I'm studying the relationship between aquatic insects (as biomonitoring medium) and water quality of river. I only have the data for the number of insects/organisms based on their respective orders (ephemeroptera, plecoptera, diptera, odonata). I haven't got the information of what family they are in, so I could not calculate the actual tolerance value for each order of insects.
Is there any alternatives, modified biotic index formula or any other indices that can be calculated using only these information that I have?
Feedbacks are highly appreciated.
Sequential comparison index is possible to calculate biotic index without specifically knowing the name of family/species of an insect order.
It's in my opinion. Every insects have an individual responses to the stress.
Several years ago, I recall hearing a researcher talking about rapid bioassessment using macro invertebrate body sizes. I couldn't find the reference, nor do I know if the study was ever published. However, I was able to find the work of Basset et al. looking at the use of body size in monitoring.
Actually you can calculate biotic indices based on order-level data, but order-level data may be too coarse to reproduce biotic patterns portaryed by species-level (or lowest taxonomic level feasible) data. I conducted several studies about the higher taxa surrogacy of benthic macroinvertebrates several years ago, and we found that genus-level (sometimes family-level) can be suitable surrogate, but order-level are too coarse.
Richard K Johnson : Thank you for the reference, will look into the link of journal you attached.
Xiaoming Jiang : Yes, I have thought that order-based calculations may be too coarse to determine their diversity in the ecosystem. I have tried calculating using the biotic index but then I was stuck because different families of the same order have different tolerance values (TV). I don't think using the average of all family to assign onto an order is convenient? That's why I don't know how to proceed with biotic index. Thanks for the journal.
Mohammadali Bouzarjomehr : Have thought of it but is it okay to use SPEAR index when we don't actually involve any pesticides in this study?
Looks like a dead end of a problem. I would not recommend using the average of all insect family to assign into an order. Try figuring out which insects belong to which family before proceeding with the biotic index. Whichever method you use to find out will not be an issue as long as you get what you need so you can reconsider using SPEAR index.
Sequential comparison index is possible to calculate biotic index without specifically knowing the name of family/species of an insect order.
Biotic Index (BI) is a scale for measuring the quality of water of a river by indicating the types of organisms inhabiting it. In BI each family or group of the aquatic organisms (stone flies, dragonflies, damselflies etc.) is assigned biotic value and sum total of the biotic values divided by the total number gives the BI value which is measured on a 1-10 scale corresponding to the four basic water qualities such as Excellent, Good, Fair or Poor.
Hi, the question has many aswers depending of what do you want to recieive as an output of calculations - assessment/evaluation of the quality of water environment or the benthic communty itself. To use any method based on species you need to know their (of each!) ecological tolerance/resilience according to the basic ecological principles of Shelford. In case you have not possibility/capacity to use species related indices, you may use EPT-index based on three main insect orders - Ephemeroptera, Plecoptera and Trichoptera. There are also community related indices such as Shannon-Weaver's species diversity index, Pielou's equitabilyty index, Simpsom's domination index, Margalef's diversity index, etc., which all have not so strong requirement to know species' latin binoms, it's enough to recognioze species A from species B and C, etc... and based on these "species list" to calculate indices. This was practicized for years in official state water/river monitoring in my country.
I'm sending a chapter of mine in the university text-book on Biogeography with some more explanatkions on the topic.
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