20 Jan 2017
Today, we were accompanied by Felipe Velasco again, although this time instead of driving south toward Lake Tota we headed northeast toward the town of Mongua. We are extremely grateful for the time that Felipe has devoted to our efforts, as we would have had a difficult time finding these sites without him and it was reassuring to have a local person along. Our goal today was to explore and hopefully collect a core from Laguna Negra, a lake located in a different sort of paramo ecosystem. The drive was quite different than previous days, because we were able to see a much more industrial area of Boyaca. Between the cement factories and the steel mill, the pollution levels were quite high; in fact, much of the drive to Mongua smelled of a fragrant mixture of burning coal and diesel, and when we ascended the mountain above Mongua we observed a thick layer of smog in the valley. However, it was fascinating to see a fully functional steel mill, as gave me an appreciation of what Bethlehem Steel in Pennsylvania must have been like when it was operational. We observed many small family-owned coal mines along the road near Mongua, as this is the primary economic activity in this region.
Laguna Negra and the surrounding landscape was spectacular, and pictures really can’t convey the natural beauty of this place. While Jason and Jaime took measurements of the depth profile of the lake, I had the opportunity to hike around the lake margin. Unlike other lakes that we have visited, the lake margin was not peatland. Hypericum (St. John’s Wort) was common along the lake edge, along with a number of Carex species, and bright red Azolla grew in the littoral zone along with submerged aquatic plants like Myriophyllum. Inflow into the lake comes in the form of a spectacular waterfall, with abundant mosses and ferns growing adjacent to the waterfall in the perpetually humid environment.
The lake was about 9 meters deep with at least 3 meters of sediment, so we inflated a second boat, set our anchors, and commenced sediment coring. Mark Brenner and Felipe Velasco observed from shore, taking pictures of the coring process. We obtained several meters of mud, and once again we carefully kept the upper drive containing the mud-water interface upright on the trip back to Finca SanPedro.
On our way home we stopped in Mongua for some delicious empanadas and then went further down the road to Tópaga to take a look at the church on the main square. The Tópaga church is over 400 years old, and the inside is ornately decorated in gold. Colombia has abundant gold; in fact the yellow in the Colombian flag symbolizes the tremendous gold resources. This church in Tópaga is also probably one of the few churches that not only has artwork incorporating Jesus, the disciples, and other typical biblical representations, but also the devil. Yes, Lucifer himself is on a beam in the ceiling near the front of the church, directly center.
Our fieldwork is now complete. Tomorrow we will ship samples and cores from Sogamoso and then drive down to Bogota to pick up samples from our work in Manizales and prepare to depart on Sunday. This trip has been an amazing experience, and I feel extremely lucky to have had the opportunity to explore this fascinating country and see its amazing natural beauty. I am excited about this new collaboration, and the potential to develop long-term perspectives on water availability and ecology of the critically important paramo regions.
I sincerely thank Jaime Escobar for making this all happen. And I especially thank him for the doing all the driving!
18 January 2017
We traveled back up to Aquitania Lake today, managing to navigate back to it without the help of Felipe. We spent the day successfully collecting the full sediment record from the lake, over 7 meters of mud. While Mark, Jason, and Jaime did the coring, I collected plenty of surface samples from the surrounding peatland. Part way through the coring, we had a Colombian visitor who came to the lake on his horse to ask us what we were up to. He seemed amused by our activities. Not wanting to strap all the PVC and wood back onto the car, we offered it to him. He was thrilled to take it, and we gave him rope so that he could strap it all together and then tie it to his horse. I was really impressed with his rope tying ability, and although the horse did not seem particularly happy about the situation, it carried all the pipe and wood away.
Anyone know what kind of bird is in the video below? A sandpiper of some sort?
A collage of some of the interesting plants observed around the margin of the lake:
After a quick dinner in Sogamoso, we returned to Finca SanPedro where Mark Brenner gave a public talk highlighting the paleoclimate work that he has conducted with Jaime, Jason, and others in Latin America. Impressively, Mark gave the talk in both English and Spanish! I’m really going to have to learn some Spanish before my next trip to Colombia.
17 Jan 2017
It was dark when we arrived last night, so we didn’t have a chance to really see the beautiful Finca SanPedro Hostel. The house has a number of nice rooms for guests and the grounds were beautifully planted and maintained. Chickens, peacocks, vegetable gardens, a yoga studio, and four friendly dogs all added to the charm.
Felipe Velasco, director of the Foundation Montecito, graciously agreed to take us to a small lake in the paramo above Lake Tota. Our goal was to assess the potential of the lake for sediment coring, and potentially collect more surface samples from the associated wetlands. However, before embarking on our trip we needed to purchase a few more supplies from a local hardware store in Sogamoso, including some PVC pipe and some wooden boards to secure our inflatable boats together for a coring platform. The folks at the hardware store were fantastic, providing supplies and assistance as we mounted the pipe and boards on top of our car. Furthermore, about half way through the process, they provided us with free coffee and delicious empanadas. And they gave us free hats and windbreakers with their logo! As Jason commented, “it is strange that the best empanadas I’ve had were from a hardware store.”
The drive to the paramo took about an hour and half, but along the way we got see Lake Tota and the town of Aquitania. Lake Tota is the largest natural lake in Colombia and lies at an elevation of about 10,000 feet. As we crossed into the lake’s watershed, we were immediately hit by the smell of onions. Most of the area around the lake and the surrounding hillslope is covered in onions; in fact, according to Felipe, the area produces more than 90% of the onions consumed in Colombia. The lake is also used for fish aquaculture, and along with fertilizer runoff from the onion farms, environmental degradation of the lake is of considerable concern. Apparently for every ton of chicken poop that comes in by truck, a ton of onions goes out.
Furthermore, the introduction of rainbow trout into Lake Tota likely led to considerable changes in food-web structure, and the extinction of a species of catfish, known as greasefish (Rhizosomichthys totae) that was endemic to the lake. An all to common story: invasive species + human impacts like eutrophication = extinction.
The town of Aquitania borders the lake, and we had to weave our way through it to reach a steep dirt road that led up into the paramo. A small town with obvious economic hardship, the central square of Aquitania is dominated by the church like in many of the small Colombian towns that we have seen. On top of the church is a large statue of Jesus standing on a boat, although because the boat is small it looks like Jesus is surfing. The road up into the paramo was in bad shape so we went slow, but we eventually arrived at the small lake that we hoped to reach.
Lake Aquitania, as we called it, was beautiful. Surrounded by paramo, including lots of frailejón (Espeletia sp.), the lake is bordered by extensive wetland in places. Several nearby depressions also contain wetlands. After inflating a boat, Jason and Jaime used a sonar depth finder to quickly determine the depth of the lake. Although the lake is relatively shallow throughout (~40 cm), there was over 7 meters of sediment! Mark, Jaime, and Jason spent a few hours collecting a surface core to carefully capture the mud-water interface, and I spent the time collecting surface samples from the adjacent wetlands. We then returned back to Sogamoso while Mark held the core upright, partially sticking out of the car window, and upon returning we extruded the core centimeter by centimeter into bags. Tomorrow we will return to collect the full sediment core, as well as additional surface samples from wetlands surrounding the lake.
12 Jan 2017
As I write this, I am flying above the Florida Everglades at night. The contrast between the Miami-Fort Lauderdale region and the adjacent Florida Everglades is quite striking – lines and lines of bright lights to the east and nothing but darkness to the west. Although a century of degradation has led to the largest restoration effort ever attempted, you still have to admire the resistance of this large wetland to human pressure. Shortly, we will continue southward over the Atlantic on our way to South America…
I am on my way to Bogota, Colombia to initiate and develop a new collaboration focused on better understanding the long-term hydrological and ecological history of high-elevation Andean ecosystems. My primary collaborator is Jaime Escobar of the Universidad del Norte in Barranquilla. Our focus is on the paramo, an extremely biodiverse ecosystem (one of 25 global biodiversity hotspots) located above the tree line and below the permanent snowline in the Andes of tropical South America and the highlands of Costa Rica. Up to 60% of its plant species are endemic, which means they are found nowhere else in the world. Together with the surrounding Andean forest the region is home to 50% of the plant diversity found in mountain ecosystems. In addition to its high conservation value, the paramo and its watersheds store and supply critical water resources to major Andean rivers and cities. High-altitude tropical ecosystems such as the paramo are expected to experience very high rates of temperature change in the coming decades, with stronger and longer dry seasons, yet little is known about the how the hydrology and ecology of these ecosystems may respond to these anticipated changes.
This new collaboration will focus on understanding the ecological and hydrological sensitivity of paramo ecosystems and their watersheds through investigating the long-term environmental history of the region. Lakes and peatlands are scattered across the paramo, and they preserve records of past ecological and hydrological history in their sediments and deposits. The long-term perspectives provided by these paleoenvironmental reconstructions will potentially help assess climate model projections, anticipate climate-induced ecological and hydrological impacts, and assist in risk assessment and adaptive management efforts. For the next ten days we will explore the paramo, collecting ecological and paleoecological samples and discussing ideas to further develop our research and educational collaboration. I’ll be posting updates and pictures as our adventure proceeds…
Today the Pymatuning wetlands spent the entire day in the lab. Our first day without any fieldwork since the course began. However, we made up for it by doing a bit of time travel…
We examined the core we collected from Titus Bog yesterday. We subsampled the sediment and peat, sieved the samples to isolate plant macrofossils (i.e., seeds, leaves, needles, etc.), and identified and tallied the microfossils to determine how the vegetation of the wetland has changed over the past 8000 or 9000 years. The students determined that the site was occupied by a shallow lake prior to the establishment of the modern peatland, with submerged and floating leaved aquatic plants like Najas (water nymph), Nuphar (spatterdock), and Nymphaea (water lily) growing in the deeper portions of the littoral zone. Emergents like Cladium (sawgrass), Rhynchospora (beaked sedge), and other sedges likely occupied the lake margin along with small amounts of Sphagnum moss. The area abruptly became a floating peatland about 350 years ago, when Sphagnum became dominant. The upland vegetation around the site contained Tsuga canadensis (hemlock), Pinus strobus (white pine), and Betula alleghaniensis (yellow birch) for much of the record. Most of the species in the paleoecological record have been observed at the wetlands we have visited during the past two weeks of the course; in fact, quite a few are the “must-know” list.
Our age estimates for the record are tentative and come from a broader study of peatland development at the site by Ireland and Booth (2011). We will discuss our paleoecological record in class tomorrow, along with the Ireland and Booth study, emphasizing the implications for understanding long-term wetland development and hydroseral succession.
After spending considerable time in marshes and swamps over the past two weeks, the Pymatuning wetlanders spent much of today in a bog (well, as they all know it is technically a poor fen). We drove to Titus Bog, located about an hour northeast of the Pymatuning Laboratory of Ecology, and Tim Lyons of the Botanical Society of Western Pennsylvania accompanied us into the bog. The moat swamp surrounding the bog was fun to cross, as the water levels were quite high from the recent rain, and several students were delighted to have the opportunity to get a little water into their waders again.
Peatland ecosystems are quite unique. They leave a detailed record of their own development through time, recording past changes in plant communities, hydrology, and other environmental conditions within the stratigraphy of their waterlogged peat. To examine the paleoecological history of Titus Bog, we collected a peat core capturing most of the upper 9 meters. The students did a great job collecting the core, and tomorrow we will carefully examine the peat and sediments under the microscope to reconstruct how the present-day wetland came to be. We will use the record of past vegetation change as a springboard for a broader discussion of wetland development.
After collecting the peat core, we hiked around the surface of the floating peat mat, where we saw many typical bog plant species including several orchids, cranberries (Vaccinium oxycoccus), leatherleaf (Chamaedaphne calyculata), podgrass (Scheuchzeria palustris), bog bean (Menyanthes trifoliata), and of course lots of Sphagnum moss. We were lucky enough to be on the bog during the brief window that the bog copper (Lycaena epixanthe) was active and mating. These small butterflies occur exclusively in these acidic peatland habitats, where cranberries serve as the host plant.
After we finished our exploration of Titus Bog, we went on a short hike to a very small peatland that has a nice population of purple pitcher plants (Sarracenia purpurea). The students have now seen all of their “must-know” plant species in the field.
A nice summary of our recent field work adventure in Maine is now up at the PalEON blog:
It includes a fun video, which is embedded below as well…
One afternoon. Nine students. Approximately 8500 years of history.
The Pymatuning wetlanders spent the morning learning about wetland development and the roles that wetlands play in the broader earth system. In the afternoon, we examined the sediment core that we collected from Titus Bog yesterday – all 8.5 meters of it! The students sieved samples from along the core, and identified and tallied plant macrofossils (e.g., leaves, seeds). By applying age-depth information from previous work on the bog (Ireland et al., 2011), we estimated the age of the samples along the length of the core.
The diagram below shows our paleoecological results, and clearly shows that the site started as a deep kettle lake (the lower samples lacked macrofossils) some 8500-10,000 years ago, and was occupied by a shallow lake with abundant submerged aquatics like nodding waternymph (Najas flexilis) and pondweed (Potamogeton sp.) throughout much of the mid Holocene. In the later Holocene the area was shallower, supporting a mix of submerged aquatic plants like nodding waternymph, along with floating leaved plants like white water lilies (Nymphaea odorata). About 800-900 years ago a floating peatland established at the site, with various sedges, Sphagnum, cranberries (Vaccinium oxycoccos), and leatherleaf shrubs (Chamaedaphne calculata) characterizing the surface vegetation. We will discuss the record in the context of peatland developmental models tomorrow…