Direct observation of fungal aggregates in sand dune soil

1978 ◽  
Vol 24 (3) ◽  
pp. 333-335 ◽  
Author(s):  
K. S. Clough ◽  
J. C. Sutton
Keyword(s):  
Sand Dune ◽  
Sand Dunes ◽  
Mycorrhizal Fungus ◽  
Lake Huron ◽  
Dominant Factor ◽  
Phaseolus Vulgaris L ◽  
External Mycelium ◽  
Grass Hosts ◽  
Dune Soil ◽  
Scanning Electron

The mycorrhizal fungus Glomus in association with bean hosts, Phaseolus vulgaris L., growing in pot cultures and grass hosts, Calamovilfa longiflora (Hook.) Scribn and Andropogon sp. growing on Lake Huron sand dunes produced extensive external mycelium. This mycelium was the dominant factor in the aggregation of soil particles. Light and scanning electron microscope studies indicated that the sand grains were attached to the hyphae. An amorphous deposit was often present at the interfaces of sand grains and hyphae. It appeared to act as an adhesive. Staining procedures indicated that this material contained polysaccharide. Other microorganisms were observed in association with the Glomus hyphae and the amorphous deposits.

Aggregation of sand-dune soil by endomycorrhizal fungi

1976 ◽  
Vol 54 (3-4) ◽  
pp. 326-333 ◽  
Author(s):  
J. C. Sutton ◽  
B. R. Sheppard
Keyword(s):  
Sand Dune ◽  
Mycorrhizal Fungus ◽  
Soil Extract ◽  
Dominant Factor ◽  
Phaseolus Vulgaris L ◽  
Major Mechanism ◽  
Mycorrhizal Roots ◽  
Sand Particles ◽  
Mycorrhizal Development ◽  
Dune Soil

The mycorrhizal fungus Glomus in association with bean hosts (Phaseolus vulgaris L.) was the dominant factor in the aggregation of sand particles in sterilized dune soil artificially inoculated either with Glomus, or with Glomus and a soil extract containing miscellaneous microorganisms. The weight of sand adhered to roots harvested from dried soil was about 3 times greater in mycorrhizal than in nonmycorrhizal roots. The weight of sand aggregates per kilogram dried soil from among roots of senescent beans was 10 g in nonmycorrhizal plants but 54 g in mycorrhizal plants. The fungitoxicant benomyl prevented mycorrhizal development and markedly restricted sand aggregation on and among roots of beans grown in soil inoculated with Glomus. A soil extract enhanced mycorrhizal development, the amount of sand adhered to mycorrhizal roots, and the extent of sand aggregation among mycorrhizal roots. Based on microscopic observations, the major mechanism linking sand grains in aggregates was the binding of sand to extensive Glomus mycelia.

Ecology of Endogone in Lake Huron sand dunes

1975 ◽  
Vol 53 (2) ◽  
pp. 87-93 ◽  
Author(s):  
R. E. Koske ◽  
J. C. Sutton ◽  
B. R. Sheppard
Keyword(s):  
Phaseolus Vulgaris ◽  
Sand Dunes ◽  
Dry Weight ◽  
Lake Huron ◽  
Controlled Environment ◽  
Dune Sand ◽  
Phaseolus Vulgaris L ◽  
Dune Stabilization ◽  
External Mycelium ◽  
Organic Particles

Grasses and herbs in the sand dunes of the eastern shores of Lake Huron were heavily colonized by the endomycorrhizal fungus Endogone. The fungus produced an extensive external mycelium in the dune sand. Numerous sand grains were firmly bound to the external mycelium, which was of structural importance in sand aggregates and was implicated as an important factor in dune stabilization. Sand aggregates constituted about 5 to 9% of the dry weight of sand collected from the surface 30 cm of the dunes. The weight of sand aggregates per kilogram of dune sand increased from 0.9 g to 25 g and 127 g after one and two crops, respectively, of mycorrhizal Phaseolus vulgaris L. grown in pots in a controlled environment. The increased aggregation was attributed largely to the binding of sand grains to a proliferated mycelium of Endogone. Organic fragments in the dune sand were colonized frequently by Endogone. Spores and spore-like bodies were numerous in many organic particles, which were sources of viable inoculum of Endogone. Five types of Endogone spores were found in the dune sand.

scholarly journals INVESTIGATION OF GEOTECHNICAL SPECIFICATIONS OF SAND DUNE SOIL: A CASE STUDY AROUND BAIJI IN IRAQ

2013 ◽  
Vol 14 (2) ◽  
Author(s):  
Abbas J. Al-Taie ◽  
Yousif J. Al-Shakarchi ◽  
Ali A Mohammed
Keyword(s):  
Land Surface ◽  
Sand Dune ◽  
Sand Dunes ◽  
Engineering Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strength Tests ◽  
Physical Tests ◽  
Dune Soil

ABSTRACT: While more than half the land surface of Iraq consists of deserts covered mainly with sand dunes, little research has taken place to study the characteristics and the behavior of dune soils. This paper directed toward studying the geotechnical properties of dune sands taken from Baiji city (northwest of Iraq). A vast laboratory testing program was carried out to achieve the purpose of this paper. The physical tests, chemical tests, X-ray diffraction analysis, permeability test, compaction characteristics, compressibility and collapsibility tests; and shear strength tests were included in this program. The results indicate that soil of Baiji sand dune exhibits prefer engineering properties according to their state. As such, this soil is considered suitable for use in geotechnical constructions. ABSTRAK: Walaupun lebih separuh daripada bumi Iraq terdiri daripada gurun yang dipenuhi dengan bukit-bukit pasir, tidak banyak penyelidikan dijalankan untuk mengkaji sifat-sifat dan ciri-ciri tanah pasir  tersebut. Kertas kerja ini menyelidik sifat geoteknikal bukit pasir yang diambil dari pekan Baiji (di bahagian barat utara Iraq).  Program penyelidikan makmal yang menyeluruh telah  dijalankan bagi mencapai objektif kajian ini. Ujian fizikal, ujian kimia, analisis belauan sinar-x, ujian kebolehtelapan, ciri pemadatan, faktor ketermampatan, ujian keruntuhan dan ujian kekuatan ricih diambilkira dalam program ini. Keputusan menunjukkan bahawa tanih bukit pasir Baiji mengutamakan ciri kejuruteraan berdasarkan keadaannya. Oleh itu, tanah ini dianggap sesuai untuk kegunaan pembinaan geoteknikal.

Seedling desiccation tolerance of Leymus racemosus (Poaceae) (wild rye), a perennial sand-dune grass inhabiting the Junggar Basin of Xinjiang, China

2004 ◽  
Vol 14 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Zhenying Huang ◽  
Yitzchak Gutterman
Keyword(s):  
Desiccation Tolerance ◽  
Sand Dune ◽  
Sand Dunes ◽  
Perennial Grass ◽  
Junggar Basin ◽  
Seedling Development ◽  
Ecological Implications ◽  
Leymus Racemosus ◽  
Seedling Desiccation Tolerance ◽  
Dune Grass

Leymus Racemosus, The Mammoth Wild Rye, Is A Rhizomatous Perennial Grass, Mainly Distributed In The Moving Or Semi-Stabilized Sand Dunes In Deserts Of The Junggar Basin In Xinjiang, China. The Revival Ability Of The Young Seedling After Periods Of Desiccation Can Be Influenced By Several Factors: (1) The Stage Of Seedling Development – The Later The Stage At Dehydration, The Longer The Root Length And The Lower Is The Percentage Of Seedlings That Survive; (2) The Length Of The Period Of Desiccation – The Longer The Period That The Seedlings Are Under Desiccation, The Lower Is The Percentage Of Seedlings That Survive; (3) Endosperm Size – The Smaller The Proportion Of Endosperm That Remains In The Caryopses, The Lower Is The Percentage Of Seedlings That Revive, Determined By (A) The Stage Of Seedling Development, And (B) The Proportion Of The Endosperm That Is Removed By Cutting; And (4) Caryopsis Size – The Larger The Polymorphic Caryopses, The Higher Is The Percentage Of Young Seedlings That Revive From Periods Of Desiccation. The Physiological And Ecological Implications Of L. Racemosus Seedling Desiccation Tolerance Are That Under Extreme Desert And Unpredictable Environmental Conditions, The Chances Of Seedling Establishment Are Increased.

scholarly journals Parasitism of spores of the vesicular-arbuscular mycorrhizal fungus, Glomus dimorphicum

2005 ◽  
Vol 72 (1) ◽  
pp. 27-32 ◽  
Author(s):  
S.M. Boyetchko ◽  
J.P. Tewari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Host Response ◽  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Spore Wall ◽  
Vesicular Arbuscular ◽  
Scanning Electron

Spores of Glomus dimorphicum were examined for parasitism. Light and scanning electron microscopy revealed perforations, approximately 0.25 to 1.0 µm in diameter, in the spore wall. The presence of papillae, a dynamic host response, suggested that the parasitism occurred while the vesicular-arbuscular mycorrhizal fungus was still alive. No filamentous structures were detected in the spores; however, cysts of amoeba-like organisms were found in the spores and were also observed on agar plates on which surface-sterilized spores of G. dimorphicum containing such organisms were placed. It is postulated that an amoeba-like organism was the parasite, since the perforations on the spore wall were minute and no bacteria or fungi were seen inside the spores.

Allelopathic potential of Artemisia campestris ssp. caudata on Lake Huron sand dunes

1997 ◽  
Vol 75 (11) ◽  
pp. 1903-1912 ◽  
Author(s):  
Kyeong W. Yun ◽  
M. A. Maun
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Mycorrhizal Fungi ◽  
Sand Dune ◽  
Sand Dunes ◽  
Dry Weight ◽  
Fungal Colonization ◽  
Test Species ◽  
Allelopathic Potential ◽  
Artemisia Campestris

Greenhouse studies were conducted to test allelopathic effects of Artemisia campestris ssp. caudata on seed germination and seedling growth of several sand-dune species and colonization by mycorrhizal fungi. The aqueous extracts of A. campestris showed no inhibitory effect on seed germination, seedling elongation, or dry-weight growth of plants at lower concentrations (10 and 50%), but 100% concentration of the extracts caused varying degrees of inhibition depending on the test species. The mixing of dry leaves of seedlings of A. campestris to the sand showed severe inhibition of Elymus canadensis seedlings. The percent germination of test species in soil from the rhizosphere of A. campestris was significantly lower than that of the control. The leaf area and dry weight were also lower but the differences were not significant. The aqueous extract inhibited mycorrhizal fungal colonization in roots of three sand-dune grasses. Key words: allelopathy, Artemisia campestris ssp. caudata, seed germination, seedling growth, mycorrhizal fungi.

scholarly journals Modelling and  assessing driving factors of the spatial and temporal dynamics of the sand  dunes in the district of Errachidia, Morocco

2021 ◽  
Author(s):  
Tudal SINSIN ◽  
Fouad MOUNIR ◽  
Ahmed El ABOUDI
Keyword(s):  
Sand Dune ◽  
Temporal Dynamics ◽  
Moving Average ◽  
Sand Dunes ◽  
Ecological Factors ◽  
Temperature And Precipitation ◽  
Spatial And Temporal Dynamics ◽  
Combined Action ◽  
Landsat Satellite ◽  
Dune Dynamics

The desertification affects more than 250,000 ha in the district of Errachidia and results in the expansion of desert landscapes such as the Regs, Hamadas and the Dunes. The latter is a big concern in the district since it is the source of siltation, which threatens dwellings, cultivated lands and water bodies. It is of paramount importance to understand the causes and consequences of silting to develop strategies to combat it. Thus, first, we analysed the spatial and temporal dynamics of sand dunes until 2069 by applying the Seasonal Autoregressive Integrated Moving-Average (SARIMA) model on a time series of sand dune areas. These areas were calculated annually from 1987 to 2019 by computing the sand cover index (SCI) on Landsat satellite images. Furthermore, we evaluated the influence of different natural and human factors such as temperature, precipitation, wind, vegetation, and population growth, on sand dune dynamics using Spearman’s correlation test. The results indicated that the area of sand dunes will increase by 1.7% per year between 2019 and 2069 in the district of Errachidia. This increase would be mainly caused by the combined action of ecological factors, which vary from year to year. In general, temperature and precipitation act indirectly on wind and vegetation to influence the dynamics of sand dunes in hyper-arid areas where the soil is bare or poorly covered with vegetation, where precipitation is low and where temperature is high.

scholarly journals The Sources of Moisture in the Sand Dunes – The Example of the Western Sahara Dune Field

2014 ◽  
Vol 33 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Elwira Żmudzka ◽  
Dariusz Woronko ◽  
Maciej Dłużewski
Keyword(s):  
Surface Layer ◽  
Moisture Content ◽  
Wind Velocity ◽  
Sand Dune ◽  
Sand Dunes ◽  
Shear Velocity ◽  
Meteorological Conditions ◽  
Aeolian Transport ◽  
Western Sahara ◽  
Dune Field

Abstract Climatic and meteorological conditions may limit the aeolian transport within barchans. An explanation of that issue was the main goal of the investigation held in Western Sahara dune fields located around Tarfaya and Laâyoune. Particular attention was paid to the factors causing the moisture content rising of the sand dune surface layer, which could influence the wind threshold shear velocity in the aeolian transport. The wetted surface layer of sand, when receiving moisture from precipitation or suspensions, reduces the aeolian transport, even in case of wind velocity above 4-5 m s-1. Fog and dew condensation does not affect the moisture of deeper sand layers, what occurs after rainfall.

Ecological aspects influencing the helminth community of the wood mouse Apodemus sylvaticus in Dunas de Mira, Portugal

2006 ◽  
Vol 51 (4) ◽  
Author(s):  
Catarina Eira ◽  
Jordi Torres ◽  
José Vingada ◽  
Jordi Miquel
Keyword(s):  
Species Richness ◽  
Sand Dune ◽  
Sand Dunes ◽  
Wood Mouse ◽  
Apodemus Sylvaticus ◽  
Habitat Characteristics ◽  
Helminth Community ◽  
Heligmosomoides Polygyrus ◽  
Ecological Aspects ◽  
Host Sex

AbstractThis paper presents the first extensive data on the helminth community of the wood mouse Apodemus sylvaticus in a coastal sand dune area in Portugal. The 557 hosts analysed in this study were trapped seasonally between autumn 2002 and summer 2005 across 6 habitat types. Twelve helminth species were detected among which, Taenia parva larvae, Angiostrongylus dujardini, Heligmosomoides polygyrus, Syphacia stroma and S. frederici constitute the component species, accounting for 98.7% of all worms. H. polygyrus was the most prevalent helminth parasite. Species richness varied according to habitat and season. The highest species richness was found in sand dunes during winter whereas the lowest was detected along lake margins also during the winter. Some differences in prevalence and mean intensity values were found in relation to year (T. parva larvae and H. polygyrus), habitat (A. dujardini), season (T. parva larvae, H. polygyrus, A. dujardini and S. stroma) and host sex (T. parva larvae and S. stroma). These differences are discussed both in view of the host’s biology and habitat characteristics.

Reconstructing the age of coastal sand dunes along the northwestern shore of Lake Huron in Lower Michigan: Paleoenvironmental implications and regional comparisons

2010 ◽  
Vol 2 (2-3) ◽  
pp. 83-92 ◽  
Author(s):  
Alan F. Arbogast ◽  
Michael E. Bigsby ◽  
Mark H. DeVisser ◽  
Shaun A. Langley ◽  
Paul R. Hanson ◽  
...  
Keyword(s):  
Sand Dunes ◽  
Lake Huron ◽  
Coastal Sand Dunes ◽  
Coastal Sand ◽  
Regional Comparisons
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