The first part of this post was written on a long car journey down through Minas Gerais State to Botucatu, with Andre, Felipe Amorim and Ana Moraes. It’s more than a 1000 km drive from Serra do Cipo state park, so we have done the journey in two parts, beginning at 5.30pm Saturday night, driving for over 3 hours, back through Belo Horizonte to the small town of Igarapé. Arriving at 9pm, we looked for a hotel in which to spend the night. The first one was a flea pit and Ana was sure she’d seen an insect running from the light when we assessed the rooms. All of us love biodiversity, but not that much, so we politely declined. The second place we tried was the Marketing Palace Hotel and was basic but clean. After a quick dinner and a few beers we retired to bed. I dreamt of magic and suicide in vivid technicolour, but fortunately didn’t wake Andre with whom I was sharing.
With little supporting evidence, I put the dreams down to secondary compounds in the Miconia fruit I’d been eating during field work earlier that day. The morning had started early with a trip into the State Park in search of a population of an orchid that Ana is studying for her postdoctoral project, the species Epidendrum campestre. Ana has already assessed several populations for their genetic and morphological variability and was keen to add another to her data set. There is a herbarium collection from this area from 1978 but it’s not been relocated since. The park is over 33,000 ha in area, soon to increase to about 39,000 ha with the purchase of an adjacent farm that will become part of the park.
Once we had left the main trail and headed for the low, rocky hills, the walking (really scrambling) became tough, slow going. As we picked our way from rock to rock, pushing through the less dense patches of vegetation, it was clear that this is an area of incredible plant diversity. Rocky outcrops and ravines are always good for plant diversity as species that cannot survive the greater competition found in richer soils are able to hang on in crevices and in shallow, humus-filled depressions. But we had no luck; the orchids were not in that part of the park.
As well as helping Ana and Felipe to search for these legendary orchids, Andre and I recorded all of the plant species that were in flower, and scored them for animal or wind pollination, based on the type of flowers, pollen release, flower visitors, etc. Over the day we recorded about 60 species in flower (perhaps one quarter of the total flora, as many species were not flowering), of which 10% were wind pollinated. This fits with the prediction of a study I published in 2011 of around 90% animal pollinated species for these tropical communities, compared to 70-80% on average in the temperate zone. It’s satisfying when ecology is a predictive science in this way, though understanding why these patterns exist is less straightforward; is it because there are more animals in the tropics that can act as pollinators? Perhaps, though bee diversity actually peaks in subtropical latitudes, in seasonally dry Mediterranean vegetation rather than in the tropics.
As well as scoring pollination systems, I was also looking out for species from my favourite plant family, Apocynaceae. And I wasn’t disappointed; not only did we see at least 10 species (most of them flowering) but I was able to taste the fruit of one species, Hancornia speciosa, adding another family to my life list of those that I’ve eaten.
Following a quick lunch of apples, local cheese bread and small pies, it was clear that we were running out of water. So we decided to follow a small stream up to a point where it was fast flowing and potable. The community here was low gallery forest, cool and welcoming and with a succession of shallow pools, the humidity allowing the growth of epiphytic sundews, ferns, and a few bromeliads. Tired by the climb, I sat and watched as a Green Kingfisher bobbed and displayed on a branch. Although dirty, hot, and aching, I felt myself very fortunate indeed to be in such a special place. The title of this posting comes from a comment that Andre had made the previous day as we scrumped ripe mangos from a roadside tree; according to his father, when eating mangos, “if your ears aren’t dirty, you’re not doing it correctly”. The same notion applies to field work; if by the end of a day of tropical field work you are not dripping in sweat, filthy, with insect bites and stressed muscles, and desperate for a shower and a cold beer, you’re not doing it right.