Tag Archives: science

The proof we needed

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Dryas octopetala

Originally posted on ‘On top of the world’

Good news for those ecologists studying species distributions: it turns out that the climatic niche of mountain plants is fairly conserved in space (Wasof et al. 2015).

Dryas octopetala

Mountain avens, Dryas octopetala

These results come from a study on the distribution of alpine species in the European Alps and the northern Scandes, two mountain regions with very different characteristics but a significant overlap in species composition.

Orchid

Orchid in the northern Scandes (Dactilorhiza majalis?)

The researchers compared the climatic niche of a large set of plant species that occurred in both mountain regions, and found that only a small percentage of these species experienced a regional effect on their niche. Especially species with disjunct populations (populations that are truly separated in space) showed high niche overlap, and the same was true for arctic-alpine species.

Betula nana

Dwarf birch, Betula nana

Although niches are in general surprisingly well conserved between the two regions, species occupy a wider range in the Alps than in the northern Scandes. More on the latter unexpected pattern in this informative post from Jonathan Lenoir, one of the authors.

Rubus chamaemorus

Cloudberry, Rubus chamaemorus

Why do we care? Because the large and growing field of species distribution modelling has as one of its main assumptions that climatic niches are conservative. If they are not, any extrapolation of a limited geographic dataset to the total global distribution of a species would be invalid.

Eriophorum vaginatum

Hair’s tale cottongrass, Eriophorum vaginatum

Reference

Wasof et al. (2015) Disjunct populations of European vascular plant species keep the same climatic niches, Global Ecology and Biogeography, 24: 1401-1412.

Pyrola minor

Snowline wintergreen, Pyrola minor

November 17, 2015

Uphill (and downhill!)

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Torres del Paine

Our climate is changing, that much is clear. The main effect of this changing climate is that what once was balancing now starts shifting. As if our little world became a plate full of beer pulls, losing its balance on the shaking hands of an inexperienced innkeeper. One of the most obvious effects of climate change on plant and animal life is visualised in the shifting geographical ranges of many  species.

Scientists have been hunting for these range shifts for years, resulting in a growing pile of scientific papers on the matter. Case after case, the hypothesis is clear: the climate is warming, so species will follow the track of these increasing temperatures: uphill and to higher latitudes, towards the arctic and alpine world. Indeed, more and more longterm experiments and observations bring exactly those patterns to light. These results are accompanied by the worrying message that the original inhabitants species of the invaded cold environments themselves don’t have anywhere to go.

Invasive plants like this chamomile in the Chilean Andes hike surprisingly fast uphill.

As the proof of this invasion of heat-loving species adds up and the risk for the alpine and arctic vegetation becomes more apparent, it is easy to forget that some species might act opposite of our expectations. An important amount of species indeed seems to hurry uphill, but an as important (albeit smaller) group in the meantime moves downwards, against all odds.

On a steep slope, going downhill might just be a lot easier than going up.

For years, this lasts group has been pushed aside as a mere statistical side effect, nothing more than noise on the data, the inevitable variance around a positive average. Concluding as such however ignores the importance of this group of species. Climate change includes more effects than only this warming trend. Not only temperatures change, but the climatic water balance undergoes drastic alterations as well. In several dry areas, precipitation patterns might even be more influential than the warming effect. In that case, those changing precipitation levels can unexpectedly push species downhill, in a hunt for similar climatic conditions.

In the mountains, water often plays an as important role as temperature.

There are alternative explanations for these patterns as well. A lot of species are for example not limited by the climate at the warm side of their distribution. They only taste defeat due to competition with faster growing species. As a result of the changing climate, however, those competitive dominances start shifting, which creates new opportunities at these lower range edges.

Many mountain plants have a large dispersal potential, as they can rely on the omnipresent winds.

Bottom-line is that most effects in ecology might and will be in different directions at once. As a scientist, it is important to keep this in mind and give the unexpected minority the attention it deserves. I stumbled on this story when I was looking at the expected distribution shifts of invasive species in the mountains. The lesson is clear: better not forget to look downhill once!

DSC_0382

I hope to bring you more on that matter as soon as some more stories make it through the review process. Until then, all the cool action is going on here!

Two relevant reads:

Crimmins, S. M., Dobrowski, S. Z., Greenberg, J. A., Abatzoglou, J. T. & Mynsberge, A. R. (2011) Changes in Climatic Water Balance Drive Downhill Shifts in Plant Species’ Optimum Elevations. Science, 331, 324-327. (here)

Lenoir, J., Gegout, J.-C., Guisan, A., Vittoz, P., Wohlgemuth, T., Zimmermann, N. E., Dullinger, S., Pauli, H., Willner, W. & Svenning, J.-C. (2010) Going against the flow: potential mechanisms for unexpected downslope range shifts in a warming climate. Ecography, 33, 295-303. (here)

January 22, 2015

Low

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Cotton grass on the shore of a lake

In a previous post, I wrote about the power of photography for ecologists. Now, it is time to provide some real tips for photographing ecologists. How to take home some pictures that will impress others, without – importantly – losing any working time?

Cotton grass on the shore of a lake

Most ecologists will take a camera into the field anyway. It is used to take pictures of their research site or subject, or record some important details for later. As you already have your camera in your hand, it will not cost you too much effort to take just one more picture.

Autumn seeds in Lapland

In that case, it might be a smart idea to get a little bit lower, up to the level of your study object, to check the world from its point of view.

Mountain mushroom

The combination of integrating your study object in the landscape and letting it stand out of the background results in more interesting images. It makes it possible for an observer to feel a connection with the subject and it makes the picture tell a much more interesting story.

Hiking in the Swedish mountains

Even if your study object is a dull bird or a boring plant, getting on its level will bring out the best in it and give it a soul.

House sparrow

If possible, try to include the horizon in the picture. It will ask a lot more of your knees, but the rewards are big. As the (obviously real) Lappish proverb goes: ‘A beautiful horizon can even make a dead lemming look poetic’.

Dead lemming on a rock

I did not invest too much time in getting a nice overview of my study species, the invasive plants in my plots. An awfully difficult subject for an artist, I have to admit, but by quickly spending two minutes as a photographer before you dive into the science, might have been rewarding even in this case.

Experimental plot

Take home message: low! Take your pictures from a low angle and give their stories a boost!

Achillea millefolium

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October 3, 2014

The photographing ecologist

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Plant in its natural environment

Photography is classified as art, ecology is science. Two distinct worlds that only very rarely show some overlap. I am however convinced that a combination of both disciplines could be very fruitful. Being a photographing ecologist, or ecological photographer not only gives artistic satisfaction, but it can also be a serious addition to your science.

Although taking pictures on a busy fieldwork day might feel like a waste of precious time, it can be really valuable to assign some minutes in the field to photography and make sure you are familiar with at least the basic skills of the art.

Overview of the plot

Inevitably, there will be a moment where you have to present your work: posters, powerpoint presentations, or just to a supervisor in the lab. The saying that one image is better than a 1000 words might be getting old, but it still holds true, a thing every scientist probably realizes when working on his slides.

 

Pictures for future reference

It might be common sense to spend at least five minutes of your working time in the field to photograph field sites, measuring methods and environmental characteristics, for your own reference or other peoples imagination. But it would even be better if you added another five minutes to the first five to zoom in on some details.

Plot on 1000 meters height, Abisko

Change the viewpoint and try to catch your field site in its environment. The lower scientific value is replaced by an aesthetic one. Or get some of your study species into focus…Plant in its natural environment

It is pretty obvious that a beautiful picture makes every story more attractive. If you want to convince the non-scientific world of the importance of your research, a catching picture will increase your impact factor a thousandfold (and I promise you, journalists are great at choosing the most irrelevant ones if you leave that task to them).

Hiking to the fieldwork

Even for the scientific public, however, a catchy picture will improve the results and the scope. No matter how interesting your story, nice illustrations will keep a larger audience awake during your presentation, and attract more people to your posters. Just give them those few seconds relief from the interesting but tiring statistical theories!

Plot for scale in the mountains

To finish, never forget the power of stories. Science is more than only the results and the 2 or 3 papers that come out of it. The process, arguably the largest part of the work, and the impressive, exotic, adventurous stories resulting from them can help enhancing the public’s understanding and appreciation of your research every day of the year. A photographic diary of your field trip might raise a lot more interest than all your scientific papers combined.

Angry lemming in the plot

 

Biology is a foreign discipline to a large part of the population. They do not have a clue about how our scientific statements come into existence. They will be surprised about the complexity of the scientific process, and the variation, excitement and attractiveness of ecological fieldwork. Scientific information will follow on the way. Enjoying the scenery at Torneträsk Lake, Abisko

This should make the importance of the use of photography as a powerful tool in science obvious. Let us thus all pack a camera as indispensable fieldwork gear in the future and revive our artistic alter ego’s. In some future posts, I will cover a set of useful skills to make those few artistic minutes as efficient as possible, so with only 3 or 4 clicks, you can get the best results out of your camera.

Jonas Lembrechts balances between being an ecological photographer and a photographing ecologist on his way to a PhD in mountain ecology. Follow his adventures here!

September 22, 2014