According to the study, the first plant community, the oldest in the registry studied, was a mixed rain forest with elements of coastal areas.
The Mauritia flexuosa palm is today one of the most widespread plants in the Orinoco Delta, in northeastern Venezuela. It has not always been that way. This palm tree, known locally as moriche, began to dominate the plant community of this area 3000 years ago, according to a new study that has rebuilt for the first time the history and evolution of the ecological dynamics of the Orinoco Delta of the last 6200 years. The authors of this research, published in the Quaternary Science Reviews, have been able to identify up to 3 different periods characterized by different types of vegetation.
"With this research we have been able to verify the importance of environmental agents of both local and supra-regional nature in the dynamics of vegetation," explains Encarni Montoya, a researcher at the Jaume Almera Institute of Earth Sciences (ICTJA-CSIC) and author principal of a study in which Santiago Giralt and Valentí Rull , both from ICTJA-CSIC, and researchers from the Geosciences Institute (IGEO, CSIC-UCM), the University of Barcelona and the Botanical Garden of Geneva have also participated.
Investigators extracted a control with sediments from the bottom of a swampy area adjacent to "Caño Tiger." Once in the laboratory, they analyzed the samples obtained by paleomagnetic techniques, X-ray diffraction, sediment smears and stable isotope analysis.
In addition, they carried out a study of the pollen present in the recovered witness to know the type of vegetation in the area throughout the period studied. They also carried out a radiocarbon dating with which they were able to know exactly the age of the different sediment layers analyzed. By analyzing carbon particles they obtained information about the occurrence of fires in the region, which can give information about periods of human occupation.
Image via ICTJA-CSIC