Monday, October 5, 2015

Early assessments of Chile's freshwater fish biodiversity

Carl Eigenmann is considered one of the major people in identifying the native fishes of Chile. Many of the native fishes here have his name in the designation. This, however, is the first sentence about his initial trip to Chile in 1919, as written in his biography:
In February, 1919, Eigenmann went south to Chile where he was disappointed at the paucity of the fresh-water fish fauna of only 30 odd species belonging to 10 families. On the first of June, 1919, he returned [to the US]. As usual he brought back with him a large and varied material the study of which resulted in important publications. According to Myers “it was on this trip that the strain of the great altitudes broke the indomitable strength of Eigenmann, once before weakened by fever in Colombia and it is from this time that we must mark his decline in health.”
The following summary about the Chilean ichthyofauna is also pithy and spot-on:
 On the Pacific slope between Panama and southern Chile there are two main faunas. That of Chile belonging to the south temperate Patagonian fauna is poor in species.
According to recent sources, Chile has only 44 native species, and the majority of them are located in the southern half of the country.

Thursday, May 7, 2015

Am I using landscape ecology, ecohydrology, macroecology, or biogeography?

The terms landscape ecology, ecohydrology, macroecology, and biogeography are all used to describe different fields that each have distinct histories and fundamental theories. However, I believe that they all share one thing in common: assessing biological structures and patterns over large spatial scales. The question of what sorts of factors are used in determining the biological structures and patterns that arise forms a part of how to define one discipline from another.

It is important to state, though, that I personally hold somewhat more closer to the structure of ecohydrology, despite my not being a hydrologist or engineer (which is primarily from where the discipline arose). I had training in marine biology and classical ecology during the middle-late 1990s, and learned methodologies to assess species-to-species interactions within an environment that was deemed to be effectively a background condition (except in specific cases in which studies showed that the local environment was a major factor in structuring the local ecology, such as with wave action and coral reef communities and tides and tide pool communities). However, this approach was unsatisfactory for me, especially because it wasn't really capable of assessing large-scale implications. True, we learned that physical environments shaped the niches in which species evolved into and competed for, but the focus tended to be on examining the site.

Except when it came to looking at the influences of El Niño. And in 1998, there was a major El Niño effect that caused severe impacts to marine communities that completely overrode the species-to-species interactions that we had learned as the foundation of our education. Our module on the science of climate change and its scientific implications outside of climatology showed the beginnings of the wider scientific reckonings of what could happen to ecological systems with changing climatic zones. Between these two global phenomena, it was clear to me taht the scale of a single site was not large enough to assess the impacts.

In graduate school, I joined the lab of Prof. Mike Wiley at the University of Michigan. There, I learned about freshwater ecology and was introduced to a very different approach to understanding ecology: an approach based on understanding how physical processes drove the formation of potential ecological communities in rivers, lakes, and wetlands. I joined a project at the Institute for Fisheries Research and used this framework to investiagate potential impacts of large-scale groundwater withdrawal on fish habitat availability in a nearby stream. I was also involved in research that sought to derive statistical relationships between physical parameters and fish abundance throughout the State of Michigan. This latter work would form a major part of the science underlying current state water withdrawal regulation.

During my time at the University of Michigan, I never had to define what sort of discipline of large spatial-scale ecology I was doing. There were no self-styled "ecohydrologists" or "macroecologists" in our school, and those that worked on "landscape ecology" looked at forests and pairie ecosystems, and not aquatic ones, and those that might call themselves "biogeographers" were more interested in primate community structure than that of fluvial fishes. (Note: the University of Michigan had done away with their Department of Geography, and the biogeographers that had been in that department had either left the university or had found residence in other academic units; as far as I know, none came to our school.) That has left me a bit at sixes and sevens when I try to describe my academic pedigree and to apply to conferences, since my background is not in any of the historically associated disciplines to which landscape ecologyecohydrologymacroecology, and biogeography derive.

Given, though, that ecohydrology is most closely associated with assessing the ecologied derived from physical (i.e., hydrological and fluvial geomorphological) processes in inland waters (i.e., lakes and rivers), it is to this group that I more strongly associate myself. My background in ecology, though, continues to make me somewhat outside the norm in the discipline (at least from my perspective; maybe there are far more ecologists out there than I think).

But at the end of the day, the project that I am pursuing is at a large spatial scale using GIS; it draws upon physical relationships of hydrology, climate, and landscape to build hydrological and ecological models; and it seeks to use such relationships to assess the distribution of fish communities within a watershed. If that makes me an ecohydrologist, then that's good. If it also makes me a landscape ecologist, then that's dandy. If it means that I'm a macroecologist, then that's a good thing, too. And if someone says that I'm also a biogeographer, then I'm okay with that.

Of course, if it makes me none of the above, then I'm also okay with that (so long as they do accept my findings for publication), since I am also interested in using these scientific tools to assess the potential impacts of current policy in a future with climate and land-use change. (But that's further in the future, and worth a different post.)