Ecological-floristic analysis of soil algae and cyanobacteria on the Tra-Tau and Yurak-Tau Mounts, Bashkiria

The species composition of the soil algae and cyanobacteria in the Tra-Tau and Yurak-Tau mountains is represented by 136 species belonging to five phyla: Cyanobacteria (56 species), Chlorophyta (52 species), Xanthophyta (13 species), Bacillariophyta (12 species), and Eustigmatophyta (3 species). Hantzschia amphioxys var. amphioxys, Hantzschia amphioxys var. constricta, Klebsormidium flaccidum, Leptolyngbya foveolarum, Luticola mutica, Navicula minima var. minima, Nostoc punctiforme, Phormidium jadinianum, Phormidium autumnale, and Pinnularia borealis were identified more often than other species. The composition of the algal flora depended on the soil properties; the higher plants also had a significant influence on the species composition of the soil algae.     

Algological and mycological assessments of the soil state in the impact zone of the Kirovo-Chepetsk Chemical Plant

The chemical and microbiological (on the basis of algae and micromycetes) analysis of the soils was carried out in the region of the Kirovo-Chepetsk Chemical Plant. It has been shown that the complex soil contamination resulted in essential changes in the algal-mycological complexes: the species diversity of the phototrophs decreased, nitrogen-fixing cyanobacteria practically disappeared from the algocenoses, and melanic forms of fungi dominated in the structure of the micromycetal communities. The higher sensitivity of the mycological indication method to the soil contamination was found in comparison with the methods of biotesting on the basis of protozoa and coliform bacteria.     

Blue-green algae in soils of specially protected natural territories in the Cis-Ural and Southern Ural regions

Blue-green algae (Òyanobacteria) have been studied in soils of specially protected natural territories of the Cis-Ural and Southern Ural regions. The species composition of the algae has been determined in water and dish cultures with fouling glasses. The investigated soils are characterized by the rich flora of bluegreen algae comprising 79 species and intraspecies taxa. Recreation loads on the territory have resulted in a drop in the species diversity and numbers of algae; their taxonomic structure is becoming simplified. Active development of algae from the Oscillatoriales order assigned to the P-form and to the typical xerophytes (species of the Oscillatoria, Phormidium, and Plectonema genera) has been registered in some anthropogenically disturbed areas.     

The influence of different bioremediation methods on the algal cenoses of oil-polluted soils

The influence of oil and remediation methods on soil algal cenoses was studied. The oil pollution caused the reconstruction of the soil algocenoses with the alteration of the species composition and a decrease in the number of alga cells and biomass. The diatoms and yellow-green algae turned out to be the most sensitive to the oil pollution; the cyanobacteria and green algae were less sensitive to it. The bioremediation lowered the toxic effect of the oil on the algae and restored their floristic composition on the 90th day. In the course of the whole experiment, the number of alga cells and the biomass increased. The Lenoil preparation was accepted as the most efficient.     

New trophic biomarkers for Collembola reared on algal diets

We used fatty acid (FA) analysis to investigate green algae and cyanobacteria as food sources for Collembola. We studied the effects of food quality on body mass and on neutral lipid (NLFA) and phospholipid (PLFA) fatty acid patterns of Collembola. Folsomia candida, Heteromurus nitidus and Protaphorura fimata were fed with common green algae (Chlorella vulgaris), filamentous soil algae (Klebsormidium flaccidum), cyanobacteria (Nostoc commune) and baker's yeast (Saccharomyces cerevisiae). Body mass of F. candida and H. nitidus was highest when reared on C. vulgaris and S. cerevisiae. P. fimata gained the most weight when fed baker's yeast. K. flaccidum and N. commune as resources resulted to low biomass in all Collembola. The four diets caused significant differences in the NLFA and PLFA composition of Collembola after six weeks of feeding. Two new trophic biomarker FAs indicating algal diets were assigned with 16:3ω3,6,9 and 16:2ω6,9, which were only present in NLFAs of Collembola consuming C. vulgaris and K. flaccidum. The amount of FAs from the ω7 family was high in Collembola lipids with cyanobacteria and yeast as food sources, whereas only trace amounts occurred in the NLFA fraction with algae as the resource. In summary, common soil algae and cyanobacteria differed in food quality for Collembola, depending on their growth form (unicellular versus filamentous) and/or secondary metabolites (e.g. cyanobacteria). The new FA biomarkers detected will allow further investigation of these trophic interactions under field conditions; for example, assessing the role of collembolan grazers in the formation of biological soil crusts.     

Studies on the survival of algae added to chemically treated soils—1. methodology

A modification of the method of Tchan (1952) for the direct enumeration of soil algae was evaluated with a view to determining effects of pesticides and herbicides upon soil algae. Modifications to Tchan's technique were the use of a Hg vapour u.v., light source for microscopy and a specially designed haemocytmeter slide. These modifications increased the intensity of fluorescence of algal cells, facilitated accurate estimation of numbers in soil as shown by high percentage recoveries of known numbers of algal cells added to sterile soil, and enabled transmitted or incident light systems to be used equally successfully.Using direct microscopy, various algal cells in culture were examined for fluorescence. Fluorescence during different stages of growth of two species of unicellular green algae was determined. Viable cells at all stages of growth were found to fluoresce. Newly killed cells, inactivated by heat, acid and herbicide treatment were found not to fluoresce. Twenty seven species of algae, selected for their wide range of structure and for their common occurrence in British soils were all found to fluoresce either in culture or when incubated in sterile soil.Four different (agronomic) soil types were examined for indigenous algae. To overcome seasonal variations that occur in numbers of algae, the effect of seeding soils with a mixed inoculum of algal cells was determined.The effects of shaking and ultra-sonicating soil suspensions before examination were compared in order to recover efficiently a known number of cells added to different soils. Survival of added algae in four soils of pH 5.8–7.8, and in one soil maintained at moisture contents ranging from 20–100% of the moisture holding capacity was determined. Growth of algae in soil at two different light intensities was also examined.     

Release, movement and recovery of 3,4-dimethylpyrazole phosphate (DMPP), ammonium, and nitrate from stabilized nitrogen fertilizer granules in a silty clay soil under laboratory conditions

 The composition of soil microbiota in four heated (350  °C, 1 h) soils (one Ortic Podsol over sandstone and three Humic Cambisol over granite, schist or limestone) inoculated (1.5 μg chlorophyll a g^–1 soil or 3.0 μg chlorophyll a g^–1 soil) with cyanobacteria (Oscillatoria PCC9014, Nostoc PCC9025, Nostoc PCC9104, Scytonema CCC9801, and a mixture of the four) was studied by cultural methods. The aims of the work were to investigate the potential value of cyanobacteria as biofertilizers for accelerating soil recolonization after fire as well as promoting microbiotic crust formation and to determine the microbial composition of such a crust. The inoculated cyanobacteria proliferated by 5 logarithmic units in the heated soils which were colonized very quickly and, after 2 months of incubation, the cyanobacterial filaments and associated fungal hyphae made up a matrix in which surface soil particles were gathered into crusts of up to 1.0 cm in thickness. These crusts were composed, on average, of 2.5×10¹⁰ cyanobacteria, 2.8×10⁶ algae, 6.1×10¹⁰ heterotrophic bacteria (of which 1.2×10⁸ were acidophilic, 1.3×10⁶ were Bacillus spp. and 1.5×10⁸ were actinomycetes) and 77.8 m fungal mycelium (1.4×10⁶ were fungal propagules) g^–1 crust. Counts of most microbial groups were positively correlated to cyanobacterial numbers. The efficacy of treatment depended on both the class of inoculum and the type of soil. The best inoculum was the mixture of the four strains and, whatever the inoculum used, the soil over lime showed the most developed crust followed by the soils over schist, granite and sandstone; however, the latter was comparatively the most favoured by the amendment. In the medium term there were no significant differences between the two inocula rates used. Biofertilization increased counts of cyanobacteria by 8 logarithmic units while heterotrophic bacteria, actinomycetes, algae and fungal propagules rose by >4 logarithmic units, acidophilic bacteria and Bacillus spp. by around 3 logarithmic units and fungal mycelia showed an 80-fold increase. The results showed that inoculation of burned soils with particle-binding diazotrophic cyanobacteria may be a means of both improving crust formation and restoring microbial populations. Received: 8 March 2000     

The effect of surface growth of blue-green algae and bryophytes on some microbiological,biochemical, and physical soil properties

Summary The influence of surface growth of inoculated cyanobacteria (blue-green algae) on subsurface properties of a brown earth, silt loam soil was studied in reconstituted flooded soil columns. One blue-green algae species, Nostoc muscorum, become dominant within the first 7 days of inoculation. In light control columns (not inoculated) a bryophyte, Barbula recurvirostra, was dominant although significant growth of indigenous blue-green algae occurred. The blue-green algae counts were in the range of 1×10⁶ g^-1 dry soil in the surface layer (0–0.7 cm) in both columns. Any effect of surface phototrophic growth on soil properties was restricted to the surface layer. In inoculated columns there was a twofold increase in microbial biomass and an eightfold increase in bacterial numbers by week 13. However, bacterial numbers declined so that there was only a 2.8-fold increase by week 21. Dehydrogenase (x2.1), urease (x2.8) and phosphatase (x3.1) activities and polysaccharides (+69%) increased by week 21 as a result of the blue-green algae inoculation along with a significant improvement in soil aggregation. However, similar increases occurred in the light control columns, indicating that given appropriate conditions of light and moisture indigenous species may be ultimately as effective as introduced species in bringing about biochemical and microbiological changes to soil.     

Mesofauna in soils of the ivolga depression (Western Transbaikal region)

Mesofauna of chestnut, meadow-chestnut, meadow alluvial, clayey mucky-gley swampy alluvial soils, and hydromorphic solonchaks has been studied within the Ivolga depression. Variations in the population density of soil invertebrates (from 29.9 to 284.3 specimens per m²) are controlled by the particular soil ecological conditions. Dominant mesofauna species are morphologically and physiologically adapted for living near the soil surface. About 85–90% of them are allocated to the uppermost 10-cm-thick soil layer. The hydrothermic regime (r = 0.94) and the low bioproductivity of phytocenoses (r = 0.74) are the major factors limiting the mesofauna functioning in soils of the Ivolga depression. The biocenotic similarity of the invertebrate complexes in the chestnut, meadow-chestnut, and solonchak soils and in the alluvial swampy and meadow soils is revealed. The highest diversity of the ecological groups of soil mesofauna is seen in the clayey mucky-gley swampy alluvial soils.     

Toxic Effect of Certain Metals Mixture on Some Physiological and Morphological Characteristics of Freshwater Algae

The toxic effect of multi metals mixture which exist simultaneously in aquatic ecosystem on natural phytoplankton assemblages (green algae, blue-green algae and diatoms) was studied. For this purpose a laboratory scale unit was designed to evaluate the effect of continuous flow metals mixture in forms if triple and penta metals in Nile water algae. Clear changes in algal biomass in terms of chlorophyll a (chl a) took place when subjected to metals combination. The rise or decline in chl a was in relation with other algal pigments (chl b, chl c, carotenoides and phenophytin), protein and carbohydrate content of algal cells. Substantial changes in phytoplankton community structure was detected and the most tolerant group was blue-green algae followed by green algae while diatoms was the most sensitive group. The most dominant species in all cases were blue-green alga Oscillatoria mougeotii and green alga Scenedesmus quadricauda. In addition clear changes in morphological shape was observed for tolerant species belonging to the three algal groups. Nile water algae has ability to remove and accumulate metals in the following order therefore Zn > Cd > Ni > Cu > Cr. In addition, phytoplankton has ability to recovered from the stress of metals when eliminated from the media and the recovered biomass was nearly equivalent to that before exposing to metals stress. The overall effect of metals mixture depending on the type and number of metals, the algal community structure and ratio between different morphological forms of algae (unicellular, colonial and filamentous).     

土层深度和季节变化对保护地西瓜连作土壤中丛枝菌根真菌群落结构的影响

The characteristics of arbuscular mycorrhizal fungal (AMF) community structure in various soil depths and growing seasons of watermelon (Citrullus vulgaris) grown in commercial greenhouses in Daxing of Beijing and Weifang and Laiyang of Shandong, China were investigated using both morphological identification and denaturing gradient gel electrophoresis. The sampled soils had been used for continuous greenhouse production of watermelon for 0, 5, 10, 15, or 20 years. Glomus claroideum was the dominant species in the greenhouse soils planted for 5, 10, and 15 years in Laiyang, while Glomus mosseae and Glomus etunicatum were dominant in the nearby open farmland soil. Sorenson’s similarity index of AMF community composition ranged from 0.67 to 0.84 in the soils planted for 5 years, and from 0.29 to 0.33 for 20 years among the three locations. Spore abundance, species richness, and the Shannon index were highest near the soil surface (0-10 cm) and decreased with soil depth, and higher in June and October than in August and December. Canonical correspondence analysis showed that available P and the number of years that soil had been used for greenhouse production were the main factors contributing to the variance of AMF community composition. It was concluded that the community structure of AMF was mainly influenced by soil available P and planting time of watermelon as well as by soil depth and seasonal variation in the commercial greenhouse.     

Characters of soil algae during primary succession on copper mine dumps

Purpose

Algae play an important role in degraded areas during the initial stages of soil formation by improving its physico-chemical properties, reducing the erosion of soil, and thus favoring the settlement of vascular plants. This study investigates the characters of soil algal communities on copper tailing dumps and discusses the contribution of soil algae to the primary succession progress of young mine tailings ecosystems.

Materials and methods

Five representative potential successional series (bare land, algae crust, mixed algal–moss crust, moss crust, and vegetated site) on copper tailing dumps and a nearby reference site were selected. The soil algae were identified using growth slide method, dilution plate method, and by direct microscopic observation of the soil suspensions. All experiments were carried in an incubation chamber at a temperature of 25 °C and with a 16 h/8 h light–dark cycle at a light intensity of 3,000 lux.

Results and discussion

A total of 120 algal species were recorded. Cyanophyta (blue-green algae) were the most diverse taxonomic group, followed by Bacillariophyta (diatoms) and Chlorophyta (green algae), although diatoms were absolutely absent in bare sites. Diversity of soil algae was highest in vegetated site, whereas it was lowest in bare sites. Total algal abundance ranged between 0.15?×?10³ cells/g to 46.8?×?10³ cells/g dry soil, with the lowest abundance in the youngest site and the highest abundance in the mixed algal–moss crust site. Correlation analysis showed that the growth of soil algae was inhibited by high Cu, Zn, and Fe concentrations and low nutrient content and that the green algae were more sensitive to nutrient content than blue-green algae.

Conclusions

Our results suggest that blue-green algae were most diverse, followed by diatoms and green algae. Species and abundance of soil algae in the tailings increased with the early succession process because of the decrease in heavy metal content and the improvement of nutrient conditions. The growth of soil algae created conditions for the settlement and growth of higher plants, but the appearance of moss and vascular plants inhibited the growth of soil algae.     

Growth potential and biocide tolerance of non-heterocystous filamentous cyanobacterial isolates from rice fields of Uttar Pradesh, India

Twenty-eight non-heterocystous filamentous cyanobacterial strains were isolated from different locations in the rice fields of Uttar Pradesh. These strains belonged to seven genera, namely Pseudanabaena, Limnothrix, Phormidium, Microcoleus, Plectonema, Lyngbya and Oscillatoria. A wide variation was observed in these strains with respect to dry weight, generation time and tolerance to biocides. Lyngbya palmarum and Oscillatoria acuminata showed maximum biomass (dry weight), while Pseudanabaena frigidum, Phormidium foveolarum, O. acuminata, Lyngbya palmarum and Lyngbya spiralis showed a significantly shorter generation time as compared to other strains studied. An interesting feature observed was that these non-heterocystous filamentous cyanobacteria possessed a remarkable tolerance to the biocides 2,4-dichlorophenoxyacetic acid, Malathion and Dimecron, at doses much higher than those recommended for rice crops.     

Floristic changes in soil algae and cyanobacteria in reclaimed metal-contaminated land at Sudbury,Canada

Logging, fires and smelting have produced extensive barren areas in Sudbury, Ontario. Soils from these areas have a low pH (3.7 to 4.2), elevated concentrations of Cu and Ni, and are subject to erosion. A successful revegetation program has been in operation since 1978. Manual applications of limestone, fertilizers and seeds have produced extensive grassy swards. Enrichment cultures (Bold Basal and Allen's medium) were used to compare the soil algae and cyanobacteria from barren sites with those treated 6 mo, 2, 4, and 5 yr ago. Cultures of soils from barren sites were characterized by a low diversity of chlorophytes and a few diatoms. Cyanobacteria were absent. In comparison, treated soils yielded an increased diversity of chlorophytes and included a number of cyanobacterial genera. Chlorophyll a analysis indicates a higher biomass of autotrophic organisms on treated sites. Increased diversity and biomass on treated soils may reduce erosion while the presence of N fixing cyanobacteria could contribute to the fertility of these soils. A filamentous picocyanobacterium appeared in enrichment cultures (1/3 strength Allen's medium) of treated soils but not of untreated soils. The techniques of epifluorescence microscopy may be valuable in further investigations of autotrophic soil organisms.     

In vitro studies of the impact of the naked soil amoeba Thecamoeba similis Greef,feeding on phototrophic soil biofilms

The effect of grazing by the naked soil amoeba Thecamoeba similis feeding on algae of in vitro phototrophic soil biofilms was investigated in terms of carbon biomass of algae, bacteria and amoebae and compared to shifts in the microbial community determined by 16S rDNA t-RFLP patterns. In a first approach, grazing of T. similis on unialgal Xanthonema hormidioides biofilms growing on regosol was investigated. The growth rate of T. similis was 0.5 divisions per day and the production efficiency reached 25% (allocation of prey-carbon to predator-carbon). The algal biomass decreased from the original 100% down to 7% at the end of the experiment. The increase of egested residues enhanced bacterial growth; the biomass carbon ratio bacteria vs. algae increased from 0.25 to 4.5 indicating the degradation of the algal biofilm, while the 16S rDNA t-RFLP patterns indicated changes in the composition of the microbial community. A subsequent experiment was conducted by inoculating T. similis on a natural biofilm community consisting of trichomes of cyanobacteria, several species of Chlorophyceae and Xanthophyceae. The total algal biomass (including cyanobacteria) remained constant during the experiment. However, 73% of the algal biomass without cyanobacteria was grazed, while the amount of mucous Chlamydocapsa spec. doubled from 32% to 68%. The growth rate of T. similis was 0.4 divisions per day and the production efficiency was only 13%. The 16S rDNA t-RFLP patterns showed a shift of the microbial community. Our results give a first insight into the obviously high potential of naked soil amoebae feeding on algae to change the structures of both the algal and bacterial communities of phototrophic soil biofilms.     

Functioning of cyanobacteria in soil ecosystems

The data of long-term studies pertinent to functioning of cyanobacteria and their effects on soil fertility during periods of soil “blossoming” over more than 50% of the soil surface are presented. Parameters of and participants in this process and its features typical for the temperate zone are discussed. Using modern methods of investigations (field ¹⁵N₂ and ¹³CO₂ chambers, spectral-isotope and gas chromatographic analyses), cyanobacteria were revealed to produce 725 kg/ha. They are characterized by intense photosynthesis inherent to mosses and lichens. The conditions of cyanobacteria functioning in plowed soils are discussed. Their contribution to the nitrogen pool of soils reaches 30 kg/ha. Based on the model experiments, a concept of transforming the organic matter of cyanobacteria in soil and its movement along trophic chains of the biological cycle has been developed.     

Urban Soils: Diagnostics and Taxonomic Position according to Materials of Scientific Excursion in Moscow at the Suitma-9 Workshop

Using the latest version of the international soil classification (WRB 2014/2015) and the classification of soils of Russia (2004/2008), the authors attempted to demonstrate how specific profiles of urban soils in green massifs are classified at different taxonomic levels. The soil profiles were shown in the excursions of the 9th International Conference “Soils of Urban, Industrial, Traffic, Mining and Military Areas” and were discussed by the representatives of national scientific schools. The diversity of the soils studied is determined primarily by the technology of their creation or by the nature of human impact, soil age, properties of the soil-forming rock, and, to a lesser extent, by the type of artificial phytocenosis. By the properties of their profiles, soils are qualified as ones on technogenic deposits (artificial buildings or displaced natural grounds with fragments of soil horizons), buried agrozems and cultural layers. The comparison of two classification systems showed their similarity with respect to the taxonomic level. One can note a similarity of the main solution: are the soils natural or anthropogenic, although the degrees of “anthropogeneity” given in their names may not coincide. The existing differences in the sets of characteristics–qualifiers reflect the genetic trend in the Russian soil classification and strict following the rules in the WRB system.     

Shrub-interspace dynamics alter relationships between microbial community composition and belowground ecosystem characteristics

In desert ecosystems, belowground characteristics are influenced chiefly by the formation and persistence of “shrub-islands of fertility” in contrast to barren plant interspaces. If soil microbial communities are exclusively compared between these two biogeochemically distinct soil types, the impact of characteristics altered by shrub species, especially soil C and N, are likely to be overemphasized and overshadow the role of other characteristics in structuring microbial composition. To determine how belowground characteristics influence microbial community composition, and if the relative importance of these characteristics shifts across the landscape (i.e., between and within shrub and interspace soils), changes in microbial communities across a 3000-year cold desert chronosequence were related to 27 belowground characteristics in surface and subsurface soils. When shrub and interspace communities in surface and subsurface soils were combined across the entire chronosequence, communities differed and were primarily influenced by soil C, NO₃⁻ concentrations, bulk density, pH, and root presence. Within shrub soils, microbial communities were shrub species-specific, especially in surface soils, highlighting differences in soil characteristics created by specific shrub species and/or similarity in stresses structuring shrub species and microbial communities alike. Microbial communities in shrub soils were not influenced by soil C, but by NO₃⁻ and NH₄⁺ concentrations, pH, and silt in surface soils; and Cl, P, soil N, and NO₃⁻ concentrations in subsurface soils. Interspace soil communities were distinct across the chronosequence at both depths and were strongly influenced by dune development. Interspace communities were primarily associated with soil stresses (i.e., high B and Cl concentrations), which decreased with dune development. The distribution of Gram-positive bacteria, Actinobacteria, and fungi highlighted community differences between and within shrub and interspace soils, while Gram-negative bacteria were common in all soils across the chronosequence. Of the 27 belowground characteristics investigated, 13 separated shrub from interspace communities, and of those, only five emerged as factors influencing community composition within shrub and interspace soils. As dunes develop across this cold desert chronosequence, microbial community composition was not regulated primarily by soil C, but by N and P availability and soil stresses in shrub soils, and exclusively by soil stresses in interspace soils.     

Effect of two species of cyanobacteria as biofertilizers on some metabolic activities, growth, and yield of pea plant

Two cyanobacterial species (Nostoc entophytum and Oscillatoria angustissima) were tested as biofertilizers, substituting the normally used chemical fertilizer, for pea plant. Inoculation of soil with a suspension of each species or a combination of the two species significantly increased the germination percentage and stimulated the other measured growth parameters and photosynthetic pigment fractions of pea. However, the soil inoculation with one cyanobacterial species and the addition of the recommended dose or half the recommended dose of chemical fertilizer were usually more effective and also increased carbohydrate and protein contents of produced pea seeds. However, biofertilization combined with half the recommended dose of the chemical fertilizer was usually more effective than the addition of the full rate of the chemical fertilizer, and this may allow saving 50% of the used chemical fertilizer. The protein profile of the produced seeds showed appearance and disappearance of some protein bands in response to fertilization treatments compared to the control. Blue green algae analyses show that N. entophytum fixed more N, produced more exopolysaccharide, and contained more auxin and cytokinin than O. angustissima, the latter contained more gibberellins. These data may explain their different influences on growth and yield of pea.     

Plant and soil responses to a commercial blue-green algae inoculant

A commercial blue-green algae inoculant (Genesis II) for improving the N content of soils was applied to basalt and pumice soils in a greenhouse pot test with orchardgrass, pinegrass, Douglasfir, and ponderosa pine. Treatments were control (deionized water), live algae, killed algae, live algae plus P, K and S and P, K and S only. Plant biomass yields with live inoculant generally were significantly greater than with the control treatment but were the same as with killed inoculant. Live algae plus P, K and S further enhanced productivity. P, K and S alone produced no increase over the control treatment. Response to the inoculant compared to the control appears to be a result of addition of nutrients present in the inoculant stock solution. Further biomass increases with the P, K and S plus live algae treatment compared to live and dead algae treatments occurred because these nutrients became limiting as N was added. Total organic-N and total C in surface soils were similar in all treatments.When the stock solution was sampled via culture methods, the most prominent species found was Chlorella, a green alga. Anabaena, an N₂ fixing blue-green alga, produced less than one colony per plate on the average. Phormidium, a blue-green alga not found in the inoculant, was dominant on the soil surface at the end of the test suggesting a soil origin for this species. Results indicate that Genesis II probably has very limited potential to enhance blue-green algal populations and, consequently, N of the forest soils used in this test.