scholarly journals Flowering Phenology Adjustment and Flower Longevity in a South American Alpine Species

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 461
Author(s):  
Mary T. K. Arroyo ◽  
Ítalo Tamburrino ◽  
Patricio Pliscoff ◽  
Valeria Robles ◽  
Maria Colldecarrera ◽  
...  
Keyword(s):  
Natural Populations ◽  
Flowering Phenology ◽  
Snow Accumulation ◽  
Growth Potential ◽  
Controlled Study ◽  
Temperature Threshold ◽  
Flower Longevity ◽  
Passive Warming ◽  
Alpine Species ◽  
Flowering Onset

Delayed flowering due to later snowmelt and colder temperatures at higher elevations in the alpine are expected to lead to flowering phenological adjustment to prevent decoupling of peak flowering from the warmest time of the year, thereby favoring pollination. However, even if flowering is brought forward in the season at higher elevations, an elevational temperature gap is likely to remain between the high- and low-elevation populations of a species at the time these reach peak flowering on account of the atmospheric reduction in temperature with increasing elevation. The negative effect of this temperature gap on pollination could be compensated by plastically-prolonged flower life spans at higher elevations, increasing the probability of pollination. In a tightly temperature-controlled study, the flowering phenology adjustment and flower longevity compensation hypotheses were investigated in an alpine species in the Andes of central Chile. The snow free period varied from 7 to 8.2 months over 810 m elevation. Temperatures were suitable for growth on 82–98% of the snow free days. Flowering onset was temporally displaced at the rate of 4.6 d per 100 m increase in elevation and flowering was more synchronous at higher elevations. Flowering phenology was adjusted over elevation. The latter was manifest in thermal sums tending to decrease with elevation for population flowering onset, 50% flowering, and peak flowering when the lower thermal limit for growth (TBASE) was held constant over elevation. For TBASE graded over elevation so as to reflect the growing season temperature decline, thermal sums did not vary with elevation, opening the door to a possible elevational decline in the thermal temperature threshold for growth. Potential flower longevity was reduced by passive warming and was more prolonged in natural populations when temperatures were lower, indicating a plastic trait. Pollination rates, as evaluated with the Relative Pollination Rate index (RPR), when weighted for differences in floral abundance over the flowering season, declined with elevation as did fruit set. Contrary to expectation, the life-spans of flowers at higher elevations were not more prolonged and failed to compensate for the elevational decrease in pollination rates. Although strong evidence for phenological adjustment was forthcoming, flower longevity compensation did not occur over Oxalis squamata’s elevational range. Thus, flower longevity compensation is not applicable in all alpine species. Comparison with work conducted several decades ago on the same species in the same area provides valuable clues regarding the effects of climate change on flowering phenology and fitness in the central Chilean alpine where temperatures have been increasing and winter snow accumulation has been declining.

scholarly journals Temperature-driven flower longevity in a high-alpine species ofOxalisinfluences reproductive assurance

2013 ◽  
Vol 200 (4) ◽  
pp. 1260-1268 ◽  
Author(s):  
Mary T. K. Arroyo ◽  
Leah S. Dudley ◽  
Gus Jespersen ◽  
Diego A. Pacheco ◽  
Lohengrin A. Cavieres
Keyword(s):  
Flower Longevity ◽  
Reproductive Assurance ◽  
Alpine Species

Environmental and genetic influences on phenology and plant size in a perennial herb, Senecio integrifolius

1991 ◽  
Vol 69 (1) ◽  
pp. 209-217 ◽  
Author(s):  
Björn Widén
Keyword(s):  
Natural Population ◽  
Rank Order ◽  
Natural Populations ◽  
Flowering Phenology ◽  
Plant Size ◽  
Genetic Influences ◽  
Perennial Herb ◽  
Cultivated Plants ◽  
Mother Plants ◽  
Progeny Size

Individual plants of the perennial herb Senecio integrifolius showed a highly significant correlation between rank order of the dates of first flowering and of first fruiting in a natural population and in cultivation. Plants exposed to full sunshine were smaller and flowered earlier than shaded plants both in a natural population and in cultivation. Within the two groups, plants with large inflorescences started to flower first. Duration of flowering was regulated by the size of the inflorescence; plants with many heads flowered longer than plants with few heads. There was a significant correlation between phenological rank order of mother plants in natural populations and their progenies in cultivation, but no consistent relationship between mother size and progeny size was found. Cultivated plants were consistent in rank order of flowering and in size over the years. Key words: flowering phenology, plant size, genetic variation, Senecio.

scholarly journals Cool–Warm Temperature Stratification and Simulated Bird Digestion Optimize Removal of Dormancy in Rosa rugosa Seeds

2022 ◽  
Vol 12 ◽  
Author(s):  
Peng Gao ◽  
Jie Dong ◽  
Sihan Wang ◽  
Wuhua Zhang ◽  
Tao Yang ◽  
...  
Keyword(s):  
Water Absorption ◽  
Seed Dormancy ◽  
Global Climate ◽  
Natural Populations ◽  
Suitable Condition ◽  
Growth Potential ◽  
Cold Stratification ◽  
Rosa Rugosa ◽  
Physiological Dormancy ◽  
Mechanical Constraint

Rosa rugosa Thunb. has been explored multi-function in medicinal, edible, cosmetic, ornamental and ecological etc. However, R. rugosa natural populations have recently declined substantially in China, besides of global climate change, this species also has the defect of limiting the reproduction of itself such as the hard-to-release seed dormancy. In this study, only 30% of R. rugosa seeds were viable, and the others were incompletely developed or diseased seeds. Without stratification, morphologically complete viable seeds imbibed water but those seeds could not germinate even after seed husk removal under suitable condition to exhibit a physiological dormancy. After cold (4°C) and warm (18 ± 2°C) stratification, macromolecular substances containing carbon or nitrogen accumulated, and respiration, antioxidant enzyme activity, and gibberellin (GA3) /abscisic acid (ABA) and auxin (IAA)/ABA ratios increased significantly in seeds. Water absorption also increased as endocarps softened. Thus, physiological dormancy of seed was broken. Although warm and cold stratification increased separation between endocarp and embryo, the endocarp binding force was removed insufficiently, because only 10.20% of seeds germinated. Therefore, stratified seeds were treated with simulated bird digestion. Then, folds and cracks in loosened endocarps increased permeability, and water absorption rate increased to 64.43% compare to 21.14% in cold and warm stratification treatment. With simulated digestion, 24.20% of radicles broke through the endocarp with plumules and cambiums to develop into seedlings. Thus, the seed dormancy type of R. rugosa is physiological as seeds imbibed water and possessed fully developed embryos with a low growth potential in combination with a mechanical constraint from the endocarp. Cold stratification helped remove physiological dormancy, and additional warm stratification accelerated the process. The optimal stratification treatment was 4°C for 45 days followed by 18 ± 2°C for 15 days. After warm and cold stratification, simulated bird digestion broke the mechanical constraint from the seed covering layers. Based on this research, production of R. rugosa seedlings can be greatly increased to help protect the species from further declines.

scholarly journals Long-term effects of snowmelt timing and climate warming on phenology, growth and reproductive effort of arctic tundra plant species

2021 ◽  
Author(s):  
Esther R. Frei ◽  
Greg H.R. Henry
Keyword(s):  
Plant Species ◽  
Reproductive Effort ◽  
High Arctic ◽  
Snow Accumulation ◽  
The Arctic ◽  
Plant Responses ◽  
Long Term Effects ◽  
Passive Warming ◽  
Species Specific

Arctic regions are particularly affected by rapidly rising temperatures and altered snow regimes. Snowmelt timing depends on spring temperatures and winter snow accumulation. Scenarios for the Arctic include both decreases and increases in snow accumulation. Predictions of future snowmelt timing are thus difficult and experimental evidence for ecological consequences is scarce. In 1995, a long-term factorial experiment was set up in a High Arctic evergreen shrub heath community on Ellesmere Island, Canada. We investigated how snow removal, snow addition and passive warming affected phenology, growth and reproductive effort of the four common tundra plant species <i>Cassiope tetragona</i>, <i>Dryas integrifolia</i>, <i>Luzula arctica</i> and <i>Papaver radicatum</i>. Timing of flowering and seed maturation as well as flower production were more strongly influenced by the combined effects of snowmelt timing and warming in the two shrub species than in the two herbaceous species. Warming effects persisted over the course of the growing season and resulted in increased shrub growth. Moreover, the long-term trend of increasing growth in two species suggests that ambient warming promotes tundra plant growth. Our results confirm the importance of complex interactions between temperature and snowmelt timing in driving species-specific plant responses to climate change in the Arctic.

The Timing and Patterning of Flowering

2011 ◽  
Author(s):  
Pat Willmer
Keyword(s):  
Reproductive Success ◽  
Plant Species ◽  
Flowering Phenology ◽  
Flowering Period ◽  
Flower Longevity ◽  
Pollen Transfer ◽  
Flowering Pattern ◽  
Floral Longevity ◽  
Pollen Receipt

This chapter examines the factors that affect the timing and patterning of flowering, as well as the effects of different flowering patterns on pollination outcomes. Plants should flower in ways that maximize their own reproductive success. The “flowering pattern” is a composite of the timing and frequency of individual flowers opening, and also of floral longevity. These phenological factors vary between and within species. Flowering phenology can influence the plant’s manipulation of its visitors in ways that should increase either or both of pollen transfer and pollen receipt. The chapter first considers the frequency of flowering and the shape of the flowering period before discussing flower longevity and flowering period. It also explores the question of how big a flower should be, how many flowers a plant should have at any one time, what determines the phenological parameters for a particular plant species, and where the flowers should be placed.

Importance of natural cloud regimes to ecophysiology in the alpine species, Caltha leptosepala and Arnica parryi, Snowy Range Mountains, southeast Wyoming, USA

2015 ◽  
Vol 42 (2) ◽  
pp. 186 ◽  
Author(s):  
Adriana Sanchez ◽  
Nicole M. Hughes ◽  
William K. Smith
Keyword(s):  
Convective Cloud ◽  
Snow Accumulation ◽  
Cloud Formation ◽  
South Central ◽  
Fluorescence Measurements ◽  
Winter Snow ◽  
Alpine Species ◽  
Central Rocky Mountains ◽  
Cloud Patterns ◽  
Associated Species

The south-central Rocky Mountains, USA, are characterised by a dry, continental mesoclimate with typical convective cloud formation during the afternoon. Little is known about the specific influence of such predictable cloud patterns on the microclimate and ecophysiology of associated species. During the summer of 2012, days with afternoon clouds were most common (50% of all days) compared with completely clear (24%) or cloudy days (6.5%). In two representative alpine species, Caltha leptosepala DC. and Arnica parryi A. Gray, fully overcast days reduced mean daily photosynthesis (A) by nearly 50% relative to fully clear days. Mean afternoon A was significantly lower on fully cloudy days relative to days with afternoon clouds only or no clouds in both species. Notably, A did not differ during afternoon cloud days relative to clear afternoons. Afternoon clouds significantly reduced transpiration (E) in C. leptosepala relative to clear days, and both species showed mean reductions in plant water stress (i.e. higher Ψ), though this difference was not significant. Water use efficiency (WUE) (A/E) decreased from morning to afternoon, especially on cloudy days, and the presence of clouds had a positive effect on the light reactions of photosynthesis based on fluorescence measurements (Fv′/Fm′), in both species. Cloudy days were characterised by higher Fv/Fm than afternoon clouds and clear days during both the morning and the afternoon (especially for A. parryi) and recovery to near pre-dawn values for cloudy and afternoon cloud day types, but not clear days. Overall, similar ecophysiological advantages of this typical afternoon cloud pattern was apparent in both species, although their spatial microsite differences related to winter snow accumulation may also play an important role.

scholarly journals MODELING DEMOGRAPHIC RESPONSE TO CONSTANT TEMPERATURE IN BRYOBIA RUBRIOCULUS (ACARI: TETRANYCHIDAE)

2014 ◽  
Vol 1 (1) ◽  
pp. 18-29
Author(s):  
Saeid Javadi Khederi ◽  
Mohammad Khanjani
Keyword(s):  
Population Growth ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Growth Potential ◽  
Distribution Model ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Immature Stages ◽  
Net Reproductive Rate ◽  
Rate Of Increase

The demographic parameters of brown mite, Bryobia rubrioculus Scheuten were carried out in order to characterize the population growth potential at five constant temperatures: 20, 22.5, 25, 27.5 and 30ºC, 60 ± 5 % RH and 16: 8 (L: D) h. The highest intrinsic rate of natural increase (rm = 0.0243/day), net reproductive rate (R0 = 2.4 ♀/♀/T) and finite rate of increase (λ = 1.0245 day-1) values were determined at 22.5°C. The mean generation time (T) of the population ranged from 22.7 days at 30°C to 45.8 days at 20°C. The maximum and minimum survival rates (lx) were recorded at 22.5ºC and 30ºC. Survivorship data (lx) of adult females were summarized and compared using the shape and scale parameters of the Weibull frequency distribution model across. The age specific fecundity data (mx) was modeled as a function of time by using Polynomial model. The lower temperature threshold (t) and thermal constant (k) of the immature stages were estimated using Ikemoto and Takai linear model to be 12.85ºC and 279.7 degree days (DD), respectively. Of the non-linear models, the Analitis-1, Analitis-2, Analitis-3 and Analitis/Allahyari models were found to be the best for the modeling development rate of immature stages of B. rubrioculus. The optimal temperature for population growth of brown mite on apple was found at 22.5°C.

Relationships between flowering phenology, plant size, and female reproductive output in a dioecious shrub, Ilex leucoclada (Aquifoliaceae)

2006 ◽  
Vol 84 (12) ◽  
pp. 1860-1869 ◽  
Author(s):  
Takeshi Torimaru ◽  
Nobuhiro Tomaru
Keyword(s):  
Reproductive Output ◽  
Fruit Set ◽  
Flowering Phenology ◽  
Plant Size ◽  
Beech Forest ◽  
Major Effect ◽  
Onset Date ◽  
Dioecious Species ◽  
Physiological Factors ◽  
Flowering Onset

Flowering phenology is critical for reproduction in dioecious species, but selection on timing of flowering may be weakened by physiological factors such as plant size, and external factors such as climate. We investigated the flowering phenology of male and female adults, and female reproductive output, in 10 patches with various sex ratios, of the dioecious shrub Ilex leucoclada (Maxim.) Makino over three consecutive years in an old-growth beech forest. Sexual dimorphism was observed in flowering amplitude, but not in other traits examined, including flowering onset date, duration, peak date, and synchrony with plants of the opposite sex in the population. Plant size had a consistent, positive effect on flowering amplitude in both sexes throughout the study period, but its effects on other factors, including the extent of fruit set, varied. Females in mixed patches showed higher fruit set than those in female patches. Furthermore, although the reproductive output of the female I. leucoclada plants is likely to be affected by flowering phenological traits in the mixed patches, the importance of these factor is probably modulated by other variables, including precipitation (which had a major effect on male flowering patterns) and the spatial distribution of the males.

scholarly journals The Genetical and Environmental Determination of Phally Polymorphism in the Freshwater Snail Bulinus truncatus

Genetics ◽  
1996 ◽  
Vol 142 (1) ◽  
pp. 217-225
Author(s):  
Claudie Doums ◽  
Philippe Bremond ◽  
Bernard Delay ◽  
Philippe Jarne
Keyword(s):  
Natural Populations ◽  
Reaction Norm ◽  
Freshwater Snail ◽  
Temperature Threshold ◽  
Genetic Determination ◽  
Bulinus Truncatus ◽  
Polygenic Inheritance ◽  
Precise Knowledge ◽  
The Family

In some species of self-fertile pulmonate snails, two sexual morphs co-occur in natural populations: regular individuals and aphallic individuals that cannot transmit sperm to other snails. Purely aphallic populations therefore reproduce obligatorily by selfing. Understanding the evolution of aphally and selfing in these snails requires a precise knowledge of phally determination. In this paper, we investigate the genetic and environmental determination of aphally in Bulinus truncatus by a survey of the family (offspring) aphally ratio of 233 individuals originating from seven natural populations and a study of the reaction norm of the family aphally ratio to temperature using 60 individuals from 10 selfed lineages of one population. Our results indicate a high genetic variability for the determination of aphally between populations and within some populations, associated with a high level of genetic determination. Our second experiment indicates a significant temperature and lineage effect though no interaction between these two effects. We discuss our results in the framework of threshold models developed for dimorphic traits with polygenic inheritance. We propose that the sexual morph of an individual at a given temperature is determined by a temperature threshold value depending on both the individual genotype and probabilistic processes.

Enhancing Icing Detection and Characterization using the New York State Mesonet

2021 ◽  
Author(s):  
Junhong Wang ◽  
Jerry Brotzge ◽  
Jacob Shultis ◽  
Nathan Bain
Keyword(s):  
New York ◽  
Wind Speed ◽  
New York State ◽  
Snow Accumulation ◽  
Temperature Threshold ◽  
Ice Storm ◽  
Freezing Rain ◽  
York State ◽  
Automated Method ◽  
Sonic Anemometers

AbstractThe accurate detection and monitoring of freezing rain and icing conditions at the surface is a notoriously challenging but important problem. This work attempts to enhance icing detection and characterization utilizing data from the New York State Mesonet (NYSM). NYSM is the first operational network measuring winds at 10 meters from two independent sensors: propeller and sonic anemometers. During and after freezing rain events, large wind speed differences are frequently reported between the two anemometers because the propeller develops a coating of ice, thus either stopping or slowing its rotation. Such errors of propeller data provide a signal for identifying icing conditions. An automated method for identifying “active freezing rain” (AFR) and a continuation of “frozen surface” (FS) conditions is developed. Hourly maps of AFR and FS sites are generated using four criteria: (1) a wind speed difference (sonic – propeller) of > 1 m s-1 or 0 m s-1 propeller wind speed for at least half hour, (2) a temperature threshold of -5°C to 2°C for AFR and less than 2°C for FS, (3) insignificant hourly snow accumulation, and (4) with (or without) significant hourly precipitation accumulation for AFR (or FS). The AFR events detected by the automated method for last four winters (2017-2021) show very good agreements in starting and ending times with that from ASOS data. A case study of the ice storm during 14-16 April 2018 further demonstrates the validity of the methodology and highlights the benefit of NYSM profiler and camera data.

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