scholarly journals Large-scale vs. small-scale factors affecting flowering patterns in Senecio macrophyllus M.BIEB., a long-lived perennial

2012 ◽  
Vol 59 (1) ◽  
pp. 233-239 ◽  
Author(s):  
Bożenna Czarnecka
Keyword(s):  
Soil Moisture ◽  
Environmental Factors ◽  
Light Intensity ◽  
Large Scale ◽  
Climatic Factors ◽  
Small Scale ◽  
Herbaceous Plant ◽  
Factors Affecting ◽  
Reproductive Patterns ◽  
Scale Factors

The aim of the study was to establish which of environmental factors affect flowering patterns in a long-lived herbaceous plant <i>Senecio macrophyllus</i>. The study was conducted in the population of Biała Góra (White Mountain) near Tomaszów Lubelski in the years 1989-2004. The results allow to conclude that in the reproductive patterns of the analysed population small-scale environmental factors (soil moisture and trophism, light intensity) are more important than large-scale climatic factors (temperature, precipitation), which to a comparable extent affect the plants in the whole population area.

Species Responses to Grazing and Environmental-Factors in an Arid Halophytic Shrubland Community

1987 ◽  
Vol 35 (2) ◽  
pp. 135 ◽  
Author(s):  
RB Hacker
Keyword(s):  
Environmental Factors ◽  
Soil Salinity ◽  
Large Scale ◽  
Chemical Properties ◽  
Grazing Pressure ◽  
Aerial Photographs ◽  
Small Scale ◽  
Factors Affecting ◽  
Species Responses

Species responses to grazing and environmental factors were studied in an arid halophytic shrubland community in Western Australia. The grazing responses of major shrub species were defined by using reciprocal averaging ordination of botanical data, interpreted in conjunction with a similar ordination of soil chemical properties and measures of soil erosion derived from large-scale aerial photographs. An apparent small-scale interaction between grazing and soil salinity was also defined. Long-term grazing pressure is apparently reduced on localised areas of high salinity. Environmental factors affecting species distribution are complex and appear to include soil salinity, soil cationic balance, geomorphological variation and the influence of cryptogamic crusts on seedling establishment.

scholarly journals Caracterización ficológica en manantiales de la cuenca baja del sistema hidrológico del Pánuco, México

2017 ◽  
pp. 21 ◽  
Author(s):  
Javier Carmona-Jiménez ◽  
Gustavo Montejano-Zurita
Keyword(s):  
Environmental Factors ◽  
Light Intensity ◽  
Current Velocity ◽  
Growth Forms ◽  
Factors Affecting ◽  
Similarities And Differences ◽  
The Relationship

The results of a phycofloristic study on three springs in the Huasteca Potosina region are presented; 67 species are reported. Floristic similarities and differences among the springsare analized, as well as the relationship between species and environmental factors. Microhabitas were defined in the springs as well as the principal algal asociations that characterize them. Light intensity and current velocity are the most important factors affecting the predominant growth forms present in this type of habitat.

scholarly journals Changes in Metabolome and Nutritional Quality of Lycium barbarum Fruits from Three Typical Growing Areas of China as Revealed by Widely Targeted Metabolomics

Metabolites ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 46 ◽  
Author(s):  
Yajun Wang ◽  
Xiaojie Liang ◽  
Yuekun Li ◽  
Yunfang Fan ◽  
Yanlong Li ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Light Intensity ◽  
Nutritional Quality ◽  
Climatic Factors ◽  
Northwest China ◽  
High Light Intensity ◽  
Climatic Conditions ◽  
Targeted Metabolomics ◽  
Lycium Barbarum ◽  
Widely Targeted Metabolomics

This study aimed at assessing the climatic factors influencing the wolfberry fruit morphology, and the composition of its nutritious metabolites. The cultivar Ningqi1, widely grown in Northwest China was collected from three typical ecological growing counties with contrasting climatic conditions: Ningxia Zhongning (NF), Xinjiang Jinghe (XF) and Qinghai Nomuhong (QF). During the ripening period, 45 fruits from different plantations at each location were sampled. A total of 393 metabolites were detected in all samples through the widely targeted metabolomics approach and grouped into 19 known classes. Fruits from QF were the biggest followed by those from XF and NF. The altitude, relative humidity and light intensity had negative and strong correlations with most of the metabolites, suggesting that growing wolfberry in very high altitudes and under high light intensity is detrimental for the fruit nutritional quality. Soil moisture content is highly and negatively correlated with vitamins, organic acids and carbohydrates while moderately and positively correlated with other classes of metabolites. In contrast, air and soil temperatures exhibited positive correlation with majority of the metabolites. Overall, our results suggest high soil and air temperatures, low altitude and light intensity and moderate soil moisture, as the suitable conditions to produce Lycium fruits with high content of nutritious metabolites.

scholarly journals Experimental insights into consolidation rates during one-dimensional loading with special reference to excess pore water pressure

2020 ◽  
Vol 15 (12) ◽  
pp. 3571-3591
Author(s):  
Bartłomiej Szczepan Olek
Keyword(s):  
Pore Water ◽  
Large Scale ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Small Scale ◽  
Coefficient Of Consolidation ◽  
Consolidation Process ◽  
Factors Affecting ◽  
Fine Grained ◽  
Fine Grained Soil

AbstractConsolidation rate has significant influence on the settlement of structures founded on soft fine-grained soil. This paper presents the results of a series of small-scale and large-scale Rowe cell consolidation tests with pore water pressure measurements to investigate the factors affecting the consolidation process. Permeability and creep/resistance structure factors were considered as the governing factors. Intact and reconstituted marine clay from the Polish Carpathian Foredeep basin as well as clay–sand mixtures was examined in the present study. The fundamental relationship correlating consolidation degrees based on compression and pore water pressure was assessed to indicate the nonlinear soil behaviour. It was observed that the instantaneous consolidation parameters vary as the process progresses. The instantaneous coefficient of consolidation first drastically increases or decreases with increase in the degree of consolidation and stabilises in the middle stage of the consolidation; it then decreases significantly due to viscoplastic effects occurring in the soil structure. Based on the characteristics of the relationship between coefficient of consolidation and degree of dissipation at the base, the consolidation range that complies with theoretical assumptions was established. Furthermore, the influence of coarser fraction in clay–sand mixtures in controlling the consolidation rates is discussed.

The Factors Affecting the Stem Water Potential of Tamarix ramosissima Lbd. in the Extremely Arid Regions

2013 ◽  
Vol 800 ◽  
pp. 143-148 ◽  
Author(s):  
Ai Hong Fu ◽  
Wei Hong Li ◽  
Ya Ning Chen
Keyword(s):  
Soil Moisture ◽  
Environmental Factors ◽  
Water Potential ◽  
Arid Regions ◽  
Normal Growth ◽  
Tamarix Ramosissima ◽  
Tarim River ◽  
Stem Water Potential ◽  
Factors Affecting ◽  
Stem Water

Using Tamarix ramosissima Lbd. growing in the extremely arid regions along the lower reaches of Tarim River, Xinjiang, we preformed a series of investigations on the effects of weather, soil moisture and salt on the stem water potential (ψs) of T. ramosissima. We identified the leading environmental factors affecting ψs of T. ramosissima and detected the thresholds of the environmental factors. First, the soil moisture was the most important factor affecting ψs of T. ramosissima among all the environmental factors. While there was no minimum threshold of the soil moisture for T. ramosissima to absorb moisture from soil, the highest threshold of the soil moisture was 36%. When the soil moisture was higher than 36%, there was a significant change on ψs of T. ramosissima. Our study provides crucial empirical data for keeping the normal growth of T. ramosissima.

scholarly journals Environmental factors affecting the success of exotic plant invasion in a wildland-urban ecotone in temperate South America

2019 ◽  
Vol 14 (2) ◽  
pp. 257-274
Author(s):  
Romina Paola Nievas ◽  
Mirian Roxana Calderon ◽  
Marta Matilde Moglia
Keyword(s):  
Soil Moisture ◽  
Environmental Factors ◽  
Environmental Variables ◽  
Anthropogenic Disturbance ◽  
Plant Invasion ◽  
Exotic Plants ◽  
Scaling Analysis ◽  
Exotic Plant ◽  
Factors Affecting ◽  
Exotic Plant Invasion

Urbanization is one of the main causes driving changes in biodiversity patterns and it is regarded as a major threat to native biota. Successful exotic plant invasion depends on invasiveness and invasibility. Invasiveness is related to the characteristics of exotic plants and invasibility to the features of the sites. The objective of this study was to identify the invasibility environmental factors affecting the success of exotic plant invasion in a wildland-urban ecotone of the central region of Argentina (Potrero de los Funes Village, San Luis). Fifty phytosociological inventories were recorded in an area of 700 ha during spring and summer seasons (2013–2015). Abundance-coverage values of plants and environmental variables such as soil characteristics, anthropogenic disturbance, and altitude of the sites were assessed. Soil moisture, electrical conductivity (EC), acidity (pH), organic matter content, and nitrates were determined as part of the soil analysis. A Nonmetric Multidimensional Scaling analysis was used to identify the possible relationship between abundance-coverage of the vegetation and environmental variables. Abundance-coverage of exotic plants was positively influenced by anthropogenic disturbance and nitrate levels, and negatively affected by altitude. However, no significant correlation was found between percentage of exotic plants and pH, EC, or soil moisture. Thus, urbanization and touristic activities influenced the success of exotic plant invasion.

Distribution of annual Trifolium species in Morocco

1993 ◽  
Vol 44 (6) ◽  
pp. 1303 ◽  
Author(s):  
PE Beale ◽  
M Bounejmate ◽  
A Lahlou ◽  
DB Marx ◽  
S Christiansen
Keyword(s):  
Environmental Factors ◽  
Seed Yield ◽  
Phosphorus Content ◽  
Climatic Factors ◽  
Natural Distribution ◽  
Factors Affecting ◽  
Determinant Factors ◽  
Number Of Species ◽  
The Relationship

An ecogeographic survey was conducted in six key agricultural zones in Morocco to study the abundance and the relationship between the natural distribution of annual Trifolium species and environmental factors. Sixteen species of annual Trifolium species were identified. Most prolific was T. scabrum and the least were T. striatum and T. bocconei. Fifty-five percent of the sites had no Trifolium and the average number of species per site was 2.2. An average seed yield of 4.8 kg ha-1 was obtained. Both soil and climatic factors affected the occurrence of Trifolium species. Rainfall, pH and phosphorus content were the most determinant factors affecting the distribution of Trifolium species in Morocco.

Relationships between Alaskan salmon catch and North Pacific climate on interannual and interdecadal time scales

1998 ◽  
Vol 55 (10) ◽  
pp. 2255-2265 ◽  
Author(s):  
Mary W Downton ◽  
Kathleen A Miller
Keyword(s):  
Time Scales ◽  
North Pacific ◽  
Large Scale ◽  
Climatic Factors ◽  
Multivariate Time Series ◽  
Pink Salmon ◽  
Egg Survival ◽  
Commercial Catch ◽  
Factors Affecting ◽  
The North

Using multivariate time series models, Alaska's statewide commercial catch of three salmon species during 1925-1994 is shown to be related to surface temperatures in particular large regions of the eastern North Pacific. Previous research has indicated that interdecadal changes in Alaskan catch levels are related to large-scale changes in the climate regime of the North Pacific. The present work focuses on interannual variability by controlling for climatic shifts in the mid-1940s and mid-1970s. For sockeye (Oncorhynchus nerka) and chum (O. keta), relationships with temperature occur within a few months after ocean entry with warmer regional temperatures enhancing survival. For sockeye and pink salmon (O. gorbuscha), relationships with temperature occur at the time and location of the return migration, suggesting that colder ocean temperatures may enhance spawning success or egg survival. In addition, the models show a significant positive relationship of chum catch to pink catch 2 years earlier, suggesting a common influence on smolts of the two species. The results support the contention that climatic factors affecting the marine environment play a significant role in salmon production on interannual, as well as interdecadal, time scales.

scholarly journals The first century of Phalaris aquatica L. cultivation and genetic improvement: a review

2009 ◽  
Vol 60 (1) ◽  
pp. 1 ◽  
Author(s):  
R. N. Oram ◽  
V. Ferreira ◽  
R. A. Culvenor ◽  
A. A. Hopkins ◽  
A. Stewart
Keyword(s):  
South Africa ◽  
New Zealand ◽  
Large Scale ◽  
Small Scale ◽  
Scale Production ◽  
Department Of Agriculture ◽  
Factors Affecting ◽  
Phalaris Aquatica ◽  
Seed Retention ◽  
The Usa

2006 marked the centenary of the commercial propagation of phalaris (Phalaris aquatica L.) as a cultivated pasture plant, firstly in Australia, and soon after in New Zealand, South Africa, and North and South America. Small-scale evaluation of cv. Australian began in the Toowoomba Botanic Gardens, Queensland, in 1884. The first recorded large-scale production of seed was at the Glen Innes Research Farm of the NSW Department of Agriculture in February 1906. By 1908–15, several graziers in Australia and New Zealand sold seed widely within Australia, New Zealand, USA, Argentina, and South Africa. Factors affecting the utilisation of the original cultivar in Australia over the first half-century are reviewed. Thereafter, the need to extend the area of perennial pastures into regions unsuitable for cv. Australian led CSIRO and the US Department of Agriculture to collect germplasm widely in the Mediterranean region. Selection between and within Moroccan populations produced cvv. Sirocco and El Golea in Australia, and cv. Perla koleagrass in the USA. In Argentina, selection within cv. Australian produced the very successful, seed-retaining cv. Pergamino El Gaucho INTA, which was re-selected in Australia to produce cv. Seedmaster. The discovery of a single seed-retaining plant within a certified line of cv. Australian gave cv. Uneta, which had excellent seed retention because the rachillae of most seeds remained intact at maturity. In Australia, selection in populations derived from crosses between cv. Australian and Mediterranean ecotypes gave a succession of winter-active cultivars: Sirosa, Sirolan, Holdfast, Landmaster, Atlas PG, Advanced AT, and Holdfast GT. The latter 5 have Uneta-type seed retention, reduced tryptamine and tyramine alkaloids, and adaptation to different soil and climatic niches. Populations for the hotter, drier inland slopes of NSW are being field-tested. Also, a promising but unstable semi-dwarf line has been found: dwarfism appears to be caused by a transposable element. Breeding and selection programs in Argentina, several states of the USA, New Zealand, Israel, Tunisia, and Greece also produced cultivars with specific adaptations. Active breeding programs are continuing at Ardmore, OK, USA, and Pergamino, Argentina. A major remaining obstacle to the further improvement and utilisation of phalaris is the unknown chemical nature of the toxin(s) causing ‘sudden death’, which temporarily interfere with nitrogen metabolism in the brains of herbivores, especially ruminants.

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