Floral Biology and Reproductive Phenology of Avicennia marina in South-Eastern Australia

1991 ◽  
Vol 39 (3) ◽  
pp. 283 ◽  
Author(s):  
PJ Clarke ◽  
PJ Myerscough
Keyword(s):  
Pollen Grains ◽  
Avicennia Marina ◽  
Floral Biology ◽  
Reproductive Phenology ◽  
Pollinator Behaviour ◽  
Whole Process ◽  
Propagule Supply ◽  
Eastern Australia ◽  
Individual Trees ◽  
Grey Mangrove

Flowering, pollination and reproductive phenology of the tree, Avicennia marina (Grey mangrove), were examined on the south-east coast of Australia in New South Wales. Individual flowers are protandrous and open for 2-5 days, while a flower cluster has open flowers for 2-4 weeks. About 16000 pollen grains and four ovules are produced per flower. Self-pollination of an individual flower is unlikely because of protandry, but the sequence and synchrony of flowering, together with pollinator behaviour, favour geitonogamy. Some fruit is set when cross-pollination is restricted by bagging flowers, which indicates partial self-compatibility. Subsequently, fruit abortion is higher in the bagged treatment than in those open-pollinated; this may reflect some pre-dispersal inbreeding depression. Between 4 and 41% of open-pollinated flower buds set fruit, most of which had one or rarely two seeds. Phenologically, each reproductive stage is unimodal and the whole process from bud initiation to abscission of mature fruit is completed within a year. Initiation of floral buds, flowering, growth and abscission of fruits are almost synchronous among fecund trees at a particular latitude each year. Latitudinal differences occur consistently among populations that are separated by less than 2° of latitude; those at lower latitudes flower earlier. Flowering of individual trees varies greatly between years and many trees fail to reproduce each year, although the populations remain fecund from year to year. A flexible breeding system and regular population fecundity ensure annual propagule supply in the populations studied.

scholarly journals Fenología reproductiva, biología floral y visitantes florales en los cultivares de mango (Mangifera indica L.) Hilacha y Tommy Atkins en el valle del alto Magdalena (Colombia).

2010 ◽  
Vol 12 (1) ◽  
pp. 21 ◽  
Author(s):  
Jenny Paola Corredor P. ◽  
Jairo García L.
Keyword(s):  
Mangifera Indica ◽  
Pollen Grains ◽  
Floral Biology ◽  
Early Morning ◽  
Morphological Characterization ◽  
Reproductive Phenology ◽  
Phonological Development ◽  
Flower Visitors ◽  
Average Size ◽  
Fruit Formation

<p>Con el fin de ampliar el conocimiento de la biología reproductiva del mango en las condiciones ambientales del trópico, se evaluó en la región del valle del alto Magdalena (Colombia) en los cultivares de mango Hilacha y Tommy Atkins el desarrollo fenológico, caracterización morfológica, antesis, descripción del grano de polen y visitantes florales. Los resultados muestran que los cultivares no difieren en los cambios fenológicos que presentan durante el desarrollo de la yema hasta la formación del fruto, sin embargo, se observaron diferencias en el número de días requeridos para la formación del fruto (‘Hilacha’55,9 ± 2,7 días; ‘Tommy Atkins’ 78,6 ± 3,3 días).Además, se encontraron discrepancias en la caracterización morfológica tanto en la forma, ancho y largo de la panícula, densidad de pelos de la panícula y el grado de ramificación de la inflorescencia. El evento de antesis se presentó mayormente entre las 17:00 h y las 7:00 h, indicando una mayor ocurrencia en condiciones de oscuridad y de menor temperatura (en la noche y en las primeras horas de la mañana). Por otra parte, el promedio del tamaño del grano de polen fue de 31 ± 0,2 µm para los dos cultivares; la viabilidad de los granos fue de 85,5% para ‘Hilacha’ y 83,4% para ‘Tommy Atkins’. En promedio se registraron 1.313 ± 100 granos por antera para ‘Hilacha’ y 1.002 ± 94 para ‘Tommy Atkins’. Entre los visitantes florales se encontraron seis ordenes taxonómicos: Coleoptera, Diptera, Hemiptera, Homoptera, Himenoptera y Lepidoptera y la clase Arachnida.</p><p> </p><p><strong>Reproductive phenology, floral biology and flower visitors in mango (Mangifera indica L.) crop Hilacha and Tommy Atkins cultivars in the Upper Magdalena Valley (Colombia).</strong></p><p>In order to advance the knowledge of the mango's reproductive biology in tropical environmental conditions; phonological development, morphological characterization, anthesis, grain pollen description and floral visitors were assessed in the mango cultivars Hilacha and Tommy Atkins in the Upper Magdalena Valley region (Colombia). Results showed that these cultivars did not differ in their phenological development from bud to fruit formation. However, differences in the number of days required for fruit formation were observed, (‘Hilacha’ 55.9 ± 2.7 days; ‘Tommy Atkins’ 78.6 ± 3.3 days). In addition, differences were found in morphological characterization, regarding shape, width and length of the panicle, hair density and the degree of branching of the inflorescence. The anthesis event, took place mostly between 17:00 h and 7:00 h, indicating a greater preference to dark conditions and lower temperatures (night or early morning). Moreover, the average size of pollen grains was 31 ± 0.2 µm for the two cultivars; grain viability was 85.5% for ‘Hilacha’ and 83.4% for ‘Tommy Atkins’. On average, there were 1,313 ± 100 grains per anther for ‘Hilacha’ and 1,002 ± 94 for ‘Tommy Atkins’. Among flower visitors, six taxonomic orders were observed: Coleoptera, Diptera, Hemiptera, Homoptera, Hymenoptera and Lepidoptera; and the Arachnida class. </p>

Mangroves as maternity roosts for a colony of the rare east-coast free-tailed bat (Mormopterus norfolkensis) in south-eastern Australia

2013 ◽  
Vol 40 (4) ◽  
pp. 318 ◽  
Author(s):  
Anna McConville ◽  
Bradley S. Law ◽  
Michael J. Mahony
Keyword(s):  
Threatened Species ◽  
Mangrove Forest ◽  
Avicennia Marina ◽  
Conservation Strategies ◽  
Mangrove Forests ◽  
Landscape Characteristics ◽  
Eastern Australia ◽  
Lactating Females ◽  
Roost Trees ◽  
Grey Mangrove

Context Maternity roosts of insectivorous bats (where females raise young) are critical to the conservation of threatened species as roost quality can influence reproductive success. Additionally, threatened species may have specialised requirements or unusual behaviour, which may be overlooked without targeted investigation. Aims To explore which factors influence the roost selection of Mormopterus norfolkensis, by comparing day roosts, identified via radio-tracking, with environmental variables collected at tree, patch and landscape scales. Methods We collected a range of variables describing maternity roosts and surrounding patches, including internal measurements of hollows and microclimate. Additionally, we derived landscape-scale variables using a geographic information system. We then explored which variables best explained roost occurrence using logistic regression. Key results Nineteen lactating females and two male M. norfolkensis were tracked to 40 roost trees, mostly grey mangrove, Avicennia marina subsp. australasica. Lactating females were found to be faithful to two patches of mangrove forest close to where they were captured, regularly switched roosts and roosted in hollows singularly or in small groups. The attributes of mangrove patches, especially a high proportion of hollows, better predicted roosting by lactating females than roost-tree or landscape characteristics. Additionally, although the microclimate of roost hollows was not significantly different from ambient mangrove conditions, the mangrove forest was slightly more stable and had higher humidity than did other nearby habitats. Conclusions Contrary to predictions, maternity roosting group sizes were relatively small, indicating that bats were not deriving thermoregulatory benefits from communal living. However, we suggest that lactating females may benefit from the operation of a fission–fusion society among the colony as a whole. Additionally, the mature mangrove forest could offer unique roosting opportunities for bats because they support high densities of hollow-bearing trees, a stable microclimate and potentially low abundances of predators and competitors. Implications This is one of few international bat–mangrove studies and it illustrates that threatened species can behave unexpectedly and may be overlooked in conservation strategies that are based largely on anecdotal observations. We encourage further research into the value of mangrove forests to terrestrial fauna globally.

scholarly journals Spatial distribution and potential ecological risk assessment of some trace elements in sediments and grey mangrove (Avicennia marina) along the Arabian Gulf coast, Saudi Arabia

2020 ◽  
Vol 18 (1) ◽  
pp. 77-96
Author(s):  
Hameed Alsamadany ◽  
Hassan S. Al-Zahrani ◽  
El-Metwally M. Selim ◽  
Mohsen M. El-Sherbiny
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Ecological Risk ◽  
Oil Pollution ◽  
Gulf Coast ◽  
Arabian Gulf ◽  
Avicennia Marina ◽  
Potential Ecological Risk ◽  
Average Concentration ◽  
Grey Mangrove

AbstractTo assess trace element concentrations (Zn, Cu, Pb, Cr, Cd and Ni) in the mangrove swamps along the Saudi coast of the Arabian Gulf, thirteen samples of surface sediment and leaves of grey mangrove, Avicennia marina were collected and analyzed. The detected trace element contents (μg g-1) in surface sediments were in the following descending order according to their mean values; Cr (49.18) > Zn (48.48) > Cu (43.06) > Pb (26.61) > Ni (22.88) > Cd (3.21). The results showed that the average concentrations of Cd and Pb exceeded their world average concentration of shale. The geo-accumulation, potential ecological risk and toxicity response indices demonstrated that trace elements have posed a considerable ecological risk, especially Cd. The inter-relationships between physico-chemical characters and trace elements suggests that grained particles of mud represent a noteworthy character in the distribution of trace elements compared to organic materials. Moreover, the results revealed that Zn was clearly bioaccumulated in leaf tissues A. marina. Dredging, landfilling, sewage effluents and oil pollution can be the paramount sources of pollution in the area under investigation.

Reproductive biology of Melaleuca alternifolia (Myrtaceae) 1. Floral biology

2010 ◽  
Vol 58 (5) ◽  
pp. 373 ◽  
Author(s):  
L. Baskorowati ◽  
M. W. Moncur ◽  
J. C. Doran ◽  
P. J. Kanowski
Keyword(s):  
Reproductive Biology ◽  
Floral Biology ◽  
Morphological Development ◽  
Tea Tree Oil ◽  
Melaleuca Alternifolia ◽  
Tea Tree ◽  
Viable Seeds ◽  
Individual Trees ◽  
Days After Anthesis ◽  
Flowering Intensity

Melaleuca alternifolia (Maiden & Betche) Cheel is commercially important as the source of essential oil for the Australian tea tree-oil industry. Information on reproductive biology of M. alternifolia is important to the Australian breeding program directed at improving the quality and quantity of tea tree oil. Flowering in three geographically separated sites – two planted seed orchards and one managed natural population, all in NSW – was observed in the present study, with supporting data obtained from glasshouse-grown plants in Canberra. The majority of the work was conducted from 2004 to 2007, although the study also drew on some prior observations. M. alternifolia has spikes of flowers that open acropetally over a 6-day period. No strong separation of male and female phases was found in any individual flower; pollen was shed by 1.4 days after anthesis and the stigma reached peak receptivity 3–5 days after anthesis. Dichogamy and acropetal floral development may lead to geitonogamy. Flowering occurred during the months of October–November, with the peak in November, and was synchronous across all three sites. Flowering intensity and success in producing capsules appeared to be associated with total spring rainfall. Initiation of flowering in M. alternifolia appears to be correlated with daylength, or an environmental parameter closely correlated with daylength. Flowering intensity varied considerably among the years surveyed, sites and families, and appears to be promoted by a period of winter minimum temperatures below 5°C. In M. alternifolia, the morphological development of buds, flowers and fruit leading to the development of mature seed takes place over a period 16–18 months from flowering. M. alternifolia differed significantly in the number of viable seeds per capsule from individual trees, from 26 ± 3.8 to 57 ± 3.8 germinants.

scholarly journals Thunderstorm outflows preceding epidemics of asthma during spring and summer

Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 468-471
Author(s):  
G B Marks ◽  
J R Colquhoun ◽  
S T Girgis ◽  
M Hjelmroos Koski ◽  
A B A Treloar ◽  
...  
Keyword(s):  
Pollen Grains ◽  
Ground Level ◽  
Fold Increase ◽  
Underlying Mechanism ◽  
Detailed Examination ◽  
Asthma Exacerbations ◽  
Eastern Australia ◽  
The Difference ◽  
High Concentrations ◽  
Thunderstorm Outflow

BACKGROUNDA study was undertaken to assess the importance of thunderstorms as a cause of epidemics of asthma exacerbations and to investigate the underlying mechanism.METHODSA case control study was performed in six towns in south eastern Australia. Epidemic case days (n = 48) and a random sample of control days (n = 191) were identified by reference to the difference between the observed and expected number of emergency department attendances for asthma. The occurrence of thunderstorms, their associated outflows and cold fronts were ascertained, blind to case status, for each of these days. In addition, the relation of hourly pollen counts to automatic weather station data was examined in detail for the period around one severe epidemic of asthma exacerbations. The main outcome measure was the number of epidemics of asthma exacerbations.RESULTSThunderstorm outflows were detected on 33% of epidemic days and only 3% of control days (odds ratio 15.0, 95% confidence interval 6.0 to 37.6). The association was strongest in late spring and summer. Detailed examination of one severe epidemic showed that its onset coincided with the arrival of the thunderstorm outflow and a 4–12 fold increase in the ambient concentration of grass pollen grains.CONCLUSIONSThese findings are consistent with the hypothesis that some epidemics of exacerbations of asthma are caused by high concentrations of allergenic particles produced by an outflow of colder air, associated with the downdraught from a thunderstorm, sweeping up pollen grains and particles and then concentrating them in a shallow band of air at ground level. This is a common cause of exacerbations of asthma during the pollen season.

Hydroclimate proxies for eastern Australia using stable isotopes in grey mangroves (Avicennia marina)

2021 ◽  
pp. 103691
Author(s):  
Matthew J. Goodwin ◽  
Danielle C. Verdon-Kidd ◽  
Quan Hua ◽  
Nathan B. English ◽  
Heather A. Haines ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Avicennia Marina ◽  
Eastern Australia

scholarly journals Polinização de Vellozia candida Mikan (Velloziaceae) nos Afloramentos Rochosos do Costão de Itacoatiara, Niterói, RJ: Um Caso de Melitofilia em Inselbergue do Brasil

2012 ◽  
Vol 5 (1) ◽  
pp. 29-32
Author(s):  
Fábio Castro Verçoza
Keyword(s):  
Floral Biology ◽  
Pollination Ecology ◽  
Reproductive Phenology ◽  
Flowering Period ◽  
Rock Outcrops ◽  
Floral Visitors ◽  
Rocky Outcrops ◽  
And Behavior ◽  
Effective Pollinator

Este trabalho apresenta dados sobre a fenologia reprodutiva, a biologia floral e a ecologia da polinização de Vellozia candida Mikan (Velloziaceae) nos afloramentos rochosos do Costão de Itacoatiara, Niterói, RJ. Uma população de dez indivíduos da espécie foi estudada nessa localidade no período de junho de 2006 a dezembro de 2008. Foram realizadas observações sobre período de floração, morfologia, cor e odor das flores, ocorrência e comportamento dos visitantes florais. A floração de V. candida ocorreu de setembro a dezembro nos dois anos consecutivos do estudo. As flores são brancas, nectaríferas e exalam odor suave e adocicado. Reúnem características típicas da síndrome da melitofilia e foram intensamente visitadas por três espécies de abelhas. Xylocopa ordinaria Smith se destacou como o polinizador efetivo da espécie estudada. Por ser uma abelha de grande porte e robusta, durante a coleta de néctar e de pólen, deposita este último no estigma, polinizando as flores. Pollination of Vellozia candida Mikan (Velloziaceae) on Rock Outcrops of Costão de Itacoatiara, Niterói, RJ: A Case of Mellitophily Inselberg BrazilAbstract. This paper presents data on the reproductive phenology, floral biology and pollination ecology of Vellozia candida Mikan (Velloziaceae) on rocky outcrops of Costão Itacoatiara, Niterói, RJ. A population of ten individuals of the species was studied in this location from June 2006 to December 2008. Observations were made on flowering period, morphology, color and odor of flowers, the occurrence and behavior of floral visitors. The flowering of V. candida occurred from September to December in two successive years of study. The flowers are white, exude nectar and sweet odor. Meet typical syndrome melitophyly and were intensively visited by three species of bees. Xylocopa ordinaria Smith stood out as the effective pollinator of the species studied. Being a bee large and robust, while collecting nectar and pollen, the latter deposited on the stigma, pollinating the flowers.

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