Indicator species serve an indispensable purpose in conservation; they allow for monitoring of overall ecosystem health without actually having to measure every individual plant, animal, or function within the ecosystem. The ease of measurement and interpretation of biological indicators is what makes them so attractive to those involved in conservation, however, the process of deciding which species are best is not a quick one. Incorrectly picking and monitoring a poor indicator for an ecosystem not only may waste resources, but it also may lead to the ecosystem health greatly diminishing without even minimal notice.
Where my post is going and where it is coming from it rather simple. As part of the Conservation of Changing Landscapes course, taught by Dr. Beverly Collins at Western Carolina University, my class and I attempted to work through identifying and justifying biological indicator species for six ecosystems in the SALCC range: freshwater ecosystems, forested wetlands, hardwood forests, pine forests, scrub-shrub, and grasslands. Justification was to be achieved through providing primary scientific literature. Our class consisted of eight Master’s of Science students with a wide range of expertise and biological focus, such as herpetology, invertebrate zoology, plant pollen dispersal. The process we laid out was one of divide and conquer. With eight students, we had summary SALCC meetings that would consist of two of the ecosystems, for a total of four summary meetings. Each system would have four students assigned to it to investigate an individual species that may work, giving four species for each ecosystem at each meeting. We looked at parameters such as sensitivity to the environment, speed of response to environmental changes, trophic level, and marketability. For some of these, it was about trying to find an array of species to encompass a range of factors. As an example, we decided it would be best if we had species that were being monitored at the plant level and top carnivore level because a declining indicator at various levels informs us of various possible problems. I think the more important aspect of this post is not to simply rehash through the final list of species, now submitted and with SALCC, but to discuss specifically the process and highlights.
The process, as outlined above, appears simple and straightforward, but as the research increased so did the questions and problems. The most important issue was figuring out which species would actually be found in basically all occurrences of the selected ecosystem. For instance, when looking at freshwater systems, it was difficult to find a fish species that occurred in all systems over the entirety of the SALCC range so the final report does not include a fish. Even forest types had varying species depending on location of the system. Because of that, many of the biological indicators we reported were groups of organisms. For instance, with hardwood forests, as opposed to focusing in on one species we presented the indicator of Ground Beetle (Carabidae) species diversity. This became a common trend with other systems as well, where functional groups made more intuitive sense due to the variation that existed between the individual ecosystems. Although some indicators were specific species (e.g. Eastern Box Turtle), groups were often used (EPT, Diatoms, Plant Facultative Ratios).
Another issue was the general lack of monitoring previously done, as most of our indicators did not have baseline data over most of the SALCC range. It is not possible to note the speed and degree of response by an indicator without proper monitoring or else false conclusions may be reached. Not only was baseline data unavailable but there was an ongoing concern by the members of the class because even after conservation and restoration efforts occur in many regions continued monitoring does not occur. Many times we came across restoration projects, both with the SALCC and non-SALCC sections of the class, but there was a void of data after restoration and conservation actions occurred. Trees were planted, but what happens over the next few years as they become established? Wildlife ordinances were passed, but what effect did it actually have on the wildlife? These questions and many more arise when data is missing after conservation and restoration.
Overall, the process was enlightening and fun. It was interesting to see how a person’s research focus effects how they perceive the scale of the landscape (something I could discuss for hours). There were also some very interesting indicators that I personally enjoyed. Diatoms, single celled algae, were one of my favorites that came up for the aquatic systems. Although determining species is difficult, the alternative presented was to do morphospecies, which is the process of not worrying about actual species names and just counting the number of different looking diatoms that one sees under the microscope. They can actually be quite beautiful and artistic. The on-going joke was that we should take some of the cylinder and circular shaped ones and make a t-shirt that said “HOPE,” to increase the marketability of diatoms as indicators. In the end, we hope that our efforts and review of the scientific literature may help guide SALCC towards the most efficient and practical use of resources.