Manaus (the red star in the map below) is in the eastern half of the state of Amazonas (in the light green.) It is at the confluence of the Rio Negro and Rio Solomoes, two of the major branches of the Amazon River.
Starting Sunday morning, we spent three days on the Rio Negro. Our first stop was the "Meeting of the Rivers" Rio Negro and Rio Solomoes.
The composition of the two rivers is quite different. The Rio Negro has a lower pH due to tannins (compounds from plant leaves) that give it a darker color, and it is colder. The Solomoes is a tan color from sediments. You can see below that the difference in temperature means they have different densities so they do not mix. Although it looks like an oil slick, that's just the color of the two different rivers where they meet. This color boundary continues for 12 km down the river. The nice thing about the tannins and pH of the Rio Negro is that mosquitoes and piranhas do not live in it.
Note the distance of the far shore. Here it is about 9 km from shore to shore. The next day at a different location, the width would be 17 km across! If that is not crazy enough, the volume of the river changes from wet to dry seasons such that the river fluctuates vertically 15 m from one part of the year to another. This is based on snowmelt from the Andes, as well as the timing of rainy seasons up stream. This vertical variation is fascinating to Michael, because it means that many species of trees in this region are flooded for much of their life. There are probably zillions of adaptations of these trees to this kind of seasonal flooding that we know nothing about.
We spent a lot of time touring around in the flooded forests (above) in a motorized aluminum launch that had pretty flat clearance. The extent of these forests was mind-boggling.
There were no end of beautiful birds here. At one point, we stopped and tried our hand at fishing. The toothy piranha above was one of a few different species that our guide Elmo (yes, you read that correctly) caught that afternoon.
Back on the boat, we relaxed and watched the sunset (above) before dinner. After we ate, we were back in the launch to head out to look for caimans (alligator-like reptiles of South America.). At one point while going along at a pretty good clip, we hit a log (or maybe it was a rock), the boat lurched, and Elmo tumbled headfirst into the drink. I think we were in one of the piranha-free parts, but we decided to get him back in the boat quickly anyway.
That night we slept in hammocks on the upper level of the barcolleta, which is named for a distinct Italian style of boat that was introduced here in colonial times.
Our guide Elmo was very interesting. He has an elementary school education but was incredibly knowledgeable about the biology of the river and forests, and he spoke English very well. He teaches English to the staff of the boats that he works on, and has even written a book to teach them English. He told us he learned English by reading a lot and by listening to a lot of music over the years. He was able to name several Canadian rock bands including The Guess Who, Rush, and April Wine. He also somehow came up the name of the town of Peterborough, Ontario and asked if I knew the Algonquin language.
We spent that evening camping in the forest on the north shore of the river. Elmo and a local resident taught Michael a few things about cooking in the forest. For one thing, they collected some tree resin and used it to light the fire for cooking chicken. It was a great fire starter for getting the kindling going!
Below: a birding spider. No matter what size you think this spider might be, it is bigger. It is difficult to demonstrate its actual size, which was about five inches across.
The next morning we visited an Indigenous village of the Toucana people. The construction of the buildings was very interesting. Elmo asked a resident to take us out to tell us about how they use the forest plants.
Below: Group photo. Elmo in the yellow shirt. Note Michael's green palm-frond hat, courtesy of our Toucana host.
After this visit ended, we had lunch at a beautiful beach, then motored back to Manaus. But our time with Elmo was not finished! Karen's father had told us we should see the Opera House in Manuas, so Elmo got in a cab with us at the Manaus dock and shuttled us over there. He then gave us an impromptu tour of the place, complete with pointing out construction details and some cool optical illusions in some of the ceiling paintings. We spent a day at the INPA (the National Institute of Amazonian research) where Karen gave a talk.
The next morning we flew to Belem, not far from where the Amazon empties into the Atlantic (purple star on the map above). Here the river is about 240 km across! Michael was continuously thinking about how much terrestrial carbon captured by the Amazon rainforest would be transferred to the river then transported to the ocean. Karen and Michael both gave research talks at different research institutions in the city. On Friday we took a tour of some secondary forest sites to the east with Karen's colleague Ima Vieira, pictured below.
The highlight (besides the acai and manioc at lunch) was an unscheduled tour of a palm oil processing plant. Although expansion of palm oil plantations is responsible for a lot of deforestation in tropical regions (read your food labels!), this company - a relatively smaller operation - is trying to do as much as possible in an environmentally friendly manner. We were quite surprised at how much time the plant manager spent talking with us and showing us around.
On Saturday, we spent the day touring around town, including the Museu de Goeldi and the Bosque Rodrigues Alves. The latter is a 16 hectare (~40 acre) section of intact forest in the middle of Belem that was set aside as a preserve when the city was first colonize by Europeans. Many of the trees were bigger than the ones we had seen in intact forest.
On Sunday 13 September,we left the equator and flew to Piracicaba, which is in the region that was once Atlantic forest (in the south, shown in blue below, and the yellow star on the map above) but which is now largely agricultural land (sugar cane, especially.)
Piracicaba is abut two hours from São Paulo. It is home of one of the campuses of the University of São Paulo. Recently, Karen began collaborating with Pedro Brancalion and his graduate students on several interesting restoration ecology projects. Below is a 5-yr old 300 ha (~650 acres) forest restoration site; they are doing whole watershed experiments of restored, reference and agricultural watersheds.
For this trip, Michael was invited to advise some of Pedro's students on their PhD research projects.
One of these projects deals with how they can best encourage establishment, growth and reproduction of tropical epiphytes in restored forests. Epiphytes are plants that live on the branches of tropical trees in a form of high-rise living (they are not parasites). Due to the sunny, temporally hot and dry nature of these tree-branch sites, some cacti have evolved to live in this lifestyle. So, naturally, when Michael was invited to visit this restoration project with tropical cacti, he jumped at the chance.
Above: a tropical, epiphytic cactus of the genus Epiphyllum. Tis one is growing on a rather low portion of a tree trunk. The warm, often dry upper reaches of branches in tropical trees were a great place for cacti to inhabit over evolutionary time.
Below: See any cacti? The plant with the yellow fruits is the most primitive of the extant ("still-living") cacti. As you can see, it does not look like a water-storing desert cactus, but more like a scraggly rose bush. It is probably very similar to the form that gave rise in geologic times to the succulent life forms that we recognize today. Michael did not notice this species until Ph.D. student Ricardo Cesar offered him some to taste. Needless to say, Michael was very, very excited to see this primitive cactus species in its natural habitat for the first time.
Below: We spare no expense to stay fashionable! The white Tyvec-like suits are to keep ticks out of our clothes. The ticks can carry a pretty nasty disease. The research at this site aims to better understand how climbers and lianas (what many of us would call jungle vines) affect the growth of forests. L - R: Michael, Ricardo, Felipe, and Karen.
Below: Part of the work that Michael was interested is being done by one of Pedro's graduate students Frederico Domene, who is trying to determine the best way to get epiphytes to recover in restored forests. In the photo below you can see an epiphytic orchid, and how the roots are stuck to the tree.
Frederico is experimenting with ways to get epiphyte seeds to germinate on the tree. In the photo below, he has embedded cactus seeds in a paper pulp mixture that is stapled to the tree trunk. You can see several baby epiphytic cactus plants that have emerged although they look nothing like desert cacti at this stage.
Karen and Michael spent the week meeting with students and colleagues, visiting research sites, and giving talks. Karen and Pedro gave talks to a group of Chinese and Indonesian land managers working on reforestation. They were visiting through an exchange organized by the IUCN (International Union of the Conservation of Nature) to learn from reforestation work being done by the Brazilians.
Our final Saturday we went with Pedro's family to a nearby waterfall. Michael flew back to the US to return in time for graduate student orientation, since he's the Faculty Chair of our graduate program. Karen stayed for a couple more days to participate in a symposium on tropical forest restoration at the Brazilian Ecology Congress before returning.
We appreciated the help of one of Karen's graduate students and her parents who each stayed for a week at our house and helped oversee the various activities of Travis and Nico, a 17-yr old Chilean exchange student who is staying at our house for the fall.
We got back just in time for the start of classes at UCSC and have a busy fall ahead of us.
Michael and Karen
