Post #3 Ongoing Field Observations

I have looked at a few ideas for study options up to this point. Most of my experience has been in forestry and vegetation, so a vegetation-based project was my natural first choice. The fact that it is winter here in northern BC and the ground is under a few feet of snow is one reason why looking at something other than plants is maybe a good idea. Here are some of my ideas up to this point:

I thought of looking at shrub abundance in relation to conifer crown closure, but this would require a truly landscape-level study.

I thought of looking at beaver presence-absence as a predictor for shrub and aspen-ramet abundance, but once again this would require being able to see evidence of beaver which would likely be under the snow.

I thought of looking at pine plantations and observing how young individuals grow bigger and taller in the presence of nitrogen-fixing shrubs such as alder than those individuals growing where alder isn’t so abundant.

What I’ve finally settled on is something truly fascinating and present in so many different environments in these parts – an organism I see all around my home as well as in the forests that I walk, ski, snowshoe, and work in. I will number the following points as per the blog instructions in order to keep everything easy to follow.

1) We (my family and the people around me) call them snow fleas but they are actually springtails, tiny arthropods that present themselves in different abundances all throughout the winter. In the order of Collembola, they come out on warm winter days and jump around on the snow and their bodies contain proteins that act like antifreeze to allow them to function in sub-zero temperatures (wikepedia). I would like to study their abundance and distribution in terms of density under different circumstances.

2) I will describe three environmental gradients in which I’ve observed them:

• Open undisturbed snow in which (as of today March 7 2021) they were fairly uniformly and sparsely distributed.
• Forested ground with crown closure where I saw they were quite a bit more dense, interspersed throughout bits of tree debris and forest matter
• Disturbed snow, particularly relatively fresh disturbances like footprints from a few hours prior before new snow has fallen, in which they seem to congregate in large numbers, sometimes on one side of the footprint or the other which begs a couple questions. Are they seeking shade within the disturbance? Do they just happen to be in greater numbers because the disturbance has decreased the snow depth in that one place?
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3.) As far as processes that may contribute to their relative abundance in different circumstances – open, closed or forested, and disturbed – there are likely several reasons:

•  As they are soil organisms, they are likely present in greater numbers over-top of ground that is richer or more nutrient-dense.
• Snow-depth probably has a part to play – I would predict that as snow depth decreases, springtail density would increase.
• Under cover of trees and with other bits of forest matter and debris scattered on the snow they would have more camouflage and be less visible to predators.
• Direct or indirect sunlight may have an effect on their abundance.

One hypothesis I would like to explore – one that I think would lend itself to a study that would be possible to implement – is this:

Springtail density on the surface of the snow is determined by the presence of direct sunlight.

One formal prediction based on this hypothesis:

Though sunlight contributes to a warming environment conducive to springtail emergence, springtail density will be higher under cover or under a source of shade.

4.) The response variable in this case would be the density of springtails – this is a continuous variable. The explanatory variable would be presence or absence of direct sun (i.e. sun or shade) – this is a categorical variable. For this study, the experimental design would be a one-way ANOVA.