Mapping past human land use using archaeological data: A new classification for global land use synthesis and data harmonization

Abstract

In the 12,000 years preceding the Industrial Revolution, human activities led to significant changes in land cover, plant and animal distributions, surface hydrology, and biochemical cycles. Earth system models suggest that this anthropogenic land cover change influenced regional and global climate. However, the representation of past land use in earth system models is currently oversimplified. As a result, there are large uncertainties in the current understanding of the past and current state of the earth system. In order to improve representation of the variety and scale of impacts that past land use had on the earth system, a global effort is underway to aggregate and synthesize archaeological and historical evidence of land use systems. Here we present a simple, hierarchical classification of land use systems designed to be used with archaeological and historical data at a global scale and a schema of codes that identify land use practices common to a range of systems, both implemented in a geospatial database. The classification scheme and database resulted from an extensive process of consultation with researchers worldwide. Our scheme is designed to deliver consistent, empirically robust data for the improvement of land use models, while simultaneously allowing for a comparative, detailed mapping of land use relevant to the needs of historical scholars. To illustrate the benefits of the classification scheme and methods for mapping historical land use, we apply it to Mesopotamia and Arabia at 6 kya (c. 4000 BCE). The scheme will be used to describe land use by the Past Global Changes (PAGES) LandCover6k working group, an international project comprised of archaeologists, historians, geographers, paleoecologists, and modelers. Beyond this, the scheme has a wide utility for creating a common language between research and policy communities, linking archaeologists with climate modelers, biodiversity conservation workers and initiatives.

Coping with Risk. A Deep-Time Perspective on Societal Responses to Ecological Uncertainty in the River Dalälven Catchment Area in Sweden

“…We developed these categorizations as purposefully general or high-level descriptors of niche construction activities across our 11,000-year time scale of interest, as activities are not homogenous over time or space; however, we were interested in general trends and patterns. Those trends and patterns are better seen with inclusive categories [50]. Defining land use allows for exploration of human niche constructions and their role in risk management in response to ecological uncertainty.…”

Mapping Food Production in Hyper-Arid and Arid Saharan Africa in the Holocene—A View from the Present

“…The classification of land use followed the PAGES LandCover6k categories, which are organised hierarchically. The first level (Land Use 1, LU1) represents a global level of land use and the second (LU2) a regional one [3].…”

“…After a general consideration of past and present land use in the Sahara, we report on modern and historic examples of three specific forms of land use within extremely arid areas characterised by an AI up to 0.07 (Figure 1), specifically pastoralism, oasis agriculture and rainfed agriculture. Ultimately, starting from ethnographic observations and models, we will discuss how to extend land use classification in the past for these specific cases, by applying the recent framework developed by the PAGES LandCover6K initiative [3,4]. The goal of this international effort is to combine a wide array of proxies to reconstruct past land cover and land use changes to improve current climatic models.…”

Enhancing archaeology's role in addressing grand challenges needs more reflection on known unknowns

“…Sadly, for the most part, archaeologists have yet to identify many such known unknowns that may be amenable to conversion into known knowns through their endeavours. One example that seems to achieve this is the work of the LandUse6K research group that aims to generate knowledge of the changing proportions of different kinds of land use at different points in time over the last 6000 years, in a manner that makes the data readily usable by climate modellers (Morrison et al 2021). For many of the other grand challenges, it seems that we are still a long way from identifying in any precise way how our archaeological knowledge might be both usable and useful.…”