The natural vegetation has been substantially changed over the last millenium, especially from forest to agricultural areas in Europe. To study the effects of deforestation on carbon and climate ...system, it is essential to construct spatially precise maps in forest cover. The current representative historical forest data sets are either derivatives of agricultural datasets or are produced based on the deforestation-population relationship. Almost no attempts have been made to use the inherently linked relationship between deforestation and cropland expansion that has run through Europe for millennia. This study created an approach based on the relationship between cultivation intensity and forest fraction to reconstruct forest cover changes in central and southeast Europe from AD 1800 to 2000 by the following steps: (1) To develop the spatial relationship curve (spatial resolution is 1°) between the “cultivation intensity (0–100%)” and the “forest fraction (0–100%)” derived from modern land cover datasets; (2) To generate the national-scale cropland data based on historical records from AD 1800 to 2000, and to allocate them to a 1° pixel; (3) To reconstruct the forest cover using the aforementioned relationship curve and the historical gridded cropland database. The results show that: (1) The forest fraction in central and southeast Europe decreased from 38.4% in AD 1800 to 27.0% in AD 1900, and then increased to 32.5% in AD 2000. (2) In AD 1800, large areas of forests can be primarily found in Luxembourg, Netherlands and Belgium, the south of France, the south of Germany, the Alps region, Poland, and the majority of the Balkans. (3) Throughout the 19th century, the entire region was generally subjected to deforestation, with large areas of forest coverage only being preserved in the Alps and the western and southern Balkans after 100 years of exploration. (4) The forest coverage in most of the study regions increased again at the end of the 20th century.
The incorporation of plant biomass into soil usually leads to long-chain
n-alkanes with a relative predominance of odd carbon numbered homologues. Contrastingly, an increase in short-chain even ...carbon numbered
n-alkanes was found in charred biomass with progressing temperatures. We applied lipid analysis to buried ancient topsoils that contained charred organic matter and to corresponding control soils, which were characterized by a lighter color and lower contents of charred materials. Commonly, the proportion of lipid extracts was found to be lower in the ancient soil than in the control samples, which indicated an enhanced degradation of organic matter, e.g., by thermal degradation. All samples displayed a particular pattern of short-chain and even carbon numbered
n-alkanes (maximum at
n-C
16 or
n-C
18). The ratios CPI (carbon preference index) and ACL (average chain length) for the investigated soil samples matched the ratios found for maize and rye straw charred at 400
°C or 500
°C, respectively. These molecular ratios indicate the presence of charred biomass. The predominance of short-chain and even carbon numbered
n-alkanes was a result of thermal degradation of biomass. The degradation products were preserved in ancient soils and could be applied as molecular markers in archaeological or palaeoenvironmental research.
Neolithic and Bronze Age topsoil relicts revealed enhanced extractable phosphorus (P) and plant available inorganic P fractions, thus raising the question whether there was targeted soil amelioration ...in prehistoric times. This study aimed (i) at assessing the overall nutrient status and the soil organic matter content of these arable topsoil relicts, and (ii) at tracing ancient soil fertilizing practices by respective stable isotope and biomarker analyses. Prehistoric arable topsoils were preserved in archaeological pit fillings, whereas adjacent subsoils served as controls. One Early Weichselian humic zone represented the soil status before the introduction of agriculture. Recent topsoils served as an additional reference. The applied multi-proxy approach comprised total P and micronutrient contents, stable N isotope ratios, amino acid, steroid, and black carbon analyses as well as soil color measurements. Total contents of P and selected micronutrients (I, Cu, Mn, Mo, Se, Zn) of the arable soil relicts were above the limits for which nutrient deficiencies could be assumed. All pit fillings exhibited elevated δ15N values close to those of recent topsoils (δ15N>6 to 7‰), giving first hints for prehistoric organic N-input. Ancient legume cultivation as a potential source for N input could not be verified by means of amino acid analysis. In contrast, bile acids as markers for faecal input exhibited larger concentrations in the pit fillings compared with the reference and control soils indicating faeces (i.e. manure) input to Neolithic arable topsoils. Also black carbon contents were elevated, amounting up to 38% of soil organic carbon, therewith explaining the dark soil color in the pit fillings and pointing to inputs of burned biomass. The combination of different geochemical analyses revealed a sufficient nutrient status of prehistoric arable soils, as well as signs of amelioration (inputs of organic material like charcoal and faeces-containing manure).
•Black carbon (BC) was preserved in up to 130,000yr old loess–palaeosol.•No vertical translocation of BC to loess and palaeo-subsoils found.•Palaeosol BC provided comprehensive regional information ...on past fire regimes.•Maximum BC amount occurred at times of intensive pedogenesis.
Past environmental changes were frequently accompanied by changes in fire regimes. However, the extent to which the residue of ancient fires (black carbon, BC) is abundant in Pleistocene palaeosols remains largely unknown, and whether, and to which degree its occurrence and composition relates to pedogenetic processes and palaeoenvironmental change. We studied three Pleistocene loess–palaeosol sequences from western Germany for systematic variation in BC quantity and quality during Marine Isotope Stages 5e to 4 (ca. 130–65ka BP), using the benzene polycarboxylic acid (BPCA) oxidation method. Palaeopedogenetic processes were elucidated from grain size distribution, colour, organic and inorganic carbon and Ba/Sr ratio. The results showed that BC peaked during phases of soil formation, indicated by increases in Ba/Sr, carbonate loss and colour change. Its concentration reached 0.6–2.1g BC C/kg of former topsoil. The content was close to the detection limit in the parent loess and subsoil, suggesting that there was little if any vertical translocation. Parameters for BC quality (i.e. proportion of mellitic acid) were typical for BC derived from the burning of grass and leaves, as common for tundra-like and forest steppe vegetation dominating in stadials and interstadials of the Weichselian Glaciation. We conclude that BC was preserved in, and bears comparable information in, the three palaeosols. Hence, we recommend BPCA analysis of terrestrial archives for regional fire regime assessment in the Pleistocene.
Long-term slash-and-burn experiments, when compared with intensive tillage without manuring, resulted in a huge data set relating to potential crop yields, depending on soil quality, crop type, and ...agricultural measures. Cultivation without manuring or fallow phases did not produce satisfying yields, and mono-season cropping on freshly cleared and burned plots resulted in rather high yields, comparable to those produced during modern industrial agriculture - at least ten-fold the ones estimated for the medieval period. Continuous cultivation on the same plot, using imported wood from adjacent areas as fuel, causes decreasing yields over several years. The high yield of the first harvest of a slash-and-burn agriculture is caused by nutrient input through the ash produced and mobilization from the organic matter of the topsoil, due to high soil temperatures during the burning process and higher topsoil temperatures due to the soil’s black surface. The harvested crops are pure, without contamination of any weeds. Considering the amount of work required to fight weeds without burning, the slash-and-burn technique yields much better results than any other tested agricultural approach. Therefore, in dense woodland, without optimal soils and climate, slash-and-burn agriculture seems to be the best, if not the only, feasible method to start agriculture, for example, during the Late Neolithic, when agriculture expanded from the loess belt into landscapes less suitable for agriculture. Extensive and cultivation with manuring is more practical in an already-open landscape and with a denser population, but its efficiency in terms of the ratio of the manpower input to food output, is worse. Slash-and-burn agriculture is not only a phenomenon of temperate European agriculture during the Neolithic, but played a major role in land-use in forested regions worldwide, creating anthromes on a huge spatial scale.
•Ridge and furrows were studied by morphological and physicochemical analyses.•Study sites revealed a diversity in morphology, environmental setting and use.•Ridge and furrow cultivation was and is ...influencing the environment.•Elevated amounts of P and δ15N indicate the application of manure in the past.
Ridge and furrow cultivation is an example for a historic agriculture technique that has been very common in Germany, especially during medieval times. It seemed to be well-known how the ridge and furrows (RIFUs) were used and formed but previous studies came to contradictory conclusions which raised additional questions concerning their formation. Furthermore, the RIFUs’ morphological and physicochemical soil properties and their influence on current soils that developed after the RIFUs had been abandoned are not fully understood. In order to answer these questions, morphological and physicochemical analyses (pH, EC, TOC, TN, δ15N, C:N ratios, “Olsen P”, soil texture) were conducted on 11 preserved RIFUs in forested areas of Northern and Central Germany. The results showed that the studied RIFUs occur on sites with different properties (e.g. soil texture, inclination, vegetation) and presented various morphological shapes. They are also characterised by differences in the formation of soil horizons and general low TN (<1.5 g kg−1) and TOC (<10 g kg−1) contents. However, higher contents at some sites comparing to their references, indicated that the RIFU cultivation promoted a slight long-lasting soil improvement if not induced by secondary soil processes after RIFU use. Moreover, for some sites, high P and δ15N values may suggest the application of manure. Recent morphological changes also had a significant influence on some study sites. In summary, neither the formation and agricultural strategies of RIFU cultivation nor their function and any influences on the current soil and woodland characteristics can be regarded as identical for all RIFU sites.
The beginnings of food production—animal husbandry and crop cultivation—and of a sedentary way of life represent one of the most drastic changes in human history. Likewise, this is accompanied by an ...increasing human impact on nature, which is mainly caused by agricultural practices. Agriculture is related to the clearing of forests, tillage, maintenance of the cultivated land, and finally harvesting, which alters not only the vegetation cover but also soil fertility as there is a potential risk for a loss of nutrients. People already countered this loss of nutrients in the times of early agriculture through different techniques and practices. The article summarizes the earliest evidence of fertilization in the prehistory of Central Europe and presents the most important methods for their investigation. What significance fertilization had for early farming societies can presently not be estimated due to the small amount of data. We therefore advocate the development of a routine for sampling during archaeological excavations and for the analysis of various materials (sediment and plant remains) using various methods. For this, the awareness must be raised that anthropogenic sediments, such as pit fills, are important archives for research into the history of humankind.
Testing potential prehistoric fertilization techniques (slash‐and‐burn cultivation) in the Forchtenberg experiment (left: burnt field; right: unburnt field; photos: Renate Gerlach).
Anthropogenic burning, including slash-and-burn, was deliberately used in (pre)historic Central Europe. Biomass burning has affected the global carbon cycle since, presumably, the early Holocene. The ...understanding of processes and rates of charcoal formation in temperate deciduous forests is limited, as is the extent of prehistoric human impact on the environment. We took advantage of an experimental burning to simulate Neolithic slash-and-burn, and we quantified the biomass fuel and charcoal produced, determined the resulting distribution of the charcoal size fractions and calculated the carbon mass balance. Two-thirds of the charcoal particles (6.71 t/ha) were larger than 2000 μm and the spatial distribution of charcoal was highly variable (15—90% per m2). The conversion rate of the biomass fuel to charcoal mass was 4.8%, or 8.1% for the conversion of biomass carbon to charcoal carbon, and 58.4 t C/ha was lost during the fire, presumably as a component of aerosols or gases.
Ridge and furrow cultivation is the most widely used agricultural technique in medieval and postmedieval Europe, but the fertilization of soils during their use is not yet fully understood. ...Pedological analyses of this cultivation technique provided information, which led to the assumption that some of the investigated sites in Northern and Central Germany were manured with livestock excrements during cultivation. The objective of this study is to determine whether and how the soils have been fertilized and which materials were applied for this purpose. We investigated soils at five sites using phosphate and steroid analyses (stanols and bile acids), black carbon analyses, and a micromorphology study. The results showed that livestock waste was likely used as fertilizer at four of the five studied sites at low intensities, with pigs and herbivores being the probable sources of the excrement. But also the application of human feces to the soil might be possible at least at one site. Often used agricultural methods such as plaggen cultivation and an intentional charcoal input to enhance soil fertility could not be clearly verified for our study sites.
Two loess-paleosol-sequences from the northern Harz foreland, Hecklingen and Zilly, have been investigated. In general, loess-paleosol-sequences represent valuable terrestrial archives of regional ...environmental and climatic conditions during past glacial periods. The study area is part of the northern European loess belt and was in the vicinity of the Scandinavian ice sheet during the Weichselian. Aiming towards a better understanding of the paleoenvironmental conditions during the Weichselian in an area close to the Scandinavian ice sheet, results from grain-size, geochemical (XRF, CNS), color and magnetic susceptibility measurements are combined. The findings demonstrate an increased input of aeolian material during the last glacial maximum and the last cover loess period, which is in accordance to the theory of drier and colder conditions during this time frame. Further, data reveal a strong input not only of loess but also of coarser material coming from a shorter distance during the last glacial maximum in both profiles. Material of the last glacial maximum clearly indicates a shift of wind direction towards easterly winds. In Hecklingen, an enhancement of coarser material has been observed within the recent soil and MIS 3 soil material. Since soil material that dates back to the MIS 3 is present in the profile, it can be assumed that surface processes were less intrusive during the MIS 3 and 2 than in e.g. the Lower Rhine Embayment and Saxony.
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