Inside The New York Botanical Garden

In the Field: Garden Scientist Reports from Brazil

Posted in People, Science on May 25 2010, by Plant Talk

Wayt Thomas Collaborating on Research in Tropical Forests

Wayt Thomas, Ph.D., is the Elizabeth G. Britton Curator of Botany in the Institute of Systematic Botany.

I’ve been studying the flora of the Atlantic coastal forest in northeastern Brazil for 20 years. These forests are one of the world’s “biodiversity hotspots” because of the heavy deforestation, high species diversity, and large number of species that occur nowhere else. Much of my work has been focused on the forests of southern Bahia, near Ilhéus, but I recently was awarded a grant from the National Science Foundation to study the forests farther to the northeast.

As you read this, I am again in Brazil, having left New York on May 9. The purpose of my trip is several-fold: to check up on the field work of my student, Daniel Piotto, near Ilhéus, Bahia; to meet with professors at the State University of Santa Cruz in Ilhéus; to travel inland to Jequié, Bahia, to meet with a collaborator at the State University of Southern Bahia; to visit the Guaribas Biological Reserve in Paraíba; and to organize the newly funded project with my Brazilian collaborators, an essential element in field research.

I will file reports such as this one and photos from Brazil as access to the Internet on my end allows.

9 May: I’ve remembered to pack everything from machete and passport to silica gel and digital camera. The vagaries of modern air travel propel me to another continent in a day. The sun rises early at 35,000 feet over eastern Brazil, and a few hours later, we land in Salvador, Bahia. I join up with my principal collaborator, Dr. Regina Barbosa, for the drive south to Ilhéus to meet with my student, Daniel Piotto, who is finishing up two years of field research for his Ph.D. from the Yale School of Forestry. Daniel has been studying how quickly a cleared area in the forests north of Ilhéus returns to mature forest. He also decided to revisit an old research site of mine in a reserve called the Fazenda Catitu. In 1992 my colleagues and I measured the tree diversity of one hectare (2.5 acres) of forest there. Daniel re-measured the plot to see what had changed in 18 years. I’m very interested to see what he has found.

10 May: We set out in the morning to the Fazenda Catitu. Eighteen years earlier, we had measured all the trees over 5 cm (2 inches) diameter in an area of 500 meters by 20 meters (540 by 21.7 yards). We found an extremely high level of diversity—over 400 species of trees. We also measured the height and diameter of each tree so that we could estimate the volume of wood in the forest. Daniel was finding out which trees had died, measuring and identifying new ones that had come in, and re-measuring the size (height and diameter) of every tree. Although he hasn’t analyzed his data, it is clear that there is a turnover in the trees—big, old ones have fallen, opening up large light gaps where seedlings and small trees have quickly grown toward the light.

11 May: Back to Fazenda Catitu. More on the forest: It is a classic tropical forest (rain forest) with giant emergent trees reaching over 120 feet tall, a canopy of mature trees of 80–90 feet, subcanopy trees (both younger trees growing toward the canopy and species of trees that never grow that tall but which are adapted to live in the shaded subcanopy), lianas, epiphytes, and herbs and shrubs of the forest floor. Since we started studying this forest, over a dozen species new to science have been found here.

Today we went in search of a new species of Swartzia, a genus of topical trees in the Legume family. Our earlier collections were identified as Swartzia reticulata, a species known from the Amazon Basin. When the Brazilian Swartzia specialist put his head together with NYBG’s own specialist, it became clear that the tree found in Bahia was not the same—similar, but consistently distinct. We found the tree, but, unfortunately, not in flower. That gives us an excuse to come back later!

We helped Daniel press plants from the forest transect (photo above), and took a careful look at the rates of individual tree growth over 18 years. I found it fascinating that not all trees, and not even all trees of the same species, grew at similar rates. Some individuals only grew one millimeter in diameter in 18 years! Others grew enough to cover up the tag we attached years ago: the 2.5-inch aluminum label as well as the exposed 3 inches of the nail.

As is common in the early afternoon, it began to rain; we covered up our cameras and kept on going. The life of the field biologist doesn’t stop unless it is a washout. We did have at least on interruption—when we hammered a new label into a tree with a wasp’s nest about 4 feet over our heads! Biologists can run! We did come back and finished up, Daniel nursing a couple of nice stings.

After we returned to Serra Grande, we met up with Rui Rocha, one of the region’s most effective conservationists. He is mobilizing forces to counter a proposal to build a deep-sea port in Ponto da Tulha, only 12 miles south of Serra Grande, in the midst of this diverse and sensitive region that lives off of environmentally friendly tourism. I, of course, offer any help I can give.

12 May: At breakfast, I met with Roberto Barreto who works for the Educational TV channel of the state of Bahia. He wanted to film me talking about the history of my work in the region and its impact on conservation. He filmed and I talked for about 45 minutes. I wonder how it will turn out.

Then, we went with Daniel to see his own research plots. For his Ph.D., he is studying how fast the forest regenerates to the full complement of mature forest species. His results are quite interesting and show that in some cases, forests can regenerate more quickly than previously thought. We walked through mature forest as well as young forests in varying stages of regeneration.

One of the most common questions I get about rain forests is, “Do you see many snakes.” Actually, no, I don’t. I don’t look for them, and they usually stay clear. One exception was today, it was cloudy and threatening to rain, and often creatures that stay hidden during the day will come out under those conditions. We were brushing back leaf litter looking for fruit and uncovered a beautiful little salmon-colored snake, which I haven’t been able to identify yet. It scooted off and hid itself in the leaf litter before I could take its photo.

We came back, cleaned up, and drove into Ilhéus, 25 miles to the south, and on to the campus of the State University of Santa Cruz, where we met with two molecular biologists interested in collaborating on a project to study the genetic diversity of Brazilwood (also known as Pernambuco). More on that later.

Comments

leonardo patrial said:

Hi, my name is Leonardo, i am an ornithologist from Bahia (Brazil). living now in Itacaré. I saw your report about the Fazenda Catitu, and I was thinking if you could me send the contacts so I can research a endemic Berryeater in the farm too. I tried a couplke times to get in there but without permission I avoided for an year maybe.
I really thanks your help
Regards
Leo Patrial