scholarly journals Impacts of Geomorphic Disturbances on Plant Colonization in Ebba Valley, Central Spitsbergen, Svalbard

2017 ◽  
Vol 36 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Monika Stawska
Keyword(s):  
Marginal Zone ◽  
Plant Cover ◽  
Climatic Conditions ◽  
Plant Colonization ◽  
Polar Regions ◽  
Vegetation Development ◽  
Plant Coverage ◽  
Vegetation Sampling ◽  
Marine Terraces ◽  
Main Factors

Abstract Global warming observed nowadays causes an increase in geomorphic activity in polar regions. Within the areas influenced by cold climatic conditions, relief dynamics and vegetation development are the main landscape shaping processes. The study is limited to the Ebba Valley (78°43’N; 16°37’E) in central Spitsbergen (Svalbard), where geomorphologic observations and vegetation sampling were conducted in 2007. The valley was divided into three zones differentiated by dominating geomorphic activity and stability of deposits. The settlement and the evolution of plant cover have been documented there. The main factors that control well developed vegetation cover within raised marine terraces are frost heave and solifluction. In deeper parts of the valley, aeolian processes dominate and high differentiation of microsite conditions causes high variability in plant coverage. The area close to the Ebba glacier marginal zone is characterized by initial stages of plant colonisation where disturbance to vegetation is mainly caused by hydrological processes.

scholarly journals Seabirds and seals as drivers of plant succession on Surtsey

2020 ◽  
Vol 14 ◽  
pp. 115-130
Author(s):  
Borgthór Magnússon ◽  
Gudmundur A. Gudmundsson ◽  
Sigmar Metúsalemsson ◽  
Sandra M. Granquist
Keyword(s):  
Plant Cover ◽  
Plant Succession ◽  
Present Species ◽  
Permanent Plots ◽  
Plant Colonization ◽  
Grey Seal ◽  
Breeding Area ◽  
Vegetation Development ◽  
Dense Patch ◽  
First Time

Plant colonization and succession on Surtsey have been monitored since 1965. In 2019, the 75th species of vascular plants was detected on the island, 62 species were present and about 40 species had established viable populations. Over the last decade colonization has slowed down and the number of present species not increased. The rising number of seagulls breeding on the island after 1985 had a great impact on plant colonization and vegetation development. While most parts of the island remained barren, a grassland area (13 ha in 2018) developed in the main seagull breeding colony on the southern part of the island. This development is attributed to transfer of nutrients from sea to land by the seagulls. In recent years a dense patch of vegetation, 2 ha in 2018, has also developed on the low, northern spit of the island, where a few pairs of seagulls breed in the spring and grey seals haul out and breed in the fall in considerable numbers. In a survey conducted during the grey seal pupping period in 2019, the seal abundance and spatial distribution was mapped accurately for the first time. The results show that the dense vegetation of the spit and seal distribution are clearly overlapping. The continuous shrinking of the island and its spit has led to an increasing concentration of the seals in their breeding area. Based on a literature survey we estimated the nitrogen (N) input from sea to land by the grey seals as 9-13 kg N/ha in 2019. This compares to an estimated input of 5-30 kg N/ha/yr by the seagulls breeding in the same area during 2015-2019. Within the grey seal and seagull breeding area on the spit of the island, a distinct community of shore plants has developed. Measurements of plant cover and biomass in permanent plots on Surtsey in 2018 and 2019 show that development on part of the spit is reaching a similar state as in the old gull colony on the southern part of the island. This suggests that the grey seals along with the seagulls are important drivers of plant succession on the northern spit. Further research on the effects of the seals on nutrient transfer from sea to land and ecosystem development on Surtsey is recommended.

Пригодность очищенного картофеля к вакуумной упаковке и быстрой заморозке

2018 ◽  
Author(s):  
S.V. Maltsev
Keyword(s):  
Potato Variety ◽  
Climatic Conditions ◽  
Vacuum Packaging ◽  
Mineral Fertilizers ◽  
Main Factors ◽  
Fast Freezing

Отражены результаты исследования основных факторов (сорт, почвенно-климатические условия выращивания, фон минерального питания, температура хранения сырья и готового продукта, срок переработки), определяющих пригодность картофеля к вакуумной упаковке и быстрой заморозке без применения консервантов.The article reveals main factors (such as potato variety, soil and climatic conditions, doses of mineral fertilizers, store temperatures, different timelines of processing) determining the suitability of potatoes for vacuum packaging and fast freezing without usage of chemicals.

scholarly journals Bryophytes on the devastated territories of sulphur deposits and their role in restoration of dump substrate

2018 ◽  
Vol 26 (4) ◽  
pp. 339-353
Author(s):  
I. V. Rabyk ◽  
O. V. Lobachevska ◽  
N. Y. Kyyak ◽  
O. I. Shcherbachenko
Keyword(s):  
Plant Cover ◽  
Photosynthetic Apparatus ◽  
Life Forms ◽  
Climatic Conditions ◽  
Projective Cover ◽  
Biogenic Elements ◽  
Moisture Regime ◽  
Moss Species ◽  
Vegetative Period ◽  
Specific Composition

Bryophytes possess a wide ecological diapason allowing them to populate substrates of technogenic origins which are scarcely suitable or completely unsuitable for viability of vascular plants. 49 bryophyte species, which belong to 2 divisions, 3 classes, 8 orders, 17 families, and 33 genera have been found on the dump territory of sulphur extraction of the mining-chemical enterprise “Sirka” (Yavoriv district, Lviv region). Seven transects, three on the north slope (base, slope, top), three on the south slope and one on the plateau were laid for sample selections. 20 investigated 0.5 × 0.5 m plots located 2 m apart were analyzed within each 10 × 10 m transect. Specific composition, life forms, projective cover, biomass of bryophytes, numbers of male, female and sterile plants, moisture content in the turfs, pH and physiological investigation of mosses were determined on each plot. The quantitative analysis of the biomorphological structure allowed us to establish the dependence of the spread of life forms on exposition and slope height; essential variability of the projective cover and moss biomass. Bryophyte cover plays an essential part in optimization of the moisture regime and surface layer temperature of technogenic substrates, improving the conditions of growth localities. We established that on the dump the dominant moss species are dioecious with a high level of reproductive effort (sexual and sexless), with short ontogenesis and age of first reproduction, which provides the chance to produce the maximum number of progeny in the minimum period and to form a complete moss cover. The analysis of seasonal moss photosynthesis dynamics has demonstrated the adaptability of moss photosynthetic apparatus to contrasting climatic conditions and the ability to support the intensity of photosynthetic processes on a rather stable level during the vegetative period. Our research showed that bryophytes play an important role in productivity of plant cover on the post-technogenic territories of sulphur extraction. It was found that bryophytes play a role in accumulation of organic carbon and biogenic elements in the substrate of the sulphur extraction dump . Carrying out research of specific composition dynamics and species activity is the precondition for revealing the essence of the dynamic processes taking place in the structure of the bryophyte communities on devastated territories and the influence of these processes on the formation of vegetation on dump complexes.

Automated observatories for geospace research in polar regions

1998 ◽  
Vol 10 (2) ◽  
pp. 192-203 ◽  
Author(s):  
J.R. Dudeney ◽  
R.I. Kressman ◽  
A.S. Rodger
Keyword(s):  
Control System ◽  
Electrical Power ◽  
Thermal Control ◽  
Climatic Conditions ◽  
Operational Experience ◽  
Polar Regions ◽  
Automated Systems ◽  
Thermal Control System ◽  
Optical Disks ◽  
Plastic Containers

The specification, development and deployment of an automated observatory designed to operate unattended for a year in the extreme climatic conditions of the polar regions is presented. Solar- and wind-powered electric generators are used to charge lead/acid batteries to provide a nominal 100 W of electrical power for operating scientific sensors. The equipment is housed in a highly insulated caboose (3m by 2m by 2m). The temperature in the latter is regulated using a unique thermal control system which utilizes the latent heat of 500 l of water stored in 25-l plastic containers. Data are logged to optical disks for collection once per year. The observatory is designed to be air-deployed using a DHC-6 aircraft. The paper discusses the rationale for designing such automated systems, the operational experience gained from several years of operation, and the application of a network of observatories to solar-terrestrial physics research.

Effects of Continents and Supercontinents on Climate

2004 ◽  
Author(s):  
John J. W. Rogers ◽  
M. Santosh
Keyword(s):  
Global Climate ◽  
Climatic Conditions ◽  
Polar Regions ◽  
The North ◽  
Rock Types ◽  
Control Climate ◽  
The Earth ◽  
History Of ◽  
Earth’S Climate ◽  
Geologic Record

Continents affect the earth’s climate because they modify global wind patterns, control the paths of ocean currents, and absorb less heat than seawater. Throughout earth history the constant movement of continents and the episodic assembly of supercontinents has influenced both global climate and the climates of individual continents. In this chapter we discuss both present climate and the history of climate as far back in the geologic record as we can draw inferences. We concentrate on longterm changes that are affected by continental movements and omit discussion of processes with periodicities less than about 20,000 years. We refer readers to Clark et al. (1999) and Cronin (1999) if they are interested in such short-term processes as El Nino, periodic variations in solar irradiance, and Heinrich events. The chapter is divided into three sections. The first section describes the processes that control climate on the earth and includes a discussion of possible causes of glaciation that occurred over much of the earth at more than one time in the past. The second section investigates the types of evidence that geologists use to infer past climates. They include specific rock types that can form only under restricted climatic conditions, varieties of individual fossils, diversity of fossil populations, and information that the 18O/16O isotopic system can provide about temperatures of formation of ancient sediments. The third section recounts the history of the earth’s climate and relates changes to the growth and movement of continents. This history takes us from the Archean, when climates are virtually unknown, through various stages in the evolution of organic life, and ultimately to the causes of the present glaciation in both the north and the south polar regions. The earth’s climate is controlled both by processes that would operate even if continents did not exist and also by the positions and topographies of continents. We begin with the general controls, then discuss the specific effects of continents, and close with a brief discussion of processes that cause glaciation. The general climate of the earth is determined by the variation in the amount of sunshine received at different latitudes, by the earth’s rotation, and by the amount of arriving solar energy that is retained in the atmosphere.

scholarly journals Effect Of Agrotechnical Measures And Varieties On Seasonal Dynamics Of Tetranychus Urticae Koch (Acari, Trombidiformes, Tetranychidae) On High Tunnel-Cultivated Garden Strawberries

2015 ◽  
Vol 69 (1-2) ◽  
pp. 45-49
Author(s):  
Ineta Salmane
Keyword(s):  
Tetranychus Urticae ◽  
Air Temperature ◽  
Spider Mite ◽  
Seasonal Pattern ◽  
Plant Cover ◽  
Climatic Conditions ◽  
Early Season ◽  
High Tunnel ◽  
Negative Effect ◽  
Two Spotted Spider Mite

Abstract The aim of the present study was to determine the seasonal pattern of two-spotted spider mite Tetranychus urticae on strawberries cultivated in polythene-covered high tunnels in temperate climatic conditions. Various cultivars were used and the effect of modification of plant covering indices on abundance and incidence of these mites was also tested. The number of two-spotted spider mites was relatively low at the beginning of the vegetation season and started to increase when average air temperature rose above 20 to 25 °C. In the experiment two types of tunnels differing in additional plant cover were used. The maximum mite abundance did not significantly vary between varieties in tunnel 1 conditions, but it was significantly lower for variety 'Sonata' in tunnel 2 conditions. Mite numbers significantly declined after strawberry foliage mowing and removal of polythene cover. Mite development was prolonged in tunnel 1, where additional cover of plants was used and higher early season air temperature was recorded in comparison to tunnel 2. It was concluded that increase in early season temperature can increase two-spotted spider mite abundance and have a more negative effect on strawberry plants in respect of foliage damage by mites.

scholarly journals Plant colonization, succession and ecosystem development on Surtsey with reference to neighbouring islands

2014 ◽  
Vol 11 (19) ◽  
pp. 5521-5537 ◽  
Author(s):  
B. Magnússon ◽  
S. H. Magnússon ◽  
E. Ólafsson ◽  
B. D. Sigurdsson
Keyword(s):  
Species Richness ◽  
Plant Biomass ◽  
Vascular Plant ◽  
Plant Cover ◽  
Soil Formation ◽  
Plant Succession ◽  
Permanent Plots ◽  
Plant Colonization ◽  
Nutrient Input ◽  
Species Richness And Diversity

Abstract. Plant colonization and succession on the volcanic island of Surtsey, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these, 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands, and all of their common species had established on Surtsey. The first colonizers were dispersed by sea, but, after 1985, bird dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007, there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls, dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliđaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliđaey was very dense and species-poor. It was dominated by Festuca and Poa, and very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca/Agrostis/Ranunculus). We forecast that, with continued erosion of Surtsey, loss of habitats and increasing impact from seabirds a lush, species-poor grassland will develop and persist, as on the old neighbouring islands.

scholarly journals Vegetation variability in Greece during the last interglacial

2000 ◽  
Vol 79 (2-3) ◽  
pp. 355-367 ◽  
Author(s):  
P.C. Tzedakis
Keyword(s):  
Late Glacial ◽  
Climatic Conditions ◽  
Last Interglacial ◽  
Regional Variability ◽  
Vegetation Development ◽  
Mixed Forests ◽  
Common Features ◽  
Central Greece ◽  
Environmental Setting ◽  
Short Episode

AbstractThe extent of regional variability in vegetation development in mainland Greece during the last interglacial is considered. Three pollen sequences – Ioannina (northwest Greece),Tenaghi Philippon (northeast Greece) and Kopais (central Greece) – all located in different environmental settings, extend into the last interglacial. Examination of the vegetation histories of the three sites during the last interglacial reveals the influence of local climatic conditions with closed mixed forests in the northwest, becoming progressively more open and less diverse farther to the east and south. All three sequences contain a number of similar trends, however, in the expansion of certain taxa. In addition, they also show the presence of a two-step late glacial interval, a short episode of forest reduction in the second part of the interglacial and a final small expansion of tree populations at the very end of the interglacial. Comparison with other European records shows a number of common features, but also suggests differences consistent with the particular environmental setting of the Greek sites.

Ecological Characteristics of Sites Invaded by Buffelgrass (Pennisetum ciliare)

2012 ◽  
Vol 5 (4) ◽  
pp. 443-453 ◽  
Author(s):  
Scott R. Abella ◽  
Lindsay P. Chiquoine ◽  
Dana M. Backer
Keyword(s):  
Seed Bank ◽  
Sonoran Desert ◽  
Native Species ◽  
Plant Cover ◽  
The United States ◽  
Slope Aspect ◽  
Plant Colonization ◽  
Native Plant ◽  
Organic C ◽  
Ecological Characteristics

AbstractUnderstanding the ecological characteristics of areas invaded and not invaded by exotic plants is a priority for invasive plant science and management. Buffelgrass is an invasive perennial species that managers view as a major threat to indigenous ecosystems of conservation lands in Australia, Mexico, the United States, and other locations where the species is not native. At 14 sites in Saguaro National Park in the Arizona Uplands of the Sonoran Desert, we compared the soil, vegetation, and soil seed bank of patches invaded and not invaded by buffelgrass. Abiotic variables, such as slope aspect and soil texture, did not differ between buffelgrass patches and patches without buffelgrass. In contrast, variables under primarily biotic control differed between patch types. Soil nutrients, such as organic C and NO3–N, were approximately twofold greater in buffelgrass compared with nonbuffelgrass patches. Average native species richness was identical (14 species 100 m−2) between patch types, but native plant cover was 43% lower in buffelgrass patches. Unexpectedly, native seed-bank densities did not differ significantly between patch types and were 40% greater than buffelgrass seed density below buffelgrass canopies. Results suggest that (1) soil nutrient status should not be unfavorable for native plant colonization at buffelgrass sites if buffelgrass is treated; (2) at least in the early stages of buffelgrass patch formation (studied patches were about 10 yr old), native vegetation species were not excluded, but rather, their cover was reduced; and (3) native soil seed banks were not reduced in buffelgrass patches.

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