Tag Archives: Biogeography

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

The uneasy academic and the importance of dipping outside your discipline: reflections on The Urban University conference

Uneasy Academic 20141011_144756

It’s important for academics to occasionally move out of their disciplinary comfort zones and to interact with academics and practitioners from beyond their own silos, experiencing approaches that are alien and hearing voices that are not repeating the normative values of their own subject area.  Time spent in this way can be both stimulating and mundane, enlightening and boring, exciting and frustrating.  Above all, unpredictable.  At an ecological conference I know what I will experience; drop me into one devoted to the arts or social sciences, and anything can happen.  It’s an uneasy experience.

With that in mind I spent the end of last week attending a conference at which I was the lone scientist speaker, and indeed one of the very few people with a science background in the audience, as far as I could tell. The Urban University was sub-titled “Universities as place makers and agents of civic success in medium sized towns and cities” and was largely aimed at urban planners, architects, policy makers, and social geographers.  Not muddy boots ecologists.  However I’d offered the organisers (the University of Northampton’s Collaborative Centre for the Built Environment) a 30 minute talk about the monitoring work we’ve been doing on the bird assemblage at Northampton’s new Waterside Campus, which I discussed in an earlier post. The abstract for my talk is below, co-authored with my colleagues Janet Jackson and Duncan McCollin, plus two of our undergraduate students, Jo Underwood and Charlie Baker.

I had hoped that providing a very different perspective on the role of an urban campus, one focussed on the biodiversity it can potentially support and the ecosystem services that stem from it, might be of interest to this broad-based audience.  In the back of my mind I also thought it might be fun to reverse roles and, for 30 minutes, make them the uneasy ones.  It’s always hard to judge but I got the impression afterwards that the talk was well received and it elicited some discussion and questions.

Overall it was a stimulating couple of days and (I think) I’ve learned a lot, or at least learned more about the approaches and priorities of academics and practitioners beyond my immediate field. The talks ranged from the rather abstract to the very practical, from theoretical discussions to local activism. Particular highlights for me were:

John Goddard‘s overview of the relationship between the university and the city, and the fact that many academics don’t feel a personal link, or responsibility, to the urban centre in which they work.

Allan Cochrane discussing the unintended consequences of a university’s economic and social power, including gentrification and studentification of local residential areas.

Robin Hambleton on universities as a corrective to “placeless power”, i.e. multinational firms that can facilitate enormous social and economic change in an area despite having no geographic connection to the place.  Of course the internationalisation agenda of most UK universities means that they may themselves be in danger of wielding placeless power overseas.

Michael Edwards recounting how UCL academics and students have engaged in local activism in North London, for example fighting destructive planning applications, and sometimes positioned on the opposing side to the university itself.

Wendy Cukier on the experience of her Canadian university’s role as a “changemaker”, and the value of the Ashoka U Changemaker Campus programme, to which the University of Northampton is committed.

Cathy Smith on the medieval origins of the original University of Northampton, which was dissolved in 1265.  By happy coincidence 2015 is both the 750th anniversary of that dissolution and the 10th anniversary of the current University of Northampton’s full upgrade to university status in 2005.

The conference strongly impressed upon me the fact that academics sometimes take their institutions for granted in the sense that they don’t reflect on, or even challenge, the role of higher education within their geographical location. There may even be a danger of this becoming more pronounced as, in the rush to internationalise and chase overseas student fees, we in fact forget the physical and historical roots of our institutions.

Above all the two days I spent trying to navigate these unfamiliar waters reinforced my belief that it can be very dangerous for academics to isolate themselves within their disciplines, no matter how comforting and familiar that may be.  If the only voices that you are hearing (audibly and on the page) are the ones that are telling you stories that you already know and understand (even if you don’t agree with them) then it can be very easy to drift into a kind of disciplinary complacency in which you take the (self) importance and role of your own subject area for granted, without any external perspective on how it might be perceived by those beyond your academic boundaries.

Taking the occasional disciplinary leap could involve as little as going to a seminar in another department, or widening your reading to include areas beyond your subject.  Attending and presenting at a two day conference involves a greater commitment of time and energy, but it’s worth the effort.  It’s an approach to academia that I’ve tried to follow over the past 25 years and I’d recommend it as a way of broadening perspectives.  Sometimes it’s good to feel uneasy.

Many thanks to the organisers of The Urban University conference, particualrly Sabine Coady Schaebitz and Bob Colenutt, for their hard work in putting together such a great couple of days.  Here’s the details of my talk:

Biodiversity monitoring on urban university campuses

Jeff Ollerton, Joanne Underwood, Janet Jackson, Charles Baker & Duncan McCollin

Biodiversity, the variety of species and habitats to be found in a defined area, is a critical component of the natural world, and the ecosystem services that it provides supports modern society in economically tangible ways.  Urban campuses have long been acknowledged as supporting significant biodiversity, as evidenced by the many universities that have written biodiversity action plans.  However there has been relatively little quantitative research published on the biodiversity of British urban campuses, and how that diversity changes over time, particularly with respect to large-scale infrastructure development.  Academics and students in the Department of Environmental and Geographical Sciences have been collecting data on the biodiversity of Park and Avenue Campuses for more than 20 years, including plants, invertebrates, mammals, and birds.  This talk focuses on bird diversity as birds are an indicator group for assessing ecosystems, and are arguably the best understood group of species in the UK.  We present data on the birds that have been recorded on these campuses from 1993 to 2015, assessed in terms of their UK conservation status.  We then discuss the potential impact of the new Waterside Campus on the existing bird assemblage of the site, and present preliminary data showing how bird diversity has changed since building work began.  We end by discussing whether it is possible to maintain or even enhance bird diversity and abundance at the new campus.   The location of Waterside Campus, within the Nene Valley Nature Improvement Area and in close proximity to internationally important wetland bird sites, means that the University of Northampton has a civic duty to maintain the biodiversity of its campuses.

Note: in the end I actually didn’t include the data from Park and Avenue campuses, there wasn’t time to fit everything in!

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Filed under Biodiversity, Birds, University of Northampton

There were hummingbirds over the White Cliffs of Dover

Hummingbird bowl from BM

Biogeography has been on my mind of late, in part stimulated by thinking about the work we’re writing up on the frequency of wind versus animal pollination in plant communities in different parts of the world that I mentioned in one of my earlier Brazil posts.  André has added more communities to the data set following some field work in Uruguay, and we are collaborating with Bo Dalsgaard and his colleagues in Denmark on analysing how historical and contemporary climates may have shaped the patterns we’re seeing.  It follows on neatly from the previous work Bo has done on climate and hummingbird-flower interactions.  I’ll report back when we have more to say.

The other reason for thinking about biogeography is that a couple of recent scientific reports have captured my attention.  The first dealt with new fossil discoveries of species related to that enigmatic South American bird the hoatzin (Opisthocomus hoazin).  The report can be read here but in summary, the evidence suggests that the bird family to which hoatzins belong was once much more widespread and may have originated in Europe.  Hoatzins are not the only such example: hummingbirds, which are also currently restricted to the Americas, were found in Europe in earlier times, according to reports from back in 2004 and more recently in 2007.  It appears that contemporary biogeography may not reflect past biogeography for some (perhaps most?) groups of species.

As a lesson in contemporary biogeography, it’s often been pointed out that the famous Vera Lynn song The White Cliffs of Dover falls short in its scientific accuracy:

There’ll be bluebirds over
The White Cliffs of Dover
Tomorrow, just you wait and see

Bluebirds are members of the genus Sialia, a group of three species which do not naturally occur in Britain, in fact are not present in Europe at all.  So you’re not likely to hear them singing in southern England.  But perhaps the genus was present in the distant past?  Who knows?  In the meantime we may have to change the lyrics to the song.  Unless the writer was predicting what might happen in the future when continental drift means that Europe and the Americas will be much closer together.

The other report that caught my eye was of an interesting study that has compared plants and birds in cities across the globe, and looked at how urbanisation reduced the diversity of the native species compared to non-urban areas nearby.  However I do hope that the lead author was being misquoted when she said that: “Owing to the fact that cities around the world share similar structural characteristics – buildings, roads etc – it is thought that cities share a similar biota no matter where they are in the world”.  She goes on to say that they had discovered that some species: “are shared across cities, such as pigeons and annual meadow grass, but overall, the composition of cities reflects the unique biotic heritage of their geographic location”.  Well yes, of course:  any of our undergraduate students taking the second year module in biogeography could have told you that!  As a serious hypothesis to test it lacked rigour: few tropical birds and plants could survive in temperate-zone cities, for example.  There’s more to the study than just this, of course, as you can see from the abstract. Nonetheless it was an odd statement to make in my view.

The Wikipedia definition of biogeography that I linked to at the beginning of this post is perhaps a little limited in its scope:  “the study of the distribution of species and ecosystems in geographic space and through geological time” doesn’t cover the species interactions that have been a focus of my research, for instance.  Perhaps “macroecology” fits it better, though (as I’ve mentioned before) there’s been a lot of debate in the scientific literature about where biogeography ends and macroecology begins, or whether the two are synonymous.  My own view is that the two overlap considerably, but that macroecology is bringing a lot of new tools and approaches to the study of organisms at large spatial scales.  Whether that warrants the definition of a different discipline is debatable, but like all such debates (e.g. the difference between ecology and natural history as recently discussed on the Dynamic Ecology blog) it provides us with a way of reassessing our own views on the work we do, which is always a good thing.

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Filed under Biodiversity, Biogeography, Birds, Evolution, Macroecology, University of Northampton, Urban biodiversity