Holocene vegetation and climate of central-west Argentina: understanding past ecosystem dynamics
funded by CONICET, the Research Council of Argentina, 2015-2020
Climate changes, volcanic eruptions, fire and human activities, have controlled the pace of recent vegetation history of southern South America. Additionally, vegetation has changed through its own internal dynamics, including the spread of plants, competition for suitable habitats and succession. Understanding the processes and mechanisms that have controlled changes in the past is essential to reveal the degree to which we can expect to be able to predict how vegetation is affected by external events, including future climate change.
A series of high-quality palaeoecological records will be generated during this project, with the aim to (i) understand vegetation change in time and space; (ii) test for the importance of contemporaneous climatic events; (iii) understand causal relationships between vegetation and external events and possible lags in vegetation response. This will then enable us to determine which aspects of vegetation change have no currently visible external explanation and in consequence are attributable to internal vegetation dynamics such as competition and succession.
This research makes use of the steep vegetation gradient of central-west Argentina, at 33-39° S, and the location of palaeoenvironmental records within three specific zones along a transect intersecting the arid diagonal. The three zones (1) northern Neuquén, (2) southern Mendoza and (3) central San Luis are spread out over ca. 700 km in a southwest - northeast direction. This distribution will enable us to compare the time and dynamic of changes in vegetation caused by climate.
In January 2015 a field campaign took place at Laguna Coipo Lauquen, a small 2.5m deep lake located within the Monte desert of southern Mendoza. A xerophytic open shrubland of Larrea and Prosopis, associated with other shrubs, occurs around the site. The 3.5m long sequence recovered has begun analysing for pollen and ostracods. The record offers a unique opportunity to study high-resolution vegetation dynamics over thousands of years to disentangling triggers of past environmental changes.
Sonia Fontana, Univ. of Göttingen, and Leandro Rojo, Univ. of Cuyo, project leaders
Natalia La Spina PhD candidate, Museo de Historia Natural de San Rafael
Thomas Giesecke, Univ. of Göttingen
Sabina D'Ambrosio, La Plata University