I am an undergrad student from the Philippines and my thesis is about Ant diversity and their possible potential of being bioindicators of disturbance in an area. I would like to ask help from you guys for any related literature about ants here in the Philippines. Anything will help me a lot, be it about diversity, foraging, or other indication studies about ants published.
Please help me.
Thanks for your question. That's a really interesting topic, and there has been quite a bit of research into the use of ants as bioindicators. I'm not aware of any research that has specifically focused on the Philippines, but I can give you some citations of relevant studies from nearby areas like Borneo (e.g., Bruhl et al. 2003) and Papua New Guinea. It is further away, but some of the best Ants as Bioindicators work has been done in Australia.
But first: Anyone considering using ants as bioindicators, or sampling a large amount of leaf litter ants for any sort of ecological question, should read this book:
Agosti et al., 2000. Ants: standard methods for measuring and monitoring biodiversity
It is available here almost in its entirety for download in pdf form.
A recent paper that deals with statistically sound ways of sampling ants was just published in Myrmecological News:
Gotelli et al. 2011. Counting ants (Hymenoptera: Formicidae): biodiversity sampling and statistical analysis for myrmecologists.
Regarding Philippine ants, there was a very useful revision of the genus Odontomachus in that same issue of Myrmecological News:
Sorger, D.M. & Zettel, H. On the ants (Hymenoptera: Formicidae) of the Philippine Islands: V. The genus Odontomachus Latreille, 1804
Another recent revision is by Zettel (2006) of the genus Pristomyrmex.
Of the few works to be published about Philippine ant assemblages in the past 50 years or so are:
Way et al. 1998
Samson et al. 1997. Ant Diversity and Abundance along an Elevational Gradient in the Philippines. , and this one that might be useful with regards to the negative indicator species described below.
There is also, I might add, an excellent list of ants from the Philippines here and a useful key to their identification here.
That being said, you should try and do as much reading as you can about other case studies in which ants have been used or proposed as biomonitoring tools. For those readers not yet familiar with the "Google Scholar" search tool within Google, it is an excellent supplement to and even substitute for most online literature search engines. Click here for results relevant to this post.
Of the many articles that are retrieved, one of the most useful for justifying the use of ants as bioindicators is by Majer et al. 2007
Perhaps my favorite study on the subject is Anderson et al.'s 2002 Using Ants as Bioindicators in Land Management: Simplifying Assessment of Ant Community Responses. Anderson and colleagues clearly articulate one of the most important things to look for in a biomonitoring protocol: feasibility. "Will we actually have the time and expertise to continue this protocol, or is it so elaborate that we're dooming ourselves to a one-shot deal?" That is a very important question to ask.
In my mind, there are four main styles of using ants (or any other organisms) as bioindicators:
Umbrella species - make sure these species are protected, and all other species will be safe. Their absence should send out warning alarms. This approach is essentially the "Spotted owl" approach that environmental activists in the Northwestern United States used to justify saving big trees. From an ecological standpoint, it makes sense to select species that are very sensitive to disturbance, because that way, if they are safe, everything is safe. The logic of the umbrella species is that you want to take the most sensitive, asthmatic canary with you when you descend down that coal mine. With respect to ants, umbrella species would be tricky to use in a place like the Philippines because many of the most sensitive ants will be undescribed species, and it will take years to establish their identity. However, if there are known rare endemic ants on a particular island, this approach might be helpful, especially in combination with another outlined below.
Negative indicator species (NIS)- Bad Species! No! Go Home!
Negative indicator species should not be there. If you find them somewhere, then something is wrong. In many areas around the world, invasive species are present where ever there is human-caused disturbance. They themselves are also a force of ecological change. Five species of invasive ants (Anoplolepis gracilipes, Linepithema humile, Pheidole megacephala, Solenopsis invicta, and Wasmannia auropunctata) are among the 100 worst invasive species world-wide, and each have been show to change ecosystems in their introduced range. These species are excellent candidates for inclusion in a biomonitoring protocol in an area with many unidentified species, because they can often be unambiguously assigned a taxonomic name and an ecological value. In the Philippines, two out of the five have been reported so far: Anoplolepis gracilipes, Phediole megacephala. Those two and a third, Solenopsis geminata, might make good candidates for use in a negative indicator species biomonitoring protocol. And certainly any of the other ones would be worth watching out for if they were to show up. The satisfying thing about NIS as opposed to umbrella species is that when an NIS appears there are two proactive things you can do: try to figure out what went wrong with the environment to let the NIS in, and try to eradicate the NIS from its new range. When your umbrella species starts to decline or disappears altogether, you're often left with fewer clues and, well, no more umbrella.
Functional groups (at or above the species level)- This is when you look at a bunch of different species in a particular group (say, ants, for example) and check to make sure everyone is there. Or, you look at the average value for some trait of that group, or perhaps make sure that the group displays some ratio of traits. People who study rivers and streams in North America have shown that there are certain taxa, that are usually present when streams are unmodified and unpolluted. Because ants, as a family, display a wide variety of ecological roles, they can also be divided up into functional groups, and a characteristic combination of those functional groups should be present in each ecosystem. Australia has a very strong ant research tradition, especially in applied ecology, and the Australians were the first to follow the stream biologists and apply the functional group concept to ants. You can read more about the functional groups of ants here and here
Unfortunately, the functional group model of ant community composition is based upon the ants of Australia, and Australia's ants, like many of its other organisms, are quite distinctive. So a functional group approach to biomonitoring will not always be productive outside of Australia, unless perhaps new functional groups are established in each new place. Because relatively little is known about Philippine ant assemblages, it might be more productive to use a more generalizable approach, like Negative Indicator Species or fluctuating asymmetry (below).
Assemblage properties (of individuals) - Finally, there are some studies that deal with properties of individual organisms, specifically, asymmetry. Ants, frogs, and people are all pretty much bilaterally symmetrical. However, stress during development can cause slight abnormalities to occur, which make us more asymmetrical than usual. The key phrases for this line of research are "fluctuating asymmetry" and "Developmental instability"
Basically, one could take any group of normally bilaterally symmetrical organisms (even some plants and algae have been studied this way!), and measure the same thing on both sides of a lot of organisms. For insects, good things to measure might be eye width or wing length.
I hope this helps, Rafael. Biomonitoring is a very admirable idea, but difficult to accomplish effectively. Ants are a very strong candidate taxon for use as biomonitoring tools because they are very common in many different environments, and display a wide range of ecological preferences and tolerances. They are also fun and exciting to study! I hope you get a chance to look at some while you're writing your paper!
Jesse Czekanski-Moir & the AntAsk Team