Dr. Pamela Nagler is a Research Physical Scientist with the USGS Southwest Biological Science Center. She resides in Tucson, AZ. 

Dr. Kim Van Meter is transitioning from a post doc position at University of Water Loo to an Assistant Professor position at the University of Illinois at Chicago in January 2019.    Twitter: @VanmeterKVM

What does ecohydrology mean to you?
For me, ecohydrology is about seeing the connections between systems.  The intersecting disciplines of ecology and hydrology are, of course, built into the word “ecohydrology.” As the field has grown, however, there have been further crossovers and synergies to include a range of different domains, from geochemistry to economics and sociology. To study ecohydrology is to study feedbacks between systems, the impacts of hydrology on ecosystems, of ecosystems on hydrology.  As an ecohydrologist, I ask questions about how humans interact with water and the environment, and how water systems and ecosystems coevolve with human systems.
 
What are your undergraduate and graduate degrees in?
My educational background has been a winding road!  My undergraduate degree was in Literature.  I have two master’s degrees, one in Organic Chemistry and another in Environmental Engineering.  My Ph.D. is in Earth and Environmental Sciences.
 
How did you arrive at working in/thinking about ecohydrology?
I came to my interest in water and water quality from a very practical perspective.  I was traveling in Haiti, where I adopted my son, and was devastated by the death of two young babies at my son’s orphanage due to contaminated water.  I became determined at that time to build a career that expanded beyond the lab to include larger interactions between science and the environment, between human and natural systems. From that point, my interests and my research grew to encompass a range of questions about human impacts on water quality and about feedbacks between water quality and ecosystem health. I think that these kinds of questions and concerns place me squarely in the middle of the new and growing science of ecohydrology.
 
What do you see as an important emerging area of ecohydrology?
I see urban ecohydrology as an exciting new frontier.  Cities in the 21st century are growing quickly—it has been predicted that by 2050 approximately 65% of the developing world and 85% of the developed world will be living in urban areas. As noted by Diane Pataki, urban settlements are one of the few ecosystems on earth that are actually increasing in extent. Accordingly, there are range of important research questions for the urban ecohydrologist. I am particularly interested in the ways in which cities alter both regional and global-scale nutrient cycling. As the built environment increases in extent, it will be crucial to understand how cities mediate the flow of water, nutrients, and a range of contaminants across the urban/suburban/rural continuum.
 
Do you have a favorite ecohydrology paper?  Describe/explain.
Although it’s difficult to pick a favorite paper, one that has been influential in my thinking is a 2014 paper led by Peter Groffman on the “Ecological homogenization of Urban USA.” 
In the paper, the authors explore the urban “homogenization” hypothesis. In other words, they ask the question, does urban land use exert a homogenizing effect across urban areas? Is a Phoenix lawn more similar to a Baltimore or a Minneapolis lawn than to the Sonoran Desert ecosystem surrounding the city.? The findings of their work are important, as they suggest that while decisions about things as seemingly trivial as suburban lawn management may be individual decisions, they are actually tied to broader forces, from social structures and socioeconomic status to national-scale marketing.  Because human behavior, like the biophysical behavior of natural systems, is strongly shaped by a panoply of broader forces, we are able to develop a theory and science of human habitats. From this point, we can move forward to understanding complex feedbacks between cities, water, and ecosystems.
 
What do you do for fun (apart from ecohydrology)?
My dog Darcy (named after the Darcy equation, of course) is a great source of fun and entertainment.  I’ve also recently become obsessed with escape rooms.

​Dr. Daniele Penna is an Associate Professor at the University of Florence (Italy).
www.danielepenna.co.nf

What does ecohydrology mean to you?
As others in this blog have reported, ecohydrology is strictly associated to the broad concept of “interaction” between water-related processes and the biotic component of the ecosystems. I’m currently teaching a graduate course in “Hydrology of the Wildlife Systems”, basically a combination of stream ecology and ecohydrology: I have not done any statistics but I can easily realize that the words I tell most often to the students are “water”, “ecosystems” and “interaction”, and I’m trying to stimulate them to achieve a wide thinking and a far-reaching view on how the different components in the environment are closely linked and influencing each other. To me, ecohydrology means studying the functional interrelations between water and vegetation in the critical zone, with a particular focus on forested catchments and agricultural areas. I’m particularly interested in how plants (trees but not only) affect the hydrological cycle and the hydrological processes at the catchment scale, and vice-versa, and how human inputs in anthropic settings (e.g, irrigation) influence tree response and sources of water uptake which in turn play a role on water stored in soil and in shallow groundwater.
 
What are your undergraduate and graduate degrees in?
I have a B.S. and M.S. in Natural Sciences from the University of Milan (Italy), with a thesis based on a phytosociological (and partially geomorphological) analysis of spruce population dynamics in an Alpine valley. So, trees were my first love. I then moved to the University of Padua (Italy) where I obtained a one-year degree on Hydrological and Geological Hazard Assessment and Mitigation followed by another M.S. in Forest and Environmental Sciences.
I have a PhD in Management of Water Resources from the same university: I pushed vegetation dynamics aside for a while and started to work on spatial and temporal patterns of soil moisture in a beautiful mountain catchment in the Italian Dolomites, under the supervision of prof. Marco Borga.
 
How did you arrive at working in/thinking about ecohydrology?
During my PhD I was trained as an experimental catchment hydrologist, and I began using environmental tracers to study catchment- and hillslope-scale runoff generation processes. I did not forget my background on trees but I tended to see precipitation, meltwater, stream water and subsurface water as the only fundamental elements of any catchment, while (evapo)transpiration was somehow a “resulting” process. Then, the rapid development of laser spectroscopy for the determination of stable isotope ratios in water, easier to operate and more affordable compared to traditional mass spectrometry, combined with a growing interest of the scientific community towards isotope-based analysis of tree water uptake pushed me to start investigating the spatial and temporal variability of water sources accessed by trees in forest and agricultural settings. These efforts are leading me to learn more, expand my knowledge and obtain a broader, more comprehensive and exciting perspective on the ecohydrological relations between vegetation and the other components of the water cycle in the critical zone.
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What do you see as an important emerging area of ecohydrology?
Although it should be implicit in the concept of ecohydrology, I think that increasing the interdisciplinary approach is a critical step to further advance ecohydrological studies. I have the feeling that quite often, at least in my experience, researchers try to expand their own research lines, interests and knowledge to include multiple analysis perspectives but a real combination of people with different expertise and backgrounds is not fully achieved. I realize this, for instance, when I try to think as a plant physiologist or a geomorphologist or an ecologist to frame some questions. But I’m not, and this affects the way I analyse data and interpret results. I believe a stronger collaboration among different but related disciplines is necessary in order to address scientific aspects of ecohydrology (including the role of anthropic pressure) with a wider angle of view and thus in a less-skewed, more solid way.

I agree with Holly (see her post below) about the scaling issue. Most studies are typically carried out at the plant or stand scale but we still need to figure out how to build models to upscale the spatio-temporal variability in plant water uptake from the plant/stand scale to the catchment/landscape scale. This is an open challenge that has relevant practical implications, for instance for water resource management in forestry and agriculture.

I like the potential (but I’m also aware of the limitations) of meta-analyses (Evaristo and McDonnell, 2017). As far as I, know this approach is quite common in medical science, especially with the aim to increase data availability and reach higher statistical power. I think this tool can have fruitful applicability in ecohydrology in order to achieve a better understanding of processes in a wide variety of environments. At the same time, I advocate the more frequent use of multi-comparison investigations (in ecohydrology as well as in catchment hydrology). Although comparative studies can be time- and money-consuming, through the analysis of differences they can go beyond understanding the behavior of individuals or single study sites and allow for a better perception of the factors that control those differences. And the factors that drive changes in the ecosystems and of their services are what we should be more interested in.
 
Do you have a favorite ecohydrology paper? Describe/explain.
It’s hard to pick just one. Considering papers that focus on the intertwined processes between water and trees, I especially like the review by Susan Brantley and co-authors (Brantley et al., 2017) who tested several hypotheses to highlight how trees, seen as biotic engines, promote soil-landscape co-evolution by acting as “builders and plumbers” of the critical zone. One of the first papers I read when I dove in on the use of isotopes to investigate sources for tree water uptake and related ecohydrological dynamics is the work by Greg Goldsmith and colleagues on ecohydrological processes in a mountain cloud forest in the tropics (Goldsmith et al., 2012). This paper, along with the already-cited and inspiring one by Dawson and Ehleringer, 1991 (I agree with Holly again!) opened my eyes on the exciting opportunities isotopes offer to explore interrelations between vegetation and hydrological processes, including still unsolved (and therefore fascinating) issues. Finally, I recommend a recent paper by Barbeta and Peñuelas, 2017: their isotope-based work underlines the importance of groundwater contribution to plant transpiration across different biomes and provides new insight about the occurrence and interpretation of the highly-discussed “two water worlds hypothesis” (McDonnell, 2014).
 
What do you do for fun (apart from ecohydrology)?
Apart from ecohydrology I do catchment hydrology, of course! Joking aside, I’m a commuter and I’m away very often. So, when at home, I try to spend as much time as possible with my wife and our two children and with our friends, preferably in the outdoors. I love cycling, hiking in the mountains, skiing, playing guitar, reading, and I’m fond of nature photography.

Dr. Enrico A. Yépez is Profesor Investigador Titular “C” at Departamento de Ciencias del Agua y Medio Ambiente at Instituto Tecnológico de Sonora in Ciudad Obregón, México. 

What does ecohydrology mean to you?
This interdisciplinary science has been in the core of my research goals simply because I investigate ecosystem processes in water limited ecosystems. An early realization in my career was that for life, and any biogeochemical cycle, to occur in these systems, water is needed. So, the aim of finding the “functional fate of rainfall” has been central in my thinking and has given me the basis to link hydrological processes with ecosystem production. Ecohydrology also provides knowledge to manage water resources and preserve ecosystems, which are themes that are very relevant in Northwestern Mexico where water is certainly scarce.

What are your undergraduate and graduate degrees in?
I obtained a degree in Biology from the Universidad de Guadalajara in Mexico where I was trained in plant physiological ecology (cacti research). Then I moved to Tucson to get my MS and PhD in Rangeland Management with a minor in Global Change at the University of Arizona (2006). Here is where  I succumbed to study seasonally dry ecosystems.

How did you arrive at working in/thinking about ecohydrology?
In my graduate work I was confronted with a very fundamental issue in ecohydrology: How can we partition the evapotranspiration flux into its components without losing coherence to study processes at the ecosystem scale? This simple, yet fundamental, question obligated me to think about soil, plant and atmospheric processed combined and exposed me to modern technology (flux towers, IRGAs, elemental analyzers and mass spects) to trace the water molecule in ecosystems. Thinking about ET in separated terms demands inquiring how is the biology influencing this physical driven flux and what are the consequences for ecosystem production if water moves through the physical or the biological path.

What do you see as an important emerging area of ecohydrology?
There is still room for finding fine connections between the water cycle and other ecosystem processes. For instance, modelling highly dynamic water and carbon fluxes in pulse driven and seasonally dry ecosystems is still very challenging and it is an area that requires profound ecohydrological criteria. I must mention as well that as water scarcity and pollution augments in the planet ecohydrological knowledge should now confront water management issues.

Do you have a favorite ecohydrology paper?  Describe/explain.
An ecological paper that transmitted an important hydrological message early in my career was the Laureroth and Sala 1992 (DOI: 10.2307/1941874), where the relationship between rainfall and ecosystem production was highlighted but specially how the space by time substitutions are useful to study and integrate ecohydrological processes, an idea that was later on explored by Huxman et al 2004 (DOI:10.1038/nature02561) with a more explicit argument on how this relationship and the space by time substitution is indeed useful to make synthesis and compare ecosystem processes across ecosystems. As nicely depicted by Biederman et al 2016 (doi: 10.1111/gcb.13222) this is an idea that is worth exploiting as we study ecosystem processes nowadays.

What do you do for fun (apart from ecohydrology)?
I enjoy dealing with the analytical instrumentation in lab; I love to see the machines beeping and LEDs blinking while data comes out; I particularly enjoy opening their guts to see how they work. I still try to go out to the field with my students, but when I go home to be with my wife and our two kids (Tlaloc and Ehecatl a.k.a. the Monsoons), card games after a fine Sonoran steak and red wine are usually in order.

Dr. Holly Barnard is an Associate Professor in the Institute of Arctic and Alpine Research and Department of Geography at the University of Colorado – Boulder.

What does ecohydrology mean to you?
To me ecohydrology means “interdisciplinary” research in the most synergistic meaning of the word – where investigating a problem or a curiosity with approaches from multiple fields results in findings that advance our understanding of the greater system. Not every study I pursue matches this ideology, sometimes the advancement is more in one field than the other, but it is a goal to strive for.

What are your undergraduate and graduate degrees in?
Forestry, forestry, forestry! I have B.S. in Forest Resources from the University of Washington, an M.S. in Forest Science from Colorado State University, and dual degree Ph.D. in Forest Engineering and Forest Science from Oregon State University. Um, yeah, I like trees (and water) and at one time I was pretty good at axe throwing.
 
How did you arrive at working in/thinking about ecohydrology?
As an undergrad, I worked in Tom Hinckley’s water relations tree physiology lab and then pursued that research area for my master’s.  After my master’s, I worked in environmental consulting where I did a lot of groundwater and surface water sampling. When I decided to go back to school for my Ph.D. and was presented with ecohydrology as a research option, it was a natural fit and extension of my past experience.

What do you see as an important emerging area of ecohydrology?
I feel that scaling in ecohydrology is a persistent conundrum: when, where, and why (or not) are the ecohydro interactions we observe at the plant, plot or hillslope scale important for processes at the catchment, landscape or global scales? Issues of scale in spatial-temporal data are compounded due to the highly multi-scale nature of ecologic and hydrologic processes. One can argue that all smaller scale processes are important (the small catchment scale and below is where my personal interests lie), but what needs to be included in larger scale, bi-directional models to avoid misrepresentation of either the ecology or the hydrology? Maybe this isn’t an emerging area, but it is certainly a grand challenge.

Do you have a favorite ecohydrology paper?  Describe/explain.
Dawson and Ehleringer 1991: Streamside trees that don’t use stream water
It has is all: streams, trees, mystery, intrigue, and isotopes - all in an elegantly simple study that offers surprises and drives complex questions about the interactions among vegetation, soil moisture, groundwater and surface water. Ecohydrology well before its time. I love this paper.

Newman et al. 2006: Ecohydrology of water‐limited environments: A scientific vision
Early in my Ph.D. I felt like ecohydrology wasn’t a true discipline, but simply that the two fields weren’t reading each other’s literature. This paper provided such a clear articulation of ecohydrology as its own discipline and the grand challenges put forward really helped to guide my thinking in how ecohydrology can be greater than sum of its parts.

In terms of social-media publications, I’m a fan of The Egohydrologist on Twitter.  Their tweets have higher impact factors any of your papers (or so they say).

What do you do for fun (apart from ecohydrology)?
I’m a Boulder stereo-type for outdoor recreation.  I enjoy climbing, road biking, skiing and deadlifting.  I’m also very happy laying on the couch with several pets and watching football. My partner and I enjoy going to the plays at the Denver Center for the Performing Arts. 

:Dr. Sally Thompson is currently an Associate Professor of Civil and Environmental Engineering at University of California Berkeley…however, she is soon to move "home" to become an Associate Professor of Environmental Engineering at the University of Western Australia.

Dr. Bradford Wilcox is the Sid Kyle Endowed Professor in Arid and Semi-Arid Land Ecohydrology in the Department of Ecosystem Science and Management at Texas A&M University where he is also Director of the Wilcox Ecohydrology Lab.

What does Ecohydrology mean to you?
As others have noted previous posts, ecohydrology is the science of interactions of between biota and water. My own interest centers on how plants—particularly trees—influence the water cycle at multiple scales.  I have always seen ecohydrology very much as an applied science, and one that focuses on understanding the implications of environmental change for the water cycle. 
 
What are your undergraduate and graduate degrees in?
I have a B.S. in Rangeland Ecology from Texas Tech University.  It was there that I developed a fascination and a passion for how plants and soils interact in semiarid landscapes.  I went on to earn an M.S. from Texas Tech University as well, also in range science, which afforded me the opportunity to live in Peru for 13 months studying soils and ecological communities in the high Andes. My Ph.D. is from New Mexico State University, also in what was then called watershed management, where my research focused on understanding how grazing alters runoff and erosion on steep semiarid landscapes.
 
How did you arrive at working in and thinking about ecohydrology?  
Early in my career, the term ecohydrology was not part of the popular scientific vernacular.  My research interests were not appreciably different than they are now. I self-identified as a rangeland hydrologist.  It was the seminal paper by Ignacio Rodriquez- Iturbe in 2000 that really changed everything.  I am simplifying, but in that paper he made a clarion call to the hydrology community that plants are really important to the water cycle and there is much that we do not understand about how plants modify water fluxes at multiple temporal and spatial scales.  Hearing this from such an eminent hydrologist was extremely exciting because he was essentially saying that what I was interested in was really important and at the cutting edge of a new and exciting emerging discipline—ecohydrology!  Soon after that, Brent Newman and I organized our first AGU Chapman conference (2002) focusing on the ecohydrology of drylands.  The conference was a success in many aspects, but in particular it was a landmark event in terms of bringing together ecologists and hydrologists with similar interests and facilitating cross-disciplinary interactions and communications. 
 
What do you see as an important emerging area of ecohydrology?
I have always viewed ecohydrology as an applied science that can provide insights into many of the seemingly intractable environmental challenges we are currently facing.  It is urgent that we address these challenges, but doing so will require more interdisciplinary interaction and collaboration—particularly in regard to doing a better job of understanding the human factors that are driving global change.  Collaboration with those far outside our discipline, such as social scientists, is hard (and not always productive in terms of how we are evaluated as scientists)—but I believe it is vital if we are going to have a real impact on problems that are important to people.
 
 
Do you have a favorite ecohydrology paper?
Again I return to the “pre-ecohydrology era” during my formative years as a scientist.  The late 1980s and 1990s was an introspective period for the discipline of hydrology, and for me was an exciting time.  One set of papers in particular had a profound influence on me.  In 1986, Water Resources Research published a special issue: Trends and Directions in Hydrology, edited by Steve Burges. In that issue were a number of landmark papers, but in particular I recall the paper by J.C.I. Dooge, Looking for Hydrologic Laws, and another by V. Klemes, Dilettantism in Hydrology: Transition or Destiny?. Both papers, I believe, were making the argument that the science of hydrology had tilted too much toward engineering and needed to readjust to become a true earth science; AND that there were some exciting things to discover—one only had to look!
 
What do you do for fun?
I have more leisure time now that my three daughters are grown and I am trying to make the most of it.  This summer I spent 4 weeks on an “epic” camping adventure across the western USA with two grandsons. My current passions—besides ecohydrology—are road cycling and fly fishing. I love traveling even if most of it is related to work, and in particular I enjoy traveling and working in Latin America. I also spend quite a bit of time working to improve my Spanish and Portuguese.  

Dr. Lixin Wang is an Associate Professor in the Department of Earth Sciences at Indiana University-Purdue University Indianapolis Twitter: @ecohydro_wang

What does ecohydrology mean to you?
Ecohydrology is an interdisciplinary science bridging hydrology and ecosystem science. Ecohydrology answers some of the most pressing questions facing human society. For example, how does earth system respond to climate change? Whether we will have enough food to feed everyone under climate change?
 
What are your undergraduate and graduate degrees in?
My BS degree is in Biology (Hebei University) and PhD degree is in Environmental Science (University of Virginia). I had two great PhD advisors - Dr. Steve Macko taught me everything about stable isotopes (which is a major tool I use in ecohydrology), and Dr. Paolo D’Odorico led me to the exciting field of ecohydrology.
 
How did you arrive at working in/thinking about ecohydrology?
My PhD work focused on savanna ecosystems in southern Africa, where ecohydrology is very relevant and important. That is where my ecohydrology journey started. My postdoc work with Dr. Kelly Caylor reinforced my passion in dryland ecohydrology.
 
What do you see as an important emerging area of ecohydrology?
I’m sure everyone has their own perspectives. I think how vegetation responds to water-stress across scales and the interactions between water and biogeochemical cycles are two important emerging areas. Big data is also an important emerging area not only to ecohydrology, but to most disciplines.
 
Do you have a favorite ecohydrology paper?  Describe/explain.
I have difficulty answering “favorite” questions. I remember reading the following paper repeatedly when I first started appreciating stochastic modeling framework and thinking about the linkage between hydrology and biogeochemical cycles.
Porporato, A., D’odorico, P., Laio, F. and Rodriguez-Iturbe, I., 2003. Hydrologic controls on soil carbon and nitrogen cycles. I. Modeling scheme. Advances in Water Resources, 26(1), pp.45-58.
 
What do you do for fun (apart from ecohydrology)?
I enjoy traveling to appreciate various landscapes and to experience different cultures. I enjoy reading biography books and see how the great minds think of lives. I was a big fan of science fiction when I was young and still truly enjoy them when I get time.

​​Dr. David G. Chandler is an Associate Professor of Civil and Environmental Engineering at Syracuse University dgchandl@syr.edu

Dr. Aline Jaimes-Hernandez is a Postdoctoral Research Associate in the Department of Ecosystem Science and Management at Texas A&M University. Twitter: @AlineJaimes7

What does ecohydrology mean to you?
To me, ecohydrology is the study of the processes that regulate how carbon, water, and energy move (in and out) in the dynamic living layer of the earth that extends from the top of the atmospheric boundary layer through the soil, bedrock, and the bottom of groundwater. I am especially interested in learning the lateral and vertical processes that regulate the interactions of carbon, water, and energy in ecosystems, and the importance of those to regulate earth’s climate and vice-versa.

What are your undergraduate and graduate degrees in?
I earned my BSc in Biology, with a minor in Hydrology and my MSc in Oceanography focused on Physical and Biological interactions, I studied both in Mexico where I was born.  I came to the USA, to pursue a post-master scholar summer fellowship, were I continued my PhD studies in Environmental Science and Engineering focused on Land–Atmosphere interactions.
​
How did you arrive at working in/thinking about ecohydrology?
I think initially by my fascination of photosynthesis developed early in my biology classes. Then, when I was pursing my MS in Oceanography in La Paz, BCS, Mexico; I volunteered with a group of scientists from SDSU, who had portable towers, a bunch of sensors and a small plane, they all seemed to be enjoying their field campaign studying the mangroves of Bahia Magdalena. They introduced me to the world of eddy covariance, plant physiology, spectral indices, overall the use of technology to measure different components of the biosphere. I was amazed of how much data was collected and how much insight to understanding wetlands dynamics we learned in a relative short period. So, I was hooked!

What do you see as an important emerging area of ecohydrology?
The future of water availability for ecosystem functions, goods, and services in fragmented ecosystems undergoing environmental change.

Do you have a favorite ecohydrology paper? Describe/explain.
Many, especially the ones that help to communicate across disciplines as our research becomes more transdisciplinary. For example Chapin, F. S., et al. (2006). "Reconciling Carbon-cycle Concepts, Terminology, and Methods." Ecosystems 9(7): 1041-1050.

Also, Mares, R., et al. (2016). "Examining diel patterns of soil and xylem moisture using electrical resistivity imaging." Journal of Hydrology 536: 327-338, that describes the bidirectional water flux dynamics in the earth’s permeable Skin. This is another favorite as provide demonstrable insights to hydrology-ecology as a coupled system.

What do you do for fun (apart from ecohydrology)?
I enjoy sports, such as running, crossfit, cycling, and occasionally swimming, more lately meditation, in general all activities that I can do with my 25lb dog named Rupee. I also enjoy making new friends from different academic backgrounds and cultures. Traveling to all the small and big towns across Texas and elsewhere, tasting local cuisine and local breweries is always fun too.