Science is a long process…this newly published research article, in the journal Agriculture, Ecosystems, and the Environment, is the culmination of nearly two years of writing a grant proposal with my advisors (Profs Jane Stout and Yvonne Buckley), two years of hard field work, and then two years of writing, revising, and resubmitting the manuscript. Nonetheless, after all that, I must say I am proud of this particular piece of science. The manuscript itself is long, with many detailed statistical tests, and involves several independent datasets that I collected over my two years in Dublin.
Our experiment was designed to determine whether small concentrations of fertiliser and herbicide had any effects on the growth of ruderal plants and the insects that visit their flowers. We chose the species in the study (Cirsium vulgare, Hypochaeris radicata, Filipendula ulmaria, Epilobium hirsutum, Origanum vulgare, Plantago lanceolata, and Phacelia tanacetifolia) based on their prevalence in Irish agricultural systems. I hand-collected individuals of the plants from a conservation area near Kilkenny (thanks Hannah!) in the springs of 2017 and 2018.
Our data show that even exposure to tiny amounts of fertiliser and herbicide change the growth of these plants, and the visitation of their pollinating insects. Mostly, these results conform to hypotheses: plants exposed to tiny amounts of fertiliser grow taller and have longer leaves, while plants exposed to herbicide are shorter and have shorter leaves. Interestingly, there is no difference in the size of the floral display, which means that plants exposed to a little fertiliser have fewer flowers per individual (but at a much taller height), while herbicide exposed plants have more flowers per individual (but at a much shorter height). Plants exposed to herbicide also had a lower visitation rate per unit floral area, meaning that the flowers were on average less preferred by flower-visiting insects.
I obsessively collected so much data for this study, including a completely independent greenhouse experiment, that I plan to publish several more papers from it, so stay tuned!
One of the challenges of this dataset was the sheer number of zeroes. For collection data in the study, more than 50% of my five-minute observations yielded zero visitors. That’s a lot of time starting at flowers with no insects (85.75 hours to be exact), and a great deal many more samples where only one insect visited. This led me to describe the study to anyone who would listen as “Zen and the art of pollinator watching.”
What the manuscript doesn’t include is the process of learning to live in a new country (Ireland), figuring out the name of the store where I could buy their entire stock of watering cans (Woodie’s), begging people to let me put these weird garden plots on their land, navigating the windy streets of Dublin on my bicycle (without getting killed or shouted at, preferably), or surviving the particularly muddy times where I could never seem to get clean and dry.
I did the math at the end of the 2018 field season and learned that I had been cycling an average of 160 miles per week to visit all of my plots repeatedly, and hand-carrying an average of 3000 liters of water to water and treat my plots in two 10 liter watering cans per site. Across the 2 years of the study, I actually cycled more than 15,000 km (9,320 mi), the vast majority of which was in urban Dublin, round and round to my sites.
Would I recommend field work by bicycle to young scientists? Not exactly! Cycling limits the weight and volume of equipment you can carry, and it is more time consuming than simply driving. But science by bicycle seemed to be the most feasible option for me in Dublin (which is, after all, very cyclable), given time and financial constraints, and I think it worked for the purposes of this study.
Bredagh and my favourite collaborator, Pushkin at UCD Rosemount. (photos courtesy of my ancient flip phone)
As detailed by the lengthy acknowledgements in the manuscript, this work would not have been possible without the help of many people. In particular, I want to thank all of the sites that allowed my to have my plots on their land and tolerated me showing up repeatedly to sample and water them: Raidió Teilifís Éireann, Riverview Nature School, Gas Networks Ireland, Trinity College Dublin, University College Dublin and the Lamb Clarke Irish Historical Apple Collection at Rosemount Environmental Research Station, the Marino Institute, and the Airfield Estate. Also thanks to all the people who facilitated my work at these sites: Dr. W. Deasy, B. Moran, Dr. K. McAdoo, T. Bannon, C. van der Kamp, R. Hession, C. Bennett, E. Kavanagh, C. Fogarty, S. Austin, M. Burke, R. Judge, S. Waldren, E. Bird, and M. McCann. Thanks also to my coauthors and everyone in the Stout lab and all the technical assistance at TCD: S. Palumbo, A. Flaherty, J. Stone, S. McNamee, B. Malone, O. Fenton, D. OHuallachain, J. Finn, J. Zimmerman, J. Parnell, and S. Hodge. I can’t thank those who helped me with identifications enough: U. Fitzpatrick, T. Murray, M. Speight, M. Smith, B. Nelson, and S, Falk. Finally, thanks to Hannah Hamilton for feeding me enough to keep me alive, helping me to find valuable research sites, and generally being such a great friend.
And I have to say thanks to Ireland for being my home for two years. I absolutely loved learning as much as I could about you in my short time there. Stay beautiful!
Funding for this study was provided by a Marie Skłodowska-Curie Independent Fellowship [grant number FOMN-705287] to LR, JS, and YB.
About the author: Dr Laura Russo was a Post-doctoral Research Fellow in the Plant-Animal Interactions group at Trinity College Dublin from early 2017 to early 2019. She is now an Assistant Professor in Ecology & Evolutionary Biology at the University of Tennessee.