greater occurrence of wind pollination in some habitats and towards higher latitudes. To date, however, there has been no comprehensive global investigation of these hypotheses.

Aims: Investigating a range of hypotheses for the role of biotic and abiotic factors as determinants of the global variation in animal vs. wind pollination.

Methods: We analysed 67 plant communities ranging from 70º north to 34º south. For these we determined habitat type, species richness, insularity, topographic heterogeneity, current climate and late-Quaternary climate change. The predictive effects of these factors on the proportion of wind- and animal-pollinated plants were tested using correlations, ordinary least squares (OLS) and logistic regression analyses with information-theoretic model selection.

Results: The proportion of animal-pollinated plant species was positively associated with plant species richness and current temperature. Furthermore, in forest, animal pollination was positively related to precipitation. Historical climate was only weakly and idiosyncratically correlated with animal pollination.

Conclusion: Results were consistent with the hypothesised reduced chance for wind-transported pollen reaching conspecific flowers in species-rich communities, fewer constraints on nectar production in warm and wet habitats, and reduced relative effectiveness of wind dispersal in humid areas. There was little evidence of a legacy of historical climate change affecting these patterns.

andre-capa-1

 

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Filed under Biodiversity, Biogeography, Brazil, Climate change, Macroecology, Pollination