sediment | Ecology of the past

Cloudy with a chance of adventure

April 8, 2019
WDG

Rachel Sales, Bryan Valencia, and Majoi de Novaes Nascimento coring a different lake. In this picture, we have just pulled a core of mud up from the bottom of the lake. Photo credit: Seringe Huisman

Cloudy with a chance of adventure
By Rachel Sales (PhD researcher at the Institute for Global Ecology, Florida Institute of Technology)

I am sitting on the shore of Lago Condorcillo in Southern Ecuador, after a long day of travel, trying to control my shivering. At roughly 10,500 ft. above sea level, the lake is very cold, with wind that howls over the barren hills dotted with giant boulders. The lake is also almost always blanketed by thick fog and pelted by driving rain. When you’re surrounded by the thick fog punctuated by lightning bolts, it’s easy to believe that some lost civilization lurks just out of sight. Tonight we are experiencing lightning storms, which is adding to the feeling that some angry, ancient life form must live at Lago Condorcillo.

Tomorrow, I will be out in the cold and rain, balancing on an inflatable boat and fighting frostbite. Mark Bush, who is my Ph.D. advisor, Courtney Shadik, who is my lab partner and tent buddy, and I will be collecting cores of mud from the bottom of Condorcillo. We will create our rig for coring by tying two inflatable boats together, and placing a wooden platform between them. Mark, Courtney, and I will then collect our mud cores from this platform.

As I’m contemplating the hazards of camping in a lightning storm, Mark says, “Tell me everything that went wrong today.” Courtney pulls a sleeping bag closer to her. I begin to describe how Google Maps can’t seem to understand distance in the Andes, and so traveling to Lago Condorcillo took much longer than we anticipated. Courtney laughs beside me and adds, “We don’t have any matches to start a fire.” Despite our troubles, I am grinning from ear to ear, no doubt spoiling the grim mood Mark is attempting to cultivate and Lago Condorcillo is doing its best to enforce.

Loughlin PhD Thesis 2018

July 25, 2018
nicholasloughlin

Nick recovers a sediment core for his PhD project.

Nick Loughlin

Loughlin, N.J.D. (2017) Changing human impact on the montane forests of the eastern Andean flank, Ecuador. PhD Thesis. School of Environment, Earth and Ecosystem Sciences, The Open University.

Abstract:

The montane cloud forests of South America are some of the most biodiverse habitats in the world, whilst also being especially vulnerable to climate change and human disturbance.

Today much of this landscape has been transformed into a mosaic of secondary forest and agricultural fields. This thesis uses palaeoecological proxies (pollen, non-pollen palynomorphs, charcoal, organic content) to interpret ecosystem dynamics during the late Quaternary, unravelling the vegetation history of the landscape and the relationship between people and the montane cloud forest of the eastern Andean flank of Ecuador. Two new sedimentary records are examined from the montane forest adjacent to the Río Cosanga (Vinillos) and in the Quijos Valley (Huila). These sites characterise the natural dynamics of a pre-human arrival montane forest and reveal how vegetation responded during historical changes in local human populations.

Non-pollen palynomorphs (NPPs) are employed in a novel approach to analyse a forest cover gradient across these sites. The analysis identifies a distinctive NPP assemblage connected to low forest cover and increased regional burning. Investigation into the late Pleistocene Vinillos sediments show volcanic activity to be the primary landscape-scale driver of ecosystem dynamics prior to human arrival, influencing montane forest populations but having little effect on vegetation composition.

Lake sediments at Huila from the last 700 years indicate the presence of pre-Hispanic peoples, managing and cultivating an open landscape. The subsequent colonization of the region by Europeans in the late 1500’s decimated the indigenous population, leading to the abandonment of the region in conjunction with an expansion in forest cover ca. 1588 CE. After approximately 130 years of vegetation recovery, montane cloud forest reached a stage of structural maturity comparable to that seen in the pre-human arrival forest. The following 100 years (1718-1822 CE) of low human population and minimal human impact in the region is proposed as a shifted ecological baseline for future restoration and conservation goals. This ‘cultural ecological baseline’ features a landscape that retains many of the ecosystem service provided by a pristine montane forest, while retaining the cultural history of its indigenous people within the vegetation. Continue Reading

Aquatic community response to volcanic eruptions on the Ecuadorian Andean flank

October 9, 2017
WDG

Online, open access:

Matthews-Bird, F., Brooks, S.J., Gosling, W.D., Gulliver, P., Mothes, P. & Montoya, E. (2017) Aquatic community response to volcanic eruptions on the Ecuadorian Andean flank: Evidence from the palaeoecological record. Journal of Paleolimnology 58: 437-453. DOI: 10.1007/s10933-017-0001-0

An undergraduate eye-view of an Andean lake-coring expedition

August 25, 2017
WDG

Part 2: Progresso
by Molly Kingston (a BSc Biological Sciences student at Florida Institute of Technology, taking part in an expedition lead by Prof. Mark Bush)

With a fresh set of clothes and a shower after almost a week without one, it was time to set off for the next lake, Progresso.

Scientific methods in archaeology

November 10, 2016
WDG

Preparing my lecture for the new Scientific Methods in Archaeology course for VU Amsterdam and University of Amsterdam students studying a minor in Geoarchaeology. The focus will be on detecting human activity in the past, to illustrate this I will include Easter Island/Rapa Nui as a case study. We will focus on how palaeoecological evidence can be used to gain insights into past human activity. Whilst putting this together I discovered these nice documentaries looking at humans and their environmental impacts on Easter Island/Rapa Nui which I wanted to share, they show how much effort people would have had to put into altering their landscape:

For further information see also:

Rull, V., Cañellas-Boltà, N., Saez, A., Margalef, O., Bao, R., Pla-Rabes, S., Valero-Garcés, B. & Giralt, S. (2013) Challenging Easter Island’s collapse: The need for interdisciplinary synergies. Frontiers in Ecology and Evolution 1, DOI: 10.3389/fevo.2013.00003

Past environmental change on Mauritius: Unknown macro-fossils

December 18, 2015
WDG

Unknown macro-fossil JdK-type2

Past environmental change on Mauritius has been the focus of research with the Palaeoecology & Landscape Ecology group at the University of Amsterdam (UvA) for a number of years. This research has been lead by Erik de Boer and Henry Hooghiemstra and has already resulted in a number of key publications on the environmental history of the island (de Boer et al., 2013, 2014, 2015). One current past environmental change research project working on Mauritius is being undertaken by Jona de Krui; a student within the UvA BSc Biology program supervised by myself and Erik. Jona’s is working on a study site (modern day swamp) on the north-east of the island and is focused on improving our understanding changes in the:

depositional environment (loss-on-ignition analysis),
fire activity (macro-charcoal analysis), and
vegetation (macro-fossils) over the last c. 1000 years.

Jona has now completed the analysis of all his samples and we are currently collating the data sets; however, a number of the macro-fossils which he has discovered remain unidentified. Below are images of the unknown macro-fossils if you have any suggestions on identifications please comment, or get in touch directly.

: Unknown maro-fossil JdK-type1 (c. 5 mm)

: Unknown macro-fossil JdK-type1 (c. 5 mm)

: Unknown macro-fossil JdK-type2 (c. 4.5 mm)

: Unknown macro-fossil JdK-type3 (c. 1.9 mm)

: Unknown macro-fossil JdK-type4 (c. 0.9 mm)

: Unknown macro-fossil JdK-type5 (c. 0.3 mm)

: Unknown macro-fossil JdK-type6 (c. 3.2 mm)

: Unknown macro-fossil JdK-type6 (c. 3.2 mm)

: Unknown macro-fossil JdK-type7 (c. 4.1 mm)

: Unknown macro-fossil JdK-type8 (c. 4.3 mm)

Sediment coring in Lake Erazo

April 14, 2015
WDG

XPERT field school is underway…

Palaeoenvironment

Sediment coring on Lake Erazo. Photo by Valerie van den Bos (who spent the flight over reading a book on how to take the perfect photo)

By Alexandra Lee and Nick Primmer

To study the palaeo-environmental record of the Andean cloud forest, sediment cores were taken from the recently discovered Erazo lake. In mixed conditions of blazing sun and pouring rain, 14 researchers, one bus driver and several Ecuadorian guides hauled what felt like a ton of equipment up to the lake 2,300 m asl. In the centre of the lake, a wooden coring platform was mounted between two boats securely anchored at three positions. Using a modified Livingston corer with a drop hammer, five cores were successfully recovered from the lake up to a maximum depth of two metres. The main challenge encountered was the stability of the platform which resulted in several complications limiting the number of cores…

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Teaching in the field: Foundations, feedback and fun

September 16, 2014
WDG

My final teaching job for The Open University was to help deliver the “Sedimentary Rocks & Fossils in the Field” section of the Level 2 Practical Science module (SXG288) offered by the Science Faculty. I have been involved in all three presentations of this section of the SXG288 module, which will now cease to be offered, and a number of other Earth and environmental science residential schools over the last 9 years.

Having the opportunity to engage directly with students and enthuse them face-to-face about the subject I specialise in is a privilege I have gained a lot from. Furthermore, my over-riding impression from the students I have taught is that they feel they benefit greatly from the opportunity to explore first hand the concepts and subjects which they have previously studied in books and online. Based on my experiences on “Sedimentary Rocks and Fossils”, and other modules as both a tutor and a student, I am convinced that to effectively teach geological, geographical, environmental and ecological subjects effectively an element of field-based teaching is required.

In the news:

First Farmers Were Also Sailors, by Michael Balter in Science.

John Bostock: The man who ‘discovered’ hay fever, by Justin Parkinson in BBC News Magazine.

DNA study shows yeti is real (sort of) – and Oxford scientist prepares expedition to find it, by Adam Withnall in The Independent.

Tibetan altitude gene inherited ‘from extinct species’, by Paul Rincon BBC News Website

Scientific articles:

Bonatelli, I.A.S., Perez, M.F., Peterson, A.T., Taylor, N.P., Zappi, D.C., Machado, M.C., Koch, I., Pires, A.H.C. & Moraes, E.M. (2014) Interglacial microrefugia and diversification of a cactus species complex: phylogeography and palaeodistributional reconstructions for Pilosocereus aurisetus and allies. Molecular Ecology, 23, 3044-3063.

Bush, M.B., Restrepo, A. and Collins, A.F. (2014) Galápagos history, restoration, and a shifted baseline. Restoration Ecology, 22, 3, 296-298.
Summary (Nick): A concise and pithy look at how a robust long-term ecological system can be transformed rapidly by human impact. The paper demonstrates how the fossil pollen record is fundamental if a near-natural vegetation state is to be restored to the Galápagos islands, to avoid restoration to a shifted baseline.

Froyd, C.A., Coffey, E.E.D., van der Knaap, W.O., van Leeuwen, J.F.N., Tye, A. & Willis, K.J. (2014) The ecological consequences of megafaunal loss: giant tortoises and wetland biodiversity. Ecology Letters, 17, 144-154.

Giguet-Covex, C., Pansu, J., Arnaud, F., Rey, P.-J., Griggo, C., Gielly, L., Domaizon, I., Coissac, E., David, F., Choler, P., Poulenard, J. & Taberlet, P. (2014) Long livestock farming history and human landscape shaping revealed by lake sediment DNA. Nat Commun, 5

Gillson, L. & Marchant, R. (2014) From myopia to clarity: sharpening the focus of ecosystem management through the lens of palaeoecology. Trends in Ecology & Evolution, 29, 317-325.
Comment (Will): For a good example of feeding palaeoecology into management see Bush et al. above.

Insects, sediment and climate change

Frazer Bird and William Gosling talk about how to conduct palaeoecological research in the tropics for NERC’s Planet Earth pod-cast. Click here to here to listen to the conversation.

For other similar stories online visit the Planet Earth website.