2024 HARPER PRIZE SHORTLIST: For the next two weeks, we are featuring the articles shortlisted for the 2024 Harper Prize. The Harper Prize is an annual award for the best early career research paper published in Journal of Ecology. Rémi Bardou’s ‘Effects of cold water and aridity on Baja California mangrove survival and ecophysiological traits’ is one of those shortlisted for the award.
About the paper:
- What is your shortlisted paper about, and what are you seeking to answer with your research?
Our study investigates how cold water temperatures and arid conditions influence the survival and physiological traits of mangroves at their northernmost Pacific range in Baja California. Through controlled experiments on red (Rhizophora mangle), white (Laguncularia racemosa), and black (Avicennia germinans) mangrove seedlings, we found that black mangroves were less tolerant to cold water and aridity than expected, while red and white mangroves demonstrated greater resilience, particularly at higher humidity levels. These findings suggest that the interplay between cold water and aridity significantly shapes the distribution limits of these species in this region.
- Were you surprised by anything when working on it? Did you have any challenges to overcome?
I was surprised by how intricate the interaction between cold air, cold water, and aridity turned out to be. These mangroves persist in a setting that seems entirely inhospitable at first glance. The main challenge was piecing together microclimate data from such a remote location and understanding how subtle processes interact to enable survival at the edge of a species’ range.
- What is the next step in this field going to be?
One exciting next step would be to run controlled outplanting experiments—basically planting mangrove seedlings just north of their current range to see if they can survive and grow. But that’s easier said than done. There’s good reason to be cautious: mangroves introduced to San Diego decades ago became invasive and had to be removed. So, while the idea is promising for understanding future range shifts, it also highlights how important it is to approach these kinds of experiments carefully, with the right permits and ecological safeguards in place.
- What are the broader impacts or implications of your research for policy or practice?
Our research highlights the importance of considering localized environmental factors, such as the interaction between water temperature and humidity, in predicting species distribution under climate change. For conservation and management, this means that strategies should be tailored to specific regional conditions rather than relying solely on broader climatic trends. Recognizing the resilience of certain mangrove species to cold and arid environments can inform restoration projects and the establishment of protected areas, ensuring the preservation of these vital ecosystems in the face of shifting climates.
About the author:
- How did you get involved in ecology?
Growing up in the Basque Country, surrounded by mountains and the Atlantic Ocean, I always felt connected to nature. But I truly became involved in ecology during my PhD, when I partnered with scientists at the Smithsonian Environmental Research Center. A fellowship allowed me to spend a year with them doing hands-on experiments and learning across many ecological systems—it was transformative.
- What is your current position?
I recently completed my postdoc, and just got married! I’m currently in the process of obtaining a green card so I can continue working in the USA and applying for academic and research positions.
- Have you continued the research your paper is about?
Yes, we’ve set up longer-term monitoring with Hobo sensors tracking air and water temperatures, humidity, and seasonal changes. We also initiated nutrient enrichment experiments to test whether these northern mangrove populations are limited by nutrient availability, which could further explain their constrained distribution.
- What one piece of advice would you give to someone in your field?
Enjoy the field trips—the long drives, the early mornings, the laughs with friends and colleagues. It’s easy to get caught up in papers and deadlines, but some of my favorite memories from this project happened far from the lab or laptop. I’ve realized that once the funding ends or people move on, those shared experiences become rare. So make space for the human side and personal connections. It really matters.
Find the other early career researchers and their articles that have been shortlisted for the 2024 Harper Prize here!
