SANTA CRUZ DE TENERIFE, Nov. 15 (EUROPA PRESS) –
New findings by a team of researchers from the Department of Geography and History and the Island Ecology and Biography group of the University of La Laguna shed light on the impact of climatic variations and human activities on the tropical forests of the island of São Tomé , in the Gulf of Guinea, during the last 14,000 years.
It was assumed that the regulating influence of the sea had kept São Tomé’s forests stable during long-term climate changes, and that human colonization had had minimal impacts on the island’s summit. However, recent research led by postdoctoral researcher Álvaro Castilla Beltrán, together with Lea de Nascimento and José María Fernández-Palacios, and an international team, suggests otherwise.
Through an exhaustive examination of a 14,000-year-old sediment record, collected in a volcanic crater in the montane forests of São Tomé, great transformations are evident in these tropical landscapes derived from climate changes and human impacts.
“Our findings challenge the notion that the tropical forests of the Gulf of Guinea Islands remained stable over time, showing a complex history of forest fires and vegetation changes. In the long term, these modifications were due to climatic changes. “, and more recently, since humans arrived on this island a few years ago, our findings suggest that colonial use of the landscape played a fundamental role in shaping these forests, mainly through fire and introduced species,” says Castilla. Beltran.
This research, funded by the Quaternary Research Association and supported by the Margarita Salas postdoctoral fellowship (EU funds for the NextGeneration), has just been published in the journal Quaternary Science Reviews.
This article is the result of research efforts that began in 2017 and involved an expedition to the impressive crater where ‘Lagoa Amélia’ is located, located 1,400 meters above sea level. After field work, the team carried out multiple analyzes in the laboratory to provide several lines of evidence for landscape changes, including pollen grains, carbon particles and sediment composition.
Unraveling the historical impact of global climate changes and the human footprint on the threatened forests of these tropical islands represents a great challenge, say researchers from the University of La Laguna. Instrumental records, such as satellite data, provide only recent decades of information, and archaeological sites are difficult to locate in dense forests such as those on the island of São Tomé.
Therefore, pollen grains and other microfossils from well-preserved sediment records are valuable for uncovering the environmental history of island regions where scientific studies have not existed until now, they add.
The study is the first of its kind in the Gulf of Guinea Islands, provides evidence base for archaeological and ecological research in the region, and establishes a historical reference point from which to understand current human interactions with the environment in small island states such as São Tomé and Príncipe.
