What exactly is a “pollination system”?

Pollination systems

This is a post I’ve been meaning to write for some time, but have never got round to.  What’s catalysed me is an email this morning from Casper van der Kooi asking me about how I define the term “pollination system”, as he’d had some discussions about its use with his colleagues in The Netherlands.

“Pollination system” is one of those terms that seems to mean different things to different people. The way I use it, and I think the way we meant it in the 1996 paper Generalization in pollination systems and why it matters, is that the pollination system = floral phenotype + pollinators.  That is to say, the colour, shape, size, odour, rewards, etc. produced by a flower (or an inflorescence functioning as a single reproductive unit) plus the animals that effectively transfer pollen.

To me this is distinct from a “pollination syndrome” which refers only to the floral phenotype, or “pollinator guild/functional group” which refers only to the flower visitors.  However I have seen “pollination syndrome” used to include floral phenotype + pollinators.  But to my mind they are distinct things.

I have also seen other authors use “pollination system” to mean the community of plants and pollinators in an area, or as analogous to the breeding system, but neither of those are the way that I use it.  I decided to look at the history of the term on Web of Science and the earliest use on there is a paper by Levin & Berube (1972): Phlox and Colias – efficiency of a pollination system.  There were a few other papers from the same decade and all were using pollination system in the way I described above, i.e. floral phenotype + pollinators.

To look for earlier usage of pollination system I searched the Google Ngram Viewer; as you can see in the image above, I found examples of the term back as far as the 1940s in which the pollination system of grasses is referred to as being “cross pollination” (i.e. what we would now refer to as the breeding system).  There’s also texts from the 1950s referring to artificial wind pollination of date palms as a “helicopter pollination system”.

Does it matter how “pollination system” is used, or that it varies in meaning according to the author?  Probably not as long as the meaning is defined in the text.  Ecology is replete with terminology that has slightly different usage according to the researcher (“biodiversity” being an obvious example) and I don’t get a sense that this has held back the field.  Or is that too optimistic a conclusion?  Do you use the term in a different way to me?  As always, your comments are welcomed.

6 thoughts on “What exactly is a “pollination system”?

  1. davidtimerman

    In my work on ambophily, I use the term to describe the specific mechanism of pollination. Whether or not a plant benefits from wind or insect pollination may depend on having specific floral structures, but it may just as easily depend on the ecological context of mating. So in the case of ambophily, it may not be meaningful to include floral traits in the definition.

    I see a parallel with the term mating system, which is used to describe the continuum from cross to self pollination. The mating system may be associated with a syndrome of characteristics, or not. The selfing rate may depend entirely on the presence or absence of pollinators, or their behaviour. The mating system is defined as “who mates with who”, not by floral traits.

    1. jeffollerton Post author

      Thanks for the comment David. I’m not sure what you meant by “So in the case of ambophily, it may not be meaningful to include floral traits in the definition.” Surely in order for a flower to be ambophilous it has to have floral traits that allow both wind and animal pollination? Or did I miss your point?

      Also, in your second paragraph, isn’t the first part you describe really the _breeding_ system, whereas the “who mates with who” is the mating system? I’m reminded of Paul Neal and Greg Anderson’s paper discussing this: https://www.jstor.org/stable/23654199?seq=1#page_scan_tab_contents

  2. André Rech

    Great comment Jeff, we kind of agreed in Brazil to use Pollination System (Sistema de Polinização in Portuguese) as a way to refer to flower morphology plus effective pollinators. We compare it to Pollination Syndrome when you don’t know the pollinators, as suggest students to use syndrome as a hypothesis to test with observation and discover the pollination system.

  3. Manu Saunders

    Nice post. Agree, I don’t think it necessarily holds the field back and as long as researcher defines their use it’s all good. I think the only problem with these kinds of ambiguous terms arises when someone down the track does a literature review- hence why it’s so important for authors publishing systematic reviews to make a genuine attempt to cover all possible terms for what they are asking, esp historical use


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