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As today, in antiquity the importance of coastal and deltaic environments lay in the sea’s integrating role in the subsistence, resources, and trade opportunities of its people. For the first large towns of the late Bronze/early Iron Age in Central Italy, salt was an indispensable commodity being the only means available to preserve food, both for consumption and trade. It was produced in the coastal areas but the early production sites, techniques employed, and trade are still uncertain/poorly understood. In the southern part of the Tiber delta palaeo-lagoon of Ostia, at the archeological site of Piscina Torta, heaps made of hundreds of thousands of potsherds were found, possibly related to the salt production technique known as briquetage and pointing at the existence of a major early salt production and trading industry. This coastal area likely holds an outstanding record of the Late Holocene paleoenvironmental changes and of the interaction between climatic variations and coastal processes in an area actively modified and adapted by human activity. An intensive coring campaign at the site and subsequent analyses led to the identification of three stages in the development of the lagoon and its palaeo-inlet towards the sea. During the first phase, the lagoon was well connected to the sea and filled with marine sands. Later on, the inlet was blocked by a newly formed beach ridge, and peat accumulation started. During this second stage, the margins of both the lagoon and inlet were characterized by a highly evaporative environment with carbonate precipitation. Most probably, these sediments were used and leached for producing the brine needed for the salt production by briquetage, a method which consists in boiling such brine in typical reddish jars to obtain a salt cake. Furthermore, heaps composed of both inlet fill, and pottery found around the archeological site suggest how the channel connecting the sea with the lagoon may have been modified by anthropic activities. In a last (third) phase, presumably of medieval age, a marine transgression led to inundation of the lagoon and deposition of highly fossiliferous fine textured sediments.In this contribution, we show the results of a detailed geochemical and micropaleontological analysis (benthic foraminifers) of a continuous section sampled in the ancient lagoon of Ostia, in the form of a paleoenvironmental reconstruction of the area before, during and after its human occupation. Radiocarbon dates provide a firm time frame for the palaeo-lagoon evolutionary phases, while grain size analyses performed both on the inlet fill and the sediment heaps found at the site, revealed new details regarding the human modification of the landscape.

An ideal nanomedicine system improves the therapeutic efficacy of a drug. However, most nanomedicines enter the cell via endosomal/lysosomal pathways and typically only a small fraction of the cargo enters the cytosol inducing a therapeutic effect. To circumvent these inefficient drug delivery pathways, alternative approaches are desired. Inspired by fusion machinery found in nature, various synthetic fusogens have been developed to mediate the fusion of vesicles. Previously we used lipidated versions of the heterodimeric peptide pair E4/K4 to induce membrane fusion and applied this approach to deliver drugs in vitro and in vivo. Peptide K4 was designed to interact specifically with peptide E, but it was also shown to have an affinity for lipid membranes resulting in membrane remodeling. As the next step towards efficient in vivo membrane fusion for potential therapeutic applications, our rationale was to design efficient fusogen variants that could have multiple interactions simultaneously. To achieve this goal, we synthesized dimeric coiled-coil peptide variants of peptide K to facilitate improved fusion with peptide E-modified liposomes and mammalian cells. The secondary structure and self-assembly of various dimers were studied; the parallel PK4 dimer forms temperature-dependent higher-order assemblies, while linear K4 dimers form tetramer-like homodimers. The findings regarding the structures and membrane interactions of the PK4 dimer were supported by molecular dynamics simulations. Upon addition of the complementary peptide E4, the parallel PK4 dimer induced the strongest coiled-coil interaction resulting in a higher cellular uptake of the liposome-encapsulated cargo, as compared to the linear dimer and monomeric designs. Using a wide spectrum of endocytosis inhibitors, it was shown that membrane fusion was the main cellular uptake pathway. Delivery of the antitumor drug doxorubicin (DOX) resulted in efficient cellular delivery and concomitant antitumor efficacy. These findings not only offer important mechanistic insights into the design of coiled-coil driven membrane fusion systems but also provide novel strategies for developing peptide-based biomaterials.

Soils of the Upper Volturno basin in the Central-Southern Apennines (Molise, Italy) were surveyed in detail. Trends in development are described with focus on the contrast between the mountain soils and the soils of the basin. Mountain soils are shallow and poorly developed. Topsoils in the central and eastern areas and on N-facing slopes have a large Late Pleistocene tephra component (Campi Flegrei) and are Andic. Basin soils from a distinct chronosequence: early Mid-Pleistocene deep highly weathered Chromic Luvisols/Nitosols in old surfaces of the fluvio-lacustrine fill, less developed soils in Late Pleistocene terraces and fans, and recent Fluvisols in the Holocene sediments of the Volturno River and tributaries. In the basin, Mid-Pleistocene Roccamonfina tephra play an important role. In the SW, it occurs as thick layers, blanketing the fluvio-lacustrine/fan deposits. The soil pattern clearly reflects the complex geological history of the basin, with prominent subsidence in the SW.

Gent, Gent, Belgium3Groningen Institute of Archaeology, University of Groningen, Groningen, The Netherlands4Eastern Atlas GmbH & CO. KG, Berlin, GermanyCorrespondenceJan Sevink, Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, The Netherlands.Email: j.sevink@uva.nlScientific editing by Kevin Walsh1 | INTRODUCTIONSalt has long been an important commodity and it is therefore notsurprising that numerous archaeological studies have been devotedto its production (see e.g., Harding, 2013; Hocquet & Sarrazin, 2006;Nikolov & Bacvarov, 2012; Weller, 2002). Production techniqueshave ranged from mining (rock salt) and burning material containingsalts (plants and peat), to evaporation of saline waters to produce abrine from which salt is precipitated. Brines can be obtained in manyways, from collecting saline spring and seepage waters, or salt lakewater (e.g., sebkhas), to evaporation of seawater and leaching salineevaporation of sea water is by far the dominant raw material for salt production in the drier and warmer coastal areas of the world.Early salt production techniques based on evaporation of brines have been extensively studied, in many cases supported by ethno- graphic studies of such salt production in nonindustrial societies (see e.g., Cassen & Weller, 2013; Flad et al., 2005; Graham et al., 2015; Parsons, 2001; Weller, 2015; Williams, 2002). Two broad categories are distinguished: salt production using solar energy to evaporate a brine, and production based on boiling brine held in some sort of container (Weller, 2015). The first technique prevailed in Medi- terranean and warmer (semi‐)tropical climates favouring rapid eva- poration and was often based on evaporation from brines in salt pansAbstractA protohistoric (c.10th–5th c. BC) briquetage site at Puntone (Tuscany, Italy) was studied to unravel the salt production processes and materials involved. Geophysical surveys were used to identify kilns, pits, and dumps. One of these pits and a dump were excavated, followed by detailed chemical and physical analyses of the materials encountered. The pit had been used for holding brine, obtained by leaching of la- goonal sediment over a sieve, that afterwards was discarded to form large dumps. Phases distinguished indicate that the pit filled with fine sediment and was regularly “cleaned.” The presence of ferroan‐magnesian calcite in the pit fill testifies to the prolonged presence of anoxic brine. The production processes could be reconstructed in detail by confronting the analytical results with known changes in composition of a brine upon evaporation. These pertain in particular to the accumulation of “bitterns” and increased B (boron) concentrations in a residual brine. Both could be traced in the materials studied, and were found to be far more indicative than the ubiquitously studied concentrations of Cl and Na.

The mobility patterns in the Italian peninsula during prehistory are still relatively unknown. The excavation of the Copper Age and Bronze Age deposits in La Sassa cave (Sonnino, Italy) allowed to broaden the knowledge about some local and regional dynamics. We employed a multi-disciplinary approach, including stable (carbon and nitrogen – C and N, respectively) and radiogenic (strontium-Sr) isotopes analyses and the identification of the cultural traits in the material culture to identify mobility patterns that took place in the region. The Sr isotopic analyses on the human bones show that in the Copper Age and at the beginning of the Bronze Age, the cave was used as a burial place by different villages, perhaps spread in a radius of no more than 5 km. Stable isotopes analyses suggest the introduction of C4 plants in the diet of the Middle Bronze Age (MBA) communities in the area. Remarkably, in the same period, the material culture shows increasing influxes coming from the North. This evidence is consistent with the recent genomic findings tracing the arrival of people carrying a Steppe-related ancestry in Central Italy in MBA.

While processes involved in the protohistoric briquetage at Puntone (Tuscany, Italy) have been reconstructed in detail, the age of this industry remained uncertain since materials suited for traditional dating (14C dating on charcoal and typological dating of ceramics) were very scarce. We attempted to assess its age by radiocarbon dating organic matter and carbonates in strata that were directly linked to the industry. Microbial DNA and C isotope analyses showed that the organic matter is dominantly composed of labile organic matter, of which the age is coeval with the briquetage industry. Carbonates had a complex origin and were overall unsuited for radiocarbon dating: Shells in process residues exhibited a large, uncertain ‘marine reservoir effect’, hampering their use for dating the industry; the secondary carbonates in these residues had a quite varied composition, including much more recent carbonate that precipitated from infiltrated lateral run-off, as could be concluded from C and Sr isotope analyses. Dates found that were deemed reliable (c. 1000–100 cal BCE) show that this ancient industry, which started in the Late Bronze Age - Early Iron Age (1107–841 cal BCE), extended into the Roman Republican period and was contemporary with the saltern-based larger scale salt industry in Central Lazio.

The presence of the Early Bronze Age Avellino (AV) tephra in the Holocene lacustrine deposits of the Agro Pontino and Fondi basin provides a unique opportunity to reconstruct the Holocene depositional environment at the time of AV-tephra deposition. Marine terraces of the last Pleistocene transgression have been consolidated by soil formation and incised during the last glacial. This created a gully landscape in the Fondi basin and in the southeastern Agro Pontino. The inland central part of the Agro Pontino was drained by one major gully. At the final part of subsequent Holocene sea level rise, beach ridges closed the southeastern marine lagoons, creating a lacustrine and marshy environment. Shortly after, the Avellino eruption deposited its sandy tephra in these freshwater environments. By comparing altitudes of the AV-tephra in different environments two major implications emerge. First, at those locations where the AV-tephra is underlain by thick Holocene peaty and clayey deposits, significant subsidence occurred, while this has been limited at locations where the Pleistocene marine terrace occurs close to the surface. This subsidence is independently checked by comparing a modern LiDAR DEM and a detailed DEM from 1928. Second, the altitude of the AV-tephra reflects sea level in the coastal positions around −1.5 to −2 m a.s.l., while the only gully draining the lacustrine and marshy inland Agro Pontino was blocked around 0.5 m a.s.l. by the expanding sediment wedge of the Amaseno River, the major draining axis of the Agro Pontino. The AV-tephra layer will continue to play an important role in regional geological, palaeoenvironmental and geo-archaeological research.

Distal tephra from the major Somma-Vesuvius Avellino (AV) eruption is widespread in the coastal basins of Southern Lazio (Central Italy). Dated to 1995 ± 10 cal yr BC in 2011, later on doubts arose about the reliability of this frequently cited age. This led to a major effort to date AV tephra holding sections, based on a thorough methodological approach. Various aspects were studied to identify sections yielding reliable 14C ages, including bioturbation, inbuilt age, and variable sediment accumulation rate. Lowered rates upon deposition of tephra, particularly in anoxic marshy environments and attributed to toxic F contents, showed up as sharp increases in pollen density. The ‘sampling error’ was quantified for specific sedimentary environments and derived from coring data and published data on accumulation rates for similar Central Mediterranean sites. Next, two Bayesian analyses were performed, a traditional using the full set of samples and a novel, based on samples that were deemed as suitable (no bioturbation, inbuilt age, etc.) and of which the age was corrected for the sampling error. The age obtained by the novel analysis had the smallest range (1909-1868 cal yr BC), differs about a century, and is virtually identical to the ages published by Passariello et al. (2009) and Alessandri (2019). The earlier found age (2011) is ascribed to a statistical coincidence. The results solve a long debate on the age of the AV eruption, which is the youngest of the three major eruptions in the Central Mediterranean Bronze Age. Ages of the other two, the Agnano Mt Spina (Phlegrean) and FL eruption (Etna), are still uncertain and disputed. This study illustrates the need for a thorough approach in 14C dating tephra holding sediment archives in the Central Mediterranean, and employed a methodology that can be applied in such approach. Attention is called for potentially toxic fluorine concentrations in Campanian tephra, which may have had a serious impact on the contemporary environment and induced chronological hiatuses, but hitherto were not reported for the early tephra.

In this article, we present the results of a pilot study that adopts an interdisciplinary off‐site approach combining detailed surface survey, remote sensing analyses, geo- physical prospections, geoarchaeological investigations and palaeoenvironmental analyses to investigate long‐term human‐environment interactions in the Pontine plain (Lazio, Central Italy). Focusing on a small study area just north of the ancient Roman way station of Ad Medias, in the middle of this former wetland, the developed integrated approach turned out to be very much successful, providing additional information on (a) the interpretation of the surface record in light of landscape and environmental dynamics, (b) the exposure of “hidden landscapes” that date from before the Roman phase of exploitation that is well‐attested in the surface ar- chaeological record, and (c) the texture of this Roman landscape, allowing for a more accurate interpretation of both mapped surface materials and the wider context in which these surface sites were set.

Following on the discovery (in 2011) of a layer of distal tephra from the Pomici di Avellino eruption (Somma-Vesuvius, EU5) in the Agro Pontino (southern Lazio, Italy), further detailed study of the Holocene sediment archives in this graben and in the nearby Fondi coastal basin showed that distal tephra from this EU5 eruption occurs as a rather continuous, conspicuous layer. Two other, less conspicuous tephra layers were found, identified as the earlier Astroni 6 eruption from the Campi Flegrei (Fondi basin) and the later AP2 eruption of the Somma-Vesuvius (Agro Pontino). The identification of the distal tephra layers rests upon a combination of criteria, including stratigraphy, macro characteristics, mineralogy, geochemical data on glass composition, Sr-isotopic ratios, and the known tephrochronology for the period concerned, i.e. between c. 2500 and 1000 BCE. 14C datings serve to constrain their age. No significant spatial variation in the characteristics of the main tephra layer (EU5) was observed, other than distinct fining with increasing distance from the vent. Based on a detailed palaeogeographical reconstruction, the occurrence and preservation of these tephra are explained by the local environmental conditions governing their preservation during this time span (the Central Italian Bronze Age), and by the later evolution of the area. The observations underpin that multiple corings are needed to fully assess whether sedimentary hiatuses exist in palaeorecords, based on cores from sediment archives. Lastly, our study shows that hazard evaluations for future eruptions by Campanian volcanoes should pay more attention to their potential impacts on distal areas.

In the Agro Pontino and Fondi basin (Southern Lazio, Italy), burnt clay type material is common and was generally ascribed to the impact of ignicoltura. Based on the widespread occurrence of this material it was hypothesized that in these areas such ignicoltura was widely practiced in pre- and protohistoric times. However, direct evidence thereof, in the form of distinctly fired material, is extremely scarce. Earlier published and recent observations and analyses of a number of characteristic burnt clay sites together provide strong evidence for a pedogenetic origin of this material, i.e. by weathering of Holocene pyritic humic to peaty clays, brought about by their drainage. The process is well known from studies on acid sulphate soils and results in the accumulation of secondary iron concretions that resemble burnt clay but have a pedogenetic origin. Other products formed include jarosite and eventually gypsum, both regularly found in connection with burnt clay type material in these Holocene coastal basins. It is concluded that current hypotheses concerning the role and intensity of ignicoltura in both areas need to be seriously revised. Lastly, it seems likely that such pedogenetic burnt clay also occurs in other Mediterranean coastal basins where during the Holocene pyritic sediments formed and later on were drained for agriculture.

The area ‘Het Gooi’ in the Netherlands is part of a Pleistocene ice-pushed ridge system that partially drowned during the Holocene upon sea level and associated groundwater rise. As a result, the ridge system was gradually encroached by peat. From the late Middle Ages onward, man reclaimed the peatlands surrounding Het Gooi, heavily reducing their extension and lowering the regional groundwater level by increasingly intensive drainage. Based on historical and archaeological arguments, several authors assume that the Holocene peat cover in the border zones of ‘Het Gooi’ formed the extension of large raised peat bogs that formed further to the west and east, respectively. They presume that in the late Middle Ages these extensions reached ‘upslope’ to a maximum altitude of 3 m + NAP (Dutch Ordnance Datum – approximating mean sea level). However, the original extension is difficult to reconstruct, as this peat has disappeared as a result of its exploitation and oxidation, if having been present at all. In this study, the maximum extension of the Holocene peat cover on the ice-pushed ridge system was reconstructed based on soil characteristics. Used soil characteristics concerned the presence of iron coatings around sand grains and the upper boundary of gleyic features, because these are indicators for the mean highest groundwater level (MHG). For peat to form, this MHG needs to be at or just above the ground surface for most of the year. Based on study of a number of soil transects, we reconstructed to what maximum altitude peat encroachment may have occurred. This ‘maximum extension’ can alternatively be described as the maximum altitude of the bottom of the peat onlapping the ridge system. In the western border zone, this peat cover was found to have reached to c. NAP or just above, near Hilversum. No indications were found for the occurrence of raised bogs. We conclude that the phreatic groundwater level in this zone was controlled by the sea level and associated lake levels (Naardermeer and Horstermeer), a dominant role being played by the shallow presence of Pleistocene formations with a high hydraulic conductivity. In the eastern border zone, altitudes were more variable and in places reached 2 m + NAP. Peat at this higher elevation probably formed under the influence of a higher phreatic groundwater level, induced by the presence of a clayey Eemian fill with low hydraulic conductivity in the adjacent glacial basin (the Eem valley). This study demonstrates the value of detailed soil transect studies for palaeogeographical reconstructions of the former Holocene peat cover in Pleistocene landscapes of NW Europe. It also provides independent data for validation of geohydrological models for such landscapes.

The mountainous inland of northern Calabria (Southern Italy) is known for its sparse prehistoric human occupation. Nevertheless, a thorough multidisciplinary approach of field walking, geophysical survey and invasive research led to the discovery of a major archaeological archive. This archive concerns a rich multi-phased dump, spanning about 3000 years (Late Neolithic to Late Imperial Roman Age) and holding two Somma-Vesuvius tephra. Of these, the younger is a distinct layer of juvenile tephra from the Pompeii eruption, while the older concerns reworked tephra from the Bronze Age AP2 eruption (ca. 1700 cal. yr BP). The large dump contains abundant ceramics, faunal remains and charcoal, and most probably originated through long-continued deposition of waste in a former gully like system of depressions. This resulted in an inversed, mound-like relief, whose anthropogenic origin had not been recognized in earlier research. The tephras were found to be important markers that support the reconstruction of the occupational history of the site. The sequence of occupational phases is very similar to that observed in a recent palaeoecological study from nearby situated former lakes (Lago Forano/Fontana Manca). This suggests that this sequence reflects the more regional occupational history of Calabria, which goes back to ca. 3000 BC. Attention is paid to the potential link between this history and Holocene climatic phases, for which no indication was found. The history deviates strongly from histories deduced from the few, but major palaeorecords elsewhere in the inlands of Southern Italy (Lago Grande di Monticchio and Lago Trifoglietti). We conclude that major regional variation occurred in prehistoric land use and its impacts on the vegetation cover of Southern Italy, and studies of additional palaeoarchives are needed to unravel this complex history. Finally, shortcomings of archaeological predictive models are discussed and the advantages of truly integrated multidisciplinary research.

The molar of a giant deer, Megaloceros giganteus (Blumenbach, 1799), was discovered in sandy deposits of the North Sea, about 10 km west of the present shoreline of the Netherlands. Compacted masticated plant remains were preserved in the molar's deep folds. A palaeoecological analysis of these plant remains shows the complete dominance of pollen from Artemisia (sage) and other Asteraceae Tubuliflorae (Compositae), indicating that the animal foraged in a steppe environment, and may have preferred to eat Artemisia, which contain a high level of nutrients such as calcium and phosphorous components, which are important for antler building. Radiocarbon dating indicates that the plant remains are of mid‐Weichselian age [38 570 (+300, −290) 14C a BP, Greenland Interstadial‐11]. This is the first study of the food choice of M. giganteus based on palaeoecological evidence. We hypothesize about links between the extirpation of M. giganteus at the onset of the Holocene in North‐West Europe and the transition from a landscape with highly dynamic geomorphological processes and consequently prevalence of immature and nutrient‐rich soils, to a less dynamic landscape with stable, leached and acidifying soils, and the decline of Artemisia and other calciphilous plants.

In the Laarder Wasmeren area in the western Netherlands, Late Pleistocene cover sands and overlying early Holocene drift sands show various paleosols, which can be characterized as more or less incipient podzols. We dated those soils and sands by radiocarbon analysis and OSL, and we used biostratigraphical dating based on the known chronology of the vegetation history. Apart from Usselo soils of Allerod age, we found early Holocene soils - showing Usselo soil characteristics but with relatively advanced podzolisation - covered by Early Holocene-early Middle Holocene drift sands. We discuss their age and origin, and reflect on the role of fires and ecosystem degradation in the early development of heathland, podzols and drift sands in the Netherlands, prior to any Neolithic farming. We hypothesize about the possible role of Mesolithic man, stimulating habitats for Corylus avellana by burning pine forest, in the longer term inducing the observed ecosystem degradation (transformation of forest into open short vegetation, acidification and concurrent podzolisation, wind erosion). This hypothesis is in line with studies in adjacent NW-European countries, which are reviewed, and an alternative for the theory of Vera (2000), who assumed that open forests and short vegetation resulted from grazing pressure by large herbivores.

A significant part of our knowledge on Holocene landscape development and associated human history in northwestern Europe is based on radiocarbon dating of charcoal originating from podzols. However, these soils are characterized by leaching of soil organic matter (SOM) that may adsorb to older charcoal, resulting in incorrect charcoal radiocarbon ages. Several pretreatments, such as an acid-base-acid (ABA) sequence for Holocene-aged samples and a harsher acid-base-oxidation (ABOx) sequence for older samples, have been developed to remove the adsorbed fractions. While commonly used, evidence for the effectiveness of these pre treatments thus far has been circumstantial, by assessing the impact of these pretreatments on the radiocarbon age.In this study, we performed a direct molecular assessment of the presence, adsorption, and removal of SOM-compounds by pyrolysis-GC-MS based characterization of charcoal fragments and SOM obtained from a podzol located in the Laarder Wasmeren area, the Netherlands. In addition, the removal efficiency of adsorbed SOM by four different pretreatments was analysed. Molecular evidence for significant adsorption of SOM was found and the four pretreatments showed different efficiencies in removal thereof as evidenced by the residual charcoal composition. ABOx resulted in the most simplified Py-GC-MS chromatogram and thus comes closest to the isolation of recalcitrant carbon. The most recalcitrant organic fraction is likely to have the best interpretable age, since the highest decontamination can be expected for this fraction. Hence, it is advisable to use ABOx as standard pretreatment for the removal of adsorbed SOM fractions from charcoal, provided that the sample size is large enough.

Archaeological field survey data can be biased by many factors, such as ground visibility conditions (e.g. vegetation, plowing) and geomorphological processes (erosion, deposition). Both visibility and geomorphological factors need, therefore, to be assessed when patterns of settlement and location preferences are inferred from survey data. Although both factors have been taken into account in a variety of fieldwork projects and studies, their combined effects remain hard to predict. In this paper, we aim to address this issue by presenting a visualization method that helps in evaluating in combination the possible visibility and geomorphological effects in regional, site‐oriented field surveys. Capitalizing on first‐hand data on both archaeology and soil types produced by the recent Leiden University field survey project in the area of Isernia (Roman Aesernia, Central‐Southern Italy), we propose a combined application of statistical tests and geo‐pedological analysis to assess the extent and scale of the main biases possibly affecting the interpretation of the ancient settlement organization. Translating both sets of biases into GIS maps, we indicate the likelihood that negative field survey observations (absence of sites), in specific parts of the landscape, are genuine or rather distorted by biasing factors. The resulting “archaeological detectability” maps allow researchers to formally highlight critical surveyed zones where the recording of evidence is likely unreliable, and thus provide a filter through which archaeologists can calibrate their interpretations of field survey datasets.

We studied a Holocene peat fill of a small depression in Pleistocene coversand, in the western border zone of Het Gooi, to assess the early local and regional vegetation history in relation to sea-level rise, soil development and potential human impact. In the fourth millenium BC, a podzol which had formed in the depression became stagnative, leading to the development of a moorland pool. The local vegetation changed from dry heathland, through an amphibic vegetation type with, among others, Littorella uniflora and Lycopodiella inundata, to a permanently moist Sphagnum-dominated vegetation. The existence of moorland pools and the development of such habitats into Sphagnum-dominated vegetation are known from Late-Holocene anthropogenic, more or less open landscapes that were formed on a podzolising sandy soil under ericaceous vegetation. However, the recorded vegetation succession did not show any recognisable local human impact and therefore is attributed to natural succession. In the period concerned, sea level was still about 4 m below the land surface in the depression, implying that water logging occurred independent from a rise in sea level and associated groundwater level. It took until the Late Middle Ages before such rise led to significant water logging and peat growth in this border zone, but the mean groundwater level never reached to above NAP (Dutch Ordnance Datum).

Earlier studies on Holocene fills of upland lakes (Lago Forano and FontanaManca) in northern Calabria, Italy, showed that these hold importantpalaeoecological archives, which however remained poorly dated. Theirtime frame is improved by new 14C dates on plant remains from newcores. Existing pollen data are reinterpreted, using this new time frame.Two early forest decline phases are distinguished. The earliest is linked tothe 4.2 kyr BP climatic event, when climate became distinctly drier, otherthan at Lago Trifoglietti on the wetter Tyrrhenian side, where this event isless prominent. The second is attributed to human impacts and linked toMiddle Bronze Age mobile pastoralism. At Fontana Manca (c. 1000 m asl) itstarted around 1700 BC, in the higher uplands a few centuries later (LagoForano, c. 1500 m asl). In the Fontana Manca fill, a thin tephra layeroccurs, which appears to result from the AP2 event (Vesuvius, c. 1700 BC).A third, major degradation phase dates from the Roman period. Land useand its impacts, as inferred from the regional archaeological record for theRaganello catchment, are confronted with the impacts deduced from thepalaeo-archives.

Altres ajuts: NWO/360-61-060 In 2017, an excavation led by the Groningen Institute of Archaeology and in collaboration with the Tor Vergata University of Rome, took place on two small islands in the Caprolace lagoon (Sabaudia, Italy), where Middle Bronze Age layers had previously been reported. Combining the results of an environmental reconstruction of the surroundings and a detailed study of the pottery assemblages, we were able to trace a specialised area on the southern island, in all probability devoted to salt production by means of the briquetage technique. The latter basically consists of boiling a brine through which a salt cake is obtained. The technique was widespread all over Europe, from Neolithic to Roman Times. Since the evidence points to an elite-driven workshop, this result has deep implications for the development of the Bronze Age socio-economic framework of Central Italy. Pottery evidence also suggests that in the Bronze Age sites along the Tyrrhenian coast of Central Italy where briquetage has already been hypothesised, more complex processes may have taken place. On the northern island, we collected a large number of so-called pedestals, which are characteristic features of briquetage, while chemical analyses point to salt or fish sauce production, like the roman liquamen, in a Middle Bronze Age domestic context.

Land subsidence has played and is still playing a significant role in coastal wetlands worldwide and in palaeogeographical reconstructions of such wetlands. The varying thickness of compaction-prone sediments over a stable subsurface is a key factor in determining its magnitude and in locating the most affected areas. In the coastal low-lying Agro Pontino (Lazio, Italy), subsidence of the past 90 years has been mapped using historical elevation data. Due to the fortunate preservation of distal Avellino tephra (AV-tephra, ca. 1900 cal. BCE) within its marshy strata, discovered a decade ago, detailed palaeogeographical reconstruction of the landscape in preparation for an assessment of its land use suitability in the Early Bronze Age (EBA) was possible. Current altitude variations of water-lain tephra in lake areas assumed to be connected necessitated a closer look at its original deposition altitude and the role of post-depositional subsidence. Recent subsidence patterns proved very useful for distinguishing stable from subsidence-prone areas. Two different EBA palaeo lake environments are distinguished: an inland and a near-coastal lake. The AV-tephra altitude variation within these lakes partly marks differential post-depositional subsidence within these lakes. Calculation of initial ripening of tephra-bearing lake deposits on top of shallowly buried Pleistocene ridges allowed for an estimation of original tephra deposition altitudes and associated lake levels. For the inland lake, a wide lake edge zone between 0.5 and 2 m above current sea level (m asl) was reconstructed, where EBA habitation or land use was possible. At the near-coastal lake, a water level of −1.5 to −1.3 m asl at the time of AV-tephra deposition was constrained. Because tephra deposition occurred here just after marine influence ceased, this altitude range is proposed to be a Relative Sea Level (RSL) index point at the time of AV-tephra deposition. The altitude range is in agreement with RSL models for tectonically stable areas in this region. The importance of subsidence in palaeogeographical, water level and RSL reconstructions in the region is stressed.

Volcanic ash soil contains large stocks of organic matter per unit area. A large proportion of organic matter is stored in the subsoil; therefore, a thorough understanding of its vertical distribution is needed to predict the effects of change in climate and land use. Faunal bioturbation is often cited as the dominant process that affects the vertical distribution of organic matter. An additional but often overlooked process is change in the volume of the soil. Such change might affect the vertical distribution of organic matter by changing the position of the soil surface, which can affect the soil-forming processes related to depth, such as weathering, decomposition, bioturbation and rooting. We calculated the change in volume with geochemical mass balance equations, and showed the effect of change in soil volume on the vertical distribution of organic matter using a dynamic model. Then we evaluated the plausibility of the model concept with an independent model for parameter identification and through a model sensitivity analysis. Results show that volume change is a major soil-forming process that determines the vertical distribution of organic matter in volcanic ash soil as the active bioturbation zone moves upwards in response to soil thickening.

A lithoid tuff, found in 2011 (Ricci pit, Agro Pontino, Southern Lazio, Italy), was studied for its composition, origin and palaeogeographical implications. This tuff was the first occurrence of a Wurmian-age tephra layer, encountered in the coastal basins of Southern Lazio. Based on its mineralogy and isotopic composition (Sr and Nd), it was identified as a distal tephra deposit from the Volcano Laziale, connected with the Albano 6-7 eruptive phase (‘Lapis Albanus’) and dating from 41-36 ka BP. The lithoid tuff consists of tephra that were slightly reworked and subsequently lithified, when this central part of the Agro Pontino graben still consisted of a non-dissected, level lagoonal plain. The study confirms the earlier established importance of this tephra layer as stratigraphic marker for Central Italy, and shows that its distribution is wider than earlier assumed, notably to the SE of the Volcano Laziale.

The morphology of the Agro Pontino (Latina, Italy) has been greatly modified by the fascist reclamation (Bonifica), in particular by the subsequent soil subsidence due to the drainage of its peaty lowlands and by massive dredging and land raising. Obviously, this constitutes a strong bias for reconstructing the ancient landscapes. However, pre-reclamation maps can be used to address the problem. In particular, the 1930s maps made by the Italian Military Geographical Institute are of exceptional importance for both the reconstruction of prehistoric and historic landscape, and for detecting the more recent, human-induced changes in its morphology. Unfortunately, the datum of the maps is unknown. In this paper we try to estimate a standard Molodensky transformation to convert the map to the current projections, by surveying points which are unambiguously identifiable both in the terrain and on the maps.

In the Monnikenberg estate, built in the mid-19th century in a Pleistocene coversand area to the south of Hilversum (the Netherlands), a depression with a small man-made mire was found to contain the remains of a complex peaty fill of a larger mire. Microfossil study and radiocarbon dating showed that its development started at the beginning of the third millennium BC through water stagnation on a podzol in combination with a high groundwater level, and about two millennia ago the vegetation had progressed from a mesotrophic mire to an ombrotrophic bog. Such origin, development and age are in conformity with the results for some other recently studied mires in the Het Gooi region (Gijzenveen; Van Geel et al., 2016). In the Monnikenberg mire, a discrepancy was found between the radiocarbon age of the upper part of the peaty fill and its clearly medieval or younger age as evidenced by its microfossil content, notably the occurrence of pollen of buckwheat (Fagopyrum) and cornflower (Centaurea cyanus). These species were first introduced in the Netherlands during the late Middle Ages. From further observations in a large pit in the former border zone of the mire, it is concluded that this discrepancy and the unique sedimentary structures, observed in this pit, result from peat exploitation and contemporary reworking of its sandy overburden during the Late Middle Ages or Early Modern Times. This is the first evidence for local early peat exploitation for such mires in Het Gooi. The results underpin the importance of microfossil analyses for proper interpretation of radiocarbon data, when studying mire fills. Additionally, they provide further proof for the development of podzols and ericaceous vegetation prior to and independent of early prehistoric agriculture in the Dutch Pleistocene coversand areas, and for the early (pre-medieval) start of wind erosion and deposition of drift sands.

In the past decade (2000-2010), research within the scope of the 'Hidden Landscapes' project by RUG archaeologists provided important information on the Holocene history of the Agro Pontino graben. This information complemented earlier studies by Dutch Universities (UvA, RUG and UL). The graben was found to hold important tephrochronological, palaeoecological and archaeological archives, which deserve to be studied in more detail. This is demonstrated by the recent robust dating of the Avellino pumice layer at 3945 +/- 10 cal BP obtained from this archive (Sevink et al., 2011) and by the complex denudation record resulting from early land use in its hinterland. An overview is given of the recent knowledge on the Bronze Age to recent landscape that existed in the graben and of the major Early Bronze Age sites, of which most were associated with a large lake. Doubts have grown about the reliability of the existing chronological framework derived from earlier pollen cores by conventional radiocarbon dating. These doubts are discussed in the context of results from recent research, with emphasis on the 'hard water effect' that has been largely neglected in the earlier studies. The main current research topics are indicated. (C) 2013 Elsevier Ltd and INQUA. All rights reserved.

A unique complex of multiphased Holocene drift sands and paleosols, with at least two lacustrine phases, was discovered during a major sanitation project in the Laarder Wasmeren area near Hilversum, the Netherlands. The complex could be studied in detail, highly facilitated by the excellent and large-scale exposure of the various deposits and soils. OSL dating was used to establish ages of the phases, where possible differentiating between time of deposition and time of burial by taking into account the potential effects of bioturbation. Pollen analysis served to reconstruct the vegetation during the various phases.A first minor phase of aeolian activity already started before approx. 5,000 BC, followed around 4,000 BC by a second phase and a rather massive third phase around 3,000 BC. After a long phase of soil formation, the latest, massive drift sand phase started around the 14th to 15th century. It clearly represents the classic drift sand phase that started in the Late Middle Ages in the Netherlands. Sand drifting followed on soil forming phases during which the vegetation became increasingly dominated by ericaceous plants and culminated in heathlands. The first three aeolian phases and associated heathlands are much older than generally assumed for heathland and drift sand to occur in the Netherlands. Moreover, podzolisation was found to have started very early, true podzols already occurring before 4,000 BC.Around 3,000 BC groundwater in the area reached a maximum altitude of about 230 cm +NAP, resulting in local open water in the area. This rise is probably linked to the development of the Dutch coastal area, where at that time peat accumulated and drainage was poor, inducing a rise of the groundwater level in ‘het Gooi’. This groundwater level fell later on, to never reach this altitude again. The Groot Wasmeer was formed by local stagnation on a slowly permeable podzol and already reached a level of 320-325 cm +NAP by 400 BC, which more or less equals its 20thcentury level.The results demonstrate that earlier concepts on the occurrence and age of aeolian phases, podzols and heathland vegetations in the Netherlands are far too schematic, and that early, pre-agricultural cultures may already have had an impact on the stability of fragile cover sand landscapes, e.g. through burning. Results are in line with those from several contemporary studies on early prehistoric cultures and their impact in river dune areas in the Central and Eastern Netherlands.

QuestionHow does pioneer vegetation of acid inland dunes respond to addition of nitrogen (N) and phosphorus (P)?LocationTwo inland dune reserves in The Netherlands with low and high N deposition.MethodsDuring 2.5 yr, N and P addition (control, N, P, NP) took place in three different vegetation types of inland dunes (Polytrichum piliferum mats, Campylopus introflexus mats and lichen-dominated vegetation). In each site, changes in the vegetation were recorded in three replicate quadrats of 1 m × 1 m per treatment. Differences in element content of grasses and lichens were recorded, together with vegetation parameters, including cover and height of grasses, bryophytes and lichens.ResultsIn the site with high N deposition, grasses were taller, had higher N:P ratios and a generally lower lichen cover than in the low-deposition area. Experimental N application resulted in higher N and lower base metal concentrations in grasses and an increase in grass cover and size. In contrast, lichens showed a general decline in the N treatment and the lichen:grass ratio decreased. The effect of N addition was larger in the low-deposition area. The P treatment had an opposite effect: lichens increased in size and cover and overgrew grasses, especially when reindeer lichens were present. This suggests that the cryptogam layer was P-limited even in the low N deposition site.ConclusionsPioneer vegetation in inland dunes is susceptible to N and P addition. The results provide evidence for a decrease in lichen cover due to increased N deposition.

This volume details the geoarchaeological research conducted from 2011 to 2013 in the basin of the Raganello River (Calabria, Italy) within the broader 'Rural Life in Protohistoric Italy' research programme of the third author. The book focuses on a systematic understanding and description of soils and slope processes in the various foothill and upland landscape zones, and their significance for the preservation and detectability of pre-classical archaeological remains. An appendix provides a simple soil key for the study area.

We found Bronze Age lake sediments from the Agro Pontino graben (Central Italy) to contain a thin (2-3 cm) continuous tephra layer composed of lithics, crystals and minor volcanic glass. Tephrochronological and compositional constraints strongly suggest that this layer represents the Avellino pumice eruption, which has also been identified in Central Italian lake cores. Its provenance is corroborated by electron-microprobe analyses performed on juvenile pumice grains, showing that the tephra layer is probably the distal equivalent of the EU2 event of the Avellino eruption. We used multiple (14)C age estimations of two lacustrine sequences with intercalated tephra layer, from the western border zone (Migliara 44.5) and the centre of the former lake (Campo Inferiore), for in tandem dating of this eruption, employing the OxCal code, which yielded a robust age of 3945 +/- 10 calBP (1995 +/- 10 calBC). To date, this is the only study providing both a terminus post and terminus ante quem of this precision, also demonstrating the advantage of dating distal tephra layers in a clear stratigraphic context over proximal deposits in sequences with major stratigraphic hiatuses. Our new results underscore the importance of the Avellino tephra layer as a precise time marker for studies on the Early Bronze Age of Central Italy. (C) 2011 Elsevier Ltd. All rights reserved.

SUMMARYThe Andean páramo ecosystems host geodiversity of global importance, but also have important societal functions, including agricultural production and delivery of water to people and industry. Páramo geo-ecosystems are highly susceptible to environmental degradation because of their alpine relief, extreme climate and fragile soils. In contrast to other parts of the world, geodiversity assessment studies in the Andes are scarce. A geodiversity assessment method was adapted and used to produce a potential geoconservation map of the Andean páramo. The Las Lagunas area (Cajamarca, Northern Peru) has a rich archive of climate proxy data and landscape reconstruction, and plays a key role in the functioning of regional geo-ecosystems. Undisturbed proxies for climate change are contained in four Late-Glacial recessional complexes of its former local ice cap and in pollen records preserved in the post-glacial peat cover. These new findings were used to develop a refined chronostratigraphy of the Late-Glacial warming period in the Andes of Northern Peru. Geo-ecosystem functions (for example water and carbon storage) depend on the environmental vulnerability and disturbance of the landforms and deposits. Therefore, potential geoconservation areas that combine a high scientific value and environmental vulnerability with a low disturbance and low frequency of occurrence should be prioritized for geoconservation. Such a strategy should also optimize sustainable use of resources and development of these areas. Mountainous countries like Peru require future management strategies that recognize and incorporate potential geoconservation information in regional planning, to prevent unnecessary loss of irreplaceable soils, climate proxies and geo-ecosystem functions upon future changes in land use and climate.

The Amazonian rainforest is arguably the most species-rich terrestrial ecosystem in the world, yet the timing of the origin and evolutionary causes of this diversity are a matter of debate. We review the geologic and phylogenetic evidence from Amazonia and compare it with uplift records from the Andes. This uplift and its effect on regional climate fundamentally changed the Amazonian landscape by reconfiguring drainage patterns and creating a vast influx of sediments into the basin. On this >Andean> substrate, a region-wide edaphic mosaic developed that became extremely rich in species, particularly in Western Amazonia. We show that Andean uplift was crucial for the evolution of Amazonian landscapes and ecosystems, and that current biodiversity patterns are rooted deep in the pre-Quaternary.

We combined proxies traditionally used in stratigraphic research (mineral assemblages, grain size distribution, and element ratios) with soil organic carbon contents and radiocarbon dating both at a high vertical resolution, to unravel the tephra stratigraphy in volcanic ash soils. Our results show that soil profiles along an altitudinal transect intersecting the upper forest line in Northern Ecuador were formed in three distinct tephra deposits. Although the deposits contained a similar assemblage of minerals, we were able to differentiate these deposits because of their characteristic organic carbon distribution, grain size distribution and typical SrO to Na2O, CaO and crystalline Al2O3 ratios. Unravelling the tephra stratigraphy improved understanding of the vertical distribution of soil organic carbon, including paleoecological proxies, in the studied soils. We demonstrated that bioturbation likely plays an important role in current pedogenesis, resulting in overprinting (merging, mixing) of the paleosol. Surprisingly, in spite of bioturbation, a linear age depth relationship exists, leading to the hypothesis that the active zone of bioturbation shifted upwards during soil formation. Therefore, we conclude that paleoecological proxies are stratified in our soils, albeit probably somewhat more crudely than in undisturbed peat bogs or lake sediments.

The Rio Santiago in the Cordillera Negra of Peru is severely contaminated by acid mine drainage in its headwaters. In a strongly acid stream, at about 3800 m above sea level (masl), microterraces were found with terrace walls built up of dead moss, with encrustations and interstitial fine, creamy sediment. The stream water was turbid due to the presence of similar suspended sediment, which also occurred as a thin basal layer in inter-rim basins. The moss was identified as the rare bryophyte Anomobryum prostratum (Müll. Hal.) Besch. Chemical and mineralogical analyses show that green, living parts of the moss are gradually coated by Al/Fe (hydr)oxides, inducing their senescence and death. The necromass is covered by creamy crusts through precipitation of schwertmannite-type material from the stream water and simultaneous ‘capture’ of fine sediment. The latter consists of a mixture of precipitate and fine detrital primary minerals. These processes are held responsible for the formation of the microterraces, which regarding their composition and environment seem to be unique. Remarkable is the high As content of the creamy crusts and sediment, attributed to strong sorption of As, whereas its solute concentration is relatively low. This calls for more attention to suspended fine sediment in the assessment of environmental risks of stream water use. Lastly, the results raise serious doubts about the use of aquatic bryophytes as bioindicator for chemical pollution in acid mine drainage-polluted streams. Electronic supplementary material The online version of this article (doi:10.1007/s11270-015-2390-x) contains supplementary material, which is available to authorized users.

The pa´ramo soils of the mountainous upper Andean region (N3300 m a. s. l.) of the Rio Paute basin in central Ecuador are characterized by a thick, dark, highly organic epipedon and are classified as Andosols and Histosols. Their high water retention and buffering capacity play a key role in the hydrology of the region, which is subject to land use changes and increased cultivation. In the west (Western Cordillera), the soils are largely formed in the late Miocene and Pliocene volcanoclastic Tarqui formation, while in the east (Central Cordillera) they are formed in an older, mostly intermediate low-grade metamorphic rocks. Ten soil profiles were sampled and studied, using extraction techniques (oxalate and pyrophosphate) and XRD-techniques. Major differences in composition of the clay fractions were found that allow for distinction of three main groups of pa´ramo soils. A first group consists of soils influenced by recent volcanic ashes and dominated by organometallic complexes and with minor but distinct amounts of degraded mica, most probably formed by weathering of primary mica, present in these ashes. The second group comprises soils formed in volcanoclastic material of various Tertiary and earlier formations, containing residual primary and secondary crystalline clay-size minerals, as well as organometallic complexes whose genesis can be linked to the abundant presence of easily weatherable materials in these formations. A third group consists of soils in relicts of Tertiary, highly weathered regolith, formed under humid tropical conditions before the Andean uplift and occurring in the Central Cordillera. These soils contain kaolinite and gibbsite and develop into Histosols in the absence of significant organometallic complexation. volumen 127; número 1-2

Topsoil samples from cultivated and adjacent non-cultivated fields on three major agricultural soils in North Cameroon were fractionated into particle-size fractions that were analysed subsequently for their C and C-13 contents. The aim was to obtain further insight into the dynamics of soil organic matter (SOM) in relation to land use in Cameroon. Since organic carbon contents of the fractions were often very small, samples and analyses were extensively replicated to obtain robust statistical estimates of observed differences. For each soil type, differences in delta(13)C values between fields could be related to changes in the input and decomposition of organic matter arising from soil type, land management and, for example, the nature and abundance of weeds. Turnover of organic matter appeared to be fastest in the sand fraction, which is in line with results from earlier studies. In the finer fractions, clear differences in reaction to changes in input and decomposition were observed, that seem to be linked to differences in clay mineralogy. The results illustrate that SOM in the various fractions is much less stable and more strongly affected by changes in land use than might be assumed on the basis of changes in total SOM contents alone. At the same time, they demonstrate the relevance of C-13 isotope analyses of SOM for studies on the impact of land use on these savannah soils with little SOM that are highly susceptible to degradation.

The contribution of throughfall and stemflow as pathways for solute inputs into the forest floor in four mature forests in northwest Amazonia was investigated. Total solute inputs, resulting from the changes of atmospheric deposition after rainfall passes through the forest canopy, are presented in the form of throughfall and stemflow nutrient inputs and their possible sources are discussed. Throughfall is by far the most important solute input into the forest floor of the forests studied. On average, it represents about 98% of the total solute inputs. Although trends in solute enrichment varied among the forests, there is a general tendency in all ecosystems towards a distinct enrichment of SO4, K, Cl, NO3 and NH4 in throughfall and stemflow and a small increase of protons, Mn, orthoP and Fe. When comparing the net enrichment between the forests, the relative increase of solutes in throughfall and stemflow was higher in the flood plain and low terrace than in the high terrace and sedimentary plain forests. While highest values for total cation inputs were observed in the flood plain, the low terrace showed the highest value for total inorganic anions. The length of the antecedent dry period was the main factor affecting throughfall and stemflow composition, concentrations increasing with increasing length. A second, less important factor was the amount of throughfall and stemflow, which showed a poor and negative correlation with solute concentrations. The increased activity of frugivores in the canopy during fruiting periods seemed to lead to temporary increased solute concentrations in throughfall and stemflow as a result of the wash off of deposited faecal materials and detritus in the canopy. Leaching from leaves and wash off of exudes, of solutes deposited on the foliage after evaporation of intercepted rainfall and of dry deposited materials were all found to contribute to the concentration of solutes in the throughfall and stemflow. Gross rainfall enrichment after passing the forest canopy, mainly by nutrient leaching, is considerably lower than the amounts of nutrients released in litterfall implying a tight nutrient cycling and nutrient conserving mechanisms by forests studied.

A field survey of an evergreen Mediterranean woodland area in NE Spain on three silica-rich parent materials (granite, granodiorite and schist) was used to test whether parent material had a separate effect on ecosystem functioning in addition to aspect and position on the slope. As expected, vegetation was taller and denser on north-facing slopes and/or lower slope positions. However, parent material appeared to have additional effects, with significant increases in tree height, tree cover, shrub height and ratio of woodland to maquis vegetation from granite towards granodiorite and schist. There was also a parallel increase in mull humus forms, indicating increasing litter breakdown. The lower productivity on granite may be partly attributed to drought stress, as indicated by the greater proportion of shallow soils and the sandy to loamy sand texture. However, nutrient stress may be equally important. Plant N/P ratios were significantly greater on granite, and plant and soil P contents were less than on the other parent materials, suggesting that P-availability was limited on granite. The greater productivity of soils on schist than on granodiorite may reflect less severe drought stress because of their finer texture. These results suggest that parent material is an important factor regulating productivity in Mediterranean ecosystems through varying drought stress and availability of nutrients.

High altitude tropical regions have been heavily deforested and offer large areas for carbon offsets by secondary forest regeneration. However, a general assumption exists that productivity, and thus, carbon sequestration of high altitude forests is low, but the scarcity of data from high altitude tropical forests does not allow for a sound confirmation of this assumption. To determine the carbon sequestration potential of natural forest regeneration and reforestation efforts at high altitudes, aboveground biomass was quantified of several successional stages of two monospecific secondary forests in the high Ecuadorian Andes. The studied forests were, at 3200 m, an Alnus acuminata forest with 8-, 20-, 30- and 45-year-old stands and, at 3600 m, a Polylepis incana forest with 6-, 15- and 30-year-old stands and old growth forest without known age. Both trees are pioneer species. Additionally, a soil survey was conducted and leaf N/P ratios and N and P retranslocation rates were determined. Total aboveground biomass (TAGB) estimates of the oldest stages of the two forests were 241 Mg ha−1 for the Alnus and 366 Mg ha−1 for the Polylepis forest. Productivity, expressed as annual aboveground biomass accumulation (ABA) was in both forests highest in the establishment phase (14.2 and 15.0 Mg ha−1 per year at 8 and 6 years, respectively) due to high sapling numbers, and then slowed down significantly (5.9 and 6.9 Mg ha−1 per year, respectively at age 30). TAGB and ABA figures of the investigated forests are comparable to those of lowland tropical forests and do not indicate a significant decrease of these parameters at higher altitudes in the tropics. Analysis of site conditions, ecological requirements and ecophysiological properties of the tree species indicated that in both cases an optimal combination of these factors strongly favoured forest growth. It is not possible to verify whether our forests are representative for other high altitude tropical forests or if they should be treated as exceptional cases. The results do show, however, that high carbon offsets at high altitudes are possible.

A comparative study on the impact of pine plantations on soil and vegetation development was conducted in the Ecuadorian Andes (3000–4000 m). Pine plantations of different ages under different types of management were compared with extensively grazed paramo grassland (the most common former land use) and natural forest (the formerly dominant vegetation in much of the life zone). No general impact of plantations was found, although some tendencies were identified that show that soils under pine plantations are drier and less organic. Moreover, the vegetation under pine plantations was similar to paramo grassland, though some examples of regeneration of Andean woody species were observed, as well as examples of plantations where understory was completely lacking. We concluded that the impact of pine plantations cannot be generalized but should be evaluated case by case while care is taken in implementing plantations until more knowledge is obtained about the effects on the ecosystem as a whole, esp...

Pollen analysis of a 150-cm-long core from Pantano de Pecho (0°20′S, 78°37′W) at 3870 m altitude in the Ecuadorian páramo documents altitudinal migrations and the composition of the upper forest line prior to deforestation. Four successive radiocarbon dates of 293 ± 41 14C y BP, 498 ± 40 14C y BP, 626 ± 33 14C y BP, and 729 ± 44 14C y BP show that the record includes the last c. 730 radiocarbon y, corresponding to the last c. 660 calendar years (cal y BP). The natural upper forest line was at a minimum altitude of 3400-3500 m between c. AD 1290 to 1315 (zone 1), from c. AD 1315 to 1350 at 3500-3600 m (zone 2), from c. AD 1350 to 1640 at 3600-3700 m (zone 3), from c. AD 1640 to c. 1765 at 3750 m (zone 4), and from c. AD 1765 to the present at 3700-3650 m (zone 5). The most important taxa were Alnus, Hedyosmum, Miconia, other Melastomataceae, Gunnera and Solanaceae. Since c. AD 1350 Podocarpus was continuously present with low abundance, but possibly not close to the upper forest line. Rarer elements of the upper montane forest were Dodonaea, Myrsine, Weinmannia, Myrica, Myrtaceae, Sapium, Juglans, Piper, Euphorbiaceae and Rubiaceae. Human disturbance and deforestation are shown by the presence of Rumex, Spermacoce pollen and charcoal particles. We surveyed the vegetation composition from isolated forest patches located between 3650 m and 4300 m. TWINSPAN analysis indicates forest patches up to 3950 m have a similar floristic composition to closed forest below the upper forest line. We argue that this apparent similarity does not necessarily mean that the slopes between 3750 and 3950 m were covered by closed forest in the past.

In the Gavarras (NE Spain), a large number of plots on respective schists, leucogranite and granodiorite was studied for their soils and vegetation. Results were used to check conclusions from earlier studies of Mediterranean forest soils (mostly shallow Regosols and Cambisols) on such acidic to intermediate rocks. They confirmed that the humus form depends on catenary position and lithology, and that aggregate stability and infiltration characteristics of the upper mineral soil horizon relate to humus form type. Aggregate stability of the topsoil was found to be relatively high in mor and mull type humus forms, but differences with moder type humus forms were not statistically significant. Differences in aggregate stability are attributed to the presence of stable humus-clay-iron complexes in mulls and to high fungal activity and organic matter content of mors. Low infiltration rates were only encountered in topsoils with mor type humus form, in line with results from the earlier studies. In deeper soil horizons with low organic matter content, aggregate stability will be largely related to soil reaction and base saturation. On leucogranite and granodiorite, these were found to vary strongly, most probably largely due to local differences in fast acid neutralizing capacity (ANC f ). These local differences are primarily attributed to differences in the mineralogical composition and texture of the soil material, connected with differences in lithology and/or brought about by erosion, colluviation and soil formation. Consonant with earlier studies, it is concluded that the susceptibility of these forest soils to erosion largely depends on properties of the upper mineral soil horizon, which are controlled by or related with humus form development. General trends in the latter are clear and can be used to predict this susceptibility. In the case of land degradation, which implies a more severe erosion, deeper soil horizons are also involved. Spatial variability in properties of these horizons, relevant for degradation, is considerable and not clearly related to humus form development. Accordingly, the abovementioned trends in humus form development cannot be used to predict the susceptibility to land degradation.