Molecular biomarkers are a relatively new proxy in reconstructions of past environments and land-use change. Principles of biomarker analysis are explained. Three examples are elaborated to illustrate the application of biomarker analysis in combination with other proxies: (1) establishment of the Holocene upper forest line position in a deforested landscape in Ecuador, (2) understanding of soil stratigraphy and past disturbance in soil profiles in the Netherlands, and (3) reconstruction of a sediment-infill of a dead meander in a cultivated lowland area in the Dominican Republic. Molecular biomarkers analysis is in need of expanded modern calibration datasets. In combination with more traditional proxies biomarker analysis may improve environmental reconstructions from sediment archives substantially.
The local occurrence of red subsoils on the Late Pleistocene sandy deposits of the Northern European lowlands invites investigation into the formation and paleoenvironmental significance of these soils. According to the World Reference Base for Soil Resources (WRB), these soils are classified as Rhodic Brunic Arenosols or Chromic Brunic Arenosols; however, because of their unclear origins, these soils are still not considered in the German Guidelines for Soil Mapping. We aim to characterize the genesis of these rubified soils by combining pedological findings with chemical analyses and micromorphological studies at four sites in southeastern Brandenburg, Germany. Our novel analytical approach differentiates pedogenic iron (hydr-)oxides using a combination of Fourier transform infrared-multiple internal reflection (FTIR-MIR) spectroscopy and sequential sample heating (from 21 °C to 100 °C, 250 °C, 500 °C, and 950 °C). Together with a comparison of synthetic iron (hydr-)oxides, the results of this analytical approach demonstrate that the mineralogy of these Rhodic Brunic Arenosols and Chromic Brunic Arenosols are characterized mainly by hematite; some goethite and minor amounts of maghemite are also present. Our results confirm recent findings from Jankowski (2013) that rubification is not primarily a relict process in Central European soils; consequently, the German Guidelines for Soil Mapping require revision. The high total iron contents in the rubified soils suggest strongly that the iron is allochthonous in origin, emphasizing the importance of lateral inputs of iron compounds in the genesis of these soils. This finding is highly consistent with the ‘translocation catena’ concept (Sommer and Schlichting, 1997); i.e., the Rhodic Brunic Arenosols and Chromic Brunic Arenosols studied here formed due to inputs of allochthonous compounds. These rubified soils examined in this study share some genetic features with other soils described from Central Europe, such as the ‘Lockerbraunerden’ or the ‘Ockererden’. Further research should focus on these commonalities and compare the genetic pathways of such soils to support the argument that these soils should be considered in a separate soil class in the German Guidelines for Soil Mapping.
'Reading the soil archives' provides details of new techniques for understanding geoecological history in the form of quantitative pollen analyses, soil micromorphology, radiocarbon and optically stimulated luminescence dating and biomarker and phytolith analysis. It presents the genesis of cultural landscapes, based on multiproxy analysis of palaeosols and integration of geomorphological, pedological and archaeological research results, which can be a model for geo ecological land scape studies. This book provides details of new techniques to understand geological history in the form of quantitative pollen analysis, soil micromorphology, radiocarbon and optically stimulated luminescence dating, biomarker and phytoliths analysis. It presents the genesis of cultural landscapes, based on multiproxy analysis of palaeosols and integration of geomorphological, pedological and archaeological research results, which can be a model for landscape studies. Beginning with analytical methods for interpreting soil archives, Reading the Soil Archives examines methods for reconstructing the landscape genesis. It presents strength and weakness of the applications, especially in relation to data from case studies in the Netherlands. The final chapter of the book addresses landscape evolution in different cultural periods. Reading the Soil Archives offers an integrated approach to geoecological knowledge that is valuable to students and professionals in Quaternary science, physical geography, soil science archaeology, historical geography and land planning and reconstructuring.
Cultural layers are deposits resulting from settlement and human activity on natural soil in the past. Materials from past domestic activities that become buried into the soil can be used to reconstruct human impact in a specific area in the past. For instance, humans have used fire for millennia, and charcoal in soils and sediments is applied as evidence of anthropic activity. In this context, assessing the abundance and degradation level of charcoal fragments can clarify anthropic activities in cultural deposits. In European towns, cultural layers with similar characteristics, have been defined as urban "Dark Earth" (UDE) but their age, formation and composition often differ significantly across sites.This study examined three archaeological sites in Verona, Italy, where UDE layers with similar characteristics have been identified. The primary aim of this research is to understand the anthropogenic influence on the development of UDE layers, by characterizing their geochemistry and the carbonaceous materials. To pursue this goal, we provide a micromorphological description of the sites, evaluate UDE features and the abundance of charred material and characterize the amorphous/crystalline degree through µ-Raman spectroscopy. Bulk material was described in terms of amounts of total organic carbon (TOC), recalcitrant organic carbon (ROC), total inorganic carbon (TIC), and trace element concentration. Radiocarbon dating of charred and humin fractions was performed to clarify the dynamics underlying UDE origin. We investigate the relationship between the different variables analyzed in the UDE layers at each site. Results show that a diverse array of human activities including metal tool and/or ceramic manufacturing were related to the formation of UDE layers. The investigation of carbonaceous fractions highlight differences in soil organic carbon and charred material, both of which are correlated with human influence.
The state of global warming in the last few years is appalling. The temperature increase on the Earth carries a serious ecological imbalance including decomposition of organic matter. The fate of the terrestrial carbon consists of an important issue due to the possibility of the occurrence of feedback mechanisms to atmospheric CO2 concentrations. The sensitivity of soil carbon to warming consists of suspense in the prediction of future carbon dioxide concentration and further climate changes. So far, many ecosystem models proposed show a positive impact of global warming on the microbial organic matter decomposition. However, a terrestrial experiment does not coincide with those reports—they show an initial limitation of CO2 loss from the soil as a consequence of warming. This work concluded an influence of climate warming on organic decomposition as well as a difference between labile and nonlabile soil organic carbon decomposition under global warming. Attention is also paid on the possible consequence that could be even stronger than predicted.
The drift sand area near Hilversum, the Netherlands, holds a geo-archive with multiple drift sand phases and intercalated palaeosols. We studied this area to test earlier theories on the development of podzols in such aeolian sands, the occurrence of sand drifting, and the contemporary vegetation development, and to gain insight into the early human impacts on these fragile ecosystems. Based on OSL and radiocarbon datings, palaeoecological studies, and soil chemical analyses, the age and origin of the drift sand phases and palaeosols were established. Sand drifting started around 6000 BCE (Late Mesolithic), the drift sand covering a distinct podzol in the Younger Cover Sand II. A second Late Mesolithic drift sand phase dated from ca. 4900–4500 BCE. Three later drift sand phases were distinguished of which the last is the classic Late Medieval (and younger) phase, while the first two date from the Neolithic. All intercalated palaeosols exhibited more or less prominent podzolisation. The palaeocological data showed that, prior to the Neolithic, in the forest open patches had developed with non-arboreal vegetation, dominated by Poaceae and Ericaceae. This changed during the Neolithic, most probably linked to the introduction of crop farming, the vegetation gradually acquiring the characteristics of the classic heathland with patches of trees/shrubs. The early sand drifting, podzolisation and opening of the forest are attributed to Mesolithic land use, with intentional burning as major factor. We conclude that the local destruction of the deciduous forests by fire and associated creation of open patches with bare sand were essential for the early sand drifting and podzolisation to occur. The results shed new light on the origin of drift sands, heathlands, and podzols in the Netherlands, and on the environmental impacts of Mesolithic people, and testify to the fundamental instability of these dry inland dune ecosystems.
Proglacial areas represent the counterpart of glacial retreat, where a new environmental equilibrium will be reached. During this long and complex stage, which represents the response to ongoing climate change, several abiotic and biotic processes occur in these freshly exposed fragile environments. Proglacial areas, considered as open-air laboratories, have been attracting the attention of scientists in the last decades, and the diversity of their features allows us to classify them based on different aspects of geodiversity (i.e., bedrock diversity, geomorphodiversity, hydrogeodiversity, pedodiversity). In this paper, we review the diversity of features of proglacial areas using several examples mainly from the European Alps. The geosystem services (i.e., regulating, supporting, provisioning and cultural) provided by these areas to society are also discussed, revealing the value of these regions as part of geoheritage. As these fragile and vulnerable areas are highly relevant to society, it is important to monitor them, and to set up adequate management strategies, including geoconservation, but also sustainable promotion.
The micromorphological and microtomographic studies of differently aged extremely aridic soils in the Trans-Altai Gobi Desert of Mongolia allowed us to determine the rates and sequences of processes associated with sedimentogenesis and pedogenetic transformation of the parent material. In the most developed extremely aridic soils, the topsoil or the surface Aye horizon consisting of the layers of different compositions and geneses (eolian and colluvial sediments) displays vesicular voids, which are virtually absent in the young soils. Two different mechanisms of the origin of vesicular voids are suggested: (a) in the case of the fresh eolian material, the bicarbonate–calcium equilibrium is displaced towards the formation of calcite with the release of CO2 under the impact of changes in the moisture and temperature; (b) in the case of the dense silty clay material, the release of sorbed air (nitrogen and oxygen) from the dry soil particles takes place under the impact of atmospheric precipitation. The locally acting pedogenesis in these soils specify the development of hypocoatings and typical coatings consisting of the amorphized phyllosilicates with the disordered structure inside the vesicular voids and the formation of iron microconcentrations and iron films on mineral grains.
Soils form the skin of the Earth’s surface, regulating water and biogeochemical cycles and generating production of food, timber, and textiles around the world. Changes in soil and its ability to perform a range of processes have important implications for Earth system function, especially in the critical zone (CZ)—the area that extends from the top of the canopy to the bottom of groundwater and that harbors most of Earth’s biosphere. A key aspect of the way soil functions results from its structure, defined as the size, shape, and arrangement of soil particles and pores. The network of pores provides storage space for at least a quarter of Earth’s biodiversity, while the abundance, size and connectivity of the pore space regulates fluxes of heat, water, nutrients and gases that define the physical and chemical environment. Here we review the nature of soil structure, focusing on its co-evolution with the plants and microbes that live within the soil, and the degree to which these processes have been incorporated into flow and transport models. Though it is well known that soil structure can change with wetting and drying events, often oscillating seasonally, the dynamic nature of soil structure that we discuss is a systematic shift that results in changes in its hydro-bio-geochemical function over decades to centuries, timescales over which major changes in carbon and nutrient cycles have been observed in the Anthropocene. We argue that the variable nature of soil structure, and its dynamics, need to be better understood and captured by land surface and ecosystem models, which currently describe soil structure as static. We further argue that modelers and empiricists both are well-poised to quantify and incorporate these dynamics into their studies. From these efforts, four fundamental questions emerge: 1) How do rates of soil aggregate formation and collapse, and their overall arrangements, interact in the Anthropocene to regulate CZ functioning from soil particle to continental scales? 2) How do alterations in rooting-depth distributions in the Anthropocene influence pore structure to control hydrological partitioning, biogeochemical transformations and fluxes, exchanges of energy and carbon with the atmosphere and climate, regolith weathering, and thus regulation of CZ functioning? 3) How does changing microbial functioning in a high CO2, warmer world with shifting precipitation patterns influence soil organic carbon dynamics and void-aggregate profile dynamics? 4) How deeply does human influence in the Anthropocene propagate into the subsurface, how does this depth relate to profile structure, and how does this alter the rate at which the CZ develops? The United Nations has recently recognized that 33% of the Earth's soils are already degraded and over 90% could become degraded by 2050. This recognition highlights the importance of addressing these proposed questions, which will promote a predictive understanding of soil structure.
As important palaeoenvironmental proxies, non-marine ostracods provide several independent lines of evidence of palaeoclimatic and hydrological change in Quaternary records. Species diversity, biogeography, ecology and shell geochemistry (δ18O, δ13C, Mg/Ca, Sr/Ca and 87Sr/86Sr) are all potential sources of information concerning past environmental conditions. However, often there is not a strong covariance between changes in species assemblages and their corresponding suite of geochemical measurements; that is, in some records, there is little change in the shell geochemistry, whereas the species assemblages show significant change, and vice versa. Thus, multivariate statistical analyses used to develop transfer functions or modern analogues, based upon species assemblages, may or may not correspond to changes in the shell geochemistry. However, this lack of covariance is in itself informative and by examining the observed changes in ostracod shell geochemical measurements and species assemblages, it is possible to identify and track process dynamics in palaeolimnological records.
We explore how molecular techniques can be applied to ostracod DNA to infer past climatic and environmental fluctuations at several time scales. Cladoceran DNA has been extracted from resting eggs up to several thousand years old but no such work on Ostracoda has yet been published. Ostracod eggs are not encased in large protective ephippia as in Cladocera, and only some are protected by thick walls. Collapsed eggs with thin walls will be more difficult to sort individually from sediments; direct extraction of DNA is likely to work only on thick-walled eggs, but could also be possible from juveniles hatched from eggs several hundred years old. The potential for direct extraction of DNA from fossils (valves, remnant soft parts) is considered. A potential method to infer large climate-induced effects on ancient lakes (e.g. large lake-level fluctuations) involves DNA analyses of extant populations, combining phylogenetic and population genetic (coalescent) techniques.
Laboratory and ‘natural environment’ cultures demonstrate that isotopic compositions of ostracod shells record environmental conditions at the time of their precipitation. Oxygen isotope composition of ostracod calcite reflects the composition and temperature of the host water, but ostracod shells are enriched in 18 O compared to the value expected for inorganic calcite precipitating under equilibrium in the same conditions. This ‘vital effect’ is generally constant for closely related species. The carbon isotope composition of ostracod calcite is controlled by complex interaction between species ecology and environmental parameters. Many taxa crystallise their shells in or very close to equilibrium with the carbon isotope composition of Dissolved Inorganic Carbon (DIC), and the composition of littoral, epifaunal species reflects seasonal variation in the carbon isotope composition of bottom water DIC according to their life cycles, while that of deep-water, infaunal species reflects variation in interstitial pore water according to microhabitat preferences.
Sediments from Valle di Castiglione in Italy provide a reference sequence for Middle Pleistocene to Holocene palaeoclimate reconstruction of the Mediterranean area. Stable isotope and trace element signals from ostracod valves, as well as palaeoenvironmental analyses (autoecology, community analysis and mutual ostracod temperature range), provided results that cannot be correlated with those derived from pollen and other proxy records. The lack of correlation is attributed to the peculiar geological, hydrogeological and hydrochemical setting of the Valle di Castiglione maar lake. The main trigger for the hydrochemical changes in the waterbody and, therefore, in the ostracod isotopic and trace element signatures, is likely the volcano-tectonic activity in the area. This illustrates how ostracod trace element and isotopic analyses are not the most appropriate tools for palaeoclimate reconstructions from lakes with complex hydrological features, such as some crater lakes, and demonstrates the need for care in selecting lacustrine sequences for such studies.
Creativity and innovation are conventionally viewed as consequences of individual mental processes and actions. Certain time and places are also remarkable for the pace of culture change and variety of cultural accomplishments, whereas others appear quite static. From this second macroscopic perspective, creativity can be seen as an emergent property of large numbers of interactions among individuals. Palaeoanthropologists are in a much better position to study emergent forms of innovation than individual creativity. This chapter reviews recent research concerning the effects of demographic factors and network structures on diversity and rates of change in behaviour. These studies demonstrate that the sizes, stability and interconnectedness of past human populations could directly influence the development, spread and persistence of novel forms of behaviour. Demographic conditions and social strategies are thus likely to have influenced rates of culture change and the scale of diversity over the course of human evolution. From this perspective, creativity and innovation can be seen as having multiple origins, both causally and temporally.
Ostracod analyses from a lake sediment core are used to reconstruct Holocene changes in monsoon intensity from a Tibetan Plateau lake. Lowest δ 18 O values, relatively high δ 13 C values and a low diversity ostracod fauna suggest high freshwater input prior to ∼ 5400 calendar years BP. From ∼ 5400 to ∼ 3800 BP, δ 18 O values increase due to evaporative enrichment, associated with an increase in ostracod diversity from one species ( Leucocytherella sinensis ) to eight species. From ∼ 3800 to ∼ 1400 BP, the increase in δ 18 O continues, and a negative shift of δ 13 C marks a transition to drier climate related to weakening monsoon strength. Between 1400 and 800 BP, ostracod abundances of Leucocythere? dorsotuberosa and L.? dorsotuberosa f. postilirata increase, suggesting rising lake level under wetter conditions. The past 800 calendar years BP are characterized by variable but generally rising lake levels interrupted by a lake-level drop for ∼ 300 years during the Little Ice Age.
In the modern world, creativity often culminates in material things or ideas about how to make them, and therefore should be of major interest of archaeologists, who deal with the material record of the past. Being the first recognizable techno-complex of hominin material culture, the Oldowan constitutes an interesting case for investigating creativity in early hominins. It presents, for the first time in the hominin record, a set of material culture signatures that make it a recognizable archaeological entity, such as the existence of “sites”, a novel behaviour of the systematic flaking of stone, and, arguably, an expansion of the dietary niche through the processing of animal resources. In this paper I rely on psychological and ecological approaches of creativity, which define different problem-solving procedures, to explore a range of feasible scenarios related to two questions about the Oldowan. Based on the known behaviours of non-human primates, I first attempt to identify derived behaviours (inventions) that can be considered truly creative events in the Oldowan record. I then focus on the question of whether the spread of the Oldowan after 2.5 Ma was due to social learning and cultural transmission, as opposed to independent re-inventions that can be defined as acts of mundane creativity. It is concluded that the majority of early Oldowan innovations are the continuation or extension of behavioural patterns that might have been shared by early hominins and nonhuman primates. Oldowan stone-tool making is the only major disjunction from behaviours of nonhuman primates and pre-Oldowan hominins. This first invention is followed by a long time of stasis in stone tool technology. Nevertheless, several organizational innovations in land-use patterns and in dietary spectra did occur. The emergence of the Oldowan represents a momentous threshold in hominin evolution because it involved exceptional creativity, essentially different from cognitive patterns shared with other hominids. This first occurrence marks a creative act in the sense that it provided an unexpected and interesting solution to problems faced by hominins. Innovations inferred from the Oldowan record after this event are mostly attributed to mundane creativity.
