Nodular symbionts ofShepherdia,Alnus, andMyricafrom a sand dune ecosystem: trends in occurrence of soilborneFrankiagenotypes

2004 ◽  
Vol 82 (5) ◽  
pp. 691-699 ◽  
Author(s):  
V Huguet ◽  
J M Batzli ◽  
J F Zimpfer ◽  
F Gourbière ◽  
J O Dawson ◽  
...  
Keyword(s):  
Sand Dune ◽  
Lake Michigan ◽  
Sand Dunes ◽  
Plant Cover ◽  
Intergenic Spacer ◽  
Dune System ◽  
Greenhouse Study ◽  
Homogeneous Cluster ◽  
Actinorhizal Species ◽  
The Impact

A successional sand dune system along the Lake Michigan shoreline was chosen to study the impact of edaphic factors, vegetation cover, and topographic position on Frankia strain distribution and infectivity. On this site, three actinorhizal species, Myrica gale L., Alnus incana (L.) Moench subsp. rugosa (Du Roi) Clausen, and Shepherdia canadensis (L.) Nutt., grew in different communities. Soil samples were collected on plots devoid of actinorhizal plants and serially diluted to inoculate the three native host plants in a greenhouse study. Strains present in the nodules formed were then genetically characterized using PCR-RFLP of the 16S–23S intergenic spacer (IGS). An additional study site was included to estimate the impact of the sympatric presence of the three host species on soil infectivity and strain diversity. On this second site, soils used as inocula were collected in the rhizosphere of M. gale and S. canadensis. The M. gale and A. incana nodular strains belonged to an homogeneous cluster, whereas the S. cana densis nodular strains were separated into two distinct genetic clusters, irrespective of edaphic conditions and proximity to the host's root systems. A χ2analysis conducted on Shepherdia-infective strains showed the dominance of two distinct genotypes, with one of them being specific to newly formed dunes lacking plant cover and the other specific to older, stable dunes with dense vegetative cover.Key words: Frankia, Myrica, Shepherdia, Alnus, IGS 16S–23S, sand dunes.

Distribution and abundance of infective, soilborne Frankia and host symbionts Shepherdia, Alnus, and Myrica in a sand dune ecosystem

2004 ◽  
Vol 82 (5) ◽  
pp. 700-709 ◽  
Author(s):  
Janet McCray Batzli ◽  
Jeff F Zimpfer ◽  
Valérie Huguet ◽  
Charles A Smyth ◽  
Maria Fernandez ◽  
...  
Keyword(s):  
Host Plant ◽  
Sand Dune ◽  
Lake Michigan ◽  
Root Nodules ◽  
Vegetative Cover ◽  
Dune System ◽  
Successional Stage ◽  
Greenhouse Study ◽  
Submerged Soils ◽  
Speckled Alder

We describe presence, abundance, and distribution of three sympatric nitrogen-fixing shrubs and their symbiotic diazatroph, Frankia, in a sand dune ecosystem differing in successional stage, vegetative cover, edaphic characteristics, and topography. Distribution of actinorhizal Myrica gale L., Alnus incana (L.) Moench subsp. rugosa (Du Roi) Clausen, and Shepherdia canadensis (L.) Nutt. was analyzed among 120 sampling locations representing a gradient of successional stages in a sand dune system along Lake Michigan. In a greenhouse study, seedlings of these species were employed to bioassay the presence and abundance of infective Frankia in soils. Shepherdia-infective Frankia was detected in 80% of the plots, while Alnus- and Myrica-infective Frankia were found in 65% and 64% of the plots, respectively, with no Frankia found in 18% of the plots. Only 14% of the plots supported actinorhizal host-plant species. Infective Frankia were present in soils of young dunes prior to the establishment of any actinorhizal hosts. Shepherdia-infective Frankia were more abundant in soils from drier, earlier successional sites, while Alnus- and Myrica-infective Frankia were more abundant in moister soils of later successional communities. A previous study had revealed that nodular Frankia strains at this site were host specific for Shepherdia and largely so for Myrica and Alnus, which had only a small proportion of shared strains (Huguet et al. 2001). The likelihood of host-plant nodulation by soilborne Frankia was increased by the presence of actinorhizal plants in general, but not by the presence of their respective specific host plants. Submerged soils had no infectious capacity, whereas soils with greater in situ moisture content and soils subject to intermittent saturation tended to have lower infectious capacities overall. Our results suggest that soilborne, infective Frankia genotypes are not only host specific, but are also associated with spatially and chronologically distinct sets of ecological conditions.Key words: speckled alder, sweet gale, Canada buffalo berry, actinorhizal, nitrogen fixation, Frankia, root nodules.

scholarly journals Genetic Diversity of Rhizobia Associated with Acacia longifolia in Two Stages of Invasion of Coastal Sand Dunes

2007 ◽  
Vol 73 (15) ◽  
pp. 5066-5070 ◽  
Author(s):  
Susana Rodríguez-Echeverría ◽  
João A. Crisóstomo ◽  
Helena Freitas
Keyword(s):  
Genetic Diversity ◽  
Sand Dune ◽  
Root Nodule ◽  
Sand Dunes ◽  
Nodule Bacteria ◽  
Coastal Sand Dunes ◽  
Dune System ◽  
Coastal Sand ◽  
Acacia Longifolia ◽  
Two Stages

ABSTRACT We examined the genetic diversity of root nodule bacteria associated with the Australian legume Acacia longifolia in two stages of invasion of a coastal sand dune system. All isolates belonged to the genus Bradyrhizobium. A higher diversity was found in the long-established trees. The results suggest the introduction of exotic bradyrhizobia with the plant.

scholarly journals Coronilla varia L. (Fabaceae): AN INVADER OF A COASTAL BARRIER BEACH IN NOVA SCOTIA, CANADA

2013 ◽  
Vol 47 (2) ◽  
Author(s):  
Andrea Flynn ◽  
Anthony G. Miller ◽  
David J. Garbary
Keyword(s):  
Nova Scotia ◽  
Invasive Plant ◽  
Sand Dunes ◽  
Plant Cover ◽  
Dune System ◽  
Vegetation Zone ◽  
Barrier Beach ◽  
Coronilla Varia ◽  
Coastal Sand ◽  
First Time

CCoronilla varia L. (crown vetch) is described as an invasive plant on a coastal sand dune system (Mahoneys Beach) in Nova Scotia facing the southern Gulf of St. Lawrence. This is the first time that C. varia has been shown as invasive in Atlantic Canada, and the first time it has been characterized as invasive on coastal sand dunes. Accordingly, colonies of C. varia forming more than 90% of the plant cover occupy 8% of the total dune system and account for 32% of the area in the vegetation zone where C. varia has become abundant. C. varia can achieve high percentage cover, with all of the major dune plants, i.e., Ammophila breviligulata, Lathyrus japonicus, Toxicodendron radicans and Myrica pensylvanica. Where C. varia achieves maximum abundance (i.e., >80% cover and ca. 200 shoots m2), it has seemingly replaced A. breviligulata and L. japonicus. We do not know when C. varia first colonized Mahoneys Beach, but conspicuous colonies were recorded there by 2005, and a colony was found on the adjacent dune system (Dunns Beach) for the first time in 2010.Key Words: Coronilla varia, crown vetch, Fabaceae, invasive species, Nova Scotia, sand dunes

Plant communities of the British sand dunes

1989 ◽  
Vol 96 ◽  
pp. 53-74
Author(s):  
A. J. C. Malloch
Keyword(s):  
Plant Communities ◽  
Sand Dune ◽  
Sand Dunes ◽  
Geographic Location ◽  
Dune Vegetation ◽  
Dune System ◽  
Ecological Relationships ◽  
Major Direction ◽  
Pattern Of Variation ◽  
Calcium Status

SynopsisThe National Vegetation Classification has details of some 2000 samples of sand dune vegetation collected nationally. Analysis of these data has resulted in the recognition of about thirteen plant communities of the sand dune system. Details of these communities are presented, elaborating on their species composition, variability, ecological relationships and distribution. As might be expected, the major direction of variation is from strandline, through the vegetation of active dunes, to the fixed dune grasslands, heath and scrub. The precise pattern is affected by the calcium status of the dune and by its geographic location. The vegetation of dune slacks is also dependent on the calcium status of the sand, as well as the amount and persistence of standing water. Superimposed on this natural pattern of variation is the use of dune systems by the grazing of domestic animals as seen on the machair of the Hebrides in particular.

scholarly journals Monitoring the Dynamics of Formby Sand Dunes Using Airborne LiDAR DTMs

2021 ◽  
Vol 13 (22) ◽  
pp. 4665
Author(s):  
Ahmed Mutasim Abdalla Mahmoud ◽  
Ekbal Hussain ◽  
Alessandro Novellino ◽  
Panos Psimoulis ◽  
Stuart Marsh
Keyword(s):  
Sand Dunes ◽  
Digital Terrain Model ◽  
Coastal Dunes ◽  
Airborne Lidar ◽  
Dune System ◽  
Erosion Risk ◽  
Dune Systems ◽  
Sand Erosion ◽  
The Uk ◽  
The Impact

Coastal dunes play an important role in coastal erosion risk management, where they act as a dynamic natural sea defence line. Formby coast is part of the Sefton coast in the Northwest of England and is one of the largest and most rapidly evolving sand dune systems in the UK. Such dune systems require continuous comprehensive monitoring activity to understand their dynamics. In this research, we investigate the use of airborne LiDAR digital terrain model DTMs for monitoring the dynamics of the sand dunes at Formby between 1999 and 2020. We found that the rate of elevation change for the beach and the dune areas ranges from −0.78 to 0.02 m/year and −0.92 to 0.73 m/year, respectively. The beach and the frontal dunes have had significant sand erosion, while the inner dunes gained sand during the measurement period. Vegetated areas remained unchanged due to the impact of vegetation in stabilizing the movement of the dunes. Formby beach had a volume loss of about 907,000 m3 in the last 21 years, while the dunes had a volume increase of about 1,049,000 m3 over the same period. The total volume of the entire dune system, consisting of both the beach and dune areas, remained unchanged, which indicates that the growth of the inland dunes is fed by sand from the beach. All the volumetric changes occurred due to sand redistribution within the system, with erosion along the beach, and deposition and erosion in the dune areas.

scholarly journals Seasonal changes in water quality and macrophytes and the impact of cattle on tropical floodplain waterholes

2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  
Keyword(s):  
Water Quality ◽  
Seasonal Changes ◽  
Aquatic Macrophyte ◽  
Plant Cover ◽  
Critical Role ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Dry Tropics ◽  
The Impact

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.

Vegetation of a coastal sand dune system in southern New Zealand

1991 ◽  
Vol 2 (4) ◽  
pp. 531-538 ◽  
Author(s):  
Martin T. Sykes ◽  
J. Bastow Wilson
Keyword(s):  
New Zealand ◽  
Sand Dune ◽  
Coastal Sand Dune ◽  
Dune System ◽  
Coastal Sand

An analysis of the chalcidoid (Hymenoptera) fauna of a sand-dune system

1977 ◽  
Vol 2 (1) ◽  
pp. 27-46 ◽  
Author(s):  
M. J. W. COPLAND ◽  
R. R. ASKEW
Keyword(s):  
Sand Dune ◽  
Dune System

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.

The Vegetation of a Sand-Dune System in the Outer Hebrides

1948 ◽  
Vol 35 (1) ◽  
pp. 82-96 ◽  
Author(s):  
C. H. Gimingham ◽  
A. R. Gemmell ◽  
P. Greig-Smith
Keyword(s):  
Sand Dune ◽  
Dune System ◽  
Outer Hebrides
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