Hans-Peter Blume

Weathering of rocks induced by lichen colonization — a review

Abstract The evidence presented by numerous investigations of the interface between lichens and their rock substrates strongly suggests that the weathering of minerals can be accelerated by the growth of at least some lichen species. The effects of lichens on their mineral substrates can be attributed to both physical and chemical processes. The physical effects are reflected by the mechanical disruption of rocks caused by hyphal penetration, expansion and contraction of lichen thallus, swelling action of the organic and inorganic salts originating from lichen activity. Lichens also have significant impact in the chemical weathering of rocks by the excretion of various organic acids, particularly oxalic acid, which can effectively dissolve minerals and chelate metallic cations. As a result of the weathering induced by lichens, many rock-forming minerals exhibit extensive surface corrosion. The precipitation of poorly ordered iron oxides and amorphous alumino-silica gels, the neoformation of crystalline metal oxalates and secondary clay minerals have been frequently identified in a variety of rocks colonized by lichens in nature. For a better understanding of the impacts of lichens on environments, further work on the comprehensive involvement of the lichen effects on weathering of natural rocks, deterioration of building stones and stonework, and formation of primitive soils should be carried out.

Variability of soils in urban and periurban areas in Northern Germany

Abstract Soils of urban areas are mixtures of old and very young soils. In the town of Eckernforde Luvisols, Arenosols, Gleysols, and Histosols developed from natural parent materials are widespread in the outer areas and Urbic Anthrosols occur especially in the inner city area. The Urbic Anthrosols are very heterogeneous with a wide range of ecologically important properties (e.g., water holding capacity, aeration, nutrient supply, heavy metal contents) resulting from lithogenesis and pedogenesis. Some examples of this soil unit are described. Specific characteristics of urban areas are lowering of the ground water table, soil surface sealing and mixing of anthropogenic materials (e.g., brick and mortar debris, garbage, rubble, ashes) with the natural parent materials. The soil pattern of urban areas is strongly influenced by human activities.

Soil organic matter composition and microbial activity in urban soils

Abstract In an urban environment soil organic matter (SOM) has manifold functions and is of considerable ecological significance. In six top layers of soils of different ages in the city of Kiel at the Baltic Sea, Northwest Germany, the SOM composition was investigated by means of wet chemistry and CPMAS 13 C-NMR spectroscopy and compared with data of natural soils and microbial eco-physiological parameters derived from basal respiration (R mic ), microbial biomass (C mic ) and total organic carbon (TOC). In comparison with natural soils, all urban soils were characterized by a very low level of the recalcitrant lipid fraction and the low molecular fulvic acid fraction. C mic was-similar to those of their natural counterparts. The mean C mic TOC and the metabolic quotient ( R mic C mic = qCO 2 ) were higher, because of the young age of the soils and an early succession step, or due to environmental stress such as methane evolution. The logarithmic time dependant decline of C mic TOC was well correlated with the decrease of the available litter compounds in the SOM (proteins and polysaccharides). In the young soils ‘free’ litter compounds dominate in the SOM, whereas in the older soils these SOM compartments were incorporated into the humic matrix by probably reducing their availability to microorganisms. In summary in the urbic soils humification has to be enhanced in order to improve soil ecology in the urban environment.

Soil microbial activities in Luvisols and Anthrosols during 9 years of region-typical tillage and fertilisation practices in northern Germany

In order to evaluate soil functions of contemporary agricultural management practices, the adjustment of microbial biomass and C and N mineralisation capacities was monitored during 9 years following the implementation of conventional and reduced tillage, and mineral N and pig slurry fertilisation systems. Soil microbial biomass content and microbial activities decreased continuously from initial values. The decrease was slowed by slurry application, compared to either no or mineral N fertilisation, and both slurry and mineral N application stimulated soil microbial activities in the long-term. There were no significant differences in microbiological characteristics between conventional and reduced tillage for the 0 to 30 cm soil depth but microbial biomass and activity were highest from 0 to 15 cm depth under reduced tillage. Changes in several microbial properties became evident when analysing the whole experiment of 9 years and the soil unit is also of importance as shown by higher microbial activity level in Anthrosols in comparison to Luvisols.

Soil organic matter composition and transformation in gelic histosols of coastal continental antarctica

Soil organic matter (SOM) of two antarctic soils was studied with special emphasis on soil formation processes under extreme climate conditions. An integrated approach of modern analytical methods, including wet-chemical analyses, cross-polarization magic-angle spinning carbon-13 nuclear magnetic resonance spectroscopy (CPMAS 13C-NMR) and pyrolysis-field ionization mass spectrometry (Py-FIMS), was applied to characterize the SOM composition at different depths in a Terri-Gelic Histosol and a Fibri-Gelic Histosol. Corresponding to the brownish-black colour of deeper soil horizons in the Terri-Gelic Histosol formed by mosses, wet-chemical analyses indicated transformation processes in the profile. Relative to the LH-horizon, the deeper horizons were characterized by an enrichment of organic-C and non-α-NH2N. However, in the Fibri-Gelic Histosol wet-chemical analyses did not show changes of SOM composition with increasing profile depth, which is clearly in accordance with the greenish-grey colour of all soil horizons. Both, the CPMAS 13C-NMR and the Py-FIMS spectra of the Terri-Gelic Histosol were dominated by signals of carbohydrates and alkylic compounds. The 13C-NMR data suggested decomposition of carbohydrates and the enrichment of alkyl-C in the deeper horizons. Py-FIMS indicated for carbohydrates a slight increase with increasing profile depth. The relative intensities (percentage of total ion intensity) of selected Py-FIMS signals for lipids (n-C10 to n-C20 alkyl-diester, n-C30 alkenes and alkanes, n-C16 to n-C34 fatty acids, n-C44 to n-C46 alkyl-monoesters, sterols) increased in the H1-and H2-horizons compared to the top and lowest horizons. Complementary to the general enrichment of alkyl-C with increasing soil depth determined by 13C-NMR spectroscopy, the detection of specific, biologically-important lipid-derived structures by Py-FIMS enabled a deeper insight in the behaviour of alkyl structures in the profile of the Terri-Gelic Histosol. For the first time a separate recording of signals for free fatty acids and sterols is presented. Although mosses do not contain lignins, both 13C-NMR and Py-FIMS spectra have shown signals for aromatics. This indicated the formation of aromatic humic substances without lignin precursors from plants. The 13C-NMR spectra of all horizons of the Fibri-Gelic Histosol were similar and showed intensive signals for carbohydrates. This indicated only a slight decomposition of carbohydrates and no selective preservation of alkylic biomacromolecules. Likewise, aromatic signals were of minor importance. Due to the extreme climatic conditions and the high water capacity, SOM transformation processes are retarded in the Fibri-Gelic Histosol.

Soil organic matter of suggested spodic horizons in relic ornithogenic soils of coastal continental Antarctica (Casey Station, Wilkes Land) in comparison with that of spodic soil horizons in Germany

In Antarctica, ornithogenic soils from penguin guano play an important role in nutrient cycles in the ecosystem. Soil organic matter (SOM) degradation and translocation are the main determinants of these dynamics, of which podzolization is probably one, in ornithogenic soil. The purpose of this

Method for characterization of inert organic carbon in Urbic Anthrosols

Abstract Organic matter in Urbic Anthrosols often contains chemically and biologically inert organic carbon. This material, called black carbon (BC), originates from municipal wastes, coal‐mine deposits and/or fly ash. This black carbon needs to be differentiated from the other soil organic substances because of its very different physical and chemical nature. In this paper, we propose a new method for determining BC, integrated into the humic fractionation procedure. The remaining organic carbon in the soil residue left after lipid extraction, alkaline extraction [0.5 M sodium hydroxide (NaOH)], and further oxidation with 30% hydrogen peroxide (H2O2) is defined as inert organic carbon or BC. The common fractions of soil organic matter, such as lipids, fulvic and humic acids, and humins are thus supplemented with a new fraction, BC. According to our results by 13C‐NMRspectroscopy, this fraction consists mainly of polyaromatic hydrocarbons with few functional groups.

Rock-weathering by lichens in Antarctic: patterns and mechanisms

Saxicolous species of lichens are able to induce and accelerate weathering of their rock substrate, and effects of lichens on substrate can be attributed to both physical and chemical causes. This paper is focused on biotic weathering actions of epilithic and endolithic species on the different rock types (sandstones and volcanogenic rocks) in Antarctica. The patterns, mechanisms, processes and neoformations of rock-weathering resulting from lichen colonization are expounded in detail. Furthermore, it is pointed out that, for a better understanding of the impacts of lichens on environments, the studies on the rate of biotic weathering and the comprehensive involvement of the lichen effects on weathering of natural rocks remain to be carried out in Antarctica.

Characteristics and classification of anthropogenic soils in the Osnabrück area, Germany

Soils in the area around Osnabruck/Northwest Germany have been strongly influenced by man. The classification of these soils based on the German and international classification systems is problematical. Eight representative soils, two Anthrosols (plaggic and hortic), four soils affected by the coal and steel industry and consisting of distinct monosubstrata (coal and ore mining heaps, slag heap, sludge area) as well as two deposits of heterogeneous waste components (reclaimed wet land, filled quarry) were investigated. The sites are assessed in relation to their contamination by heavy metals and PAH as well as suitability for plant growth. An attempt was made to classify the soils using the current classification of World Reference Base for Soil Resources (WRB), German Soil Science Society Classification, FAO and the USA. These systems enables a satisfactory classification of two Anthrosols compared with the other soils. In the US taxonomy, the pedogenesis of technological substrata was not considered. In the FAO taxonomy, it is not acceptable to term all soils as Urbic Anthrosols without any further differentiation. This differentiation was enabled in both the WRB and the German taxonomy. In the WRB taxonomy, however, only anthropic subunits of the Regosols are included. An improvement could be achieved by the introduction of comparable subunits of the Arenosols, Durisols, Gleysols, and Leptosols. In the German taxonomy (normally soil and substrata are classified separately), the induction of toxic subunits in the presence of high soil contamination influencing the edaphon would be helpful. Furthermore, soils hardened by silica should be classified as respective varieties. Eigenschaften und Klassifikation anthropogener Boden im Osnabrucker Raum Die Boden des Osnabrucker Raumes wurden im besonders starken Mase vom Menschen gepragt. Die Klassifikation derartiger Boden nach der deutschen und nach internationalen Bodenklassifikationen bereitet Probleme. Das wird am Beispiel von acht reprasentativen Boden demonstriert und es werden Verbesserungsmoglichkeiten der Klassifikation formuliert. Es wurden zwei Kultosole (Plaggenesch und Hortisol), vier Standorte montan-industrieller Pragung aus unterschiedlichen Monosubstraten (Bergehalden von Kohlebergbau und Erzbergbau, Schlackenhalde und Spulfeld der Steinindustrie) und zwei Ablagerungen aus heterogenen Mullkomponenten (trockengelegtes Sumpfgebiet und verfullter Steinbruch) untersucht. Die Standorte werden hinsichtlich ihrer Belastung mit Schwermetallen und PAK, sowie ihrer Eignung als Pflanzenstandorte bewertet. Es wurde versucht, diese Boden an Hand der allgemein gultigen Bodensystematiken der World Reference Base for Soil Resources, von Deutschland, der FAO und der USA zu klassifizieren. Eine Klassifikation der beiden Kultosole war nach allen getesteten Systemen befriedigend moglich, die der ubrigen jedoch nicht. Im US-System fehlt jede Problematisierung einer Bodenentwicklung vor allem aus technogenen Substraten, beim FAO-System befriedigt nicht, dass alle als Urbic Anthrosols bezeichnet werden und damit auch nicht zwischen anthropogener Lithogenese und Pedogenese unterschieden wird. Beim WRB- und beim deutschen System geschieht das. Im WRB-System sind dafur aber nur anthropische Untereinheiten der Regosole vorgesehen; zweckmasig waren auch entsprechende Untereinheiten der Arenosols, Durisols, Gleysols und Leptosols. Beim deutschen System (bei dem Boden und Substrat gesondert klassiert werden) waren (entsprechend WRB) toxische Untereinheiten bei starker, das Bodenleben beeintrachtigender Schadstoffbelastung zweckmasig. Auserdem sollten Boden, die durch Kieselsaure verfestigt wurden, als entsprechende Varietaten klassifiziert werden.

Mineralogy and Weathering of Antarctic Cryosols

Many soil researchers of the Antarctic (e.g., O’Brien, 1979; Campbell and Claridge, 1987; Bockheim and Ugolini, 1990) hold that no considerable chemical weathering and no new formation of minerals has taken place in soils of the Antarctic Desert and Tundra. They describe intensive changes in soil condition from cryoturbation and cryoclastic weathering but do not recognize a stronger influence of chemical weathering. However, pedologists from Central Europe assume that intensive cryoclastic weathering facilitates easier chemical weathering at low temperatures and thus allows a new formation of minerals (Kopp and Kowalkowski, 1990). Some even assume that, in many soils of Central Europe, brownification and clay formation mainly occurred under periglacial conditions (Kowalkowski and Borzyskowiski, 1973; Kopp et al., 1982).