scholarly journals Is sexual organ reciprocity related to legitimate pollen deposition in distylous Pulmonaria (Boraginaceae)?

Oikos ◽  
2018 ◽  
Vol 127 (8) ◽  
pp. 1216-1224 ◽  
Author(s):  
Hans Jacquemyn ◽  
Marie Gielen ◽  
Rein Brys
Keyword(s):  
Pollen Deposition ◽  
Sexual Organ

scholarly journals Linking modern pollen accumulation rates to biomass: Quantitative vegetation reconstruction in the western Klamath Mountains, NW California, USA

The Holocene ◽  
2021 ◽  
pp. 095968362098803
Author(s):  
Clarke A Knight ◽  
Mark Baskaran ◽  
M Jane Bunting ◽  
Marie Champagne ◽  
Matthew D Potts ◽  
...  
Keyword(s):  
Mean Squared Error ◽  
Plant Biomass ◽  
Source Area ◽  
Pollen Deposition ◽  
Accumulation Rates ◽  
Klamath Mountains ◽  
Plant Abundance ◽  
Circular Area ◽  
Value Analysis ◽  
Pollen Accumulation Rates

Quantitative reconstructions of vegetation abundance from sediment-derived pollen systems provide unique insights into past ecological conditions. Recently, the use of pollen accumulation rates (PAR, grains cm−2 year−1) has shown promise as a bioproxy for plant abundance. However, successfully reconstructing region-specific vegetation dynamics using PAR requires that accurate assessments of pollen deposition processes be quantitatively linked to spatially-explicit measures of plant abundance. Our study addressed these methodological challenges. Modern PAR and vegetation data were obtained from seven lakes in the western Klamath Mountains, California. To determine how to best calibrate our PAR-biomass model, we first calculated the spatial area of vegetation where vegetation composition and patterning is recorded by changes in the pollen signal using two metrics. These metrics were an assemblage-level relevant source area of pollen (aRSAP) derived from extended R-value analysis ( sensu Sugita, 1993) and a taxon-specific relevant source area of pollen (tRSAP) derived from PAR regression ( sensu Jackson, 1990). To the best of our knowledge, aRSAP and tRSAP have not been directly compared. We found that the tRSAP estimated a smaller area for some taxa (e.g. a circular area with a 225 m radius for Pinus) than the aRSAP (a circular area with a 625 m radius). We fit linear models to relate PAR values from modern lake sediments with empirical, distance-weighted estimates of aboveground live biomass (AGLdw) for both the aRSAP and tRSAP distances. In both cases, we found that the PARs of major tree taxa – Pseudotsuga, Pinus, Notholithocarpus, and TCT (Taxodiaceae, Cupressaceae, and Taxaceae families) – were statistically significant and reasonably precise estimators of contemporary AGLdw. However, predictions weighted by the distance defined by aRSAP tended to be more precise. The relative root-mean squared error for the aRSAP biomass estimates was 9% compared to 12% for tRSAP. Our results demonstrate that calibrated PAR-biomass relationships provide a robust method to infer changes in past plant biomass.

Floral biology of Hemigenia and Microcorys (Lamiaceae)

2005 ◽  
Vol 53 (2) ◽  
pp. 147 ◽  
Author(s):  
Greg Guerin
Keyword(s):  
Connective Tissue ◽  
Reproductive Isolation ◽  
Floral Morphology ◽  
Corolla Tube ◽  
Floral Biology ◽  
Pollen Deposition ◽  
Field Observations ◽  
Bird Pollination ◽  
Insect Pollinators

The floral morphology and pollination of Hemigenia R.Br. and Microcorys R.Br. (Lamiaceae) were examined in the field and laboratory. The protandrous flowers have tubular, two-lipped corollas. Nine floral morphotypes are described. The stamens may be completely sterile (staminodal) or have one theca reduced or absent. The anthers typically have elongated connective tissue and are mobile on the filament. When the lower end of the anther is pushed, the upper end is levered towards the mouth of the corolla tube, hence dusting the pollinator precisely where receptive stigmas will later touch. Bearding on the anthers of the adaxial stamens catches adjacent anthers so that they lever in unison. Staminodes guide insect pollinators into the throat to allow precise pollen dusting. Detailed field observations show that bees and flies are the principle pollinators of most species. Floral morphologies are related to pollinator castes, and reproductive isolation and efficiency is enhanced by precise pollen deposition. Bird pollination is likely to have arisen independently in several taxa. The floral arrangement of these taxa is superficially similar but the syndrome is achieved through different anatomy.

Breeding and Mating Systems of Australian Proteaceae

1998 ◽  
Vol 46 (4) ◽  
pp. 421 ◽  
Author(s):  
Ross L. Goldingay ◽  
Susan M. Carthew
Keyword(s):  
Fruit Development ◽  
Mating Systems ◽  
Pollen Deposition ◽  
Genetic Studies ◽  
The Past ◽  
Wide Range ◽  
The Family ◽  
Self Compatibility ◽  
Low Levels ◽  
Key Events

There has been a significant increase in the number of studies investigating plant breeding and mating systems over the past 10 years. The family Proteaceae, in particular, has dominated such research conducted in Australia. Thus it is now timely to present a critical review of the breeding and mating systems of the Australian Proteaceae. It is hoped that this will stimulate further research. The review covers key events between pollen deposition on stigmas through to fruit set. The genus Banksia, although not the most diverse of the family, has received a disproportionate amount of attention. It has featured in nine published studies of self-compatibility compared to 13 studies spanning the other 45 genera and has featured in eight genetic studies of the mating system compared to just two on other genera. Few studies have assessed the timing of stigma receptivity despite the intriguing situation in most Proteaceae of auto-deposition of self-pollen on or near stigmas at anthesis. Studies suggest that stigmas are not receptive until 0.5–4 days after anthesis. Banksia species appear to show low levels of self-compatibility although one subspecies shows high levels of selfing and evidence of selective fruit development. Self-compatibility may be more common in other genera, although a dearth of studies precludes generalisation. Assessment of mating systems indicates almost complete outcrossing for most species, lending support to the idea of selective fruit development. It is clear that many further studies of all topics are required but particularly across a wide range of genera because many have not been studied at all.

scholarly journals Linking pollen deposition and snow accumulation on the Alto dell'Ortles glacier (South Tyrol, Italy) for sub-seasonal dating of a firn temperate core

2017 ◽  
Vol 11 (2) ◽  
pp. 937-948 ◽  
Author(s):  
Daniela Festi ◽  
Luca Carturan ◽  
Werner Kofler ◽  
Giancarlo dalla Fontana ◽  
Fabrizio de Blasi ◽  
...  
Keyword(s):  
Airborne Pollen ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Balance Model ◽  
Pollen Deposition ◽  
Layer Formation ◽  
Italian Alps ◽  
Pollen Monitoring ◽  
Pollen Content ◽  
Firn Core

Abstract. Dating of ice cores from temperate non-polar glaciers is challenging and often problematic. However, a proper timescale is essential for a correct interpretation of the proxies measured in the cores. Here, we introduce a new method developed to obtain a sub-seasonal timescale relying on statistically measured similarities between pollen spectra obtained from core samples and daily airborne pollen monitoring samples collected in the same area. This approach was developed on a 10 m core retrieved from the temperate-firn portion of Alto dell'Ortles glacier (Eastern Italian Alps), for which a 5-year annual/seasonal timescale already exists. The aim was to considerably improve this timescale, reaching the highest possible temporal resolution and testing the efficiency and limits of pollen as a chronological tool. A test of the new timescale was performed by comparing our results to the output (date of layer formation) of the mass balance model EISModel, during the period encompassed by the timescale. The correspondence of the results supports the new sub-seasonal timescale based on pollen analysis. This comparison also allows us to draw important conclusions on the post-depositional effects of meltwater percolation on the pollen content of the firn core as well as on the climatic interpretation of the pollen signal.

scholarly journals Pollinator importance networks illustrate the crucial value of bees in a highly speciose plant community

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Gavin Ballantyne ◽  
Katherine C. R. Baldock ◽  
Luke Rendell ◽  
P. G. Willmer
Keyword(s):  
Plant Species ◽  
Community Level ◽  
Taxonomic Resolution ◽  
Pollen Deposition ◽  
Pollinator Effectiveness ◽  
Flower Visitors ◽  
Pollinator Importance ◽  
Visitation Frequency ◽  
Pollinator Performance ◽  
Number Of Plant Species

AbstractAccurate predictions of pollination service delivery require a comprehensive understanding of the interactions between plants and flower visitors. To improve measurements of pollinator performance underlying such predictions, we surveyed visitation frequency, pollinator effectiveness (pollen deposition ability) and pollinator importance (the product of visitation frequency and effectiveness) of flower visitors in a diverse Mediterranean flower meadow. With these data we constructed the largest pollinator importance network to date and compared it with the corresponding visitation network to estimate the specialisation of the community with greater precision. Visitation frequencies at the community level were positively correlated with the amount of pollen deposited during individual visits, though rarely correlated at lower taxonomic resolution. Bees had the highest levels of pollinator effectiveness, with Apis, Andrena, Lasioglossum and Osmiini bees being the most effective visitors to a number of plant species. Bomblyiid flies were the most effective non-bee flower visitors. Predictions of community specialisation (H2′) were higher in the pollinator importance network than the visitation network, mirroring previous studies. Our results increase confidence in existing measures of pollinator redundancy at the community level using visitation data, while also providing detailed information on interaction quality at the plant species level.

scholarly journals The intensifying requirements for white clover cultivar change

1996 ◽  
Vol 6 ◽  
pp. 19-24
Author(s):  
P.T.P. Clifford ◽  
G.A. Sparks ◽  
D.R. Woodfield
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Pollen Deposition ◽  
Foreign Pollen ◽  
Buried Seed ◽  
Environmental Requirements ◽  
Trifolium Repens L ◽  
Isolation Distances ◽  
Seed Yields ◽  
Break Period

For the last five years an average 14,761 ha of white clover has been grown for seed, with 77%, 8% and 15% sown in public cultivars, New Zealand and overseas proprietary cultivars, respectively. The area presently contaminated by proprietaries is estimated at 20,000 ha. New Zealand requirements for cultivar-change are more effective than OECD requirements. The five-year break period enables successful cultivar change in 90% of cases and is improved further when buried seed counts were used prior to sowing to indicate paddocks with unacceptable buried seed load. Current isolation distances appear adequate with virtually all foreign pollen deposition occurring within 24m of the pollen source. Capture of additional public cultivar area (77%) by proprietary cultivars will rely on increasing the seed yields of proprietary cultivars by approximately 25%. This is realisable through greater attention to the environmental requirements of each cultivar and through better technology transfer between head licencees and growers. Keywords: buried seed, crop areas, cultivar-change requirements, public cultivars, proprietary cultivars, seed production, Trifolium repens L., white clover

scholarly journals The Relative Pollen Productivity and Pollen Representation of North European Trees, and Correction Factors for Tree Pollen Spectra. Determined by Surface Pollen Analyses from Forests

1970 ◽  
Vol 96 ◽  
pp. 1-99
Author(s):  
Svend Th. Andersen
Keyword(s):  
Tree Species ◽  
Small Sample ◽  
Forest Composition ◽  
Pollen Deposition ◽  
Correction Factors ◽  
Tree Crown ◽  
Tree Pollen ◽  
Surface Samples ◽  
Pollen Productivity ◽  
Pollen Analyses

The present work deals primarily with a determination of the relative pollen productivity of various trees from North Europe by means of their representation in pollen analyses of surface samples from forests, with the aim to calculate correction factors for pollen diagrams.Surface samples from 2 forests in Denmark were examined. The forest composition was determined by tree crown areas and tree basal areas in small sample plots. The relation of the tree crown areas to the tree basal areas was determined for the various tree species, and the data for crown area composition, basal area composition and tree frequency were compared.The pollen preservation in the various surface samples was examined.Data on wind conditions are mentioned in the chapter about pollen dispersal in the forest, and the various modes of pollen transfer are discussed. The amount of exotic pollen in the samples is used as a calculation basis for the tree pollen frequencies, and the occurrence and composition of the exotic pollen is discussed.The relationship of the forest composition to the tree pollen deposition is discussed. Pollen deposition and pollen productivity is expressed by a regression equation. The relative pollen productivity of the tree species is expressed in relation to a reference species, in the present case Fagus silvatica. Pollen representation and relative pollen representation are determined by a comparison of pollen percentages with percentages for areal frequency.Pollen productivity factors, pollen representation and correction factors were determined for Danish species of Quercus, Betula, Alnus, Carpinus, Ulmus, Fagus, Tilia and Fraxinus by means of the pollen frequencies in the surface samples. Corrected pollen percentages were compared with the tree areal percentages in the sample plots. Data for the pollen frequencies of forest plants other than the trees are presented. The data on trees from Denmark are compared with other data from Northern Europe, and correction factors were calculated for species of Pinus, Picea and Abies.Tree pollen spectra from outside the forest are discussed and the relative pollen representation is calculated. The present calculations of the relative pollen productivity of the trees are compared with previous estimates, and the application of the correction factors to pollen diagrams is discussed.

scholarly journals Kesehatan Jiwa Wanita Usia Pada Usia Produktif: Suatu Kajian Masalah

2014 ◽  
Vol 1 (1) ◽  
pp. 19-23
Author(s):  
Achir Yani S Hamid
Keyword(s):  
Mental Health ◽  
Physical Condition ◽  
Health Condition ◽  
Sexual Organ ◽  
Grieving Process ◽  
The Status

Kesehatan jiwa wanita sangat mempengaruhi kesehatan wanita. Pada usia produktif gangguan kesehatan jiwa wanita sering berhubungan dengan: perannya sebagai istri, ibu dan pekerja; kondisi kesehatan fisik terutama kondisi bagian tubuh yang menjadi simbol kewanitaan; serta penganiayaan fisik atau mental. Proses berduka, kemurungan, psikosa paska melahirkan, bunuh diri merupakan reaksi negatif dari gangguan terhadap kesehatan jiwa. The status of woman mental health gives a lot of influences to the whole of her health condition. On productive age, the alteration of woman’s mental health  could be induced by her role as wife, mother and worker, her physical condition mainly the condition of sexual organ; as well as physical and mentaly abused. Grieving process, depression, psicosa after labour and suicide are negative responses that was triggered by those alterations.

scholarly journals Do abundance and proximity of the alien Impatiens glandulifera affect pollination and reproductive success of two sympatric co-flowering native species?

2012 ◽  
Vol 10 ◽  
pp. 130-139
Author(s):  
Valérie Cawoy ◽  
Mathieu Jonard ◽  
Carolin Mayer ◽  
Anne-Laure Jacquemart
Keyword(s):  
Reproductive Success ◽  
Native Species ◽  
Natural Populations ◽  
Pollen Deposition ◽  
Impatiens Glandulifera ◽  
Insect Behaviour ◽  
Native Flora ◽  
Visitation Rates ◽  
Aconitum Napellus ◽  
Negative Effect

In invasion ecology, potential impacts of aliens on native flora are still under debate. Our aim was to determine the pollinator mediated effects of both proximity and abundance of an alien species on the reproductive success of natives. We chose the highly invasive Impatiens glandulifera and two native species: Epilobium angustifolium and Aconitum napellus ssp. lusitanicum. These species share characteristics allowing for pollination interactions: similar biotopes, overlapping flowering periods and same main pollinators. The effects of abundance (5, 25 and 100 individuals) and proximity (0 and 15 m) of the alien on visitation rate, insect behaviour, pollen deposition and reproductive success of both natives were investigated during 2 flowering seasons. We used centred visitation rates as they can be directly interpreted as a positive or negative effect of the invasive.Both abundance and proximity of the alien increased bumblebee visitation rates to both natives. On the other hand, abundance of the exotic species had a slight negative effect on honeybee visits to natives while its proximity had no effect. The behaviour of bumblebees changed as visitors left significantly more often the native plants for I. glandulifera when its abundance increased. As a consequence of this “inconstancy”, bees deposited considerable quantities of alien pollen on native stigmas. Nevertheless, this interspecific pollen transfer did not decrease seed set in natives. Self-compatibility and high attractiveness of both native species probably alleviate the risk of altered pollinator services and reproductive success due to the invader in natural populations.

scholarly journals PHYTOSEIIDAE INCREASE WITH POLLEN DEPOSITION ON CITRUS LEAVES

2004 ◽  
Vol 87 (4) ◽  
pp. 609-611 ◽  
Author(s):  
R. T. Villanueva ◽  
C. C. Childers
Keyword(s):  
Pollen Deposition ◽  
Citrus Leaves
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