Non-uniform tropical forest responses to the ‘Columbian Exchange’ in the Neotropics and Asia-Pacific

Abstract

It has been suggested that Iberian arrival in the Americas in 1492 and subsequent dramatic depopulation led to forest regrowth that had global impacts on atmospheric CO2 concentrations and surface temperatures. Despite tropical forests representing the most important terrestrial carbon stock globally, systematic examination of historical afforestation in these habitats in the Neotropics is lacking. Additionally, there has been no assessment of similar depopulation–afforestation dynamics in other parts of the global tropics that were incorporated into the Spanish Empire. Here, we compile and semi-quantitatively analyse pollen records from the regions claimed by the Spanish in the Atlantic and Pacific to provide pan-tropical insights into European colonial impacts on forest dynamics. Our results suggest that periods of afforestation over the past millennium varied across space and time and depended on social, economic and biogeographic contexts. We argue that this reveals the unequal and divergent origins of the Anthropocene as a socio-political and biophysical process, highlighting the need for higher-resolution, targeted analyses to fully elucidate pre-colonial and colonial era human–tropical landscape interactions.

Planetary‐scale change to the biosphere signalled by global species translocations can be used to identify the Anthropocene

“…2019; Hamilton et al . 2021; see Table 1). Nevertheless, an interconnected web of palaeontological correlation with practical utility can be constructed to identify a globally recognizable and essentially isochronous start to the Anthropocene in the mid‐twentieth century, and this can be combined with other forms of stratigraphic data.…”

“…Indeed, the interpretation of pollen records shows how complex the stages of human–ecosystem interactions were, before and during this period (Hamilton et al . 2021). The palaeontological signal often becomes recognizable over several centuries.…”

Incorporating a palaeo-perspective into Andean montane forest restoration

“…However, within a century as much as 90% (c. 54 million people) of the population were dead as the result of European conquest and imported diseases (Koch et al, 2019). This continental scale depopulation led to population centres, managed land, and cultivated fields (c. 56 million hectares (Koch et al, 2019)) undergoing secondary succession, as vegetation reoccupied what was previously cleared (Hamilton et al, 2021).…”

“…Vegetation, previously held at bay by Indigenous land management recolonised the land, sequestering some 5-10 Gt C (Gigatonnes of carbon) (Nevle and Bird, 2008;Lewis and Maslin, 2015;Koch et al, 2019) driving changes in global climate, and potentially contributing to the Little Ice Age which reached its peak c. CE 1610 (Dull et al, 2010;Lewis and Maslin, 2015). However, the synchronicity of these events has been questioned as land abandonment and forest regrowth throughout Amazonia has been observed in the centuries prior to European arrival (Bush et al, 2021;Hamilton et al, 2021).…”

Formal Tests for Resistance-Resilience in Archaeological Time Series

“…Our method therefore paves the way for the systematic and rigorous evaluation of inferred disturbances to human societies and culture-climate links in general. We suggest that other well-known phases of abrupt climate change, for example the Younger Dryas/Bølling-Allerød, the Pleistocene/Holocene transition, the 8.2 and 4.2 ka events, and data permitting, the "Columbian Exchange" (Hamilton et al, 2021) would be ideal test beds for the approaches we advocate. While attention here has mainly been on climate as a driver, abrupt social change or reorganisation may be equally important, and interesting, targets for comparative analysis (such as periods of warfare, Edinborough et al, 2017).…”