In search of lost biodiversity

My next trip starts on Friday, to the Austral Islands (Rimatara, Rurutu, Raivavae, and Tubuai). This time I am going in the company of two paleoecologists from Australian National University, and a botanist from the French Polynesian government. Yesterday the paleobotanists came over to Mo'orea to pick up some ethanol, and to scout out potential field sites on the island. Wetlands are great because they preserve pollen and some hard bits of insects and plants, which can be collected by taking soil cores, and offer a window on the ecosystems of these islands before and after human arrival. We found one: the swamps and estuary at Temae, on the northeast corner of the island. Sadly, these wetlands have been partially filled and replaced with what one Berkeley professor I know refers to as "that fucking golf course". Here we are just behind the airport parking lot assessing the quality of mud.

We talked a lot about the environmental history of Polynesian islands as we drove around Mo'orea. By analyzing what's preserved in the mud of wetlands in the Australs, they have found evidence to suggest that the arrival of the first humans one thousand years ago led to the extinction of many plants and insects, and that Polynesians were responsible for introducing the first ants to these islands. The arrival of ants in an ecosystem that had evolved for millions of years without them must have had profound impacts. This is exciting stuff, because previously this aspect of environmental change had been presumed unknowable, and because it has ramifications for all of us who do fieldwork on the biodiversity that does remain on these islands.