Category Archives: Research
Last September, two invasive aquatic plants, water lettuce (Pistia stratiotes) and water hyacinth (Eichhornia crassipes), were discovered in the Lehigh Canal in Bethlehem PA. Both species are floating plants, like duckweeds but much larger, and they often grow in dense mats in tropical and subtropical regions. Although this was the first confirmed occurrence in natural habitat within Pennsylvania, both species are sensitive to freezing temperatures so they have not not been regarded as major threats in the Northeast. A description of the discovery of these populations and some background on the species, including a discussion of recent work suggesting that the overwintering potential may be greater than previously thought, can be found in my post from last year (New invaders in the Lehigh Valley? Or Just Summer Visitors?).
The discovery last year prompted several questions. In particular, are these populations really persisting from year-to-year and therefore surviving freezing temperatures? I suspected that they were introduced last summer from someone’s pond and that they would not survive the winter. However, the winter was mild and the recent discovery of some overwintering populations in the lower Great Lakes gave me pause. I road my bike along the canal towpath last week to have a look.
I was wrong. Both species have overwintered. A harbinger of things to come? Below are some pictures, and I’ll update this post with more later in the summer.
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.
16 January 2017
Today was a very long day of travel. We were supposed to fly from Manizales to Bogota, pick up the lake coring equipment that we left there, and then drive about 3.5 hours northeast to the city of Sogamoso. However, after spending a couple hours waiting for our plane to arrive, our flight was cancelled. The weather didn’t seem particularly bad, but the Manizales airport closed. Apparently it closes about 50% of the time. Perhaps it was ash from the volcano?
The airline provided a bus to transport passengers to Pereira, the nearest place with an airport, and we were rebooked on a flight to Bogota from there. Having seen the public bus passing cars on the winding road up the mountains from Manizales a couple days ago, I was a bit nervous about the bus trip. However, the ride was uneventful and we arrived in Pereira in about an hour and a half. We observed endless coffee fields on the drive, and given that Pereira is only at about 1000 meters in elevation, the temperature was considerably warmer when we arrived at the airport.
We arrived in Bogota about 5 hours later than we had scheduled. Unfortunately, the truck that we had reserved at the Bogota airport was not available because it was wrecked in a crash by the previous renter. I can’t say that I was surprised. So we rented an SUV instead, a Toyota Fortuner which I had never heard of, and once we loaded the coring equipment there was very little room left for passengers. However, we all squeezed in and headed out into the rush hour traffic of Bogota. Lots of public diesel buses made for pretty bad pollution. However, we made it to Sogamoso in reasonable time, stopping along the way for a tamal and flatbread for dinner, and arrived at our hostel a little after 10 pm – about 14 hours of traveling. I was tired, but excited to see a new paramo ecosystem.
15 Jan 2017
Today we visited the Tacurrumby – Laguna Negra Nature Reserve, which was located very close to the peatland we sampled yesterday. Felipe Vallejo of the Unversidad of Caldas accompanied us, and he was nice enough to secure permission for us to sample within the reserve. Felipe may also analyze diatoms (a group of algae with cell walls made of silica) in the surface samples that we are collecting, as just like testate amoebae they have been little studied in paramo ecosystems.
The painting on the trailhead sign at the nature reserve showed a ruddy duck (Oxyura jamaicensis), although from what I can find there is a fair amount of taxonomic uncertainty with species and subspecies identification (see wikipedia). There appears to be at least two subspecies, and some regard these as different species, the North American ruddy duck (O. jamaicensis jamaicensis) and the Andean ruddy duck (O. jamaicensis ferruginea). Other than differences in geographic distribution, the Andean ruddy has a completely black head whereas the North American ruddy white has a white face. Interestingly, the painting on the trailhead sign shows a white face, which seems to be consistent with the North American species. However, according to some there may also be a Colombian subspecies (O. jamaicensis andina) with some black coloration on the white face; however, these individuals may also just represent hybrids between the North American and Andean subspecies. And the painting on the sign doesn’t show any black coloration within the white face. Regardless, the Colombia population of ruddy ducks (O. jamaicensis ferruginea/andina) has declined over the past several decades, and according to the sign they are likely headed toward extinction here.
As we walked along the trail to the lake, we observed signs identifying some of the dominant plant and bird species, as well as highlighting the ecological value of the lake and associated wetland. The plant diversity was impressive, with large grass tussocks and many shrub species.
Upon reaching the lake we immediately spotted the bright blue bill of the flagship ruddy duck as advertised on the trailhead sign! However, unlike the painting the male duck’s head was completely black, consistent with the Andean ruddy duck, as one would expect here. Shortly thereafter we spotted a female Andean ruddy duck and a duckling! Add one more to the population size in Colombia.
After collecting surface samples, we drove up into the Nevado del Ruiz National Park to look for potential future research sites. After this excursion, we sampled another peatland located at a bit lower elevation than Laguna Negra. Over 70 samples collected so far!
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.
13 Jan 2017
After arriving in Bogota late last night, I awoke to sunshine and the sounds of traffic this morning. In addition to myself and Jaime Escobar, our crew includes Mark Brenner and Jason Curtis from the University Florida, who are here to collect lake-sediment cores from high-elevation lakes in the paramo. After a breakfast of eggs, fresh fruit, and good coffee we took a taxi across Bogota to a place where we could store the lake coring equipment, as we won’t need it until next week.
My first impression of Bogota was that driving in this city of 9 million people is a
terrifying thrilling experience. Although lanes may or may not be marked, any lane delineation is clearly just a suggestion. Vehicles seem to drive wherever they please, weaving in and out of traffic while motorcycles (and there are a lot of them) drive between the cars and trucks. The roads twisted and turned and I felt like we were driving in circles at times, even when we weren’t navigating the traffic-merging madness of a roundabout. Jugglers and dancers performed at some of the stoplights, and I couldn’t help but admire them for their bravery, as pedestrians do not appear to have the right-of-way. The one piece of advice I received before coming to Colombia was not to drive, and this was definitely excellent advice.
In the early afternoon we flew from Bogota west to Manizales, which is a city of about 400,000 people. The view of the Colombian landscape was fantastic, with mountains covered in coffee and plantains. Coffee is planted even on the very steep slopes. The flight was a bit bumpy as we dropped into Manizales, and I was glad that I only had a muffin for lunch.
Our hotel was just outside the city and was very nice with beautiful gardens, wetlands, and a fenced area with several ostriches and a deer. The hotel property backed up against a nature reserve, and the diversity of rain forest vegetation and birds was impressive. I wished I had been able to fit my binoculars into my luggage! It was fun to see a number of floating plants and floating-leaved plants that my EES-386 students will soon know, including abundant Azolla, Salvinia, water hyacinth (Eichhornia crassipes), and water lilies (Nymphaea sp.). Some pictures of the hotel ground are below.
We then drove into Manizales to meet with scientists in the Departamento de Ciencias Geológicas at the University of Caldas. We had a tour of their labs and facilities, and discussed our plans for exploration of the paramo tomorrow. Several of the geologists will join us in the field.
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…