Macrofungi of sand dunes

1989 ◽  
Vol 96 ◽  
pp. 111-126 ◽  
Author(s):  
R. Watling ◽  
M. Rotheroe
Keyword(s):  
North America ◽  
Sand Dune ◽  
Sand Dunes ◽  
Dune Systems ◽  
Similarities And Differences

SynopsisOur knowledge of the macrofungi of British sand dune systems is outlined and similarities and differences are discussed, based both on intensive studies and scattered observations, particularly in Scotland and Wales. Comparisons are made with European sand dune communities, and much wider observations from as far afield as N.E. Australia and North America are presented. Several records new to Britain are documented.

scholarly journals Responses of woody species to spatial and temporal ground water changes in coastal sand dune systems

2011 ◽  
Vol 8 (12) ◽  
pp. 3823-3832 ◽  
Author(s):  
C. Máguas ◽  
K. G. Rascher ◽  
A. Martins-Loução ◽  
P. Carvalho ◽  
P. Pinho ◽  
...  
Keyword(s):  
Ground Water ◽  
Plant Species ◽  
Functional Traits ◽  
Pinus Pinaster ◽  
Sand Dune ◽  
Sand Dunes ◽  
Woody Species ◽  
Rooting Depth ◽  
Summer Drought ◽  
Dune Systems

Abstract. In spite of the relative importance of groundwater in costal dune systems, studies concerning the responses of vegetation to ground water (GW) availability variations, particularly in Mediterranean regions, are scarce. Thus, the main purpose of this study is to compare the responses of co-occurring species possessing different functional traits, to changes in GW levels (i.e. the lowering of GW levels) in a sand dune ecosystem. For that, five sites were established within a 1 km2 area in a meso-mediterranean sand dune ecosystem dominated by a Pinus pinaster forest. Due to natural topographic variability and anthropogenic GW exploitation, substantial variability in depth to GW between sites was found. Under these conditions it was possible to identify the degree of usage and dependence on GW of different plant species (two deep-rooted trees, a drought adapted shrub, a phreatophyte and a non-native woody invader) and how GW dependence varied seasonally and between the heterogeneous sites. Results indicated that the plant species had differential responses to changes in GW depth according to specific functional traits (i.e. rooting depth, leaf morphology, and water use strategy). Species comparison revealed that variability in pre-dawn water potential (Ψpre) and bulk leaf δ13C was related to site differences in GW use in the deep-rooted (Pinus pinaster, Myrica faya) and phreatophyte (Salix repens) species. However, such variation was more evident during spring than during summer drought. The exotic invader, Acacia longifolia, which does not possess a very deep root system, presented the largest seasonal variability in Ψpre and bulk leaf δ13C. In contrast, the response of Corema album, an endemic understory drought-adapted shrub, seemed to be independent of water availability across seasons and sites. Thus, the susceptibility to lowering of GW due to anthropogenic exploitation, in plant species from sand dunes, is variable, being particularly relevant for deep rooted species and phreatophytes, which seem to depend heavily on access to GW.

Influence of Ammophila arenaria on half a century of vegetation change in eastern Tasmanian sand dune systems

2012 ◽  
Vol 60 (5) ◽  
pp. 450 ◽  
Author(s):  
Monica Hayes ◽  
Jamie B. Kirkpatrick
Keyword(s):  
Sea Level ◽  
Sand Dune ◽  
Vegetation Change ◽  
Sand Dunes ◽  
Aerial Photographs ◽  
Ammophila Arenaria ◽  
Dune Systems ◽  
Shrub Invasion ◽  
Bare Sand ◽  
Marram Grass

There is strong observational evidence that marram grass Ammophila arenaria transforms vegetation when it invades temperate coastal sand dunes. Because of contemporaneous marram grass introduction, sea level rise, climate change and coastal land use change, we use control dune systems to test the hypotheses that marram grass displaces native sand-binding grasses, reduces the area of bare sand and facilitates shrub invasion. We mapped vegetation from aerial photographs at four times between 1948 and 2007 on four pairs of sand dune systems, with one of each pair being heavily invaded by marram grass during the period of observation. We calculated the transitions between cover types between times. On the dune systems with marram grass, dunes became taller and more regular, native sand-binders became rare, bare sand decreased in area and native shrubs colonised the stabilised dunes. In the absence of marram grass the dunes remained dynamic, with much bare sand. At two of these control sites, increases in wind strength and sea level may have facilitated the development of transgressive dunes and eroded the native sand-binders. At the remaining two control sites, native sand-binders created low incipient foredunes. Shrub invasion occurred at most control sites. We conclude that marram grass does displace native sand-binders and decrease the proportion of bare sand, but that shrub invasion is partly independent of its introduction.

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 Charcoal in soils of the Allerød-Younger Dryas transition were the result of natural fires and not necessarily the effect of an extra-terrestrial impact

2008 ◽  
Vol 87 (4) ◽  
pp. 359-361 ◽  
Author(s):  
T. van der Hammen ◽  
B. van Geel
Keyword(s):  
North America ◽  
Large Scale ◽  
Sand Dunes ◽  
Younger Dryas ◽  
Natural Fires ◽  
Water Tables ◽  
Pine Trees ◽  
Climate Cooling ◽  
Fossil Records ◽  
Terrestrial Material

AbstractDuring the warm Bølling-Allerød interstadial, tree species migrated from their refugia in southern Europe northwards into the area within the present temperate climatic zone. It is evident from high levels of charcoal in fossil records in this region that, especially during the later part of the Bølling-Allerød interstadial, many fires occurred. The start of the Younger Dryas was characterised by rapid and intense cooling and rising water tables, with catastrophic effects on the vegetation. Thermophilous pine trees could not survive the cold Younger Dryas climate. Dead wood provided an abundant source of fuel for intense, large-scale fires seen in many records as a concentration of charcoal particles in so-called ’Usselo-soils’ dated to ca 10,95014C BP. A similar trend in increased charcoal indicating increased burning is seen at many sites across North America at this time and it has been suggested by Firestone et al. (2007) that this was caused by an explosion of extra-terrestrial material over northern North America, causing the Younger Dryas climate cooling and Megafaunal extinction. We argue that there is no need to invoke an extraterrestrial cause to explain the charcoal in the fossilized soils. The volume of forest trees that died as a result of the cold Younger Dryas climate would easily have supplied sufficient fuel for intense, large-scale fires and can be used to account for the concentration of charcoal particles. As soils were no longer covered by dense vegetation, much erosion occurred during the Younger Dryas and therefore, at many places, Usselo soils, rich in charcoal, were preserved under aeolian sand dunes.

Coastal Observations: Rapid development and colonization of a UK sand dune system

Shore & Beach ◽  
2021 ◽  
pp. 17-21
Author(s):  
A.T. Williams
Keyword(s):  
Sand Dune ◽  
Rapid Development ◽  
Sea Buckthorn ◽  
Ammophila Arenaria ◽  
Couch Grass ◽  
Dune System ◽  
Dune Systems ◽  
Frontal Part ◽  
Agrostis Tenuis ◽  
South Wales

Between the years 1200 and 1600, vast quantities of sand were brought inshore from offshore bars as a result of centuries of ferocious storms, to form a series of dune systems along the South Wales coastline. Today, as a result of many housing, leisure, and industrial developments only a few remnants exist. On one such remnant at Porthcawl, Wales, UK, became a caravan site in the 1930s, which was abandoned in 1993 for political reasons. Within 27 years a minimum of 120,000 m3 of sand was transported from the adjacent beach and formed dunes >4 m in height along a 400- m frontal edge that extended some 130 m inland, approximately a third of the site. Typical vegetation found along the frontal part of the system are Ammophila arenaria (marram), Agropyron junceiforme (sand couch grass) and Euphorbia maritimum (spurge). To the rear of the system, vegetation included Agrostis tenuis and stolonifera, (bent and creeping bent grass), Cirsium avense (creeping thistle), and Caluna vulgaris (heather). A 4-m-high and c. 3000m2 area of a vigorous stand of Hippophae rhamnoides (sea buckthorn) has also formed. The rapidity of dune formation and vegetation colonization is staggering.

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 The Use of Corporate Sustainability Indices : A Case Study on the Dow Jones Sustainability Index

2021 ◽  
Author(s):  
Doaa Mohammed Elkhawas
Keyword(s):  
North America ◽  
Corporate Sustainability ◽  
Socially Responsible ◽  
Responsible Investment ◽  
Sustainability Index ◽  
Dow Jones Sustainability Index ◽  
Sustainability Reports ◽  
Similarities And Differences ◽  
Sustainability Indices

Corporations are under growing pressure from socially responsible investors to consider the environmental and social impacts of their operations. To help highlight corporations that have taken steps to address these issues, a number of sustainability indices have been developed. While there is a growing body of literature that focuses on sustainability indices, little is known on how they are used in practice. The purpose of this project was to explore the use of sustainability indices in corporations. In this project, the Dow Jones Sustainability Index North America (DJSINA) was used in a case study. The project consisted of three key phases: a content analysis of corporate sustainability reports in North America, a survey with Canadian experts on the DJSINA, and a review of the DJSI website. The project highlights the similarities and differences in the use of the DJSI by Canadian and American corporations. As the first study focusing on the use of the DJSINA, the results will be of interest to practitioners and academics in socially responsible investment and corporate sustainability.

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.

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