For the ecologist Raul Costa Pereira from Unicamp, it is not just expressive to call São Paulo a stone jungle. Accustomed to field research in lush ecosystems like the Pantanal, Pereira is preparing to explore the biodiversity hidden in São Paulo houses – in a flower vase, in a corner of a room or in the cracks of a tile.
“We usually use binoculars and field pants to investigate ecological relationships. I want to see what you can do inside in pajamas and socks, ”joked the researcher in an interview with Folha.
The idea receives an investment of R $ 570,000 from the Instituto Serrapilheira, a private non-profit organization that finances Brazilian scientists with innovative projects. Although there has already been some research on the fauna of birds and other larger animals that can be found in parks, squares and other areas of Brazilian metropolises, the work of the ecologist has slightly different goals: to find tiny, yet very important forms of biodiversity.
“We’ll deal more with the micro, essentially with the arthropods,” he explains, referring to the most diverse group of invertebrates, including ants, spiders, beetles, mites and a variety of other creatures. The “micro” of the analysis also includes spatial delimitation: Pereira would like to investigate how the habits of each place of residence affect the occurrence of different species in it.
“I’m interested in what could be called the ecology of the individual,” he says. “We tend to put several individuals of the same species, such as a species of fish or bird, in a box. But when we look at people, the individuality is wide open, and I think it is possible to see how it reverberates and becomes a driving force for the diversity of these naturally dependent micro-ecosystems. “
For example, one can think of the interior of a house as a habitat that houses a miniature food chain, including small herbivores such as certain ants and the predators that feed on them (e.g. spiders) and so on. Details such as the presence of plants, small areas of flower beds or lawns, the type of soil in the house, lighting, ventilation, etc. can influence which species form these chains.
But another important variable is the habits of the people in each home, he points out. “Are we going to have the same species in the household of someone who is vegan, only eats processed foods, and takes practically all meals outside the home? Since we are the key species in these environments, all of these will make a difference. “
Many of our animals that the researcher wants to study are difficult to spot, either because of their size or because of their habit of going into small corners that are inaccessible to human hands and eyes. To circumvent this recognition problem, the project will use environmental genomics techniques. This means that even the dust that has accumulated in a carpet can be subjected to a DNA analysis that records the species that have passed through there, even if larger and more visible remains of them have already disappeared.
Another important tool will be stable isotopes – variants of atoms like carbon that are found in all organic molecules and that help estimate the origin of the food that a particular animal consumes. The idea is, for example, to investigate what happened in places where invertebrates were dependent on the constant presence of food thrown away by humans – until they ran out of this “self-service” with the social distance caused by the Covid. 19 pandemic. . This is the case at Unicamp itself, where the researcher normally works.
In addition, the idea is to test houses in São Paulo that take into account the regional and socio-economic differences of the city – more forested neighborhoods or just asphalt and concrete, periphery and inner city and so on. It will be possible to cross this geographic data with the arthropod elevations to understand how one affects the other.
If you are more skeptical, you might think that nothing more interesting than simple ants and cockroaches will come up in such a survey. Pereira disagrees. “The first step is to open up, cast out the net and see what comes next,” he compares with a Fischer analogy. “I think there can be good and bad surprises, including the presence of some species that in theory would only appear in well-preserved places.”