15 Jan 2017
After breakfast at the hotel, which included fresh fruit, eggs, rice, and soup, we loaded up into two cars and drove up the winding road from Manizales toward the paramo to a site located just below Nevado del Ruiz National Park. Several other scientists, including Natalia Hoyos of the Universidad del Norte, and Felipe Vallejo, Raul Trejos, and Andres Pardo of the Universidad of Caldas, joined us. We ascended over 1000 meters in about an hour, and the driving experience was just as thrilling as it was in Bogota. Cars and motorcycles would pass other vehicles even on the very windy sections of this road. Even a public bus passed around a blind curve! The double yellow line on the road is clearly just a suggestion, and taken no more seriously than the posted speed limit is in much of the US.
As we ascended, the views of the rainforest and mountains were breathtaking, with the forest vegetation clearly changing as we progressed higher. Somewhere over about 3000 meters the trees disappeared and were replaced with tussock grasses and frailejón (pronounced fry-lay-hon-nez), which are some of the most characteristic plants of the paramo. Frailejón (Espeletia sp.) is in the Asteraceae family, which includes species with composite flowers like sunflowers, daises, and dandelions. However, other than the recognizable composite flower on the plant it is quite unique, with a thick trunk, hairy leaves, and old dead leaves that remain attached to the plant, presumably to protect it from the cold. The roots don’t apparently penetrate very deep in the soil, because it was not uncommon to see individuals toppled over.
Our goal for the day was to visit and collect surface samples from a peatland that was previously cored by Jaime and others. At Lehigh University we are currently analyzing testate amoebae in this core. Testate amoebae are a subgroup of amoeba that produce a decay-resistant and morphologically distinct shell. These organisms have been used estimate past changes in the hydrology of peatlands, because different species are found in dry versus wet habitats. A major goal of this new collaboration will be to assess the potential of using testate amoebae along with other indicators to reconstruct past hydrological and ecological changes within the paramo. However, currently nothing is known about the ecology of testate amoebae in peatlands of the paramo, so we are collecting surface samples to better understand the distribution of testate amoebae today, and we will use this information to interpret the changes that we are document in the peat core.
On our short hike to the peatland we were lucky enough to observe the Nevado del Ruiz volcano venting gas and ash. Although I have seen lava flows in Hawaii, an eruption like this was a first for me. The Nevada del Ruiz has been experiencing small eruptions like this over the past several years. However, the last major eruption was in 1985 and it caused the deadliest mud and debris flows in recorded history, killing over 25,000 people and burying an entire town.
The peatland was spectacular, and we spent a productive day collecting surface samples. Jaime almost didn’t make it out, but with a little effort he managed to avoid becoming the first known bog body of the paramo.
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…
The Pymatuning wetlanders started their time-travel project today. We visited Titus Bog and observed the floating bog mat and discussed the developmental history of this unique ecosystem. The students had read previous paleoecological research on the site, part of the dissertation research of Alex Ireland (see here and here for summaries), and so they were well prepared to examine the wetland and think about its history.
We collected a peat core, recovering over 8 meters of peat and lake sediment (a class record!), and tomorrow we will collectively analyze the macro-botanical remains to reconstruct the vegetation and developmental history at our coring location. We added a few plant species to our must-know list (bringing our total for the course to 55), including sundews (Drosera sp.), leatherleaf (Chamaedaphne calyculata), cranberries (Vaccinium oxycoccos), and bog bean (Menyanthes trifoliata). We also saw two species of orchid in bloom.
After spending some time at the bog, we took another short hike at a nearby location to observe a small population of purple pitcher plants (Sarracenia purpurea), where we were fortunate enough to see a 4-toed salamander (Hemidactylium scutatum)!
The Pymatuning wetlanders began the last week of class this morning by thinking about peatland paleoenvironmental archives. We covered the the range of things that get preserved in these environments, ranging from pollen to bog bodies, and looked at the ways that paleoenvironmental records are developed. This was in preparation for our discussion of wetland development and our trip to Titus Bog tomorrow.
We then shifted gears and discussed wetland delineation procedures, including some of the indicators of wetland hydrology, the features of wetland soils, and the methods used to determine the presence of hydrophytic vegetation. After a bit of “plant math,” Brian Pilarcik of the Crawford County Conservation District visited the class to lead them through an exercise in wetland delineation, and discuss some of the common techniques and general procedures. The students ended the day by working a bit on their wetland plant collections.