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Alex Chepstow-Lusty

alex chepstonOf Mites and Men

Conducting research in Peru for France when you’re actually British might seem a bit convoluted, but it’s a straightforward career move for 45-year old Alex Chepstow-Lusty.
For the last 14 years, this paleoecologist has been relentlessly retracing the history of the Inca Empire, which disappeared in the 16th century. Like a detective, he meticulously studies lake sediment cores, on the lookout for the tiniest clue. A pollen grain, a fragment of charcoal, a mite, or a single seed are all biological indicators that can help reconstruct the climate and vegetation history of the Andean landscape, which was transformed for agriculture by pre-Columbian civilizations. It was while growing up in Sussex that Chepstow-Lusty became fascinated by natural history. When he was 19, he left southeast England for Bristol University to devote himself to the study of microfossils–a branch known as micropaleontology. In 1990, he completed his PhD in ocean climate history at Cambridge University, and realized that what he really enjoyed was combining natural history with human history. A keen botanist, he found one of his first jobs in Cambridge at the World Conservation Monitoring Center. While working there on Latin American trees in danger of extinction, he became interested in Andean societies, both past and present, that have fascinated him ever since. He rejoined Cambridge University to study changes in Andean vegetation, using the analysis of pollen found in the sediments of Marcacocha, a small lake near Cuzco, the old Inca capital perched high in the Peruvian Andes. That was in 1993, and right from his first field trip, he fell in love with the region. As he describes it, “life is preserved there like nowhere else, it’s almost a biblical landscape.”
In 2000, when his wife came to France to work in Montpellier, he moved with her, continuing his research on pre-Columbian civilization as a member of the “friendly and dynamic” team of the Paleoenvironments department attached to CNRS.
His task was to compare the effects that the Inca and Spanish populations had on the Andean vegetation. While pursuing his research, he “accidentally” came across fossilized mites in the lake sediments that turned out to be excellent indicators of past human activity, since they colonize areas of pastureland, mostly feeding on livestock excrement. Following this discovery, which was the subject of a publication that made world headlines, he joined CBAE1 in Montpellier. “Since oribatid mites live all over the planet, they can be used everywhere, and they can easily be quantified using an ordinary microscope,” Chepstow-Lusty explains. He is at last living at the heart of his research, in Cuzco, where for the past eight months he has been working for IFEA.2 He is convinced that we have much to learn from pre-Columbian civilizations when it comes to the environment. The lake sediment records he has obtained are an invaluable source of information on how the Incas and previous societies transformed the landscape during a period of warming that began about 1000 years ago: growing crops on terraces to reduce erosion, with irrigation systems that used glacial water. “Such methods increase crop yields. In fact, they are beginning to be reintroduced by the local populations.” Chepstow-Lusty has also shown the importance of agroforestry3 for the Incas. With the rapid disappearance of Peruvian glaciers, due to global warming, reforestation programs4 using threatened endemic species are one of the solutions for capturing water in the mountains, in fact using the very same trees that he studied right at the start of his career.

Caroline Dangléant

Notes :

1.Centre de bio-archéologie et d'écologie, (CNRS / EPHE / Université Montpellier-II).
2. Institut français d'études andines (CNRS / French Ministry of Foreign Affairs).
3. Agroforestry is used here to indicate the benefits that planting trees can have in association with agriculture, or separately, for providing vital environmental services.
4. Associación Ecosistemas Andinos (ECOAN), Cuzco.

Contacts :

Alex Chepstow-Lusty,
IFEA, Lima, Peru.


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