The montane cloud forests of South America are some of the most biodiverse habitats in the world, whilst also being especially vulnerable to climate change and human disturbance.
Today much of this landscape has been transformed into a mosaic of secondary forest and agricultural fields. This thesis uses palaeoecological proxies (pollen, non-pollen palynomorphs, charcoal, organic content) to interpret ecosystem dynamics during the late Quaternary, unravelling the vegetation history of the landscape and the relationship between people and the montane cloud forest of the eastern Andean flank of Ecuador. Two new sedimentary records are examined from the montane forest adjacent to the Río Cosanga (Vinillos) and in the Quijos Valley (Huila). These sites characterise the natural dynamics of a pre-human arrival montane forest and reveal how vegetation responded during historical changes in local human populations.
Non-pollen palynomorphs (NPPs) are employed in a novel approach to analyse a forest cover gradient across these sites. The analysis identifies a distinctive NPP assemblage connected to low forest cover and increased regional burning. Investigation into the late Pleistocene Vinillos sediments show volcanic activity to be the primary landscape-scale driver of ecosystem dynamics prior to human arrival, influencing montane forest populations but having little effect on vegetation composition.
Lake sediments at Huila from the last 700 years indicate the presence of pre-Hispanic peoples, managing and cultivating an open landscape. The subsequent colonization of the region by Europeans in the late 1500’s decimated the indigenous population, leading to the abandonment of the region in conjunction with an expansion in forest cover ca. 1588 CE. After approximately 130 years of vegetation recovery, montane cloud forest reached a stage of structural maturity comparable to that seen in the pre-human arrival forest. The following 100 years (1718-1822 CE) of low human population and minimal human impact in the region is proposed as a shifted ecological baseline for future restoration and conservation goals. This ‘cultural ecological baseline’ features a landscape that retains many of the ecosystem service provided by a pristine montane forest, while retaining the cultural history of its indigenous people within the vegetation. Continue Reading
Castilla-Beltrán, A., Hooghiemstra, H., Hoogland, M.L.P., Pagán-Jiménez, J., van Geel, B., Field, M.H., Prins, M., Donders, T., Malatesta, E.H., Hung, J.U., McMichael, C.H., Gosling, W.D. & Hofman, C.L. Columbus’ footprint in Hispaniola: a paleoenvironmental record of Indigenous and Colonial impacts on the landscape of the central Cibao Valley, northern Dominican Republic. Anthropocene. DOI: 10.1016/j.ancene.2018.05.003
McMichael, C.H., Feeley, K.J., Dick, C.W., Piperno, D.R. & Bush, M.B. (2017) Comment on “Persistent effects of pre-Columbian plant domestication on Amazonian forest composition”. Science 358. DOI: 10.1126/science.aan8347
Junqueira, A.B., Levis, C., Bongers, F., Peña-Claros, M., Clement, C.R., Costa, F. & ter Steege, H. (2017) Response to Comment on “Persistent effects of pre-Columbian plant domestication on Amazonian forest composition”. Science 358. DOI: 10.1126/science.aan8837
McMichael, C., Piperno, D., Neves, E., Bush, M., Almeida, F. & Mongelo, G. (2015) Phytolith assemblages along a gradient of ancient human disturbance in western Amazonia. Frontiers in Ecology and Evolution 3.DOI: 10.3389/fevo.2015.00141
Abstract Amazonia has long been considered to be a pristine wilderness, largely untouched by human activity, supporting small, scattered indigenous tribes living in harmony with their rainforest environment.
However, recent discoveries of massive geometric earthworks, revealed by deforestation in recent decades, are challenging this ‘virgin wilderness’ paradigm and pointing to substantially greater environmental impacts by pre-Columbian societies than previously supposed.
In my talk I review these archaeological discoveries and discuss how a combined palaeoecological-archaeological approach has the potential to resolve the scale of environmental land use and disturbance associated with these ancient cultures. I also consider the implications of these findings for understanding rainforest ecology and biodiversity, as well as conservation policy.
If you are external to The Open University and wish to attend this lecture please contact William Gosling in advance.