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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.

Anthropogenic changes in land use and land cover (LULC) during the pre-industrial Holocene could have affected regional and global climate. Existing scenarios of LULC changes during the Holocene are based on relatively simple assumptions and highly uncertain estimates of population changes through time. Archaeological and palaeoenvironmental reconstructions have the potential to refine these assumptions and estimates. The Past Global Changes (PAGES) LandCover6k initiative is working towards improved reconstructions of LULC globally. In this paper, we document the types of archaeological data that are being collated and how they will be used to improve LULC reconstructions. Given the large methodological uncertainties involved, both in reconstructing LULC from the archaeological data and in implementing these reconstructions into global scenarios of LULC, we propose a protocol to evaluate the revised scenarios using independent pollen-based reconstructions of land cover and climate. Further evaluation of the revised scenarios involves carbon cycle model simulations to determine whether the LULC reconstructions are consistent with constraints provided by ice core records of CO2 evolution and modern-day LULC. Finally, the protocol outlines how the improved LULC reconstructions will be used in palaeoclimate simulations in the Palaeoclimate Modelling Intercomparison Project to quantify the magnitude of anthropogenic impacts on climate through time and ultimately to improve the realism of Holocene climate simulations.

In the context of geoarchaeological investigations on Easter Island several hundred human-made pits filled with reddish silty material were discovered in fluvial terraces of two valleys on the southern slope of Maunga Terevaka, the highest volcano of the island. Micromorphological analysis of one representative pit filling and comparison of its geochemical and physical properties with sediments in the surrounding terrace was performed in order to reconstruct the probable formation and use of the material in the pits. A hypothesis of pigment production by heating of minerogenic iron-rich substrate with grass fuel resulting in formation of hematite is suggested. It is assumed that the pits represented the places for production and storage of the pigments, which were used by Rapa Nui for cultural and ritual purposes. The ongoing interdisciplinary research will enhance the interpretation of the pits and their fillings and contribute to a better understanding of cultural development on Easter Island., No contexto de investigações geo-arqueológicas na Ilha de Páscoa, diversos poços de origem antrópica preenchidos com material limoso avermelhado foram descobertos em terraços fluviais de dois vales na base da vertente sul do Maunga Terevaka, o vulcão mais alto da ilha. Efetuaram-se análises micromorfólogicas do material de preenchimento de um poço representativo e compararam-se as suas propriedades geoquímicas e físicas com as dos sedimentos de um terraço próximo para reconstruir a provável formação e uso do material de preenchimento dos poços. Sugere-se a hipótese da produção de pigmentos através do aquecimento de sedimentos ricos em ferro usando combustível herbáceo e formando deste modo hematite Assume-se que os poços representavam lugares para produção e armazenamento de pigmentos, os quais foram usados pelos Rapa Nui em rituais e manifestações culturais. Esta investigação interdisciplinar irá contribuir para uma melhor interpretação e compreensão dos poços e dos materiais usados no seu preenchimento bem como do desenvolvimento cultural na Ilha de Páscoa., En la Isla de Pascua, varios cientos de fosas artificiales rellenas de material limoso rojizo han sido descubiertas en las terrazas de dos valles de la ladera meridional de Maunga Terevaka, el volcán más alto de la isla. Se han efectuado análisis micromorfológicos del relleno de una de estas fosas, así como la comparación de sus propiedades geoquímicas y físicas con los sedimentos de la terraza en que se ubica, con el objetivo de reconstruir la formación y el uso del material de las fosas. Se sugiere la hipótesis de producción de pigmento mediante el calentamiento del sustrato (rico en hierro de origen mineral) con combustible herbáceo, dando como resultado la formación de hematita. Se asume que las fosas constituyen los lugares de producción y almacenamiento de los pigmentos, los cuales eran usados por los Rapanui para propósitos culturales y rituales. La investigación interdisciplinar en marcha mejorará la interpretación de estas fosas y de sus rellenos.

The biogenic silica extracted from samples of 28 alpine plant species belonging to 23 genera and nine families collected in the Swiss Alps (Valais) accounted for between 0.01 and 5.9% of the dry biomass of leaves and wood. Silica content, and plant contribution to the soil biogenic silica pool, varied widely among taxa. Plant net productivity and biogenic silica production from this study and from the literature have been used to predict the input made by different subalpine and alpine plant communities to soil-borne phytolith assemblages, and their contribution to the silicon biocycle. Copyright 2001 Annals of Botany Company