As part of the (on-line) bachelor level “Big History” course from the Institute for Interdisciplinary Studies at the University of Amsterdam I recently recorded a podcast with Henry Hooghiemstra. Under the banner of “How Has Climate Change Influenced History?” among other things we discussed: (i) the principles of how we can obtain information on past climatic and environmental change, (ii) how global climate changed between cold (glacial states) and warm (interglacial states) during the last 2.6 million years (Quaternary), and (iii) past human impacts and influences on environmental and climatic change.
Cárdenes-Sandí, G.M., Shadik, C.R., Correa-Metrio, A., Gosling, W.D., Cheddadi, R. & Bush, M.B. (2019) Central American climate and microrefugia: A view from the last interglacial. Quaternary Science Reviews205, 224-233. DOI: 10.1016/j.quascirev.2018.12.021
For free access click here before 19 February 2019
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
I am delighted to report that I have recently been appointed as an Associate Editor for the journal Vegetation History & Archaeobotany (VHA). The journals scope is global and covers Quaternary environmental and climatic change, with a specific focus on the Holocene and pre-historic human impacts on landscapes; often linking palaeoecological and archaeological research. My remit with VHA is to provide expertise on tropical, and in particular South American, studies. Recent articles in VHA with a South American focus include:
Assessing the influence of glacial-interglacial climate changes on the dry forest vegetation along the southern edge of Amazonia (Whitney et al., 2014),
I hope that over the next few years we can publish some more exciting articles on the tropics in VHA and I would therefore like to encourage you to submit interesting high quality original research, reviews, or short articles for our consideration.
To find out more about the journal and submit an article click here.