It's a leaf, no it's a stick, no it's a bug...

Lots of funny and strange critters in the forest. I have had a couple of days of starts and stops. Thursday I spent most of the morning searching shops in town for a generator only to find that there are none to be had this trip for some strange reason. So, Thursday afternoon I was troubleshooting the batteries for the equipment. While the instrument has batteries (phew), they don't last very long (~1 hr), so I have to time my sampling to catch the right part of the day. I did that yesterday morning only to find I was having additional problems, so yet another troubleshooting session at midday. Luckily by afternoon everything was working fine, so with a freshly charged instrument I got a good hour of field sampling in. I have another day of sampling today, and then back to Campinas to start some data analysis.

Back to Rio Branco

I returned to Rio Branco yesterday. Given that the fire was delayed during our last visit, we were only able to gather one day of post-burn data on soil mercury emissions. We realized it would be great to get additional post-burn data and do some time-course comparisons - i.e. how do post burn emissions change with time. So I will be gathering over the next few days to compare soil mercury emissions at this point - two-months after the burn - to those I measured the day after the fire.

I have paired up with a few other researchers who have returned to the site to measure the amount of biomass remaining on the plot. Tree biomass was measured pre-burn, and with the measurements they are taking this week of post-burn biomass, they can calculate the amount of biomass that was actually burned, and use this when calculating at carbon and other pollutant releases from the fire. The only catch is that today is Thanksgiving in the U.S., but obviously not in Brazil - so I will be measuring mercury rather than eating turkey :-)

Public Outreach

We had some mention in the press recently. Globo published a short article about the broader project and produced a short video of the burn.

News Article - Controlled Burn in the Amazon for Scientific Research

Data, data everywhere...

I am just starting to sort through the data we collected in Rio Branco. 24 pages of notes like this listing conditions during field monitoring of soil mercury emissions at various sites, during different times of day, and before/after the fire (my field notebook still smells like smoke). Over the next few weeks I hope to match the conditions recorded in the notebook with the results recorded by our instrument to get a sense of soil mercury emissions pre- vs. post-burn. The one tricky thing is the instrument we were using. The loaner we managed to scrounge up at the last minute had its problems. Unfortunately the baseline on the instrument continued to drift downward over the course of each day.
The peaks and valleys in this data represent mercury concentrations going into and out of our chamber, which allows me to calculate the emissions of mercury from the soil surface. However, the slow downward trend in the data, emphasized by the blackline, is due to instrument drift. I should be able to subtract that out, but I will have to get one of my statistics friends involved just to be safe.

Leaving Rio Branco

We left Rio Branco on Saturday. It was a great trip and yet it was good to come home. I hadn't seen my family for two weeks, and I got a big warm welcome from my kids. The work in Rio Branco was hard, and everyone was a bit exhausted by the end. It took several days to wash off the salt, dirt, and sunscreen. But I will miss the city.

Even more now that I have had a chance to get to know the area, it feels that we were on the edge of civilization, or at least on the edge of developed civilization as we have come to expect. Staying in the city center was a bit disorienting as it is highly developed and not dissimilar from a small-sized American city - lots of restaurants, small shops, bars, civic buildings, etc. Yet just outside of the center the area transitions quickly.

I went for an early morning run on my last day into some of the outskirts of the neighborhood, just 5 or so minutes from our hotel. At one point I found myself along a dirt path running on a hillside through a cluster of small houses. Each was the size of a large living room in the US, with only the bare necessities - a bit of electricity and minimal plumbing. I received a few long stares as I ran through the area. At first, I was a little concerned, but I eventually realized that the stares were more because I was a peculiar novelty in the area.

Most people were beginning their chores as I ran by. Men tinkering with bicycles or other things that needed to be fixed, children playing, and women sweeping in the hours before the hot midday sun. Brazilians have an interesting fascination with cleanliness. Interesting because the climate alternates between extremely dry periods that cause dirt to blow in large clouds, and torrential rains that cause rivers of mud to cascade by. Yet they were out sweeping, and not only their houses, but also the dirt paths in front of their houses to remove litter or leaves that had blown in during the night. There was a curious tranquility to the area that is hard to describe.

After the Burn

While some of the researchers' work was completed yesterday, many of us spent an additional day working at the site doing post-burn sampling. I and my colleague Anne hope to understand the impact of deforestation on the release of mercury to the atmosphere, so it was critical to sample before, during, and especially after the burn to understand how the balance of mercury in the ecosystem has changed. It is a bit early to tell, but our data suggests that deforestation is a big source of mercury to the atmosphere.

The post-burn site is really interesting, most areas are heavily burned with only ash remaining on the ground, but some are largely untouched. What surprised me yesterday was how slowly the fire progressed through the site - it took over an hour to work through the small area we had cleared. What is also surprising is how much biomass remains. Dried leaves, brush, and small branches were by and large completely burned, but most of the large tree trunks remain on the site - though most are scorched. While the fire is now out, some areas of the site are still smoldering as you can see in the background above, and these areas are still very hot. Luckily the area I am working in burned quickly and relatively completely yesterday, so it had cooled off by today - it was only a couple of degrees hotter than the 100 or so that the sun supplied.

Ignition

After several anxious days the weather conditions turned out near perfect today. Skies were clear with only a slight breeze blowing away from the staging area toward the heart of our plot. There were lots of last minute preparations. Several researchers hitched a ride on a military helicopter to measure the spread and intensity of the fire. Several gathered around a station that was pulling smoke and gases from the tower at the center of the fire. Several individuals worked to measure the rate of progression of the fire through the understory. My colleague Anne and I sampled particulate matter to later analyze for mercury and we sampled airborne mercury levels for the first part of the fire. It was really incredible to see after so much work and effort went into this project.