scholarly journals Photoprotection and high-light acclimation in semi-arid grassland lichens – a cooperation between algal and fungal partners

Symbiosis ◽  
2021 ◽  
Author(s):  
Katalin Veres ◽  
Zsolt Csintalan ◽  
Zsanett Laufer ◽  
Rita Engel ◽  
Krisztina Szabó ◽  
...  
Keyword(s):  
Photosynthetic Apparatus ◽  
Photochemical Quenching ◽  
Symbiotic Association ◽  
The South ◽  
Dune System ◽  
Carotenoid Concentration ◽  
North East ◽  
The North ◽  
South West ◽  
Non Photochemical Quenching

AbstractIn lichens, each symbiotic partner cooperates for the survival of the symbiotic association. The protection of the susceptible photosynthetic apparatus is essential for both participants. The mycobiont and photobiont contribute to the protection against the damaging effect of excess light by various mechanisms. The present study investigated the effect of seasonality and microhabitat exposure on photoprotection and photoacclimation in the photo- and the mycobiont of six lichen species with different thallus morphology in inland dune system in the Kiskunság region (Hungary) with shaded, more humid and exposed, drier dune sides. High-Performance Liquid Chromatography, spectrophotometry, chlorophyll a fluorescence kinetic technique were used, and micrometeorological data were collected. The four years data series revealed that the north-east-facing side was characterized by higher relative humidity and lower light intensities compared to the south-west-facing drier and more exposed sides. The south-west facing side was exposed to direct illumination 3–4 hours longer in winter and 1–2 hours shorter in summer than the north-east facing side of the dune, influencing the metabolism of sun and shade populations of various species. Because rapid desiccation caused short active periods of lichens during bright and drier seasons and on exposed microhabitats, the rapid, non-regulated non-photochemical quenching mechanisms in the photobiont had a significant role in protecting the photosynthetic system in the hydrated state. In dehydrated conditions, thalli were mainly defended by the solar screening metabolites produced by the mycobiont and curling during desiccation (also caused by the mycobiont). Furthermore, the efficacy of light use (higher chlorophyll and carotenoid concentration) increased because of short hydrated periods. Still, a lower level of received irradiation was appropriate for photosynthesis in dry seasons and on sun exposed habitats. In humid seasons and microhabitats, more extended active periods lead to increased photosynthesis and production of solar radiation protectant fungal metabolites, allowing a lower level of photoprotection in the form of regulated non-photochemical quenching by the photobiont. Interspecific differences were more pronounced than the intraspecific ones among seasons and microhabitat types.

The Metamorphosed Limestones and Associated Contaminated Igneous Rocks of the Carlingford District, Co. Louth

1932 ◽  
Vol 69 (5) ◽  
pp. 209-233 ◽  
Author(s):  
G. D. Osborne
Keyword(s):  
Igneous Rocks ◽  
The South ◽  
Ordnance Survey ◽  
Igneous Complex ◽  
North East ◽  
The North ◽  
South West ◽  
Carboniferous Limestone ◽  
Contamination Effects

THE Carlingford-Barnave district falls within the boundaries of Sheet 71 of the Ordnance Survey of Ireland, and forms part of a broad promontory lying between Carlingford Lough on the north-east and Dundalk Bay on the south-west. The greater part of this promontory is made up of an igneous complex of Tertiary age which has invaded the Silurian slates and quartzites and the Carboniferous Limestone Series. This complex has not yet been investigated in detail, but for the purposes of the present paper certain references to it are necessary, and these are made below. The prevalence of hybrid-relations and contamination-effects between the basic and acid igneous rocks of the region is a very marked feature, and because of this it has been difficult at times to decide which types have been responsible for the various stages of the metamorphism.

Part VI. The Cyclopean Terrace Building and the Deposit of Pottery beneath It

1954 ◽  
Vol 49 ◽  
pp. 267-291
Author(s):  
Elizabeth B. Wace
Keyword(s):  
Contour Line ◽  
The South ◽  
Main Road ◽  
North West ◽  
North East ◽  
The North ◽  
South West

The Cyclopean Terrace Building lies to the north-west of the Lion Gate on the northern end of the Panagia Ridge and faces almost due west across the valley of the Kephissos and modern main road from Corinth to Argos. It lies just below the 200 m. contour line, and one terrace below the houses excavated in 1950–51 by Dr. Papadimitriou and Mr. Petsas to the east at the same end of the ridge. The area contains a complex of buildings, both successive and contemporary, and in view of the discovery of structures both to the south-west and, by the Greek Archaeological Service, to the north-east it is likely that this whole slope was covered by a portion of the outer town of Mycenae. This report will deal only with the structure to which the name Cyclopean Terrace Building was originally given, the so-called ‘North Megaron’, supported by the heavy main terrace wall.The excavation of this structure was begun in 1923. The main terrace wall was cleared and two L.H. IIIC burials discovered in the top of the fill in the south room. In 1950 it was decided to attempt to clear this building entirely in an endeavour to find out its date and purpose. The clearing was not, however, substantially completed until the close of the 1953 excavation season, and this report presents the available evidence for the date as determined by the pottery found beneath the building; the purpose is still a matter for study, though various tentative conclusions can be put forward.

The West Court at Perachora

1967 ◽  
Vol 62 ◽  
pp. 353-371
Author(s):  
J. J. Coulton
Keyword(s):  
Short Distance ◽  
Sixth Century ◽  
East Side ◽  
The South ◽  
The West ◽  
Rock Face ◽  
North East ◽  
The North ◽  
South West ◽  
East And West

About 10 metres south-west of the sixth-century temple of Hera Akraia at Perachora, and nearly due west of the little harbour lies the small courtyard previously known as the ‘Agora’. Since its purpose is not known, it will here be non-committally referred to as the West Court. It was first excavated in 1932, and more fully, under the supervision of J. K. Brock, in 1933, but it was not entirely cleared until 1939, and it was at that time that the Roman house which stood in the middle of the court was demolished. The West Court is discussed briefly (under the name of ‘Agora’) in Perachora 1 and in the preliminary reports of the Perachora excavations. Short supplementary excavations were carried out in 1964 and 1966 to examine certain points of the structure.In shape the West Court is an irregular pentagon, about 24 metres from north to south and the same from east to west (Fig. 1; Plate 91 a, b). It is enclosed on the west, north, and on part, at least, of the east side by a wall of orthostates on an ashlar foundation. For a short distance on either side of the south corner, the court is bounded by a vertically dressed rock face which is extended to the north-east and west by walls of polygonal masonry. At the south-west corner the west orthostate wall butts against the polygonal wall, which continues for about 0·80 m. beyond it and then returns north for about 8 metres behind it.

scholarly journals A plutonic diorite complex in the north of the Fiskenæsset region

1976 ◽  
Vol 73 ◽  
pp. 72-80
Author(s):  
W.R Fitches
Keyword(s):  
The Body ◽  
Main Body ◽  
The South ◽  
North East ◽  
The North ◽  
South West ◽  
West Part ◽  
Preliminary Account ◽  
East End

A thick diorite-monzodiorite sheet over 2 km in length and up to 600 m in width (fig. 35) is exposed at 50°25'E and 63°55'N, about 7 km south of Qeqertaussaq by Kangerdluarssûngûp taserssua. Several diorite dykes, some over 10 m in thickness, tie parallel to the main body and up to 300 m from it. The north-east end of the body is covered by superficial deposits whilst the south-west part has not yet been mapped out. This is therefore a preliminary account, including petrography, fie1d relations and some geochemistry, and more information will become available during subsequent field seasons.

scholarly journals An ultrabasic pipe in the eastern Sukkertoppen region, southern West Greenland

1980 ◽  
Vol 100 ◽  
pp. 69-73
Author(s):  
R.P Hall
Keyword(s):  
Granulite Facies ◽  
The South ◽  
The West ◽  
West Side ◽  
West Greenland ◽  
North East ◽  
The North ◽  
South West ◽  
Unusual Occurrence ◽  
Anorthosite Complex

An unusual occurrence of ultrabasic material was located in the eastern Sukkertoppen region during the reconnaissance mapping programme of 1977, the findings of which were described by Allaart et al. (1978). It occurs on a small exposure on the west side of a north-pointing peninsula in the middle of the large nunatak Majorqap alangua (65°53'N, 50°40'W), to the north-east of the Majorqaq valley (Hall, 1978, fig. 21). The area is composed predominantly of a suite of granulite facies granitic gneisses which contain numerous enclaves of pyroxene-bearing amphibolites, and locally anorthositic and gabbroic rocks similar to those seen in the Fiskenæsset anorthosite complex (Myers, 1975). The gneisses in the centre af the nunatak are highly irregular in orient at ion, occupying the complex interseclion af closures af at least two major fold phases. A belt af amphibolitcs forms the cliff at the south-west tip af Majorqap alangua. Related rocks occur in arnphibolite facies in the acea around the lakc Qardlit taserssuat immediately to the soulh (Hall, 1978).

III.—On the Discovery of a Quartzose Conglomerate at Caldon Low, Staffs

1919 ◽  
Vol 6 (2) ◽  
pp. 59-64 ◽  
Author(s):  
J. Wilfrid Jackson ◽  
W. E. Alkins
Keyword(s):  
The South ◽  
North West ◽  
Good Fortune ◽  
North East ◽  
The North ◽  
South West ◽  
Limestone Quarries ◽  
Strong Joint

During a visit to the limestone quarries at Caldon Low last September we had the good fortune to discover an interesting exposure of a quartzose conglomerate containing numerous fossils. The bed was exposed in a strong joint-face running approximately N.N.W. to S.S.E., at the northern extension of the quarry on the north-west flank of the Low, just beyond the mineral line of the North Staffordshire Railway. The altitude is about 900 feet O.D. The conglomerate apparently extended some little distance to the south-west before the opening of the quarry, as we ascertained that some 20 or 30 yards had been removed in gaining access to the limestone behind. It appears to extend for some distance round the flank of the Low towards the north-east.

A study of apparent angles of emergence at Marathon Ontario from the Lake Superior data

1965 ◽  
Vol 55 (2) ◽  
pp. 405-416
Author(s):  
R. F. Mereu
Keyword(s):  
Particle Motion ◽  
Lake Superior ◽  
Seismic Events ◽  
The South ◽  
West Side ◽  
North East ◽  
The North ◽  
South West

Abstract A three component array of Willmore seismometers and a hydrophone were used to record the seismic events at Marathon, Ontario during the Lake Superior crustal experiment of 1963. The first part of each record was digitized and from an analysis of the particle motion diagrams, apparent angles of emergence of the seismic rays were determined. It was found that these angles can be used to distinguish between P2 and Pn waves. When the shot distance was less than 220 km., the first arrivals emerged with an apparent angle of 40-50°. As the shot distance was increased beyond 220 km., the rays emerged with an apparent angle of 51-70°. The apparent velocities of the (40-50) and the 51-70°) rays were 6.6 km/sec and 8.2 km/sec respectively. Further analysis of the results showed that the Moho below Marathon dipped downwards toward the south west with an angle of approximately 4°, indicating that the crust is considerably thicker on the south west side of Marathon than on the north east. A study of the ray azimuths gave some evidence of the presence of lateral inhomogeneities in the crust.

VI.—The Geology of the Highland Border from Glen Almond to Glen Artney

1941 ◽  
Vol 60 (1) ◽  
pp. 171-193 ◽  
Author(s):  
Douglas A. Allan
Keyword(s):  
Field Survey ◽  
Central Valley ◽  
Present Communication ◽  
The South ◽  
Red Sandstone ◽  
Boundary Fault ◽  
Comprehensive Account ◽  
North East ◽  
The North ◽  
South West

The author (1928) of the present communication has already published the results of a field survey of the Lower Old Red Sandstone in Perthshire and Angus, which were linked with those derived by Campbell (1913) from his study of similar and older series of beds in Kincardineshire, to the north-east. For thirty-five miles to the south-west of the R. Tay, no detailed investigation of the sequence or tectonics of the rocks immediately adjacent to the Highland Boundary Fault, separating the Grampians proper from the Central Valley of Scotland, has been undertaken. A comprehensive account of the rocks of this belt in the region around Aberfoyle is available in the paper by Campbell and Jehu (1917).

On the Chronological Order of Deposition of the Highland Schists

1930 ◽  
Vol 67 (2) ◽  
pp. 68-73 ◽  
Author(s):  
Thorolf Vogt
Keyword(s):  
Broad Band ◽  
Difficult Problem ◽  
Chronological Order ◽  
The South ◽  
Scottish Highlands ◽  
North East ◽  
The North ◽  
South West ◽  
Mountain Chain

As is well known, the chronological order of deposition of the sediments of that broad band of schists which extends across Scotland from Banffshire and Aberdeenshire in the north-east to Argyllshire in the south-west is a most difficult problem to determine. The noteworthy development that has been made during recent years, leading to a more intimate understanding of the structure of the Southern Highlands, has made this problem much more vital. The question as to the top and bottom of these beds has been much discussed in recent years, and it can not be denied that views have been widely divergent on this matter. When a foreign geologist desires to call attention (through this paper) to certain conditions of fact, it may be pointed out that he is carrying on similar studies of another section—the Norwegian—of this same mountain chain, where one meets similar problems as in the Scottish Highlands.

The Flint Gravel Deposit of Orleigh Court, Buckland Brewer, North Devon

1937 ◽  
Vol 74 (7) ◽  
pp. 309-316 ◽  
Author(s):  
Inkermann Rogers ◽  
Brian Simpson
Keyword(s):  
Average Distance ◽  
Good Deal ◽  
Left Bank ◽  
The South ◽  
North East ◽  
The North ◽  
South West ◽  
North Eastern ◽  
Low Levels ◽  
Gravel Deposit

The deposit to be described is situated at Orleigh Court, in the parish of Buckland Brewer, some four miles west of south from Bideford, where it rests unconformably on the steeply dipping Upper Culm sandstones. Its greatest extent is from Orleigh Mill to Yeo Bridge, a distance of about three-quarters of a mile in a northwest to south-east direction, and from this line it extends to the south-west for an average distance of about one-third of a mile, only exceeding that amount to the south of the Higher Lodge. The only extensive section was seen in the Rookery, where 25 feet of material rest on a yellow clay. The highest point reached by the deposit, to the south-west of the Higher Lodge, is about 400 feet above O.D. From this point it slopes to the north-east, extending down to about the 100 ft. contour on the left bank of the River Yeo. It is possible that the north-eastern boundary does not reach such low levels as those indicated on the map, Text-fig. 1, for it is difficult to distinguish the original gravel from relatively recent hill wash; and, without a good deal of trenching or augering, it would not be possible to determine the boundary more closely than has been done in the present work.

Sign in / Sign up

Export Citation Format

Share Document