Collecting Evidence
So just what is a typical day when you are studying the effects of spiders on microbial food webs? Well, as you might expect, no day is typical. There are many questions that Amanda is trying to answer with her research, and as my students will tell you, every good answer to a question involves evidence. So how does one gather evidence? What exactly do I mean when I say ”evidence”? Again, as my students will tell you (and if they were here, they would probably be giving me a pretty decent eye roll), in science, evidence usually means DATA. And as my students will also tell you (eyeroll), strong conclusions are generally made with quantitative (numerical) data. So that means a lot of collecting spiders (living and dead). And identifying spiders (and other little critters that might be in sample cups). And manipulating spider numbers in our research plots. And counting. And more counting.
Hello friend. So glad that I caught you this morning.
Manipulating Spiders
One typical day here is counting (here’s a dare: count the # of times I say count. Write your answer in “Ask the Team”) the number of spiders in each of the experimental plots to make sure we have the desired amount. There are basically 2 types of plots in Amanda’s primary experiment that we manipulate: low density (i.e. not a lot of spiders) and high density (i.e. more than the low). Each plot is then subjected to 2 different treatments based on temperature. The goal here is to see if warmer temperatures are affecting the spiders in the plots in a variety of quantitative ways. Periodically (every few days), we go in and record what’s happening in the plots (to see if the numbers are changing). We count the number of spiders we see in a 2 minute period (and catch them), record our data and then either return the spiders to the plot or set them free outside the plot.
Spider Plots. Colored flags denote the plot’s density type.
Identifying Arachnids…and other insects
Another typical day around here involves working in the lab. In addition to the experimental plots at Toolik, Amanda also sets up “pitfall” traps in various locations around the North Slope to see how many spiders exist where and also what other invertebrates are living up here. She has a variety of questions she’s asking here – is spider density (and potentially size of the spider itself) impacted by the fertilization of the soil? What is the percent of spider egg sacs that are parasitized by a particular type of wasp (more on that question in a future post)? Does the percent of parasitism change as you head further north (towards the Arctic Ocean)? What are spiders eating and where do they fit in to this permafrost soil food web? As you might expect, the answers to these questions come from counting. Countless hours are spent with samples of insects under a microscope, counting the number (and size) of wolf spiders, wasps, mites, beetles, collembola, and even an occasional fly. All of this data is diligently recorded and will be analyzed at a later date.
Typical pitfall trap. Numbers refer to the location and date the sample was collected.
Placing labels in pitfall trap. That’s me under that bugshirt.
Insects to be identified from a pitfall trap.
Recording counts.
Collecting Samples
The last typical day (don’t worry, I won’t discuss the atypical days) involves collecting and resetting pitfall traps. Once a week, we hop in the truck and head up to Deadhorse, AK (otherwise known as the Prudhoe Bay oil fields) to pick up and replace traps at several different locations along the Dalton Highway. It’s a full day endeavor – we left camp at 10 am and returned close to 8 pm. It’s also an all-weather endeavor – today it was rainy and about 35 F. In July. Thank goodness our truck was warm and our stops were short.
If you look closely, you can see the steam rising off of the body of water in the distance. That means that the water temperature in the Arctic lake was warmer than the air temperature. Brrrr.