Dr. Laura Turnbull is an Associate Professor in the Department of Geography at Durham University. ​Twitter: @ecohydrology

What does ecohydrology mean to you?
To me, ecohydrology is the interactions and feedbacks between ecological and hydrological processes, with particular emphasis on geomorphology and biogeochemistry. Within ecohydrology, I am particularly interested in how system structure (such as vegetation distribution and [micro]topography) affects the lateral redistribution of water, nutrients, sediment and seeds around the landscape, which in turn control where vegetation can continue to persist, or where new seeds will germinate.

What are your undergraduate and graduate degrees in?
My undergraduate degree was in Physical Geography at Durham University, UK (which I’ve now returned to!). During this degree I undertook my first independent research in drylands (where most of my work is now focused), on the hydraulic geometry of ephemeral channels in Spain. Following this, I moved to Kings College London where I completed a MSc in Environmental Monitoring, Modelling and Management, which led to a PhD in Physical Geography at Sheffield University, UK.
 
How did you arrive at working in/thinking about ecohydrology?
I had always been fascinated in tropical forests and I was really sure that I would end up doing research in this area during my MSc, but this wasn’t to be the case, and I ended up back in drylands – this time in New Mexico – where I undertook research on hydrological connectivity in grassland and shrubland at the Jornada Experimental Range. I was really intrigued by this environment, and the widespread vegetation transitions that have occurred over the last century, and I was keen to learn more about how these transitions actually happen. This led to my PhD research on ‘Ecohydrological interactions across a semi-arid grassland to shrubland transition’ which really reinforced the importance of considering both vertical and lateral fluxes of water, nutrients and sediment when thinking about feedbacks between vegetation and hydrology.

What do you see as an important emerging area of ecohydrology?
At the moment I am particularly fascinated about the potential to refine our understanding of the ecohydrology and resulting structure and function of drylands by applying tools from network science. For example, can we identify “critical nodes” in the system where ecohydrological feedbacks increase or decrease the resilience of a given system state? And through identification of these critical nodes and their associated ecohydrological characteristics, can we manipulate/manage them to alter system structure and function to maximize the provision of ecosystem services? Of course, the application of network science tools to ecohydrology extend far beyond drylands, but as a complex system characterized by patchy vegetation, they certainly make an interesting starting point. There’s also a lot of progress to be made in the area of ecohydrological modelling, in order to take into account sufficiently well both the vertical and lateral fluxes of energy, water, nutrients and sediment.

Do you have a favorite ecohydrology paper?  Describe/explain.
Although not strictly an ecohydrology paper, Schlesinger’s 1990 paper on “Biological feedbacks in global desertification” was particularly influential for me earlier on in my research career, in terms of thinking about how patterns of vegetation, and soil nutrients arise due to the complex interplay between lateral and vertical ecohydrological processes, which in turn affect the ongoing structure and function of the system.

The paper by Cadenasso et al (2006) on “Dimensions of ecosystem complexity: Heterogeneity, connectivity and history” is also one that I view as being particularly useful for thinking about the role of ecohydrology in the structure and functioning of water-limited systems. This paper presents a ‘biocomplexity framework’ outlining how complex ecological systems can by understood better with a focus on connectivity, heterogeneity, and contingency, which is directly relevant to understanding ecohydrologial processes and how they change in response to climatic or anthropogenic disturbances.

For a more classical ecohydrology paper, I’d probably have to choose the paper by Newman et al (2006) on “Ecohydrology of water-limited environments: A scientific vision” which I still find particularly useful because it outlines some of the key challenges facing research in ecohydrology, which still apply 15 years later.

What do you do for fun (apart from ecohydrology)?
Pre-children I really enjoyed triathlon. Nowadays I’m lucky if I can get out for a bike ride but I try to as much as I can!  I spend a lot of time outdoors, walking with the dog, playing with the children or working on the vegetable patch! 

Dr. Marco Maneta is an Associate Professor in the Department of Geosciences at the University of Montana (Missoula, MT).

Dr. Genevieve Ali is an Associate Professor in the School of Environmental Sciences at the University of Guelph, Guelph, Ontario, Canada.

What does ecohydrology mean to you?
I like the fact that I am not being asked to provide a definition of ecohydrology but rather to say what it means to me… :-) To me, ecohydrology is an umbrella term that best illustrates the two disciplines I mostly draw from in my teaching and my research. Ever since I started my Ph.D., I have been looking for new or different (statistical) analysis tools or models to address hydrological questions, just get a different perspective. I have found that regardless of whether we think of catchment classification, flowpath network topology or hydrologic connectivity, there are interesting tools we can borrow from computer science, ecology, or neuroscience. It just so happens that a lot of the tools and modeling frameworks I use are borrowed from ecology. Using the ecohydrologist label for myself means that I am not just borrowing from another discipline; I am rather merging disciplinary views and allowing myself to benefit from a greater diversity of opinions and approaches to frame my own work.      

What are your undergraduate and graduate degrees in?
I did a B.Sc. in Environmental Geography at the Université de Montréal (Québec, Canada). I found it to be a great first program because even though I was enrolled in the physical geography stream, I was required to take a bunch of human geography courses as well, and those courses really broadened my horizons early on. I then moved on to do a Ph.D. in Geography, still at the Université de Montréal.  

How did you arrive at working in/thinking about ecohydrology?
By force of circumstance, I would say. My Honors thesis was focused on the modelling of a small forested catchment, and we knew that whenever we got that model to perform OK, we were getting the right answers for the wrong reasons. Together with my Honors thesis advisor at the time, André Roy, I came to realize that it could be because the model was incapable of resolving the complex hydrologic connectivity dynamics driving the catchment response, and that is how my Ph.D. thesis topic was born. When I started working on connectivity in 2005-2006, I really had to dive deep into the ecology literature because that is where most of the connectivity research was reported at the time. So, that is how I initially got into eco-hydrology work, and my interests just grew from there. Looking at ecohydrological systems as complex systems with their thresholds and other emerging properties, studying plant-soil-water relations in agricultural regions, and trying to quantify multi-material connectivity (i.e., water, nutrients, sediment and biota) in human-impacted landscapes, are just a few areas of ecohydrology that I focus on in my teaching and research.  

What do you see as an important emerging area of ecohydrology?
There are lots of emerging areas and/or issues in ecohydrology, but the one I see as maybe the most urgent to tackle is ecohydrology at the science-policy-practice interface. Even before ecohydrology was officially called a “new discipline”, there had been fantastic theoretical developments about how water influences biota and vice versa. The “new discipline” has greatly accelerated the rate at which mechanistic process explanations are being put forward, confirmed with new data or models, or infirmed with new data or models. What we still seem to be missing, though, is a broad discussion of what those new findings mean for land, water, nutrient or ecosystem management (take your pick!). How should threshold-driven ecohydrological systems be managed? Should ecohydrological systems displaying weak emergence be managed differently than those exhibiting strong emergence? How can the concepts of hot spots and hot moments (sensu McClain et al., 2003), or the idea of ecosystem control points (sensu Bernhardt et al., 2017), be used to guide the timing and method of fertilizer application on agricultural land? Is there an optimal multi-material landscape connectivity level that environmental managers should aim for? How can community watershed models be designed in a parsimonious way to operate at large scales while retaining critical ecohydrological process information? Those are not low-hanging-fruit questions, by any means, but they are key for knowledge translation.  

Do you have a favorite ecohydrology paper?  Describe/explain.
There are a few I can think of, on a wide variety of topics, but the one I will mention is the “Watershed functions” paper by Peter Black (1997; Journal of the American Water Resources Association, 33: 1-11). It discusses five key watershed hydrological and ecological functions and how they relate to “attenuation” and “flushing” responses. There are many ways we can assess the health and/or resilience of watersheds, some of them very sophisticated and detailed, but I really like the idea of doing so through five simple, basic “ecohydrological” functions. This paper is one of my favorites because it is very pedagogical/approachable and I can use it as a discussion starter in any context: research, undergraduate teaching, graduate teaching, or discussion with stakeholders and policy makers.

What do you do for fun (apart from ecohydrology)?
In no particular order, I enjoy going on forest walks, travelling (when we can), watching natural disaster movies (the nerd in me likes fact-checking them), and trying my best at becoming an expert in allergen-free baking. Some of my new pandemic lockdown-induced hobbies include growing vegetables and knitting. Being anywhere with family wins the cake.  

Dr. John Selker is a Distinguished Professor in the Department of Biological and Ecological Engineering at Oregon State University.

Amanda Donaldson ​is a 3rd year PhD student at the University of California, Santa Cruz in Dr. Margaret Zimmer’s Watershed Hydrology Lab. 

​What does ecohydrology mean to you? 
I love that the discipline of ecohydrology is so broad. I think the boundaries between earth systems are blurred and so should be the frameworks we use to study them. I think the field of ecohydrology is simply the study of the feedbacks between ecological and hydrologic processes.

What are your undergraduate and graduate degrees in? 
My undergraduate degree is in Forest Hydrology from Humboldt State University and my graduate degree will be in Earth Science from the University of California, Santa Cruz.

How did you arrive at working in/thinking about ecohydrology? 
I have the opportunity and passion to pursue a career in ecohydrology in large part due to two undergraduate research experiences. I was an “Our Earth Lodge” REU Fellow at Cedar Creek Ecological Reserve under the mentorship of Dr. Jake Grossman. In this experience, I was not only introduced to the field of ecohydrology but the importance of natural reserves to conduct research. Shortly after that experience, at Humboldt State University, I worked in Dr. Jasper Oshun’s Critical Zone Lab and explored topics such as the potential causes of water isotope fractionation and plant-water use. This fieldwork was conducted at the heavily instrumented hillslope named “Rivendell” at Angelo Coast Range Reserve. These two research experiences stand out to me because I was not only able to explore research questions at the forefront of ecohydrology but I learned that interdisciplinary science and collaboration were critical to scientific advancements. At both Cedar Creek and Rivendell, I was inspired by the legacy of hard work by staff, undergraduates, graduate students, and PIs required to explore how water and plants shape the terrestrial landscape – I thought to myself: “wow, I want to be a part of that”. 

What do you see as an important emerging area of ecohydrology?
I would like to break this up into two branches: emerging tools and emerging ideas. Stable water isotopes have been an invaluable tool aiding in our ability to understand the age, origin, and partitioning of water at the catchment scale. I believe this is still an emerging tool in ecohydrology. By examining water extraction techniques, integrating water isotope data with other hydrologic and plant hydraulic measurements, and developing theoretical frameworks such as “StorAge Selection” functions we are still exploring the power and limitations of water isotopes as an ecohydrologic tool.  As for an emerging idea…gosh this was a hard one! I think gone are the days that trees are seen as simply straws in the ground. Trees are the “builders and plumbers” of the critical zone (Brantley et al., 2017) and central to this idea are: ROOTS! I think emerging ideas explore controls on root structural patterns, root water uptake and redistribution, and root-rock interactions.  

Do you have a favorite ecohydrology paper?  Describe/explain.
My favorite ecohydrology paper is by Brooks et al (2015) titled “Hydrologic partioning in the critical zone: Recent advances and opportunities for developing transferable understanding of water cycle dynamics”. It is a remarkable review paper that highlights the challenges and visions for the future of hydrology/ecohydrology. It reads like a good book that has a section for everyone regardless of your subdiscipline. It is a paper I return to when I need a little inspiration.

What do you do for fun (apart from ecohydrology)? 
I love to go camping, hiking and a good midnight drive to go star-gazing. In addition, I honestly can’t think of a better night than sharing science ideas with friends over good food and drinks.