Truck swap and the cloud forest

Later that evening we continued processing samples and preparing containers for the next day of sampling. Procedures for dealing with samples mostly consisted of filtering, but a lot of care was required not to cross-contaminate samples. Samples were dried if possible and frozen if not. Frozen samples were difficult to transport back to the US, but it could be done with a cooler and the maximum of 4 pounds of dry ice that was allowed to be checked in luggage. It makes sense not to allow more, the dry ice can release a large amount of carbon dioxide, and if this occurs in a confined area could possibly cause suffocation.

The next day the four early departures left for Panama City and the rest of us went to the field. After a typical day at Rio Maria, we finished our sampling and drove back. Just as we got to the hotel, Amanda’s phone began to ring. When she dug it out, we found out that Matt had taken the wrong truck to Panama City, and the people at the Smithsonian Research Institute were insisting that the correct truck be returned. This was frustrating because the trucks were the same make and the same age. They insisted on the one we had so Amanda and Alex had to drive to Panama City to exchange them. They drove down and back (4 hours) while Bob and I worked on the data we had collected. They finally retuned at 1:30 am. At least they got a good dinner at our favorite Peruvian seafood restaurant in the city while they were there.

The next morning as we traveled to the field site, I started to feel the pounding of the road. It was not as bad as during our previous trip because about half of the road had been paved since then. Still, the two steepest hills were rough clay roads with ruts, and we all mentioned how we were beginning to feel it. It is amazing that there are truck and bus drivers that take the lower half of this route all day every day.

The day was a short sampling and experiment day. We started experiments and then waited three hours to read the results. Alex had broken the edge off a termite nest attached to a tree and we watched them repair the damage as Alex narrated with infectious and perhaps slightly deranged entomological zeal.
When their nest is damaged, termite soldiers swarm out to protect it. This species of termite had soldiers with nozzle heads. The heads release a sticky excretion that clogs up any predator. After the initial disruption, the colony settled down and the workers started moving to the edge of the damage and placing bits of masticated wood or soil and then turning around and cementing them in with secretions from their abdomens. Within a day the edge of the nest was sealed off.

Termite nests are most commonly preyed upon by raiding ants. The first defense is a strong wall on the nest, the second the soldiers gumming up the ants with their adhesive. The social insects in the jungle are either constantly at war with others, or under the threat of pirate-like attackers that literally are out to eat and or enslave their prey.

While termites are a nuisance to homeowners because they eat wood, they are a vital part of tropical ecology. They break down dead wood and release locked up nutrients much more rapidly than would occur otherwise. Termites have specialized microbial communities in their guts that break down cellulose and make the carbon available to the termite. Fallen wood does not last very long on a jungle forest floor in large part because of termites and the fact that their activities increase rates of bacterial and fungal breakdown of wood in this warm moist habitat.

Interestingly, termites are one of the larger sources of methane in our atmosphere. The bacteria in their gut release the gas into the atmosphere. This is an important greenhouse gas that contributes to global warming. The first estimates of release rates were too high because they did not account for the presence of other bacteria in the walls of the mound that eat much of the released methane before it escapes into the atmosphere.

On our trip back from Rio Maria to El Valle that afternoon we stopped at the highest point in the road and hiked up a trail to an overlook. Hiking the trail was very strenuous; it was only a half mile, but it was very steep. We had all our most valuable equipment (computers and cameras) with us because of the lack of security at the hotel, and the inability to properly secure items in the trucks. The hike was made a bit more difficult with the packs we needed to carry. Impressively, the trail had many concrete steps. The concrete had to be packed in on the narrow trail. The last bit of the trail to the top was wooden stairs, and they were steep and slippery.

At the top of the trail was a true cloud forest with what appeared to be primary growth trees. Clouds poured over the high mountains and the ridge we were on. A continuous mist permeated the air. The forest was dripping wet and mosses grew on every surface that did not have higher plants on it. The trees were not extraordinarily tall, presumably because of the fierce winds that pummeled the ridge during the many tropical storms in the area. Each tree was covered with hundreds of species of epiphytic plants. Their sides were enveloped with vines, and their branches supported numerous bromeliads and orchids.

The flowers were sturdy and apparently pollinated by bees or hummingbirds. In colder areas, smaller pollinating insects cannot move well enough to fly. Bees can thermoregulate to some degree by moving their wings to increase their body temperature. Their relatively large bodies do not lose this heat as quickly as those of their smaller relatives. Hummingbirds, of course, are warm blooded. To some extent the large bees, and certainly the hummingbirds can fly up the steep hills from the warmer lower elevations in a matter of minutes.

The view from the top was spectacular, as clouds moved rapidly across the mountains and others opened temporarily nearby allowing us glimpses of pieces all around us. Immediately across the nearest valley, the large pinnacle of rock (the remains of the core of an old volcano) had a lake right at its base. Called a Marr lake, it had formed when a steam explosion underground made a perfectly round hole. Behind us, El Valle nestled in its 6 mile wide crater, was formed in a similar (albeit substantially more catastrophic and impressive) fashion. Thirty miles away, the ocean was visible and the steep gradient of moisture between it and us was apparent.

The cloud forest we were in gave way to a less stunted forest first, then eventually to a dry seasonal forest. Since this was the “dry” season, many trees on the lower slopes of the mountain had dropped their leaves and were now brown. They would grow new ones once the wet season started again. But for now, the transition from green, to brown, to the blue ocean was brilliant.

We could see the development encroaching on the entire watershed of El Valle. Tropical forest was being bulldozed to make half million dollar homes. The cul-de-sacs were evident from miles away. These cul-de-sacs looked just like those in any new subdivision in suburban US.