Climate and parent material type are important soil forming factors. On Santa Cruz Island, Galapagos, the climate shows a pronounced altitudinal zonation from arid lowlands to humid highlands, and the volcanic parent materials, although chemically rather uniform (basaltic), show pronounced differences in porosity, including dense lava flows and very vesicular scoria deposits. In this study, the effect of these two driving factors on pedogenesis was investigated. Our results show that pH and effective cation exchange capacity (CECeff) decreased, but po-tential cation exchange capacity (CECpot), phosphate retention, and Al-o +1/2Fe(o) as well as Al-p/Al-o increased with increasing elevation regardless of parent material type. Conversely, topsoil bulk density (BD) and organic carbon (OC) content did not show a clear altitudinal pattern on lava but decreased (BD) or increased (OC) with increasing elevation on scoria. Clay mineralogy changed from minor (2:1-type) mixed layer phases in the low-elevation arid zone to vermiculitic (lava) or kaolinitic mineralogy (scoria) at mid-elevation (humid), whereas short-range-order (SRO) minerals (allophane and ferrihydrite) dominated in the colloidal fraction of both lava -and scoria-derived soils under very humid conditions at high elevation. The sequence of soil types developed on lava was, with increasing elevation, Cambisol -> Phaeozem -> Andosol, while on scoria it was Regosol -> Umbrisol -> Andosol. Our results show that climate is the overriding factor controlling the major mineralogical and pedogenic changes in the studied environment; however, the higher porosity of the scoria parent materials considerably accelerated weathering and pedogenic processes compared to the denser lavas. Our study highlights the importance of the parent material's physical nature in modulating rates of chemical weathering and pedogenesis.
Insects are a potential substitute for conventional meat and can be part of a sustainable human diet due to their valuable nutrients and relatively low environmental production impact. One species that is already produced for human consumption and livestock feed is the mealworm, i.e., larvae of Tenebrio molitor. Knowledge of the effects of temperature, and particularly photoperiod, on mealworm development is scarce, but crucial for the improvement of rearing. Therefore, the effects of three temperatures (20 °C, 25 °C, and 30 °C), in combination with three photoperiods (long-day—16 h:8 h light:dark; short-day—8 h:16 h light:dark, and constant darkness) on mealworm survival, developmental time, and growth rate were tested. We describe a significant effect of temperature on survival rate, developmental time, and growth rate. Furthermore, significant effects of photoperiod on developmental time and growth rate were found. At 25 and 30 °C and constant darkness, the highest survival and growth rate, along with the shortest developmental time, were observed. Our data can be used to improve the mass rearing of mealworms for an efficient production of food and feed.
Wildfires can have major impacts on terrestrial ecosystems and climate. The analysis of charcoal fragments in peat and lake sediments is the most widely used approach to reconstruct past biomass burning and fire regimes. This method typically relies on the quantification of the total charcoal content of the sediment. However, there is an increasing effort to use morphologies (finer anatomical features) and morphometrics (length: width ratio) of charcoal particles to advance our understanding of fuel burnt and fire types. We used experimental burnings in the laboratory for plant species from boreal Siberia, which are also commonly found in the Northern Hemisphere, to expand the reference datasets on morphological distinctions between species or fuel types. We also tested the effect of burning temperature (five temperature categories ranging from 250 to 450 °C) on char mass and morphometrics of charred plant material. We found that graminoid charcoal particles are most elongate (6.7-11.5), leaves are the shortest and bulkiest (2.1-3.5) while twigs and wood are intermediate (2.0-5.2). Our findings correspond well to the few existing comparable experimental measurements. Further, the use of fine charcoal features was successful in separating wood, graminoids, and leaves, but it was difficult to further differentiate these fuel types i.e., leaves and wood from trees and shrubs, due to overlapping features. In terms of charred mass, graminoids, Sphagnum, and wood (trunk) lose the most mass at low burn temperatures (<300°C), whereas heathland shrub leaves, brown moss, and ferns at high burn temperatures. Ongoing work applying micro-Fourier Transformed Infrared Spectroscopy (FTIR) on both modern charred particles produced at different temperature ranges and fossil charcoal will help estimate the pyrolysis temperature and fuel type. Similarly, our focus is to expand reference datasets on charcoal morphologies and FTIR to other major biomes, particularly grasslands. We also highlight the further investigations into charcoal experimental studies needed to refine the histories of past wildfires.
Sexual dimorphism is a widespread phenomenon among mammals, including carnivorans. While sexual dimorphism in golden jackals ( Canis aureus ) has been analysed in the past, in the related and apparently convergent canid, the African wolf ( Canis lupaster ), it is poorly studied and showed to be relatively small. Previously, sexual size dimorphism (SSD) research in these species was mostly based on skull and body measurements. In our study, we also included dental measurements, namely the diameter of the canine. We used 11 measured sections of 104 adult specimens, comprising 61 golden jackal and 43 African wolf skulls. Data analyses were carried out through logistic regression and conditional inference trees (CIT). To compare the results of SSD to other species, sexual dimorphism indices (SDI) were calculated. Golden jackals and African wolves show significant sexual size dimorphism, both in cranial and dental size. The logistic regression revealed that the mesiodistal diameter of the upper canine is most effective in discerning the sexes. The difference in the calculated SDI of the canine diameter between the sexes amounted to 8.71 in golden jackals and 14.11 in African wolves, respectively—with regional diversity. Thus, the canine diameter is an important measure to investigate SSD as well as an easy tool to apply in the field.
Application of low-cost carbon black from lignin highly depends on the materials properties, which might by determined by raw material and processing conditions. Four different technical lignins were subjected to thermostabilization followed by stepwise heat treatment up to a temperature of 2000 °C in order to obtain micro-sized carbon particles. The development of the pore structure, graphitization and inner surfaces were investigated by X-ray scattering complemented by scanning electron microscopy and FTIR spectroscopy. Lignosulfonate-based carbons exhibit a complex pore structure with nanopores and mesopores that evolve by heat treatment. Organosolv, kraft and soda lignin-based samples exhibit distinct pores growing steadily with heat treatment temperature. All carbons exhibit increasing pore size of about 0.5–2 nm and increasing inner surface, with a strong increase between 1200 °C and 1600 °C. The chemistry and bonding nature shifts from basic organic material towards pure graphite. The crystallite size was found to increase with the increasing degree of graphitization. Heat treatment of just 1600 °C might be sufficient for many applications, allowing to reduce production energy while maintaining materials properties.
Pitch oil production from Scots pine (Pinus sylvestris L.) resinous wood is an intangible cultural heritage in the Central European region including the Czech Republic, Northern Austria and South Eastern Germany, and is related to traditions in Finland and Southern France. The heating of wood in small kilns also fueled by wood produces liquid for collection. Our detailed investigations of three pitch oil kilns in Upper Austria led to the discovery of relationships to the production of pine and birch tar in Fennoscandia and black pine tar production in Western Anatolia. Our measurements of temperatures at the bases of the kilns revealed a slow temperature rise. We predicted maximum temperatures based on infrared spectra, and measured overall temperatures in the range of 250 degrees C-650 degrees C. With gas chromatographic analyses of pitch oil we detected a dominant proportion of resin components and only a minor proportion of compounds attributable to pyrolytic transformation of solid wood mass. In most pitch oil samples the extractives comprised 90 %. Most samples were similar and only the first samples at the starting outflow were systematically dominated by pyrolysis products. Tar runoff from a traditional circular charcoal kiln for charcoal production - used as a reference - had a strongly different composition, with a high proportion of pyrolysis compounds.
The dating of organic findings is a fundamental task for many scientific fields. Radiocarbon dating is currently the most commonly used method. For wood, dendrochronology is another state-of-the-art method. Both methods suffer from systematic restrictions, leading to samples that have not yet been able to be dated. Molecular changes over time are reported for many materials under different preservation conditions. Many of them are intrinsically monotonous. These monotonous molecular decay (MD) patterns can be understood as clocks that start at the time when a given molecule was formed. Factors that influence these clocks include input material composition and preservation conditions. Different wood species, degrees of pyrolysis, and pretreatments lead to different prediction models. Preservation conditions might change the speed of a given clock and lead to different prediction models. Currently published models for predicting the age of wood, paper, and parchment depend on infrared spectroscopy. In contrast to radiocarbon dating, dating via MD does not comprise a single methodology. Some clocks may deliver less precise results than the others. Ultimately, developing a completely different, new dating strategy-such as MD dating-will help to bring to light a treasure trove of information hidden in the darkness of organic findings.
The Galapagos archipelago is a well-suited model ecosystem for investigating soil evolution. Here, we study mineral transformations and pedogenesis of the volcanic soils of Galapagos in response to weathering duration (1,500-1,070,000 yr) and climate (humid vs. dry). Our results show that soil pH, electrical conductivity, organic C content, cation exchange capacity (CEC), and water retention decreased whereas clay content and bulk density increased with soil age under humid climate. Andic properties were expressed in soils <= 4,300 yr old, but disappeared relatively early in pedogenesis and were absent in soils >= 26,000 yr old. The clay fraction of the young andic soils (<= 4,300 yr old) was dominated by allophane and ferrihydrite. After 26,000 yr of pedogenesis, illitic-vermiculitic phases were predominant, and in the older soils (>= 166,000 yr old), kaolinite, hematite, and gibbsite prevailed. The sequence of soil orders from the youngest to the second oldest site was Histosol-Andisol-Alfisol (vermiculitic)-Alfisol (parasesquic)-Ultisol. The oldest soil of the humid chronosequence (1,070,000 yr old) met all diagnostic criteria for an Oxisol except for the required low CEC. The soils at two dry comparison sites were less developed with low clay contents and vitric materials at 26,000 yr of age (Entisol), and dominantly smectitic clay mineralogy and pronounced shrink-swell features at 813,000 yr of age (Vertisol). Our results highlight a rapid transition through the Andisol stage during early pedogenesis as well as strongly divergent pedogenic development in humid vs. dry zones of the Galapagos Islands, both of which have important bearings on soil functioning and ecosystem evolution on this unique archipelago.
Hair is an important component in scat that is commonly used for prey analyses in carnivores. Chemically, hair predominately consists of keratin. The recalcitrant fiber protein is degraded in nature only by a few insects and soil microorganisms. Common proteases such as pepsin do not decompose keratin. Infrared spectroscopy was used to detect chemical differences caused by pretreatment and fate of hairs. Three sample sets were compared: original untreated hair, original milled hair, and hairs extracted from scats of golden jackals (Canis aureus L.). The results revealed that only milling affected the infrared spectral pattern, whereas digestion had no impact. Moreover, hairs from different species (e.g., boar) could be distinguished due to their spectral characteristics. They did not change through the passage of the digestive system.
Studies on the foraging ecology of wildlife species are of fundamental importance, as foraging decisions are closely linked to ecological key issues such as resource partitioning or population dynamics. Using Black grouse as a model system, we applied Fourier-transform infrared spectroscopy (FTIRS) to address some key questions in foraging ecology: (1) does FTIRS allow for determining plant taxa and plant parts? Can FTIRS suggest variation in digestibility of food and physiological mechanisms of consumers? (2) Can FTIRS be used to track changes in diets among populations? (3) Can FTIRS capture plants' phenology and shifts in diet? To answer these questions, we analyzed crop and gizzard contents of Black grouse via FTIRS looking for specific spectra and bands of plant taxa and plant parts. We compared spectral signals of undigested plant material and intestinal droppings, gained from wild-living birds and from aviaries. Our analyses yielded characteristic spectral fingerprints for several food plants and plant parts. Spectral fingerprints could differentiate between needles of J. communis and P. mugo and between fruits of J. communis, Sorbus sp., and Vaccinium sp. Spectral signals differed more between undigested material and crop samples than between crop and gizzard samples. Differences were more pronounced for berries than for needles. Apart from these differences, some fingerprints persisted for certain food items. The diverse foraging regime of wild-living individuals compared to captive Black grouse was reflected by spectral signals. Thus, FTIRS is a promising approach to explore variation in food choice of grouse species by means of non-invasively gained fecal samples.
Hair amendments were extracted from the lime plasters of historical buildings with an age ranging from recent times until the 12th century. Infrared spectroscopy has been used to assess chemical changes, small-angle X-ray scattering (SAXS) for changes of the physical structure. As a reference a sample set of 130 recent samples has been collected comprising different species. The only strong impact on hair chemistry was detected for grinding the samples. This pretreatment separated the chemical fingerprint based on methylene bands (2920 and 2850 cm(-1)) and the C=O vibration band at 1740 cm(-1). Different species were separated only on a coarse level. Historical samples did not display very clear indicators of aging processes. SAXS results registered a certain grouping of the samples according to age. A clear trend was not found, however. This suggests that age alone is not the key defining factor in the degradation processes in hair. (C) 2020 The Authors. Published by Elsevier Ltd.
Rectangular kilns are a traditional technique in charcoal production in the second half of Modern Period in Middle Europe. Only in Austria there is still an active tradition that is of broader interest in an archaeological context. One of these kilns in Rohr im Gebirge, Lower Austria, was equipped with thermocouples to record pyrolysis temperature during the whole process. The removal of ready charcoal was paralleled by sampling, in total 103 charcoal samples were collected. Based on the infrared (FTIR) spectral pattern the pyrolysis temperature was predicted. It is the first reconstruction of the temperature profile of the whole kiln. Elemental analyses were performed and prediction models for carbon (R-2 = 0.93), hydrogen (R-2 = 0.96) and oxygen (R-2 = 0.98.) content based on FTIR spectra established. Therefore, FTIR spectroscopy rolls the degree of pyrolysis and elemental analyses into one single analytics. Further analyses by means of NMR spectroscopy, X-ray diffraction and He-pycnometry complete the picture.
Dating of clay bricks (adobe) and plasters is a relevant topic not only for building historians in the Pannonian region. Especially in vernacular architecture in this region, clay with straw amendments is a dominant construction material. The paper presents the potential of the molecular decay of these amendments to establish prediction tools for age based on infrared spectroscopic measurements. Preliminary results revealed spectral differences between the different plant parts, especially culms, nodes, and ear spindles. Based on these results, a first prediction model is presented including 14 historic samples. The coefficient of determination for the validation reached 62.2%, the (RMSE) root mean squared error amounted to 93 years. Taking the limited sample amount and the high material heterogeneity into account, this result can be seen as a promising output. Accordingly, sample size should be increased to a minimum of 100 objects and separate models for the different plant parts should be established.
Based on infrared spectral characteristics, six archeological sample sets of charcoals from German (5) and Brazilian (1) sites, covering the time span from the nineteenth century CE to 3950 BCE, were compared to a chronological (present to the fifteenth century BCE) series of Austrian charcoals. A typical chronological trend of several bands (stretch vibrations: O–C–O of carboxylates at 1,585–1,565 and 1,385–1,375 cm −1 , C–O carboxylic acids at 1,260–1,250 cm −1 ) that indicate oxidation and subsequently increasing hydrophilicity (O–H stretch vibration at about 3,400 cm −1 ) was also contained in the archive samples. Three sample sets fit in the typical band development according to their age. For three sample sets this conformity was not observed. Despite the age of two sample sets (3950–2820 BCE), most charcoals were assigned to the Modern Period. Apart from the high degree of carbonization, anaerobic depositional conditions over a longer period of time seem to contribute to the surprising conservation. Non-removable mineral components in charcoals, as observed in a third sample set, strongly influence infrared band intensities and positions of organic compounds. The role of inorganic components in terms of charcoal aging, and the information we can obtain from spectral characteristics in an archeological context, are discussed.
Charcoal production is a handicraft of oldest tradition. Various types have been developed. One of the most popular in Europe was the circular kiln with vertically piled logs. Besides traditional techniques new developments arose during the last decades like drum kilns in Namibia. Infrared spectroscopy was applied to assess pyrolysis temperatures using an already existing prediction model. A comparison of the two very different kiln techniques revealed systematic differences in the pyrolysis process and profile, but also comparable temperature ranges from 400 to 700 degrees C. These results correspond to literature values for circular kilns and rectangular kilns with horizontally piled logs. Temperature measurements by means of thermocouples supported infrared spectroscopic results.
Dating of wood is a major task in historical research, archaeology and paleoclimatology. Currently, the most important dating techniques are dendrochronology and radiocarbon dating. Our approach is based on molecular decay over time under specific preservation conditions. In the models presented here, construction wood, cold soft waterlogged wood and wood from living trees are combined. Under these conditions, molecular decay as a usable clock for dating purposes takes place with comparable speed. Preservation conditions apart from those presented here are not covered by the model and cannot currently be dated with this method. For example, samples preserved in a clay matrix seem not to fit into the model. Other restrictions are discussed in the paper. One model presented covers 7,500 years with a root mean square error (RMSE) of 682 years for a single measurement. Another model reduced to the time period of the last 800 years results in a RMSE of 92 years. As multiple measurements can be performed on a single object, the total error for the whole object will be even lower.
This study presents a new chronometric method for the dating of wood. The clock used is the chemical breakdown of specific parts, such as the acetyl groups of the hemicelluloses. The presented prediction models cover a maximum of 3000 years and include old living trees, construction wood and cold waterlogged wood. Any other preservation conditions are not covered by these models. Under these conditions, abiotic factors dominate and the contribution of microbial decay is negligible. This is a pre-requisite for the application of the present models. Brittle parts of the wood cannot be dated. Infrared spectroscopy was applied to detect the molecular changes over time. Currently, four models are available for Norway spruce, European larch, oak, and silver fir.
The Galapagos archipelago has extensively been studied because of its geological and climatic setting and especially for its peculiar flora and fauna. However, there is still little information about its soils. The objective of this study was to investigate weathering and soil formation on Alcedo Volcano, which is the only volcano of Galapagos that has erupted abundant rhyolitic materials. Soils were sampled from three sites along an elevation/ moisture gradient, site 1 at 872 m above sea level (a.s.l.) (humid zone), site 2 at 621 m a.s.l. (dry zone) and site 3 at 377 m a.s.l. (very dry zone). Soil pH (in H2O) ranged from 6.0 to 6.6 but did not vary significantly among the three sites. Water retention (at 1500 kPa) and phosphate retention increased with elevation/moisture. Similarly, soil organic carbon (SOC) stocks increased from approx. 1.1 kg m(-2) in the very dry zone to approx. 7.5 kg m(-2) in the humid zone. Allophane and ferrihydrite were the dominant colloidal constituents in the humid zone (site 1), whereas halloysite was found in the dry zone (site 2) and only traces of halloysite in the very dry zone (site 3). At site 1, the soil was borderline between andic and vitric properties and was classified as Silandic Tephric Andosol or Vitric Tephric Andosol for andic and vitric character, respectively; at site 2, the soil had vitric properties and was classified as Vitric Tephric Skeletic Andosol; and at site 3, the soil was borderline with respect to the expression of vitric properties and was classified as Vitric Tephric Skeletic Andosol in the presence and as Tephric Skeletic Regosol in the absence of vitric properties. Our results show that different moisture availability strongly affected SOC accumulation and favored the formation of different types of colloidal constituents (amorphous vs. crystalline) in the rhyolitic tephra of Alcedo Volcano. This has important bearings on the expression of andic and vitric soil properties and, hence, on the distribution of Andosols in the studied environment.