Searching for ancient forests: A 2000 year history of land use in northeastern French forests deduced from the pollen compositions of closed depressions

Abstract

International audienceEvidence of the agricultural use, during Roman or Medieval times, of forested areas formerly considered to be ancient, as well as legacies of this former land use on plant biodiversity and soil properties, have encouraged the search for archives of former land use in forests. In central Lorraine (northeastern France), thousands of small closed depressions (CD) on marlstone have been inventoried in forests over the past 150 years, and we hypothesised that these CDs could be used to reconstruct patterns of land use. Closed depressions near the Seille and Sarre valleys were selected and cored for pollen and sediment analyses. Principal Components Analysis (PCA) was used to analyse variations of pollen assemblages during the last two millennia. The history of vegetation changes depicts five main phases. During the Roman period, the region appears to have been primarily covered by grasslands, with some croplands but few forests. All areas were reforested by the end of the Roman period. During the early Medieval period, croplands with grasslands developed in the region, while the late Medieval was characterised by cereal cropping, with especially intense use at sites near the Seille valley, and a lesser extension of grasslands. The present forest cover developed over the past 500 years because of the development of the salt industry in the Seille valley, which required firewood, and the general decrease of agricultural pressure over the past 150 years. Previous investigations had provided evidence of large-scale Roman field systems in the forests covering the limestone plateau and the Vosges foothills on sandstone, areas west and east of the research focus, respectively. These convergent findings suggest that that forests considered to be 'ancient' on the basis of historical documents may have been used for pasture or agriculture over extensive periods during the last 2000 years

Novel and Lost Forests in the Upper Midwestern United States, from New Estimates of Settlement-Era Composition, Stem Density, and Biomass

“…While human effects have been a component of these systems for millennia, the EuroAmerican settlement and industrialization period has increased anthropogenic effects by orders of magnitude [10–12]. Legacies of post-settlement land-use in the upper Midwest [13] and elsewhere have been shown to persist at local and regional scales [5,14,15], and nearly all North American forests have been affected by the intensification of land-use in the past three centuries. Hence, contemporary ecological processes in North American forests integrate the contemporary and historical anthropogenic impacts of the EuroAmerican settlement period and natural influences at decadal to centennial scales.…”

Past landscape explains forest periphery‐to‐core gradient of understorey plant communities in a reforestation context

“…For centuries forest landscapes have been continuously modified by natural and human drivers of land use change, resulting in successive periods of deforestation and reforestation (Kaplan et al, 2009;Rhemtulla et al, 2009;Etienne et al, 2013). Over the past 20 years the role of history in ecology has been increasingly emphasized for both a fuller understanding of the current structure and functioning of ecosystems, and the proper evaluation of conservation goals Jackson & Hobbs, 2009;Rhemtulla et al, 2009;Vellend et al, 2013), in particular in landscape ecology (Rhemtulla & Mladenoff, 2007).…”

From the Neolithic to the present day: The impact of human presence on floristic diversity in the sandstone Northern Vosges (France)

“…4, Tab (Kalis, 1985, Ruffaldi et al, 2007, Le Roy Ladurie, 2009, Mäckel et al, 2009. In the Vosges, the Black Forest and the Alsace Plain, as on the Lorraine Plateau, the Early Middle Ages was a period of anthropogenic decline (Rösch, 2007, Ruffaldi et al, 2007, Mäckel et al, 2009, Etienne et al, 2013, Bégeot et al, 2019. Finally, a further decline occurred between 1160 and 950 cal.…”

“…However, the second wave, during the eleventh-twelfth centuries, is observed in the core of the forests. The eleventh century is known as a period of increased anthropogenic pressure and population growth everywhere in the surrounding regions (Etienne et al, 2013, Ruffaldi et al, 2015, Mariet et al, 2016, Bégeot et al, 2019. In the Pays de Bitche, Sturzelbronn Abbey (6 km northeast of our study site, Fig.…”