Microclimatic conditions, meltwater moistening, and the distributional pattern of Buellia frigida on rock in a southern continental Antarctic habitat

Polar Biology ◽  
1998 ◽  
Vol 19 (2) ◽  
pp. 101-106 ◽  
Author(s):  
L. Kappen ◽  
B. Schroeter ◽  
T. G. A. Green ◽  
R. D. Seppelt
Keyword(s):  
Distributional Pattern ◽  
Buellia Frigida ◽  
Microclimatic Conditions

Evolution of Microclimatic Conditions in Paskov Mine / Ewolucja Warunków Mikroklimatycznych W Kopalni Paskov

2012 ◽  
Vol 57 (4) ◽  
pp. 1045-1055
Author(s):  
Pavel Zapletal ◽  
Pavel Prokop ◽  
Vítězslav Košňovský
Keyword(s):  
Coal Mining ◽  
Mining Activity ◽  
Mining Engineering ◽  
Special Program ◽  
Main Subject ◽  
Coal Basin ◽  
Research Activities ◽  
Microclimatic Conditions ◽  
Technical University

Abstract The main subject of this paper focuses on scientific and research activities conducted in the Institute of Mining Engineering and Safety of the VŠB-Technical University of Ostrava. Cooperation between the VŠB-Technical University of Ostrava and OKD A.S., the only representative of coal mining in the Ostrava-Karviná coal basin, has recently begun to develop again. This paper describes an example discussed in a certain study, which has been undertaken for the Paskov mine, OKD a.s., dealing specifically with the evolution of microclimate parameters in mines that depend on the progress of mining activity at deeper levels over a period of several years. To this end, a special program, aimed at determination of the necessary refrigerating capacity, was established at the VŠB-Technical University of Ostrava.

Lichens of the Oasis Molodyozhnyi and adjacent areas (Enderby Land, Antarctic)

2013 ◽  
Vol 47 ◽  
pp. 167-178 ◽  
Author(s):  
M. P. Andreev
Keyword(s):  
Liquid Water ◽  
Climate Conditions ◽  
Water Ice ◽  
Buellia Frigida ◽  
Antarctic Continent ◽  
Harsh Climate ◽  
The Antarctic ◽  
First Time ◽  
Lichen Flora

Lichen flora and vegetation in the vicinity of the Russian base «Molodyozhnaya» (Enderby Land, Antarctica) were investigated in 2010–2011 in details for the first time. About 500 specimens were collected in 100 localities in all available ecotopes. The lichen flora is the richest in the region and numbers 39 species (21 genera, 11 families). The studied vegetation is very poor and sparse, but typical for coastal oases of the Antarctic continent. The poorness is caused by the extremely harsh climate conditions, insufficient availability of liquid water, ice-free land, and high insolation levels. The dominant and most common lichens are Rinodina olivaceobrunnea, Amandinea punctata, Candelariella flava, Physcia caesia, Caloplaca tominii, Lecanora expectans, Caloplaca ammiospila, Lecidea cancriformis, Pseudephebe minuscula, Lecidella siplei, Umbilicaria decussata, Buellia frigida, Lecanora fuscobrunnea, Usnea sphacelata, Lepraria and Buellia spp.

Effects of various cutting treatments and topographic factors on microclimatic conditions in Dinaric fir-beech forests

2020 ◽  
Vol 295 ◽  
pp. 108186
Author(s):  
Janez Kermavnar ◽  
Mitja Ferlan ◽  
Aleksander Marinšek ◽  
Klemen Eler ◽  
Andrej Kobler ◽  
...  
Keyword(s):  
Beech Forests ◽  
Topographic Factors ◽  
Microclimatic Conditions

scholarly journals δ2Hn-alkane and δ18Osugar biomarker proxies from leaves and topsoils of the Bale Mountains, Ethiopia, and implications for paleoclimate reconstructions

2021 ◽  
Author(s):  
Bruk Lemma ◽  
Lucas Bittner ◽  
Bruno Glaser ◽  
Seifu Kebede ◽  
Sileshi Nemomissa ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Leaf Growth ◽  
Thermal Conversion ◽  
Oxygen Isotopic Composition ◽  
Leaf Water ◽  
Isotope Ratio Mass Spectrometer ◽  
Oxygen Isotopic ◽  
Calibration Study ◽  
Microclimatic Conditions ◽  
Paleoclimate Reconstructions

AbstractThe hydrogen isotopic composition of leaf wax–derived n-alkane (δ2Hn-alkane) and oxygen isotopic composition of hemicellulose–derived sugar (δ18Osugar) biomarkers are valuable proxies for paleoclimate reconstructions. Here, we present a calibration study along the Bale Mountains in Ethiopia to evaluate how accurately and precisely the isotopic composition of precipitation is imprinted in these biomarkers. n-Alkanes and sugars were extracted from the leaf and topsoil samples and compound–specific δ2Hn-alkane and δ18Osugar values were measured using a gas chromatograph–thermal conversion–isotope ratio mass spectrometer (GC–TC–IRMS). The weighted mean δ2Hn-alkane and δ18Osugar values range from − 186 to − 89‰ and from + 27 to + 46‰, respectively. Degradation and root inputs did not appear to alter the isotopic composition of the biomarkers in the soil samples analyzed. Yet, the δ2Hn-alkane values show a statistically significant species dependence and δ18Osugar yielded the same species–dependent trends. The reconstructed leaf water of Erica arborea and Erica trimera is 2H– and 18O–enriched by + 55 ± 5 and + 9 ± 1‰, respectively, compared to precipitation. By contrast, Festuca abyssinica reveals the most negative δ2Hn-alkane and least positive δ18Osugar values. This can be attributed to “signal–dampening” caused by basal grass leaf growth. The intermediate values for Alchemilla haumannii and Helichrysum splendidum can be likely explained with plant physiological differences or microclimatic conditions affecting relative humidity (RH) and thus RH–dependent leaf water isotope enrichment. While the actual RH values range from 69 to 82% (x̄ = 80 ± 3.4%), the reconstructed RH values based on a recently suggested coupled δ2Hn-alkane –δ18Osugar (paleo–) hygrometer approach yielded a mean of 78 ± 21%. Our findings corroborate (i) that vegetation changes, particularly in terms of grass versus non–grassy vegetation, need to be considered in paleoclimate studies based on δ2Hn-alkane and δ18Osugar records and (ii) that the coupled δ2Hn-alkane –δ18Osugar (paleo–) hygrometer approach holds great potential for deriving additional paleoclimatic information compared to single isotope approaches.

scholarly journals The Contribution of Urban Morphology to the Formation of the Microclimate in Compact Urban Cores: A Study in the City Center of Thessaloniki

Urban Science ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 37
Author(s):  
Georgios-Rafail Kouklis ◽  
Athena Yiannakou
Keyword(s):  
Field Study ◽  
Urban Form ◽  
Simulation Method ◽  
Urban Morphology ◽  
Green Spaces ◽  
City Center ◽  
Outdoor Spaces ◽  
Microclimatic Conditions ◽  
The Relationship ◽  
The City

The purpose of this paper is to investigate the contribution of urban morphology to the formation of microclimatic conditions prevailing within urban outdoor spaces. We studied the compact form of a city and examined, at a detailed, street plan level, elements related to air temperature, urban ventilation, and the individual’s thermal comfort. All elements examined are directly affected by both the urban form and the availability of open and green spaces. The field study took place in a typical compact urban fabric of an old city center, the city center of Thessaloniki, where we investigated the relationship between urban morphology and microclimate. Urban morphology was gauged by examining the detailed street plan, along with the local building patterns. We used a simulation method based on the ENVI-met© software. The findings of the field study highlight the fact that the street layout, the urban canyon, and the open and green spaces in a compact urban form contribute decisively both to the creation of the microclimatic conditions and to the influence of the bioclimatic parameters.

Silvicultural treatments, microclimatic conditions and seedling response in Southern Interior clearcuts

1998 ◽  
Vol 78 (1) ◽  
pp. 115-126 ◽  
Author(s):  
R. L. Fleming ◽  
T. A. Black ◽  
R. S. Adams ◽  
R. J. Stathers
Keyword(s):  
Soil Moisture ◽  
Seedling Establishment ◽  
Initial Period ◽  
Mineral Soil ◽  
Soil Disturbance ◽  
Near Surface ◽  
Lower Elevation ◽  
Organic Horizons ◽  
Soil Temperatures ◽  
Microclimatic Conditions

Post-harvest levels of soil disturbance and vegetation regrowth strongly influence microclimate conditions, and this has important implications for seedling establishment. We examined the effects of blading (scalping), soil loosening (ripping) and vegetation control (herbicide), as well as no soil disturbance, on growing season microclimates and 3-yr seedling response on two grass-dominated clearcuts at different elevations in the Southern Interior of British Columbia. Warmer soil temperatures were obtained by removing surface organic horizons. Ripping produced somewhat higher soil temperatures than scalping at the drier, lower-elevation site, but slightly reduced soil temperatures at the wetter, higher-elevation site. Near-surface air temperatures were more extreme (higher daily maximums and lower daily minimums) over the control than over exposed mineral soil. Root zone soil moisture deficits largely reflected transpiration by competing vegetation; vegetation removal was effective in improving soil moisture availability at the lower elevation site, but unnecessary from this perspective at the higher elevation site. The exposed mineral surfaces self-mulched and conserved soil moisture after an initial period of high evaporation. Ripping and scalping resulted in somewhat lower near-surface available soil water storage capacities. Seedling establishment on both clearcuts was better following treatments which removed vegetation and surface organic horizons and thus enhanced microclimatic conditions, despite reducing nutrient supply. Such treatments may, however, compromise subsequent stand development through negative impacts on site nutrition. Temporal changes in the relative importance of different physical (microclimate) and chemical (soil nutrition) properties to soil processes and plant growth need to be considered when evaluating site productivity. Key words: Microclimate, soil temperature, air temperature, soil moisture, clearcut, seedling establishment

Bird distributional patterns support biogeographical histories and are associated with bioclimatic units in the Atlantic Forest, Brazil

Zootaxa ◽  
2017 ◽  
Vol 4337 (2) ◽  
pp. 223 ◽  
Author(s):  
CRISTIANO DE SANTANA CARVALHO ◽  
NAYLA FÁBIA FERREIRA DO NASCIMENTO ◽  
HELDER F. P. DE ARAUJO
Keyword(s):  
Multivariate Analysis ◽  
Atlantic Forest ◽  
Analysis Of Variance ◽  
Forest Birds ◽  
Distributional Pattern ◽  
Parsimony Analysis ◽  
Multivariate Analysis Of Variance ◽  
Distributional Patterns ◽  
Parsimony Analysis Of Endemicity

Rivers as barriers to dispersal and past forest refugia are two of the hypotheses proposed to explain the patterns of biodiversity in the Atlantic Forest. It has recently been shown that possible past refugia correspond to bioclimatically different regions, so we tested whether patterns of shared distribution of bird taxa in the Atlantic Forest are 1) limited by the Doce and São Francisco rivers or 2) associated with the bioclimatically different southern and northeastern regions. We catalogued lists of forest birds from 45 locations, 36 in the Atlantic forest and nine in Amazon, and used parsimony analysis of endemicity to identify groups of shared taxa. We also compared differences between these groups by permutational multivariate analysis of variance and identified the species that best supported the resulting groups. The results showed that the distribution of forest birds is divided into two main regions in the Atlantic Forest, the first with more southern localities and the second with northeastern localities. This distributional pattern is not delimited by riverbanks, but it may be associated with bioclimatic units, surrogated by altitude, that maintain current environmental differences between two main regions on Atlantic Forest and may be related to phylogenetic histories of taxa supporting the two groups. 

Sign in / Sign up

Export Citation Format

Share Document