I don't know if it matters too much, but I always thought an eco-hydrologist was a hydrologist working to solve ecological issues, e.g. provide environmental flows; whereas a hydroecologist was an ecologists studying the ecological responses to flow conditions. Essentially I suppose it's the same thing. In the same vein, there are hydrogeologists and geohydrologists: both the same thing really, one considering themselves principally a hydrologists, before being a geologist, and the other a geologsist before being a hydrologists.

This is an interesting discussion, which is also happening at the European Geophysical Union (EGU). At the EGU 2013 meeting, there will be a session on General Ecohydrology (http://meetingorganizer.copernicus.org/EGU2013/session/11794), convened by the editor of the Wiley-Journal "Ecohydrology" and aiming to get a sense for what poeple consider to be part of the field of Ecohydrology.

My own working definition was that Ecohydrology focuses on the interactions between hydrology and mainly terrestrial ecosystems, whereas Hydroecology focuses on aquatic ("hydro") ecology, i.e. stream, lake and estuary ecosystems. Since "Ecohydrology" contains the word hydrology, while "Hydroecology" contains the word ecology, I thought that this should indicate the main focuses of the respective fields.

Similar with hydrogeologists and geohydrologists: the former are geologists that deal with water, while the latter term could refer to hydrologists that either deal with geology or geography (or anything else "geo").

Sorry, I meant "European Geosciences Union"...

Thanks for your views, lots of useful food for thought. It will be interesting to see what comes out of the discussions at EGU this year, or at HydroEco 2013 in France.

the ecologists put the eco first, and the hydros put the hydro first, so its disciplinary centrism. Its also interesting in terms of the culture of science that these terms reflect these disciplines are growing towards each-other. Otherwise there is no recognised difference between the terms.

Funny, my understanding was the opposite, i.e. that ecologists, e.g. those thinking about the effect of stream flow on stream fauna, put the "hydro" first to retain the full word "ecology", whereas hydrologists, e.g. those thinking about the effects of vegetation on water resources, put the "eco" first to retain the full word "hydrology". I don't think it would be helpful to use both terms interchangeably, as we would lose the possibility to differentiate and hence maintain clarity in our communication. Would be nice to agree on some useful and clear definitions for each term. I haven't done a literature review on this recently. If anyone else has, it would be great to share your insights here.

These people did a review, and this is the position I am partly speaking from ... the terms are arguably synonyms, but the practice is that the hydrologists and ecologists are extending their disciplines, but haven't truly come together. On a similar note, as an ecologist I find hydrologists/modellers tend to be much more comfortable with rash oversimplifications of ecological processes, and hydrologists make similar comments to me about my hydrology :). So, if you want the terms to be different, in reality they are.

I sometime say in jest that I am not a proper hydrologist anymore but that I am not a proper ecologist either! I think bridging between fields implies a certain amount of simplifcation from both sides, and often it reflects people's background and skill sets.

The paper you cite is from 2004 so nearly 10 years, would you think the gap has been bridged yet?

Yes to soem extent, but the papers conclusions still hold. I think there has been enormous development in this space, but there is still so much to do.. Models have become more sophisticated, e.g, more detailed multi-species modelling starting to look like it will be better linked to hydrodynamic models as part of our murray-darling basin plan science here in Australia. Through many ecohydrology models at this inter-basin scale we (many players) are also determining the ecological level of 'take'; i.e. what the environment needs. The science behind this has some limitations but there is no doubt we would have done less well 10 years earlier. These are all being linked to both climate change and river operation models, so the compexity is impressive, and the realism reasonable given the constraints.

This is a very interesting topic that trigers several interesting discussion with deep thoughts. It looks to me that more and more people are prone to use the term "ecohydrology" in recently publications. The launch of the journal of Ecohydrology is definately a sign of it. This term, ecohydrology, might be new. However, the focus of ecohydrology is not new at all, if you look back into mountains of previous studies using paired watershed to invegestigate the impacts of management practices on forestry hydrology. What new today in ecohydrology studies are the advanced teciniques are used such as sap flow measurements, isotope measurements, eddy covariance methods, etc. Another new aspect of ecohydrology study is the generation of more and more integrated ecosystem modeling simulating the plant physiological regulated water flux in the soil-plant-air continuum. This intergrated modeling tools are different from traditional hydrological model which may/may not even implicitly consider plant factors (root, stomatal condutance, etc) in adjusting the most important term of water balance, ET.

Dear Cédric L.R. Laizé

In hydroecology the main goal is ecology and in ecohydrology the main goal is hydrology but I prefer hydroecology such as agroecology.

Thank You

Mohammad Kazemi

Interesting discussion! I like the idea of using ecohydrology for terrestrial ecosystems, and hydroecology for aquatic ecosystems. In addition to a difference in the focuses (ecohydrology more on water, and hydroecology more on ecosystem), I think there is another difference in the degree of interactions between the hydro and bio parts in the two systems. In terrestrial ecosystems, plants play important roles in influencing water balance. While in an aquatic ecosystem, more interest is probably on fishes and other animals.  Biological impacts on water is very limited. Not sure this understanding makes sense to you.

For ecohydrology, some time eco-hydrology is also used. Using two different words for the same thing causes some difficulty in referencing papers. It would be good to use one. I think most of us prefer "ecohydrology".

I am not aware of any clear accepted definition between the two. But to add to the others perspectives, prefixing "hydro" usually refers to "of water" , like hydropower or hydroplane. Hydroecology could thus be linked with aquatic ecology as well, like the journal Hydrobiology refers mainly to freshwater ecology. Whereas the term "ecohydrology " has been used to refer to the linkages between water and the ecosystem, whether terrestrial, wetland or aquatic..as seen from all the articles that get published in the journal Ecohydrology. 

ECOHYDOLOGY and HYDROBIOLOGY:

"Ecohydrology is a subdiscipline of hydrology focused on ecological aspects of hydrological cycle"

See the link from the source. http://www.ecohydro.pl/index.php?p=ecohydrology%20concept

I see myself as an ecohydrologist, i.e. my research interest is in the water/energy balance of the terrestrial ecosystem, particularly by using the eddy covariance technique mentioned by Shiying Tian. More recently, I'm exploring machine learning methods into our data analysis and modelling.. but I like how Huade Guan put it in such a way that the difference can lie in which ecosystem is your main research interest.

Hydroecology is a branch of ecology that emphasizes on the effects of ecological process (living and non-living organisms ) on hydrological processes and their interaction in terrestrial ecosystems.

But, Ecohydrology is a branch of hydrology that emphasizes on the effects of hydrologyical processes on ecohydrology and their interaction in terrestrial ecosystems.