134 Seasonal Variation in Composition and Total Load of Leaf Blade Epicuticular Waxes on Hosta

Hosta variants for epicuticular waxes were selected based on variation in surface glaucousness, from highly glaucous to highly glossy. In an effort to determine seasonal variation in hosta waxes, gas-chromatography mass-spectrometry was used to perform detailed chemical analysis of the adaxial and abaxial leaf blade waxes four times points during the growing season, early spring, mid-spring, mid-summer, and autumn. These studies revealed that in all variants, the total wax loads increased dramatically during the period of leaf expansion in the spring, dropped roughly five fold by midsummer, and then accumulated slightly above summer levels into the fall season. The dominant wax constituent class on all hosta cultivars was primary alcohols. Changes in these alcohols were primarily responsible for seasonal changes in total wax load. In some variants, the shorter chain length alcohols were unusually high compared with alcohol distributions normally found on other plants. Besides primary alcohols, significant amounts of acids, aldehydes, and alkanes, were also found and shown to vary during the growing season. A possible association between these seasonal changes in wax profiles and hosta resistance to slugs is discussed.

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Leaf blade and petiole nutritional evolution and variability throughout the crop season for Vitis vinifera L. cv. Graciano

Spanish Journal of Agricultural Research ◽

10.5424/sjar/2015133-5142 ◽

2015 ◽

Vol 13 (3) ◽

pp. e0801 ◽

Cited By ~ 4

Author(s):

Natalia Dominguez ◽

Enrique García-Escudero ◽

Izaskun Romero ◽

Ana Benito ◽

Ignacio Martín

Keyword(s):

Vitis Vinifera ◽

Seasonal Changes ◽

Leaf Blade ◽

Nutrient Concentration ◽

Growing Season ◽

Vitis Vinifera L ◽

Phenological Stage ◽

Font Size ◽

Crop Season ◽

Total N

<p>An adequate nutritional state of a crop can be kept by means of a well-designed fertilization plan based on the assessment of the nutrient availability throughout the growing season. The objective of this study was to determine the reliability of leaf blade and petiole diagnosis and the period of validity of their references at both flowering and veraison by means of systematic monitoring throughout the complete growing season. The study was carried out in two plots planted with <em>Vitis vinifera</em> L. cv. Graciano within the AOC Rioja (Spain). Blades and petioles were collected throughout a growing season (2006) and total N, P, K, Ca, Mg, Fe, Mn, Zn, Cu and B concentrations were analyzed in both tissues. Results suggest, in general, that petioles have higher variability and lower analysis reproducibility than blades. Therefore, blade could be a more appropriate tissue to evaluate N, P, K, Ca, and Mg at both flowering and veraison in this variety. Micronutrients in blade and petiole showed different variability behaviour in each of the vineyards studied, therefore, based on our results, it was difficult to determine which one could be the best tissue for the nutritional diagnosis of the ‘Graciano’ variety. Seasonal changes of nutrient concentration in both tissues also confirmed the need for reference values for each tissue and each phenological stage.</p>

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Epicuticular Waxes and Flavonol Aglycones of the European Mistletoe, Viscum album L.

Zeitschrift für Naturforschung C ◽

10.1515/znc-2000-5-602 ◽

2000 ◽

Vol 55 (5-6) ◽

pp. 314-317 ◽

Cited By ~ 9

Author(s):

Eckhard Wollenweber ◽

Anja Wieland ◽

Klaus Haas

Keyword(s):

Oleanolic Acid ◽

Seasonal Changes ◽

Viscum Album ◽

Epicuticular Waxes ◽

Main Constituent ◽

Primary Alcohols ◽

Cuticular Waxes ◽

Aliphatic Compounds

Cuticular waxes of Viscum album ssp. album contain oleanolic acid as main constituent, accompanied by aliphatic compounds like alkanes, esters and primary alcohols. A number of flavonol aglycones (methyl ethers of quercetin and kaempferol) have also been identified. Seasonal changes in amount and composition of cuticular waxes and the presence of flavonol aglycones are described and the ecophysiological significance of flavonoids on the surface of the mistletoe is briefly discussed.

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Seasonal Variation in Cuticular Waxes on Hosta Genotypes Differing in Leaf Surface Glaucousness

HortScience ◽

10.21273/hortsci.37.4.673 ◽

2002 ◽

Vol 37 (4) ◽

pp. 673-677 ◽

Cited By ~ 26

Author(s):

Matthew A. Jenks ◽

Carole H. Gaston ◽

Mark S. Goodwin ◽

Jessie A. Keith ◽

Rebecca S. Teusink ◽

...

Keyword(s):

Seasonal Variation ◽

Stress Resistance ◽

Seasonal Changes ◽

Leaf Surface ◽

Biotic And Abiotic Stress ◽

Primary Alcohols ◽

Cuticular Waxes ◽

Leaf Wax ◽

Leaf Surfaces ◽

Genotype A

Cuticular waxes were analyzed on abaxial and adaxial leaf surfaces of three Hosta genotypes differing in leaf surface glaucousness; the glossy-leaved Hosta plantaginea, the glossy-leaved Hosta lancifolia, and the glaucous-leaved Hosta `Krossa Regal'. All three hosta had their highest total leaf wax quantity in the spring soon after full leaf expansion. The major wax constituent class on these hosta was primary alcohols, comprising up to 84.6% of the total wax. Many hosta leaves had unusually high C24 length primary alcohols, especially in the spring. However, the dominant chain length in this alcohol class varied with development and genotype. A unique class of ß-diketones were present on the glaucous `Krossa Regal', comprising as much as 28.7% of the total waxes on abaxial leaf surfaces in the summer. Interestingly, these ß-diketones were only 0.9% of total waxes on adaxial leaf surfaces of `Krossa Regal' in the summer. Studies are under way to determine whether the dramatic seasonal changes in the waxy leaf coatings described in this report are associated with biotic and abiotic stress resistance in hosta.

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Epiphytic Communities On Posidonia Oceanica (L.) Delile Leaves Along The North Tyrrhenian Coasts (N.W. Mediterranean Sea, Italy)

Mediterranean Marine Science ◽

10.12681/mms.233 ◽

2003 ◽

Vol 4 (2) ◽

pp. 99 ◽

Cited By ~ 2

Author(s):

R. BEDINI ◽

M.G. CANALI ◽

M. BERTUCCELLI

Keyword(s):

Seasonal Variation ◽

Leaf Blade ◽

Quantitative Description ◽

Central Zone ◽

Posidonia Oceanica ◽

Early Spring ◽

The North ◽

Upper Limit ◽

Epiphytic Communities ◽

Different Levels

The structure of epiphytic communities was studied from February to November 2000 at three different levels (upper limit, lower limit, central zone) in depth (- 5 to – 26 m) in five Posidonia oceanica(L.) Delile 1813 Tuscany coast meadows: Rosignano, San Vincenzo, Piombino, Punta Ala, Portoferraio (Isle of Elba). The study was focused on leaf epiphytes and epifauna. Three shoots in three plots were collected randomly in each area (nine shoots per area) in each site of each meadow. A quantitative description of the epiphytes and epifauna was carried out, regarding the three groups: Algae, Hydroids and Bryozoans, both on the outer and the inner surfaces of the leaf blade. The dynamics of communities of the leaf-stratum along a bathymetric gradient showed a seasonal variation characterized by the highest richness of epiphytes mainly in the upper limit, especially in early spring. Significant differences were demonstrated for the epiphytic communities of the external leaf-stratum both on the upper and the central limit of the studied meadows.

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Seasonal changes in the major ash constituents of leaves and some woody components of trembling aspen and red osier dogwood

Canadian Journal of Botany ◽

10.1139/b78-215 ◽

1978 ◽

Vol 56 (15) ◽

pp. 1798-1803 ◽

Cited By ~ 8

Author(s):

T. D. W. James ◽

D. W. Smith

Keyword(s):

Populus Tremuloides ◽

Seasonal Changes ◽

Growing Season ◽

Early Spring ◽

Reverse Direction ◽

Trembling Aspen ◽

Southern Ontario ◽

Cornus Stolonifera ◽

Nutrient Changes ◽

Nutrient Variability

Concentrations of N, P, K, Ca, and Mg were determined at monthly intervals over the growing season in the leaves, twig bark, and twig wood of Populus tremuloides Michx. (trembling aspen) and in the leaves and stems of Cornus stolonifera Michx. (red osier dogwood) in southern Ontario. Concentrations of N, P, and K in the leaves of both species decreased from May to August. Levels of Mg and Ca increased. Nutrient changes in aspen twigs during the May to September period, with the exception of magnesium, followed the reverse direction to those in the leaves. Seasonal changes in all of the nutrients in twigs were very small. Seasonal nutrient variability in red osier stems was also slight, but concentrations of Mg and Ca showed a July peak, and K showed a peak in June. N and P declined from early spring to midsummer but by September in dogwood the levels had returned to the April values.

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Fire, land cover, and temperature drivers of bat activity in winter

Fire Ecology ◽

10.1186/s42408-021-00105-4 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Marcelo H. Jorge ◽

Sara E. Sweeten ◽

Michael C. True ◽

Samuel R. Freeze ◽

Michael J. Cherry ◽

...

Keyword(s):

Land Cover ◽

Habitat Management ◽

Deciduous Forest ◽

Pinus Palustris ◽

Growing Season ◽

Early Spring ◽

Bat Activity ◽

White Nose Syndrome ◽

Dormant Season ◽

Wind Energy Development

Abstract Background Understanding the effects of disturbance events, land cover, and weather on wildlife activity is fundamental to wildlife management. Currently, in North America, bats are of high conservation concern due to white-nose syndrome and wind-energy development impact, but the role of fire as a potential additional stressor has received less focus. Although limited, the vast majority of research on bats and fire in the southeastern United States has been conducted during the growing season, thereby creating data gaps for bats in the region relative to overwintering conditions, particularly for non-hibernating species. The longleaf pine (Pinus palustris Mill.) ecosystem is an archetypal fire-mediated ecosystem that has been the focus of landscape-level restoration in the Southeast. Although historically fires predominately occurred during the growing season in these systems, dormant-season fire is more widely utilized for easier application and control as a means of habitat management in the region. To assess the impacts of fire and environmental factors on bat activity on Camp Blanding Joint Training Center (CB) in northern Florida, USA, we deployed 34 acoustic detectors across CB and recorded data from 26 February to 3 April 2019, and from 10 December 2019 to 14 January 2020. Results We identified eight bat species native to the region as present at CB. Bat activity was related to the proximity of mesic habitats as well as the presence of pine or deciduous forest types, depending on species morphology (i.e., body size, wing-loading, and echolocation call frequency). Activity for all bat species was influenced positively by either time since fire or mean fire return interval. Conclusion Overall, our results suggested that fire use provides a diverse landscape pattern at CB that maintains mesic, deciduous habitat within the larger pine forest matrix, thereby supporting the diverse bat community at CB during the dormant season and early spring.

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Chemical Composition and Antimicrobial Activities of the Essential Oil From the Leaves of Pterocephalus hookeri

Natural Product Communications ◽

10.1177/1934578x20981239 ◽

2020 ◽

Vol 15 (12) ◽

pp. 1934578X2098123

Author(s):

Peng-fei Yang ◽

Hui Lu ◽

Qiong-bo Wang ◽

Zhi-wei Zhao ◽

Qiang Liu ◽

...

Keyword(s):

Gas Chromatography ◽

Chemical Composition ◽

Essential Oil ◽

Chemical Constituents ◽

Antimicrobial Activities ◽

Gas Chromatography Mass Spectrometry ◽

Flame Ionization ◽

And Staphylococcus Aureus ◽

Antimicrobial Assay ◽

Detailed Chemical

Detailed chemical constituents of essential oil from the Pterocephalus hookeri leaves and its antimicrobial activities were investigated in this study. The essential oil, obtained by hydrodistillation, was characterized by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analyses. Among the 90 identified compounds, hexadecanoic acid (21.27%), phytol (8.03%), furfural (7.08%), oleic acid (5.25%), and phytone (4.56%) were the major components. In the antimicrobial assay, the essential oil showed strong inhibitory activities against Escherichia coli, Candida albicans, and Staphylococcus aureus with minimum inhibitory concentration values of 31.3, 62.5, and 125 µg/mL, respectively. To our knowledge, this is the first report concerning chemical composition and antimicrobial activities of the essential oil from Pterocephalus hookeri.

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Effect of thinning intensity on understory herbaceous diversity and biomass in mixed coniferous and broad-leaved forests of Changbai Mountain

Forest Ecosystems ◽

10.1186/s40663-021-00331-x ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Gerong Wang ◽

Yue Sun ◽

Mo Zhou ◽

Naiqian Guan ◽

Yuwen Wang ◽

...

Keyword(s):

Seasonal Changes ◽

Mixed Forest ◽

Growing Season ◽

Total Biomass ◽

Herb Layer ◽

Simpson Index ◽

Thinning Intensity ◽

Ground Biomass ◽

Below Ground ◽

Understory Herb

Abstract Background Herbs are an important part of the forest ecosystem, and their diversity and biomass can reflect the restoration of vegetation after forest thinning disturbances. Based on the near-mature secondary coniferous and broad-leaved mixed forest in Jilin Province Forestry Experimental Zone, this study analyzed seasonal changes of species diversity and biomass of the understory herb layer after different intensities of thinning. Results The results showed that although the composition of herbaceous species and the ranking of importance values were affected by thinning intensity, they were mainly determined by seasonal changes. Across the entire growing season, the species with the highest importance values in thinning treatments included Carex pilosa, Aegopodium alpestre, Meehania urticifolia, and Filipendula palmata, which dominated the herb layer of the coniferous and broad-leaved mixed forest. The number of species, Margalef index, Shannon-Wiener index and Simpson index all had their highest values in May, and gradually decreased with months. Pielou index was roughly inverted “N” throughout the growing season. Thinning did not increase the species diversity. Thinning can promote the total biomass, above- and below-ground biomass. The number of plants per unit area and coverage were related to the total biomass, above- and below-ground biomass. The average height had a significantly positive correlation with herb biomass in May but not in July. However, it exerted a significantly negative correlation with herb biomass in September. The biomass in the same month increased with increasing thinning intensity. Total herb biomass, above- and below-ground biomass showed positive correlations with Shannon-Winner index, Simpson index and Pielou evenness index in May. Conclusions Thinning mainly changed the light environment in the forest, which would improve the plant diversity and biomass of herb layer in a short time. And different thinning intensity had different effects on the diversity of understory herb layer. The findings provide theoretical basis and reference for reasonable thinning and tending in coniferous and broad-leaved mixed forests.

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Seasonal feeding plasticity can facilitate coexistence of dominant omnivores in Neotropical streams

Reviews in Fish Biology and Fisheries ◽

10.1007/s11160-021-09648-w ◽

2021 ◽

Author(s):

Mayara P. Neves ◽

Pavel Kratina ◽

Rosilene L. Delariva ◽

J. Iwan Jones ◽

Clarice B. Fialho

Keyword(s):

Seasonal Variation ◽

Fish Species ◽

Resource Availability ◽

Seasonal Changes ◽

Dry Season ◽

Diet Overlap ◽

Isotopic Niche ◽

Neotropical Streams ◽

Feeding Plasticity ◽

The Impact

AbstractCoexistence of ecomorphologically similar species in diverse Neotropical ecosystems has been a focus of long-term debate among ecologists and evolutionary biologists. Such coexistence can be promoted by trophic plasticity and seasonal changes in omnivorous feeding. We combined stomach content and stable isotope analyses to determine how seasonal variation in resource availability influences the consumption and assimilation of resources by two syntopic fish species, Psalidodon aff. gymnodontus and P. bifasciatus, in the Lower Iguaçu basin. We also tested the impact of seasonality on trophic niche breadth and diet overlap of these two dominant omnivores. Seasonal changes in resource availability strongly influenced the consumption and assimilation of resources by the two fish species. Both species exhibited high levels of omnivory, characterized by high diversity of allochthonous resources in the wet season. Terrestrial invertebrates were the main component of diet during this season. However, in the dry season, both species reduced their isotopic niches, indicating diet specialization. High diet overlap was observed in both seasons, but the isotopic niche overlap was smaller in the dry season. Substantial reduction in the isotopic niche of P. bifascistus and a shift toward aquatic invertebrates can facilitate coexistence during this season of resource shortage. Feeding plasticity allows omnivorous fish to adjust their trophic niches according to seasonality, promoting the exploitation of different resources during periods of greater resource diversity. This seasonal variation could be an important mechanism that contributes to the resource partitioning and coexistence of dominant omnivores in Neotropical streams.

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The effects of burning on Festuca hallii in the parklands of central Alberta

Canadian Journal of Botany ◽

10.1139/b95-102 ◽

1995 ◽

Vol 73 (6) ◽

pp. 937-942 ◽

Cited By ~ 8

Author(s):

Heather Sinton Gerling ◽

Arthur W. Bailey ◽

Walter D. Willms

Keyword(s):

Standing Crop ◽

Growing Season ◽

Early Spring ◽

Leaf Length ◽

Tiller Number ◽

Phenological Stages ◽

University Of Alberta ◽

Festuca Hallii ◽

Tiller Density ◽

The University

The response of Festuca hallii (Vassey) Piper to time of burning was examined on the Festuca–Stipa grasslands of the Aspen Parklands at the University of Alberta Ranch located 150 km southeast of Edmonton, Alberta. Two defoliation treatments (burning and mowing) were examined on five dates in 1978 (8 April, 27 April, 1 June, 31 July, and 18 October), corresponding to different phenological stages of F. hallii. Burning and mowing reduced the standing crop of F. hallii produced in the first growing season after treatment, but tiller densities increased. Defoliation in early spring (8 April) had little effect on the standing crop; apparently the increase in tiller density compensated for the reduction in tiller length. Inflorescence density also increased following burning or mowing from 8 April to 1 June. Soil temperature (3 cm deep) on previously burned or mown sites was greater than on the control the year after treatment. Festuca hallii tolerates single burns at any time of the year, but early spring fires have the greatest benefits by increased tillering and standing crop. Key words: standing crop, tiller number, leaf length, litter, defoliation, mowing.

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