The influence of historic land-use changes on hillslope erosion and sediment redistribution
The Holocene, 2016
Agricultural societies around the world have dramatically altered the natural landscape, particul... more Agricultural societies around the world have dramatically altered the natural landscape, particularly through accelerated soil erosion. The expansion of agricultural land use into steeper headwater areas during the Medieval period in central Europe is known to have caused large increases in soil erosion and sediment redistribution downstream. Although land-use practices changed and improved following this initial impact, it is currently unknown whether changes in land-use techniques also improved hillslope soil erosion and sediment redistribution rates. In this paper, we use a variety of techniques, including chrono-stratigraphy, wood charcoal analysis and a geostatistical model, to reconstruct land-use and erosion rates for the period spanning the Medieval Period to the present (1100–300 years ago) in a small headwater catchment in central Europe. Coupling land-use, hillslope erosion and sediment redistribution fluxes, we find the largest flux change occurs because of the initial d...
Call for paper tothe International Open Workshop "Socio-Environmental Dynamics over the last 12.000 years: The Creation of Landscape IV" (24th to the 27th March 2015) in Kiel (Germany). http://www.workshop-gshdl.uni-kiel.de Several session including: “The Holocene history of European Mountain Lan...
In the frame of the International Open Workshop "Socio-Environmental Dynamics over the last ... more In the frame of the International Open Workshop "Socio-Environmental Dynamics over the last 12.000 years: The Creation of Landscape IV", from the 24 th to the 27 th March 2015, in Kiel (Germany). http://www.workshop-gshdl.uni-kiel.de We organize a session about: "The Holocene history of European Mountain Landscapes -Dynamics of the environment, settlement, resources and subsistence strategies" http://www.workshop-gshdl.uni-kiel.de/workshop-sessions/session-7 Keynote speakers: Pr. For contributions please use the online submission form: www.workshop-gshdl.uni-kiel.de/registration DEADLINE for paper submissions is JANUARY 15, 2015 Submitters will be informed regarding acceptance of their paper by early February. Registration is open until Mid-February (later registration will be charged with an extra fee). To support the participation of young scholars, two travel grants of max. 200€ per session are available for PhD students (not residing in Schleswig-Holstein or ...
Charcoal fragments are found everywhere in soil and soilsediment archiving contexts. Given that s... more Charcoal fragments are found everywhere in soil and soilsediment archiving contexts. Given that soils and soil sediments are present globally, and charred plant material is very resistant to microbial decomposition, charcoal is a ubiquitous proxy in palaeoenvironmental research. Soil charcoal analysis, or pedoanthracology, addresses ligneous ecosystems. Pedoanthracology allows the investigation of past occurrences of fire events (i.e. fire history; Fesenmyer and Christensen, 2010) and the identification of the correlated burnt woody vegetation (Talon, 2010). The approach is based on the extraction of wood charcoal pieces from on-site-formed soils or soil sediments (e.g. colluvial soils; Leopold and Völkel, 2007), and their subsequent quantification (charcoal concentration per weight unit of sampled earth) and taxonomic identification, usually combined with radiocarbon dating (Carcaillet and Thinon, 1996; Talon et al., 1998). The presence of charcoal pieces in soils results from the occurrence of at least one fire event. The fire induces the formation of charcoal on the soil surface, which is then fragmented with time, buried and preserved over millennia. Charcoal records extracted from soils provide palaeo-signals having fine (a few meters) to relatively large spatial resolution (several hundred meters), depending on the proprieties of the catchment area and on the fire type. Pedoanthracology thus enables to study the composition of past woody plant communities at a fine spatial scale, often finer than other palaeoecological proxies (e.g. pollen) can provide. While the taxonomic analysis of charred wood from archaeological contexts (archaeo-anthracology) can be traced to the 19th century (Unger, 1846; Hollendonner, 1925), and saw a more intense development since the 1970s (Montpellier school), the explicit use of soils as an archive of charcoal records was introduced by Thinon (1978). He called this approach pedoanthracology, as a "new method of phytochronological analysis since the Neolithic". Charcoal records from human related contexts (e.g. settlement sites, charcoal production sites, etc.) are linked to the "human filter" (Théry-Parisot et al., 2010). This justified the development of analysis of charcoal records from other types of archive, which is "natural" soil and soil sediments. Soil charcoal analysis is nowadays regularly applied in the framework of palaeoenvironmental research, but also in current ecology, as indicated by the increasing number of publications on the topic. Among the overall published soil charcoal studies we can cite here,
Summary: Dunes are palaeoarchives hitherto rarely investigated for charcoal. Here we present a st... more Summary: Dunes are palaeoarchives hitherto rarely investigated for charcoal. Here we present a study of charcoals from an inland dune complex in Northern Germany. The charcoal assemblages were analyzed as part of a project which aims at the reconstruction of historical wind erosion in high spatial and temporal resolution. Different layers can be separated, containing considerable amounts of charcoals, which were taxonomically identified. Oak (Quercus) is dominating the spectra, and together with significant ...
The nutrient-poor grasslands of Western Europe are of major conservation concern because land use... more The nutrient-poor grasslands of Western Europe are of major conservation concern because land use changes threaten their high biodiversity. Studies assessing their characteristics show that their past and on-going dynamics are strongly related to human activities. Yet, the initial development patterns of this specific ecosystem remain unclear. Here, we examine findings from previous paleoecological investigations performed at local level on European grassland areas ranging from several hundred square meters to several square kilometers. Comparing data from these locally relevant studies at a regional scale, we investigate these grasslands' spatiotemporal patterns of origin and long-term dynamics. The study is based on taxonomic identification and radiocarbon AMS dating of charcoal pieces from soil/soil sediment archives of nutrient-poor grasslands in Mediterranean and temperate Western Europe (La Crau plain, Mont Lozère, Grands Causses, Vosges Mountains, Franconian Alb, and Upper-Normandy region). We address the following questions: (1) What are the key determinants of the establishment of these nutrient-poor grasslands? (2) What temporal synchronicities might there be? and What is the spatial scale of these grasslands' past dynamics? The nutrient-poor grasslands in temperate Western Europe are found to result from the first anthropogenic woodland clearings during the late Neolithic, revealed by fire events in mesophilious mature forests. In contrast, the sites with Mediterranean affinities appear to have developed at earlier plant successional stages (pine forest, matorral), established before the first human impacts in the same period. However, no general pattern of establishment and dynamics of the nutrient-poor grasslands could be identified. Local mechanisms appear to be the key determinants of the dynamics of these ecosystems. Nevertheless, this paleoecological synthesis provides insights into past climate or human impacts on present-day vegetation.
A multi-disciplinary palaeoecological approach on a sequence of dated archaeosediments was accomp... more A multi-disciplinary palaeoecological approach on a sequence of dated archaeosediments was accomplished. The sediments derive from a multilayered prehistoric settlement mound in central Germany, representing the remnants of a prehistoric village. Based on the analysis of biological remains and geochemical/physical analysis of the settlement layers its environment was reconstructed. There is a trend to increasing anthropogenic activities and impact on the environment represented through a rise of indicators for productive surplus from the Early Neolithic (5300e4900 BC) until the Roman Times (400 AD). During the Early Neolithic, shifting flat settlements were situated in a locally opened landscape. The immediate surrounding of the floodplain was used by the settlers for their economic requirements (e.g. wood from the riparian forest). After a hiatus of ca. 1900 years, a multilayered settlement mount rose from Late Neolithic Times (3000 BC) to Roman Times. Since the Middle Bronze Age (approximately 1500 BC) the riparian forest was obviously replaced by agricultural fields and meadows and henceforward the hinterland used by the settlers probably grew in size. The continuing demand of wood was maintained by the acquisition of more distant sources. The onset of house constructions substituting wood by loam (wattle and daub) might be a possible societal response to this shortfall. This is reflected in the growing thickness and composition of the settlement layers, as well as in the archaeological record (e.g. tumbled wattle and daub house walls). The rising of the groundwater table and the start of severe floods of the adjacent river Helme during pre-Roman Iron Age (approx. 800e100 BC) might reflect a geomorphological response to the increased land use intensity at a regional scale.
This paper presents highly unexpected paleobotanical data. Eight 14 C-accelerator mass spectromet... more This paper presents highly unexpected paleobotanical data. Eight 14 C-accelerator mass spectrometry (AMS) dates of soil macrocharcoal pieces, identified taxonomically, indicate the presence of oak and beech in the Younger Dryas, and pine in the Allerød, in the northernmost low mountain range of Central Europe, the Harz Mountains, in Germany. If the presence of pine at such latitude and periods is not surprising, the presence of temperate-adapted trees is highly improbable, because they are assumed to have reached the area from a southern location several thousand years later. Two hypotheses are postulated to explain this record. Both are related to the warm periods of the Bølling and Allerød: the classically 'short' duration of this warm period makes the migration of the temperate trees from the identified refuge areas in the southern location implausible , and so the presence of intermediary microrefugia at a medium latitude in Central Europe is postulated; recent data reveal that the warm period of the Late Glacial phase was much longer than considered in the classical view and, thus, would be long enough for a northward migration of temperate-adapted trees. Although our dataset does not permit disentanglement of these hypotheses, it provides significant innovative insights for the biogeography of Central Europe.
of the session proposal Dealing with the sustainability of resources and resilience of ecosystems... more of the session proposal Dealing with the sustainability of resources and resilience of ecosystems services, in a changing world, the stakeholders of the environmental management has to define, and then to use, relevant environmental policies permitting notably to integrate socioeconomic and ecological perspectives. But anthropogenic pressure had, and in many cases still has, determining influences on the composition, structure and functioning of most of the ecosystems worldwide, as anthropogenic disturbances. Thus, in many situations, especially in the cases of fragile ecosystems and hotspots of biodiversity, the stakeholders of the environmental management have to deal with issues of biological conservation and / or ecosystem restoration. Challenging these latter issues, ecological engineering has to face the dilemma between biodiversity, ecosystem services providing or naturalness. Indeed, in many situations human activities affect the biodiversity and the functionality including the provision of ecosystem services by a homogenization of systemic composition and structure. However, in some cases biodiversity and functionality have been also favored by human activities. As an example, Mediterranean grasslands present, in general, higher level of biodiversity at small scales than closed-canopy forest areas. However, these Mediterranean grasslands present a low level of naturalness, since they are maintained open " artificially " by human disturbances (grazing, mowing, fire, etc.), on recent and long term temporal scales. There are even generally considered more as "cultural ecosystems" than "natural ecosystems". Moreover, today these human activities do not correspond to any socioeconomic need, at least in industrial and urbanized countries. Thus, the human and financial efforts done to maintain the biodiversity of anthropo-ecosystems appear discussable in the context of global changes related to climate changes and changes in land-uses at the landscape level. In contrary, the management strategy of the biodiversity and habitats loss induced by the abandonment of ecosystems originated from agricultural or industrial exploitations appear also discussable. Therefore, in this session we welcome contributions that provide data, arguments, observations, etc., to make advances on the dilemma between ecosystem biodiversity, ecosystem services providing and naturalness. More precisely, it is aimed to contribute to answer the following questions (among many others): Does ecological sustainability relies on the biological diversity, ecosystem services or/and naturalness, on none of them? Are there antagonisms or a synergy between biodiversity, ecosystem services and naturalness? What are the relevant spatiotemporal scales to approach this dilemma? What are the ranges of relevant management strategy? What should be the priorities of sustainable management of ecological systems: biodiversity conservation, optimization of ecosystem services providing, restauration? A large range of contribution is expected, from various types of ecosystems, of different biomes, and based on various indicators and methods.
The term landscape is used by a diversity of scientific disciplines maintaining different concept... more The term landscape is used by a diversity of scientific disciplines maintaining different concepts and definitions. What is meant by “total character of an area of the Earth” as the explanation of landscape by Alexander von Humboldt? 1 In palaeo-environmental research encompassing a wide range of disciplines, landscape is a crucial term. With increasing interdisciplinary research cooperation between dissimilar disciplines, a basis for communication must be established.
The term landscape is used by a diversity of scientific disciplines maintaining different concept... more The term landscape is used by a diversity of scientific disciplines maintaining different concepts and definitions. What is meant by “total character of an area of the Earth” as the explanation of landscape by Alexander von Humboldt? 1 In palaeo-environmental research encompassing a wide range of disciplines, landscape is a crucial term. With increasing interdisciplinary research cooperation between dissimilar disciplines, a basis for communication must be established. This includes an awareness of the differences of ...
Floodplains are an important feature of arid landscapes, enabling intensive agricultural activity... more Floodplains are an important feature of arid landscapes, enabling intensive agricultural activity by providing a locale with a consistent and largely predictable water source that is accessible without costly infrastructural modifications. Floodplain agriculture, although likely an important part of ancient agricultural systems in the Near East, is notoriously difficult to detect, as the dynamic environments in which floodplains are situated means that these geomorphic features are rarely preserved. However, recent survey in the Wadi el-Hasa, Jordan has revealed a preserved fragment of floodplain surface indicating past floodplain usage during the 7the8th century cal AD. A multi-proxy analysis that incorporates geomorphic, geochemical, and paleobotanical analyses of this exposure has revealed a process of floodplain aggradation and incision modified by human activities and anthropogenic deposition. Analysis of the anthropogenic sediments suggests that the Wadi el-Hasa floodplain has not been adequately considered as a component of economic and subsistence activity during the early Islamic period.
Standard analysis of the sampling inventory in unmanaged forest reserves. The Josenwald example T... more Standard analysis of the sampling inventory in unmanaged forest reserves. The Josenwald example The effects of the forest reserve policy of the Confederation are controlled by monitoring selected forest reserves using a consistent methodology, which includes, as an important part, a sampling inventory. This report presents a standard analysis of the first inventory for the Josenwald reserve in the Canton of St. Gallen, which is 85 ha large and located on a steep south-facing slope in 420 to 1300 m a.s.l. above the Walensee. In this inventory, 9.5% of the forest area was assessed on 87 concentric plots of 200 and 500 m2 area. 54 more plots were inaccessible. For analysis, the data was subdivided into two strata with different site conditions: dry beech associations and oak-lime associations. In the beech forest stratum, the average number per ha of living trees with dbh≥7 cm amounts to 633.4 ± 60.5, in the oak-lime forest to 876.0 ± 57.3. The stem numbers decrease exponentially, the higher the dbh is. The basal areas are, with 33 m2/ha, comparatively low. The growing stock was also low, with 253 m3/ha in the beech forest and 235 m3/ha in the lime-oak forest, since the soils are superficial and dry up easily. In 1947, however, the growing stock was only approx. 113 m3/ha. Thus, it has more than doubled within 60 years. Around 1880, the growing stock was even clearly lower than 100 m3/ha. Despite several decades without timber extraction, trees with a dbh of 36 cm and more are still rare. European beech is the most frequent tree species in the reserve, followed by lime, ash and oak. The tree species composition has changed little since 1947. The volumes of standing and lying dead wood amount to 98.1 m3/ha in the stratum beech forest and to 62.4 m3/ha in the stratum lime-oak forest. These values are similar to those found on similar sites in old-growth forests in the western Carpathian mountains, but much higher than the Swiss average of 11.9 m3/ha. Most of the dead wood is lying. This suggests a prevalence of wind and avalanche disturbances, which is confirmed by the high average density of 73 root plates/ha. In total, 119 habitat structures per ha were found in the beech forest stratum, and 60 in the lime-oak forest. Root plates were the most frequent habitat structures, followed by cavities with mulm body, stem cavities and snags with at least 36 cm dbh as well as crown dead wood. All other habitat structures, and thus more than half of the structure types, were infrequent. Trees with dbh of at least 80 cm dbh were very scarce. Twenty-six percent of all living trees with dbh≥36 cm (103 out of 394 trees) had at least one habitat structure, and 26% of all trees with habitat structures had more than one. The inventory proves a high naturalness of the forest reserve Josenwald with respect to tree species composition and dead wood volumes. Habitat structures seem also to occur quite frequently, but comparative data from other forests are unavailable. The newly developed sampling inventory is feasible and provides meaningful results, but the report also suggests improvements for further inventories.
The charcoal content of an inland dune complex close to Joldelund in Northern Germany was analyse... more The charcoal content of an inland dune complex close to Joldelund in Northern Germany was analysed as part of a project which aims to reconstruct Holocene aeolian activity in high spatial and temporal resolution. The eleven investigated profiles contained numerous charcoal-enriched layers, providing evidence for the potential of inland dunes as palaeoarchives for anthracology. Earlier studies have found Late Roman Iron Age settlement activity and iron ore productions in the research area and in its vicinity. Charcoal assemblages date to Roman Iron Age as well as Early, High and Late Medieval Times, according to radiocarbon dating of single, species-identified charcoal fragments and the stratigraphic correlation of sedimentary units. Thedominance of Quercus (oak) and significant proportions of Ericaceae-charcoal (probably Calluna vulgaris, heather) especially in the Early and High Medieval samples indicate the presence of a heathland with Quercus trees, which was managed by fire. In the younger layers of sand, a greater diversity of taxa were found, including the dominant Quercus, Fagus (beech), Alnus (alder), Betula (birch), Corylus (hazel), Fraxinus (ash), Salix (willow), Populus-Salix (poplar-willow-type), Acer (maple), Pinus (pine), Maloideae (apple subfamily), Tilia (lime), as well as some Ericaceae. The diversity of species indicates that some charcoals were transported by wind together with the sand from the surrounding areas, and do not represent the local vegetation on the dunes, but rather a nonspecific regional input. The differences in the charcoal assemblages and thus the possible correlation of aeolian units support the stratigraphic correlation of the sedimentary aeolian units. The comparison with the available pollen data from nearby mires showed a good agreement of the proportions of woody taxa, with only few exceptions.
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