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Reproductive phenology and pre-dispersal fruit predation in Atriplex halimus L. ( Chenopodiaceae )

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ABSTRACT

Background: The flowering phenology pattern of Atriplex halimus was studied in a Mediterranean habitat in order to analyze protandry effectiveness. Fruit set evolution was recorded over two years and the impact of pre-dispersal predation by insects was also evaluated.

Results: The flowering phenology coincided in 2006 and 2007, starting in mid-July and reaching full flowering at the end of August in both years. Inflorescences are composed of glomerules with 8.78 ± 2.79 male flowers and 4.57 ± 2.58 female flowers, with no significant differences in position on the inflorescence. The peaks of male and female flower anthesis were reached in mid-August, but the male maximum occurred one week before the female. Plants at the start of flowering only bear male flowers, but female flowers soon appear. Fruit set starts at the end of August; all the flowers were transformed into fruit by mid-September and their development continued to the beginning of October, when fruit structures had matured and began to drop. Fruit predation started at the end of September and reached maximum intensity in mid-October.

Conclusions: At population level, male and female flowers seemed to open in the same weeks, but at plant and glomerule level male flowers opened one week before the females. Fruit predation levels were 62.42 and 43.14% in 2006 and 2007 respectively, with no significant differences between different parts of the inflorescence. And larvae of Coleophoridae were the most abundant predators.

Electronic supplementary material: The online version of this article (doi:10.1186/1999-3110-54-4) contains supplementary material, which is available to authorized users.

No MeSH data available.


Mean values of monthly temperature and precipitation for Moguer, and average monthly temperature and rainfall in 2006 and 2007. Data recorded at the Moguer Meteorological Station.
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Fig1: Mean values of monthly temperature and precipitation for Moguer, and average monthly temperature and rainfall in 2006 and 2007. Data recorded at the Moguer Meteorological Station.

Mentions: Atriplex halimus plants were studied in a single population at the “Marismas del Odiel” Natural Park in Huelva (SW Spain). This population grows on a saline soil island surrounded by a tidal marsh in a virtually monospecific shrub community (37°13’53”N 6°57’50”W). See Fernández-Illescas et al. (2010) for cover values. This location has a typical Mediterranean climate with an average annual temperature of 18.0°C and an average annual rainfall of 460.9 mm, calculated from data recorded at the Moguer Meteorological Station, 12 km from the location (Rivas-Martínez and Rivas-Sáenz 1996–2009) (Figure 1). The study was carried out during 2006 and 2007, in which the annual temperatures were 17.0 and 16.3°C, and annual rainfall was 663.2 and 366.8 mm, respectively (Figure 1).Figure 1


Reproductive phenology and pre-dispersal fruit predation in Atriplex halimus L. ( Chenopodiaceae )
Mean values of monthly temperature and precipitation for Moguer, and average monthly temperature and rainfall in 2006 and 2007. Data recorded at the Moguer Meteorological Station.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5383916&req=5

Fig1: Mean values of monthly temperature and precipitation for Moguer, and average monthly temperature and rainfall in 2006 and 2007. Data recorded at the Moguer Meteorological Station.
Mentions: Atriplex halimus plants were studied in a single population at the “Marismas del Odiel” Natural Park in Huelva (SW Spain). This population grows on a saline soil island surrounded by a tidal marsh in a virtually monospecific shrub community (37°13’53”N 6°57’50”W). See Fernández-Illescas et al. (2010) for cover values. This location has a typical Mediterranean climate with an average annual temperature of 18.0°C and an average annual rainfall of 460.9 mm, calculated from data recorded at the Moguer Meteorological Station, 12 km from the location (Rivas-Martínez and Rivas-Sáenz 1996–2009) (Figure 1). The study was carried out during 2006 and 2007, in which the annual temperatures were 17.0 and 16.3°C, and annual rainfall was 663.2 and 366.8 mm, respectively (Figure 1).Figure 1

View Article: PubMed Central

ABSTRACT

Background: The flowering phenology pattern of Atriplex halimus was studied in a Mediterranean habitat in order to analyze protandry effectiveness. Fruit set evolution was recorded over two years and the impact of pre-dispersal predation by insects was also evaluated.

Results: The flowering phenology coincided in 2006 and 2007, starting in mid-July and reaching full flowering at the end of August in both years. Inflorescences are composed of glomerules with 8.78 ± 2.79 male flowers and 4.57 ± 2.58 female flowers, with no significant differences in position on the inflorescence. The peaks of male and female flower anthesis were reached in mid-August, but the male maximum occurred one week before the female. Plants at the start of flowering only bear male flowers, but female flowers soon appear. Fruit set starts at the end of August; all the flowers were transformed into fruit by mid-September and their development continued to the beginning of October, when fruit structures had matured and began to drop. Fruit predation started at the end of September and reached maximum intensity in mid-October.

Conclusions: At population level, male and female flowers seemed to open in the same weeks, but at plant and glomerule level male flowers opened one week before the females. Fruit predation levels were 62.42 and 43.14% in 2006 and 2007 respectively, with no significant differences between different parts of the inflorescence. And larvae of Coleophoridae were the most abundant predators.

Electronic supplementary material: The online version of this article (doi:10.1186/1999-3110-54-4) contains supplementary material, which is available to authorized users.

No MeSH data available.