Species composition of soil algal and cyanobacterial communities was investigated in thirteen sites of different toxicity of spoil material on dumps in the Sokolov mining area (Czech Republic). The adaptation ability of various algal and cyanobacterial species to live in toxic environment and the effect of different amendments (wooden coal, organic matter, dolomitic limestone) of toxic soils were tested both in laboratory and field experiments. According to results, species composition corresponded to environmental characteristic (pH, conductivity, substrate type). Some green unicellular algae grew successfully in extracts from the most toxic substrate and seemed to be well adapted to low pH conditions. Results indicate that increase of pH is a basic precondition for the establishment of more diverse and abundant algal flora in highly acidic sites.

Gold mine tailings material facilities are characterized by sparse vegetation and an abundance of dust. Mine tailings facilities are examples of extreme geotechnical and geochemical conditions which make it almost impossible for higher plants to establish and grow without rehabilitation intervention. In most cases higher plants such as grasses and trees are the focus areas for rehabilitation, but, having a look at something a little smaller such as biological crusts, it is seen that these micro-organisms play very important roles in any ecosystem. Various studies have shown that biological crusts, consisting of micro-organisms such as lichens, algae and cyanoprokaryotes enhance the soil quality by binding soil particles together, forming aggregates which counteract the erosive forces of wind and water. They play a part in nitrogen and carbon fixation, increase the soil surface temperature and increase the water retention of the soil. Thus, these organisms improve the overall health of the soil, which will in time encourage the successful establishment of higher plants. The aim of this study was to investigate the presence of cyanoprokaryotes and soil algae on mine tailings storage facilities that have been rehabilitated for different periods of time as well as to correlate the presence of these species with the physical and chemical characteristics of the mine tailings material. Chemical, physical and biological analyses of soil samples were done. Some of the ecologically important and dominant species were isolated and protocols were developed in order to identify the most successful manner in which to re-inoculate the organisms to a chosen substrate and how to measure biomass. Due to the immense cost of standard rehabilitation practices there is a need for a more cost effective, sustainable manner in which to protect the tailings material against the erosive forces of wind and water with as little input as possible. The influence of an organism cultured in normal Bold’s Basal medium (BBM) growth medium, BBM growth medium with half the phosphate concentration and BBM growth medium with half the nitrate concentration on the establishment of a biological soil crust (BSC) was tested. To test the influence of the inoculums already present in the tailings material and in the air, trials with mulch, water and nutrients without the addition of an organism was also investigated. This was done in the controlled environment of a glasshouse, as well as in field conditions. The biomass of the cyanoprokaryotes and algae, as well as the soil surface strength was also tested. The results show that the time of rehabilitation did not have an influence on the cyanoprokaryotes as well as algal species that occurred on the tailings material. Chlorella sp., Chlorococcum sp. and Klebsormidium sp. were present on all six sites, except on the fresh material and 15 year old material where no rehabilitation has been done. As for dominance; Chlamydomonas sp., Chlorococcum sp., Klebsormidium sp. and Phormidium sp. were dominant on all six sites except for the fresh material, where nothing grew. An array of methods exists for measuring algal biomass as a measure of growth. During the development of protocols for further use in investigating the growth of algae, the extraction solvent ethanol, for use in chlorophyll a extraction, was identified as the most sufficient. The re-inoculation of cyanoprokaryotes and soil algae onto a chosen substrate is most successful when pouring the organisms, cultured in growth medium and 0.1% agar, over the substrate. During the glasshouse trials the influence of the growth medium and growth medium with half the nitrate and half the phosphate concentrations showed that Chlamydomonas sp. produced the highest biomass when cultured in BBM. With Nostoc sp. the highest biomass occurred with culturing in BBM and BBM with half the phosphate concentration. Microcoleus vaginatus showed no significant difference when cultured in the three different growth mediums (BBM, BBM with half the nitrate concentration and BBM with half the phosphate concentration). Overall Nostoc sp. produced the highest biomass (34.33 μg/g), followed by Microcoleus vaginatus (17.05 μg/g) and Chlamydomonas sp. (6.12 μg/g). Soil surface strength, measured with a hand held penetrometer showed that Chlamydomonas sp. cultured in BBM growth medium produced the most stable crust (2.58 kg/cm2), although it had the lowest biomass measurements (6.12 μg/g). Nostoc sp. produced the highest biomass (34.44 μg/g), but had the lowest soil surface strength results (1.75 kg/cm2). Microcoleus vaginatus proved to be the species with high biomass production (17.05 μg/g), as well as high soil surface strength (2.08 kg/cm2). M. vaginatus is also a pioneer species and is therefore a good choice as primary inoculum on bare tailings material. It was decided to use Nostoc sp. in the field trials due to its high biomass and Microcoleus vaginatus due to the high soil surface strength produced. Despite the occurrence of a severe thunder storm on the afternoon of application and poor water management during the field trials the significance of water on the establishment of soil algae and cyanoprokaryotes on tailings material was determined. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014

Gold mine tailings material facilities are characterized by sparse vegetation and an abundance of dust. Mine tailings facilities are examples of extreme geotechnical and geochemical conditions which make it almost impossible for higher plants to establish and grow without rehabilitation intervention. In most cases higher plants such as grasses and trees are the focus areas for rehabilitation, but, having a look at something a little smaller such as biological crusts, it is seen that these micro-organisms play very important roles in any ecosystem. Various studies have shown that biological crusts, consisting of micro-organisms such as lichens, algae and cyanoprokaryotes enhance the soil quality by binding soil particles together, forming aggregates which counteract the erosive forces of wind and water. They play a part in nitrogen and carbon fixation, increase the soil surface temperature and increase the water retention of the soil. Thus, these organisms improve the overall health of the soil, which will in time encourage the successful establishment of higher plants. The aim of this study was to investigate the presence of cyanoprokaryotes and soil algae on mine tailings storage facilities that have been rehabilitated for different periods of time as well as to correlate the presence of these species with the physical and chemical characteristics of the mine tailings material. Chemical, physical and biological analyses of soil samples were done. Some of the ecologically important and dominant species were isolated and protocols were developed in order to identify the most successful manner in which to re-inoculate the organisms to a chosen substrate and how to measure biomass. Due to the immense cost of standard rehabilitation practices there is a need for a more cost effective, sustainable manner in which to protect the tailings material against the erosive forces of wind and water with as little input as possible. The influence of an organism cultured in normal Bold’s Basal medium (BBM) growth medium, BBM growth medium with half the phosphate concentration and BBM growth medium with half the nitrate concentration on the establishment of a biological soil crust (BSC) was tested. To test the influence of the inoculums already present in the tailings material and in the air, trials with mulch, water and nutrients without the addition of an organism was also investigated. This was done in the controlled environment of a glasshouse, as well as in field conditions. The biomass of the cyanoprokaryotes and algae, as well as the soil surface strength was also tested. The results show that the time of rehabilitation did not have an influence on the cyanoprokaryotes as well as algal species that occurred on the tailings material. Chlorella sp., Chlorococcum sp. and Klebsormidium sp. were present on all six sites, except on the fresh material and 15 year old material where no rehabilitation has been done. As for dominance; Chlamydomonas sp., Chlorococcum sp., Klebsormidium sp. and Phormidium sp. were dominant on all six sites except for the fresh material, where nothing grew. An array of methods exists for measuring algal biomass as a measure of growth. During the development of protocols for further use in investigating the growth of algae, the extraction solvent ethanol, for use in chlorophyll a extraction, was identified as the most sufficient. The re-inoculation of cyanoprokaryotes and soil algae onto a chosen substrate is most successful when pouring the organisms, cultured in growth medium and 0.1% agar, over the substrate. During the glasshouse trials the influence of the growth medium and growth medium with half the nitrate and half the phosphate concentrations showed that Chlamydomonas sp. produced the highest biomass when cultured in BBM. With Nostoc sp. the highest biomass occurred with culturing in BBM and BBM with half the phosphate concentration. Microcoleus vaginatus showed no significant difference when cultured in the three different growth mediums (BBM, BBM with half the nitrate concentration and BBM with half the phosphate concentration). Overall Nostoc sp. produced the highest biomass (34.33 μg/g), followed by Microcoleus vaginatus (17.05 μg/g) and Chlamydomonas sp. (6.12 μg/g). Soil surface strength, measured with a hand held penetrometer showed that Chlamydomonas sp. cultured in BBM growth medium produced the most stable crust (2.58 kg/cm2), although it had the lowest biomass measurements (6.12 μg/g). Nostoc sp. produced the highest biomass (34.44 μg/g), but had the lowest soil surface strength results (1.75 kg/cm2). Microcoleus vaginatus proved to be the species with high biomass production (17.05 μg/g), as well as high soil surface strength (2.08 kg/cm2). M. vaginatus is also a pioneer species and is therefore a good choice as primary inoculum on bare tailings material. It was decided to use Nostoc sp. in the field trials due to its high biomass and Microcoleus vaginatus due to the high soil surface strength produced. Despite the occurrence of a severe thunder storm on the afternoon of application and poor water management during the field trials the significance of water on the establishment of soil algae and cyanoprokaryotes on tailings material was determined. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014

In arid and semi-arid deserts, soils are commonly covered with biological soil crusts. The study of arid biocrusts and their ecological function has become increasingly common in the literature over the last several decades. Interestingly, no mention is made of biological soil crusts in forested ecosystems, raising the question as to whether they exist in these areas and if they do, why they have yet to be recognized as such? Through the use a parallel logic, this study finds that biocrusts do indeed exist in forests, a novel relationship in forest ecology and seeks to determine if there exist ecophysical explanations for the abundance and distribution throughout the forest landscape. This study examined the effects of climate variables and substrate types on the abundance, distribution and overall cover of forest soil biocrust at fifty-two sites in southern Oregon, U.S.A. Sites were randomly selected within established buffer zones in the Siuslaw, Rogue-Sisikyou, Umpqua, and Fremont-Winema National Forests. The methods of Belnap et al 2001 were tested and then modified for application in forested ecosystems. Data were collected on the relative abundance and distribution of biocrust morphological groups across available substrates, community biocrust morphology, aspect, elevation and soil texture, pH and organic matter content. Site-specific data on average annual precipitation and minimum/maximum temperatures was collected using the PRISM Climate Model. This study found substrate colonization by specific morphological groups mixed across the study; though dominant communities were observed for each substrate present, substrate availability appears to be confounded by a number of variables (climate, stand age and structure and litter layer) not controlled for in this study. Biocrust community morphologies varied across sites, primarily influenced by the surface texture of the substrate and morphology of the individual. Relatively smooth surfaces (rock, bare soil) often resulted in smooth biocrust morphologies, whereas rough surfaces (dead wood, bare soil) tended to result in a rolling morphology. Litter layer directly influenced the relative proportion of substrates colonized, notably affecting dead wood and mineral soil biocrusts. Total biocrust cover increased as precipitation increased as did biocrust preference for dead wood substrates while mineral soil remained unchanged and rock surfaces were negatively represented. Aspect generally followed the anticipated distribution of total biocrust cover with the highest cover on N and NW aspects and lowest on the W aspect. Increases in elevation were negatively related to overall biocrust cover. Soil texture was not found to be directly related to overall biocrust cover, attributed in part to the highly adaptive nature of the biocrust community. Soil organic matter (SOM) influenced total biocrust cover with positive correlations between total cover and increasing SOM content. Soil pH increased as expected across the precipitation range (17 to 159 in/yr) of the transect. Total biocrust cover was found to trend with soil pH, but is believed to be attributed to the parallel relationship between precipitation and pH, rather than pH alone given the relative moderate pH range (4.39 to 6.54) of the study. The distribution and abundance of forest soil biocrusts is strongly influenced by precipitation. The confounding influence of precipitation to litter layer depth and organic matter content (through gradients of vegetative productivity) and soil pH further are concluded to influence substrate preference by morphological groups. Across the variables examined, similarities between the two communities (arid and forest) in response to climate and soil chemistry show parallel relations, justifying the formal establishment of biological soil crust community in forested regions. The differences between communities related to the presence of trees validate the establishment of forest soil biocrusts as distinct community in both form and ecological function with the forests. / Graduation date: 2013

Biotests sind für die toxikologische Bewertung von Chemikalien, Pflanzenschutzmitteln und schadstoffbelasteten Gewässern oder Böden von besonderer Bedeutung, da sie Auskünfte über die biologische Wirksamkeit eines Stoffes auf Organismen geben. Bislang gibt es für die ökotoxikologische Bewertung, insbesondere von Chemikalien und Pflanzenschutzmitteln, für die autotrophe Organismenebene neben verschiedenen Biotests mit höheren Pflanzen den DIN 28 692 Biotest "Wachstumshemmtest mit den Süßwasseralgen Scenedesmus subspicatus und Selenastrum capricornutum", der auch als OECD 201 Biotest "Algal, Growth Inhibition Test" vorliegt. Dieser aquatische Biotest wird nur mit einer Süßwasseralgenart durchgeführt und trotzdem zunehmend für die Bewertung von belasteten Böden und Sedimenten eingesetzt. Untersuchungen über aquatische Biotests, die Bodenalgen als Testorganismen nutzen, oder Boden-Biotests mit Bodenalgen gibt es nur vereinzelt. Ein Biotestsystem, das sowohl aus einem aquatischen als auch aus einem terrestrischen Biotest besteht und mehrere Bodenalgenarten als Testorganismen nutzt, existiert bisher nicht. Dieses wurde in vorliegender Arbeit entwickelt und an dem Schwermetall Cadmium als Cadmiumchlorid und dem Herbizid Arelon, Wirkstoff Isoproturon erprobt. Um Bodenalgen, die keine Resistenzen oder Toleranzen gegenüber Schadstoffen aufweisen, als Testorganismen nutzen zu können, wurden aus unbelasteten Böden Algen isoliert, Klonkulturen erstellt und die Arten bestimmt. Dies führte zu einer Sammlung mit 35 Algenarten. Aus den in die Bodenalgensammlung aufgenommenen Arten wurden Xanthonema tribonematoides, Stichococcus bacillaris, Klebsormidium flaccidum, Xanthonema montanum und Chlamydomonas noctigama für das Testsystem ausgewählt. Zusätzlich zu diesen wurde die Süßwasseralge Scenedesmus subspicatus als Referenzalge ausgewählt. Mit diesen Algen wurde der Gel-Biotest, bestehend aus einem flüssigen gelartigen Medium, das die Kontaminationspfade im Wasser nachbildet, und ein Boden-Biotest mit einem naturnahen sorptionsschwachen Boden entwickelt, der die Kontaminationspfade über Gas-, Wasser- und Festphase im Boden nachbildet. Bei der Erprobung dieses Biotestsystems mit Cadmiumchlorid und Isoproturon zeigte sich, daß Bodenalgen gegenüber Cadmiumchlorid im Gel-Biotest eine geringe bis mittlere Sensibilität aufwiesen. Im Boden-Biotest lag eine sehr geringe Sensibilität vor, wie dies auch bei anderen Bodenorganismengruppen in Biotests festgestellt wurde. Dies kann mit der Sorption der Cadmiumionen im Boden erklärt werden und dem damit geringen für die Organismen bioverfügbaren Cadmiumionenanteil. Für Isoproturon lag sowohl im Gel- als auch im Boden-Biotest eine hohe Sensibilität der Bodenalgen vor. Erstaunlich war, daß die Sensibilität in beiden Biotests nahezu identisch war, obwohl Isoproturon in sorptionsschwachen Böden zu ca. 30 % adsorbiert wird. Im Vergleich zur Sensibilität von Scenedesmus subspicatus waren die Bodenalgen bei Cadmiumchlorid bis auf zwei Ausnahmen um den Faktor 5 bis 10 unsensibler. Die Bodenalge Klebsormidium flaccidum besaß eine vergleichbare Sensibilität und Xanthonema montanum war um den Faktor 20 unsensibler. Für Isoproturon konnten keine Unterschiede in der Sensibilität zwischen Scenedesmus subspicatus und den geprüften Bodenalgen ermittelt werden, außer bei Stichococcus bacillaris, die um den Faktor 5 unempfindlicher war. Das entwickelte miniaturisierte Biotestsystem eignet sich dazu, differenzierte Aussagen über das ökotoxische Potential von Stoffen auf Bodenalgen und der Süßwasseralge Scenedesmus subspicatus zu erhalten. Durch den Einsatz von zwei unterschiedlichen Testsubstraten (Flüssigmedium und naturnaher Boden) werden der Einfluß dieser Substrate sowie die daraus resultierenden Kontaminationspfade der Teststoffe und ihre ökotoxikologische Wirkung auf Algen feststellbar und vergleichbar. Ein Normenentwurf des Biotestsystems wurde inzwischen in das "Technical Committee 190 - Soil Quality" der International Standards Organization (ISO) eingereicht. / Biotests are an important device to assess the toxicity of chemicals, pesticides, polluted water, and soils because they can provide direct information about the influence of a compound on the organism level. Besides various biotests using higher plants there is only the DIN 28 692 biotest "Growth-inhibition test using fresh water algae Scenedesmus subspicatus and Selenastrum capricornutum" (DIN 28 692) also known as the OECD 201 biotest "Algal, Growth Inhibition Test" which is currently available for an ecotoxicological assessment of chemicals such as pesticides on the autotrophic organism level. This aquatic biotest is based on a single specie of fresh water algae and is increasingly applied to evaluate polluted soils and sediments. There is almost no information on aquatic biotests which are using soil algae as test organisms instead. A more comprehensive biotest system which actually combines aquatic and terrestric biotests using several soil algae species as test organisms has not been reported, yet. Thus, a biotest system was developed and subsequently evaluated by using cadmium (cadmium chloride) as a heavy metal, and the herbicide arelon containing isoproturon as the active ingredient. Soil algae were isolated from unpolluted soil in order to obtain test organisms which are not resistant or tolerant to pollutants. The algae isolates were then cultivated, and subsequently identified. A total of 35 algae species was collected. Algae species used in the biotest system were Xanthonema tribonematoides, Stichococcus bacillaris, Klebsormidium flaccidum, Xanthonema montanum, Chlamydomonas noctigama. In addition, the fresh water specie Scenedesmus subspicatus served as a reference algae. Based on these different algae species a gel biotest using liquid gel medium was developed to investigate the contamination path via water, and also a soil biotest with a pre-treated soil of low sorption capacity was deviced to simulate the contamination path through gas, water, and solid phase. The evaluation of the biotest system using cadmium chloride and isoproturon did reveal that soil algae have had only low to medium sensitivity to cadmium chloride in the gel biotest. Algae sensitivity in the soil biotest was very low which was in accordance with data from other biotests using different soil organisms. The weak response of the algae was most likely caused by the sorption of the cadmium ions to the soil matrix what may have decreased the bioavailability of cadmium. In comparison, soil algae were very sensitive to isoproturon in both, the gel biotest and the soil biotest. Both biotests indicated almost identical sensitivities of the tested soil algae which was surprising since 30 % of the isoproturon was sorbed even in soils with a low sorption capacity. Soil algae when compared to the water algae Scenedesmus subspicatus were generally 5 to 10-fold less sensitive to cadmium chloride. Only Klebsormidium flaccidum has proved to have a similar sensitivity as Scenedesmus subspicatus had, whereas Xanthonema montanum was about 20-fold less sensitive. With isoproturon, however, no differences in sensitivity could be seen between Scenedesmus subspicatus and the tested soil algae, except Stichococcus bacillaris which was about 5-fold less sensitive. The biotest system as developed in this study has shown to be suitable for obtaining valuable information about ecotoxicological effects of chemicals on soil and water algae. Since the biotest system consists of two different test media (liquid gel and soil) it is possible to determine ecotoxicological effects on algae in both, water and soil. A first draft of the developed biotest system has been submitted to the "Technical Committee 190 - Soil Quality" of the International Standards Organization (ISO) for review.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / Previous studies have indicated that blue-green algae may affect runoff, infiltration and erosion at soil surfaces. Using soil plots upon which blue-green algae were grown under an artificial wetting regime, studies were made using simulated rainfall. A 30% clay content Pima soil and a contrasting 8% clay content river-bottom anthony soil were used. Scytonema hoffmanii and Microcoleus vaginatus grew on the pima soil while Schizothrix calcicola developed on the Anthony soil. The results showed that blue-green algal growths significantly reduced the amount of suspended soil material in runoff water as compared with bare soils. Differences in runoff suspended sediments were also related to differences in soil type and simulated rainfall intensity. An analysis of variance of the effects of these 3 factors and their interactions showed that the smaller differences in suspended sediment production on the Anthony soil due to the microvegetation treatment was verified by a highly significant soils-microvegetation interaction, probably because the finer pima soils wash away more easily without stabilizing microvegetation. Also, less vegetation seems to grow on the Anthony soil. Differences in runoff and infiltration volumes and in settleable sediment amounts were not detected.