Wednesday, May 24, 2017

Natural history and ecology go together like flowers and pollinators

I've only very recently returned from Victoria, where I attended CSEE2017 and gave a talk. CSEE2017 was fantastic, but I will save my commentary thereupon for another post. I'm only mentioning my visit to Victoria now because I went to the Butchart Gardens while there. To be perfectly honest, these days as a plant ecologist I often get grumpy visiting ornamental gardens, as they generally have few or no native plants, usually have virtually no pollinators to watch, and just lack ecological interest. Certainly I found the gardens beautiful, and if I were a horticulture aficionado I might have found more to interest my curiosity while there, but what actually caught my attention was this:

Tulip showing stem fasciation and an abnormal number of flowers.
Fasciation: an abnormal condition of growth tissues, wherein in the meristem (area of actively dividing, growing, and differentiating cells), rather than having its normal domed/round shape, is elongated in one dimension, resulting in thick, wide organs and distorted growth. For a more detailed discussion of fasciation, I invite you to read my previous blog post on the topic (linked below).

I have talked about fasciation before, in context of a rather awesome mutant thistle that displayed multiple levels of fasciation plus homeosis (substitution of one organ for another), so that was an individual with a lot of issues. But this fasciated  tulip is rather intriguing to me because it exhibits only stem fasciation, with no other visible abnormalities. The photo below shows the fasciated stem clearly.

Fasciated tulip stem
Now, the fasciation of just the stem is interesting to me because it is specifically accompanied by a subsequent splitting of the fasciated stem and the production of multiple otherwise normal flowers, as seen in the first photo and even the one below, where there are two tulips rather too close to one another, but they are not fused (i.e. they grew on separate meristems) and they seem to be anatomically normal. You may have noticed that the photo below is a different plant -- at the gardens I saw three cases of this kind of stem fasciation in tulips with an abnormally large number of otherwise anatomically normal flowers.

Fasciated tulip again
Since I saw it three times, it may well have been more common than that at the garden. Possibly this is a heritable fasciation (i.e. fasciation resulting from a genetic mutation); the probability of this option depends a bit on how the garden acquires and maintains their tulip population -- if they breed their own tulips, then it is possible that these fasciated individuals are actually related to each other, which increases the probability of this being a heritable genetic mutation.

Fasciated tulip!

However, as with the thistle, there are other reasonable possibilities, among them the possibility that the fasciation has an environmental cause (e.g. a pesticide or fertilizer applied to all the tulips), or that it results from a bacterial or fungal pathogen transmitted through the garden by gardening activities like watering and weeding.

My friend and travelling companion, Kayleigh, also found a case of fasciation in Bellis perennis (english daisy) in Victoria. First, here's a normal one:

Bellis perennis normal specimen -- photo taken by K.G. Nielson and used with permission
And our weird mutant showing floral fasciation (this is what is not seen in the tulips above; with them, the stem is fasciated but the flowers normal; with this one, the stem is normal but the flower is fasciated):

Bellis perennis fasciated individual -- photo taken by K.G. Nielson and used with permission
So you might be wondering when I'm going to get to the point. The point is this: an ecologist should also be a natural historian! There was an interesting opinion piece recently published about the importance ecologists place on natural history (the largely observational study of organisms, particularly their traits, their interactions with their environment, and their history), and how ill-equipped many young ecologists feel to teach natural history.

This story resonates with me, because I adore natural history but make no pretensions to having great skill or knowledge in the area; I am largely self-taught on this subject. I run this blog partly to share the beauty and wonder and amazing scientific appeal of nature, and partly to remind myself to root my ideas firmly in the reality (read: natural history) of the organisms and communities I study.

I believe that natural history is where it all begins: a couple of ecologists on a walk notice a bunch of fasciated plants, and this spurs all sorts of wonderful lines of inquiry about how the fasciation comes about, how the condition might spread in a population, the particular mechanisms of function, the possible associations between assorted fasciation types, etc etc etc.

Darwin is a particularly notable example of beginning ecology with natural history: his work starts with incisive observation and proceeds from there into testable hypotheses and experiments.

When it comes down to it, everything we do as ecologists starts in with natural history.

I don't have enough experience or expertise to weigh in on whether natural history training is lacking in many universities as suggested in the article I linked. I can't even say whether my own lack of extensive natural history training is due to my own neglect of my options, or due to an absence of options available to me. But at the personal heart of it, I'm an ecologist because it allows me to blend my deep and abiding love of natural history with the elegance, logic, and rigour of the scientific approach. I'm sure I'm not alone.

The best ecological questions and hypotheses happen because ecologists are also natural historians.

Besides, it's better for our health to get outside and wander around once in a while with our eyes wide open.

Monday, April 24, 2017

A new field season begins!

I have been working away at my stats, analysis, and writing in the lab since my last post in September about the transition between fieldwork and data analysis. With the melting of the snow, I'm now heading back out into the summer portion of the ecology research cycle: field research!

I will be collaborating with my labmate Cory and his old supervisor on long-term research with the population of Cypripedium arietinum (ram's head orchid) at the lake; I've written about this plant before -- there's a nice photo of the flower over on that post as well so go check it out!

Orchids are interesting for lots of reasons. Here are just a few:

(1) Many orchids are unrewarding, which means that they don't offer nectar to pollinators in exchange for pollen transport. With unrewarding orchids we can investigate questions about the evolutionary consequences and/or adaptive mechanisms for deceiving pollinators into moving pollen from plant to plant

(2) Many orchids are spring ephemerals. This means that they flower in the brief window in the spring after the snow melts and before the trees put out their leaves. Synchronizing with their pollinators, which are just waking up from their winter hibernation, is particularly important for them to successfully reproduce. With these plants, then, we have opportunities to investigate how small- and large-scale variation in climatic conditions (e.g. timing of first snow melt, date of tree leaf bud bursting, quantity of canopy that's open throughout the blooming period, variation in temperatures, etc) can affect the emergence synchronization of flowers and their pollinator.

(3) Orchids rely on fungi in the soil in order to germinate and grow, so we can ask questions about how such a system might evolve and how the orchids and fungi can affect each other over time and space.

Cory and I went out yesterday to get some basic information about the areas where the plants are found, so that we can get a sense of what kind of designs are going to work best.

At the start of the season we're often just exploring a bit, to get a sense of what we have to work with with respect to terrain and space. This kind of knowledge is invaluable for designing studies and making decisions about what kinds of tools and techniques we want to use.

We were delighted to notice that we could pinpoint a few clumps of the plants because we found some old fruiting stalks (seed pods on old stalks) that survived over the winter. They aren't easy to spot because they're small and about the same colour as dead leaves and twigs on the ground, but with a bit of crawling around and some prior knowledge, they can be found.

These old seed pods are great not just to help us locate plants, but also because they allow us to glean a bit of information about last year, too; a rough count of how many old seed pods there were this spring gives us a minimum number of seed pods that were produced last year (we can't know what proportion were lost over the winter, so we can't say how many more than this count were produced).

Old seed pod of C. arietinum
Because these orchids are perennials, finding these old stalks allowed us to locate at least some of the clumps of C. arietinum at our sites. What's more, we even found some very young shoots already coming up!

In the centre of this photo (look closely) there are several little C. arietinum shoots just starting to come up; the white thing is a tag that we put in to mark the location of this clump

Cory and I put in some temporary tags and some flags to mark off the general areas where we know there are plants; this will make our work easier next week when we go back next weekend to install permanent tags for the clumps of C. arietinum, since we're going to want to be able to track them across years.

Cory, next to a pole that he placed to mark one of the areas of the property where we found some C. arietinum clumps
At that point, we'll also start making a GPS map of the coordinates of our populations and clumps for good long-term data maintenance, and as insurance against long-term markers being lost or displaced accidentally.

My husband was recruited as an unpaid but dearly appreciated field assistant; here we are counting old stalks, fruit, and new shoots in a clump of C. arietinum that he found.
We'll be going back throughout the season to track these plants as they grow, bloom, and fruit. I will post some more updates as the season progresses.

Purely out of curiosity, we spent a bit of time fiddling with the old seed pods; we noticed that most of them had opened and dispersed all their seeds, already, but that some still contained seeds and were in varying stages of openness. Those that were partially open were interesting because when shaken or nudged, they sent out clouds of thousands of miniscule seeds! We took a video that is unfortunately out of focus, but you can see the seeds as little blurry pale things in the video clip below:

video


We also collected a couple of old seed pods from last year that hadn't opened and released all their seeds and spent a few minutes today looking at the seeds under the microscope out of curiosity. We weren't using the fancy Zeiss research scope in the lab upstairs, so there's no camera mount on this microscope and it's not the most amazing scope ever, but I can at least give an idea of what the seeds look like:

C. arietinum seeds; the dark spot in the centre is the seed itself. The old cell walls are visible in this image as dark lines that seem to be outlining somewhat rectangular shapes. This image is at taken at 100X magnification, so the entire structure including coat is maybe 1mm long or a bit less, while the seed is less than that. Tiny!
I am absolutely delighted that the field season has started up again. This is just one of a few projects I'm hoping to work on this year. I will make sure to post a bit more this year than last about what I'm up to and why over the field season.