There’s no place like your field site home…

This week we are excited to have Zarah Pattison from the University of Stirling, Scotland, tell us about her field work on invasive alien plant species along rivers in Scotland for her PhD work. To learn more about Zarah, check out her bio at the end of this post.

Supervisor: “So you need about twenty rivers for your project”

Me: “Right, OK…” I stand, staring at him blankly.

Supervisor: “Go buy some maps of Scotland, 6 to 10 will do, lay them out and find rivers.”

Me: “Right, OK…” I stand, staring at him blankly, and then scurry off to the nearest shops.

Maps of central Scotland stuck together to find rivers for field sites.

I had always thought of myself as a resourceful person. Give me a problem, I’ll ‘make a plan’ (a very South African turn of phrase). However, having just passed my driving test and moved to Scotland, and having no experience of working along rivers, or knowledge of what I was looking for, I just panicked. Now, I did have two crucial criteria to aim for: Make sure I can walk at least 500 metres along the river, which must be invaded by the invasive plant Himalayan balsam (Impatiens glandulifera). This plant is tall, with bright pink pungent flowers, and I soon became a dab hand at spotting it whilst driving anywhere near a river and, on parking the car, smelling it. After a month of google maps, google earth, broken GPSs and sat navs, I finally found the 20 rivers with 20 suitable survey sights. All the sites were predominantly urban or alongside farm land, which came with its own suite of problems.

In Scotland you have ‘the right to roam’, so when gaining permission to work along my chosen river sites, people were generally helpful and interested in the project. Sometimes we were even brought tea and cake by some of the landowners, who thought us standing in the rain for 10 hours was horrific (I loved it). The vegetation could reach up to 4 metres high, with stinging nettles up to 3 metres. We got used to the constant burning on our skin and kept ourselves sane by shaking the Himalayan balsam plants to see which of us would get an exploding seed pod in the eye.

Tea and cake provided by kind cottage Lady on the River Tweed.

When crossing the Annick Water to access a survey site, David, my field assistant, was using a 1 metre solid wood wading pole to bash back the nettles so we could climb up the bank. He stood still for a moment.

Me: “David, what’s the problem? Time is precious!”

Then he started shouting, trying to cross back to the other side of the river whilst we were both repeatedly stung by the angry wasps whose nest he had disturbed. I wanted to dive in the water, but all I could think of was my phone in my pocket, with all the fieldwork pictures on it, , and all the unsightly floating objects in the river. We finally clambered up the other river bank, running back and forth until the wasps gave up.

Me: “David, where is the equipment bag?”

We looked at each other and then over to the other side of the river where the bag sat, covered in wasps. After an hour, we suited up with every bit of clothing and plastic in our possession, as well as some burning reeds, and finally retrieved the field bag. Many beers were drunk that night.

Geared up and ready to retrieve our field work equipment bag from under the angry wasps nest.

I had to revisit these sites 3 times over the next year and got to know them pretty well. In early spring I had to collect the 360 30 x 30cm green AstroTurf mats which had been placed at each site the year before. After winter floods, my red spray painted wooden stakes had mostly vanished and most of the mats were covered in mounds of sediment deposition. I had tried to use a visual marker, like a telephone pole, for each transect that had mats on, measuring the distance between each mat. Sally, my field assistant, and I had a ‘mat dance’: every time we found a mat we proceeded to wave our hands in air and gyrate to the ‘Venga boys are coming’ tune…much to the dismay of many dog walkers.

Finding the AstroTurf mats, covered by mounds of sediment deposition, on the Dean Water.

Have you ever seen a mole swim? On the River Almond we had to access the survey site by going down one path on a steep embankment. The river was flowing fast, but I was confident that if we worked quickly we could get the work done. We were about 300 metres from the path, measuring the distance to each mat. I asked Sally to head back to get some more bags for the soil cores and as she turned around, she let out her high pitched alarm call (scream). The river had engulfed the bank. The bagged soil cores were starting to float down the river, along with the rucksack, which had our car keys in it. I managed to wade out (stupidly) and get the soil core bags and the rucksack (I was not losing any samples!), and we got up the bank safely. Sad to say we lost those mats, but we successfully retrieved 278 across all sites. And the mole? The mole was on the remaining bit of unsubmerged bank, and Sally was ready to dive in and save it. I literally held her back, but it turns out moles are great swimmers! Super mole, as she now calls it.

Trying to climb through trees and 4 metre high Himalayan balsam on the River Endrick, whilst David fights through brambles and Rose Bay Willow herb on the Black Cart Water.

Attacked by wasps, intimidated by aggressive dogs on sites located in run down areas, accused of bombing the river as a poacher, constantly being mistaken for fishermen, stung by stinging nettles, even offered to a farmer’s 21 year old son as a birthday present… I wouldn’t change a thing. Most of the time you are alone, it is peaceful and beautiful, and you get used to the sickly sweet smell of Himalayan balsam. The bad experiences make the best stories. And there is nothing quite like being in the field.

 

Wading through the River Gryfe with a Himalayan balsam plant in tow.

          Zarah Pattison completed her BSc in Ecology and the Environment in 2011 and an MSc in scientific research in 2012 at Royal Holloway University of London. Her undergraduate and master’s degree focused on invasive alien plant species (IAPs) and their impact on below- and above-ground microbial communities, particularly mycorrhizal fungi and foliar endophytes. Zarah is currently doing a PhD at the University of Stirling, Scotland, researching the ecology and impacts of riparian IAPs, particularly Impatiens glandulifera, Fallopia japonica, Heracleum mantegazzianum and Mimulus guttatus, and how their impact varies under climate related changes to river flow regime.