After a month of fieldwork in the eastern Andes, I have arrived in Cusco for a brief contact with the wider world and wanted to share a small vignette from this project. The overall aim is to predict carbon fluxes in forests using simple measurements. Dozens of people from several universities are working on the project (led by Yadvinder Malhi at Oxford University), and I wanted to show you a little of what efforts are required to meet our scientific goals.

The study system is a climate gradient spanning the high Andes to the Amazon basin in southeastern Peru. Along this gradient we have multiple one-hectare forest plots, originally set up (after much had work) by William Farfan from Wake Forest University. In each plot all the trees larger than a certain diameter have been identified and tagged, and are ready to be studied. The challenge is working in these sites with a large research team comprised of dozens of people and hundreds of kilograms of scientific instruments.

One issue is getting the equipment to the sites. Here you can see us loading up one of several vehicles – this one with gasoline, electrical generators, plastic tables, tents, gas analyzers, one cook, three tree-climbers, two car batteries, sleeping gear, plastic chairs, and myself. On this trip we filled up several vehicles with equipment and people.

The base of project operations is Cusco, but the current forest plot (Trocha Union) is much more difficult to reach. Cars leave from Cusco, drive five hours east to Acjanaco and the border of Manu National Park. Here you can see part of the road.

The final part of the road is thirteen kilometers through the mud (we got stuck), eventually reaching Tres Cruces (elevation 3660 meters), overlooking the Amazon basin. Here the road ends, and all the equipment has to be hand-carried to the forest plot. The only access is via a footpath that at times becomes a riverbed.

A second issue with working in Trocha Union is the rain – clouds come in from the Amazon basin each day, and bring frequent rains that turn the soils to mud. It is a difficult place for twenty people (and tens of thousands of dollars of delicate equipment) to work, so a wooden platform is being constructed in a small clearing in the forest. Along with the scientific equipment, the raw materials for this platform have to be brought into the forest, all carried by hand. This was our job earlier this week.

Here you can see us descending the mountain, carrying wooden timbers and sacks of concrete. The distance is an additional several kilometers’ walk, and a slippery steep descent of approximately 1000 meters through treeline and the entire elevational range of the Andean cloud forest.

In many places the trail becomes a tunnel – water has carved narrow canyons into the rock, and trees have established roots and new soil above. The walls of the trail are covered in soft and deep layers of moss. Here you can see us navigating our timbers through one tunnel. Several hours’ walking makes heavy wood feel far heavier.

Once we finally arrived (sweaty and exhausted) at the field site, the next challenge was to clear space for the platform. Here you can see a large tree fern that we uprooted and transplanted to a new location. The impact of fieldwork on the land is not small, but we do try to minimize the disturbance.

Once all the construction materials are in place, it will take an additional week to build the final structure that will permit the movement of the full research team and all the equipment carried to Tres Cruces by car. And only then will it be possible to make our first measurements and come closer to our scientific goals.

Climbing the steep muddy path back to treeline, I thought hard about the price of ecological data. Such data are dearly purchased, and projects like these make me appreciate all the more how much sweat is required for each data point that we will analyze in the months to come.