Authors: Mark Robinson*, University of Exeter, Jose Iriarte, University of Exeter, Jonas Gregorio De Souza, University of Exeter
Topics: Human-Environment Geography, Land Use and Land Cover Change, Sustainability Science
Keywords: araucaria, southern Brazil, vegetation modelling, lidar, soil profiles
Session Type: Paper
Start / End Time: 3:20 PM / 5:00 PM
Room: Grand Ballroom C, Astor, 2nd Floor
Presentation File: No File Uploaded
Understanding the relative causal impacts of climate and humans on vegetation dynamics is critical to developing appropriate and effective conservation strategies in the face of future climate change and social demands. A dramatic expansion of forest, at the expense of grasslands in the southern Brazilian highlands, between 1410 and 900 cal BP, coincided with a period of dynamic cultural change in the region. The drivers of this dynamic period have been debated in a chicken or egg situation, but in this case was it people or forest that came first? Did wetter climate drive forest expansion, providing a greater resource base that enabled community development? Or, did growing populations enact widespread anthropogenic management of the landscape to increase economic resources? Here, we develop and test a model of natural ecosystem distribution against vegetation histories and the archaeological record to distinguish human from climatic impacts on the distribution and expansion of Araucaria forests during the late Holocene. Drone based lidar aids the accurate mapping of land cover and archaeology to test the model of vegetation distribution. Carbon isotopes in soil profiles confirm that regardless of climatic fluctuations, vegetation is stable and forests are spatially limited to south-facing slopes in the absence of human inputs. However, in areas of past human activity, the economically important forest was expanded beyond its natural geographic boundaries.