PAGES Landcover6k Workshop: “Land-use and land-cover for Climate Modelling” Hemmenhofen, Germany, 28th-30th January 2019
I was delighted to receive a Scottish Archaeological Research Framework (ScARF) and Society of Antiquaries of Scotland Early Career Researcher Bursary to enable me to attend the Past Global Changes (PAGES) Landcover6k Europe “Land-use and land-cover for Climate Modelling” workshop in Germany from 28th-30th January 2019. The workshop was kindly hosted by Dr Elena Marinova in the Research Centre for Wetland Archaeology in Hemmenhofen, a dedicated wetland archaeological research institute overlooking Lake Constance, where numerous exceptionally well-preserved prehistoric pile dwellings have been discovered. The Europe group is led by Dr Nicki Whitehouse (University of Plymouth), Prof. Marco Madella (UPF, Barcelona, Spain) and Dr Ferran Antolin (University of Basel). Dr Marc Vander Linden (University of Cambridge) is the data manager for the group.
As a member of the Landcover6k Europe group, I previously attended 2 workshops in 2018 (both in Barcelona, Spain) as part of this project and the workshop in January built on the discussion and research that has been undertaken by the group over the past year. My attendance at the workshop provided me with an excellent opportunity to connect with international researchers and to contribute to a global initiative that will inform climate change models, which deal with one of the biggest global challenges for the 21st century – accurately predicting future climate change. As part of the project, I am collaborating to incorporate information on land use in Scotland at 4000 cal BC (+/- 250 years) into maps of European land use using information from my doctoral research on Mesolithic and Neolithic plant use (Bishop et al 2009, 2013). The period 4250-3750 cal BC presents specific challenges for British and Irish archaeological datasets because it represents the key period of change from hunter-gathering to agriculture. During the workshop there were detailed discussions about how to map this transition. The workshop was very productive and enjoyable, and I look forward to contributing further to the project as it progresses.
PAGES Landcover6k project
The PAGES Landcover6k project aims to generate maps of global land cover (vegetation: pollen data) and land use (human practices: archaeological and historical data) change throughout the Holocene, which will be used to inform and evaluate existing models of climate change. In order to create accurate reconstructions of past and future climate change, it is necessary to understand the changing scale and nature of past human impacts on land cover through time. People have dramatically transformed their environments over the past 10,000 years, for instance through the creation and maintenance of open land for farming, and through deforestation as a result of fuel and timber procurement (Morrison et al 2018). Prehistoric hunter-gatherers also likely influenced land cover through the management of vegetation using land-scale level burning (Bishop et al 2015). These humanly caused land-cover changes resulted in modifications to the carbon cycle and increased CO2 emissions (Harrison et al 2018). However, current models of pre-industrial land use have been constructed using estimates of past populations and the amount of arable/pasture land needed per person, rather than detailed archaeological or historical data (ibid). Therefore, the extent to which prehistoric and historic human impacts on land cover caused shifts in climate remains uncertain (ibid). The PAGES Landcover6k project seeks to address this by developing global land-use maps based on archaeological data for 3 major time-slices: 12,000, 6000 and 4000 cal BP.
PAGES Landcover6k Workshop January 2019
An interdisciplinary group of European researchers – archaeobotanists, zooarchaeologists, landscape archaeologists, and environmental scientists – attended the January meeting in Hemmenhofen.
The workshop focused on several key themes:
- Evaluating the project methodologies for mapping land-use and considering how far the current archaeological data synthesis was meeting the minimum requirements of the climate modelling community.
- Evaluating initial regional European land-use maps for the period 4250-3750 cal BC.
- Refining definitions of land-use for global mapping and the categories for the accompanying database of sites.
- Data ownership and plans for future publications from the project.
Day one involved a series of presentations from different participants. The workshop began with a welcome address from Renate Ebersbach, the Director of the Research Centre. Following this, the European group coordinators, Nicki Whitehouse and Marco Madella, updated the group on progress since the previous meeting, and introduced the agenda for the workshop and publication plans.
Oliver Boles (University of Pennsylvania) presented the definitions of land-use that will be used for mapping and there was discussion of the standardised categories to be used for the database of site information to accompany the maps. It is necessary to develop standardised definitions of different types of land-use (e.g. hunter-gathering, pastoralism, agriculture) to enable global comparisons to be made (Morrison et al 2018). The workshop built on previous extensive discussions of these categories, focusing on defining when an area of land should be classified as “Agriculture” as opposed to “Hunting, foraging, fishing”. It was concluded that a specific percentage threshold for land surface covered by agriculture was not required for defining which land use category to use.
This discussion was followed by a series of papers reviewing methodological issues for modelling past land use. Marc van der Linden (University of Cambridge) updated the group on the site mapping that had been undertaken since the previous meeting and explained the decision to use kernel densities to map European land use. Sandy Harrison (University of Reading) then outlined the types of information that are needed as input into climate models and how archaeologists can provide relevant data or improve existing estimates based on expert knowledge. Key information modellers require include: the dates of first agriculture and percentage of agricultural land, estimates of population growth, how much biomass was removed (% of different crops, domestic animals, kg/m2 of wood and nuts harvested) and the mix of C3 versus C4 crop plants grown. Finally, Tilman Baum (University of Basel) discussed a modelling land use case-study in the Alpine Foreland using agent based simulations which provided land-area estimates of different types of land use.
In the second part of the meeting, the preliminary land use maps which had been generated at a previous meeting in May 2018 (Whitehouse et al 2018) were evaluated by regional sub-groups (North-West Europe, Central Europe, South-West Europe) to establish data-gaps and errors. The initial maps were constructed using expert knowledge, together with a European database of radiocarbon dates collated by Marc Vander Linden and subsequent data collections by the group.
Day 2 focused on refining the standardised categories which will be used in the database of sites which will accompany the maps, and discussing the plans for papers that will be produced from the project by the European group.
The project team are currently working to fill in gaps in data-sets. The aim is to produce initial land-use maps using basic top-level classifications of land-use (e.g. hunter-gathering/agriculture) to allow climate modellers to test whether human impacts on land cover in prehistory were large enough to influence climate change. The datasets will be increasingly refined and used to produce more detailed maps which will incorporate information on different hunting and gathering, farming, and fuel procurement strategies. It is hoped that the final output of the project will prove useful for both the modelling and archaeological communities.
Rosie R. Bishop, Post-doctoral Researcher, Department of Archaeology, Durham University
Bishop, R. R., Church, M. J. & Rowley-Conwy, P. A. 2009. Cereals, fruits and nuts in the Scottish Neolithic. Proceedings of the Society of Antiquaries of Scotland 139:47-103. (http://archaeologydataservice.ac.uk/archives/view/psas/contents.cfm?vol=139&CFID=57b58cb5-c24d-4107-a6d8-574fc694ac75&CFTOKEN=0)
Bishop, R. R., Church, M. J. & Rowley-Conwy, P. A. 2014. Seeds, fruits and nuts in the Scottish Mesolithic. Proceedings of the Society of Antiquaries of Scotland 143(2013):9–71.
Bishop, R. R., Church, M. J. & Rowley-Conwy, P. A. 2015. Firewood, food and niche construction: the potential role of Mesolithic hunter-gatherers in actively structuring Scotland’s woodlands. Quaternary Science Reviews 108:51-75.
Harrison, S. P., Stocker, B. D., Goldewijk, K. K., Kaplan, J. O. and Braconnot, P. 2018. Do we need to include anthropogenic land-use and land-cover changes in paleoclimate simulations? Pages Magazine 26(1):4-5. https://doi.org/10.22498/pages.26.1.4
Morrison, K.D., Hammer, E., Popova, L., Madella, M., Whitehouse, N., Gaillard, M.-J., Aleru, J., Ibadan, U., Arroyo-Kalin, M., Bauer, A., Betancourt, C., Biagetti, S., Bishop, R., Boles, O., Clement, C.R., Cruz, P., Dennis, B.S., Ekblom, A., Elizabeth, K., Ellis, E., Flantua, S., Foster, T., Gronenborn, D., Hannaford, M., Iriarte, J., Junqueira, A., Kay, A., Klein-Goldewijk, K., Kolář, J., Lancelotti, C., Lane, P., Leclerc, C., Ledru, M.-P., Lemmen, C., Levis, C., Lombardo, U., Maezumi, S., Manyanga, M., Marchant, R., Maughan, N., Mayle, F., McMichael, C., Monprapussorn, S., Moraes, C.P., Muchena, R., Neves, E.G., Pandey, S., Phelps, L., Pinke, Z., Riris, P., Rostain, S., Russel, T., Saini, R., Schmidt, M.J., Shikoni, A., Sluyter, A., Ssemulende, R., Stump, D., Styring, A., Sultan, B., Szabo, P., Tamanaha, E., Tello, E., Thomas, E., Vanniere, B., Wandsnider, L., Widgren, M. 2018. Global-scale comparisons of human land use: developing shared terminology for land-use practices for global change. Pages Magazine 26(1):8-9. https://doi.org/10.22498/pages.26.1.8
Whitehouse, N., Madella, M. and Antolín, F. 2018. European land-use at 6000 BP: from on-site data to the large-scale view. Pages Magazine 26(2). http://pastglobalchanges.org/download/docs/magazine/2018-2/PAGESmagazine_2018%282%29_90.pdf