ISSN:
1440-1703
Schlagwort(e):
male-bias
;
reproductive cost
;
resource allocation
;
sex differential mortality
;
successional stage
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract Three hundred and thirty-eight plants ofAcer rufinerve Sieb. et Zucc. were monitored in a secondary deciduous forest for 5 years in terms of their sex expression and fruiting habit. Two types of flowers, functionally male and female, were recognized. The adult population consisted of constant males, inconstants and constant females. Constant males, plants that bore exclusively male flowers throughout the study period, accounted for 87% of the adult population. Thirty-four inconstant plants (11%) changed their sex in various ways. Constant females which accounted for only 2% of the population, were significantly smaller plants than the other two morphs, and suffered greater mortality. Fruit set was consistent and generally high for plants bearing female flowers. Thirteen juvenile plants out of 17 began reproduction during the 5 years, and all became male. For inconstant plants, fluctuation in sex expression tended to be more frequent and/or greater in magnitude for smaller plants. However, there was no evidence of the directional sex transition predicted by the size advantage hypothesis. Plant health and the successional stage of the stand should be taken into account as well as resource allocation problems to explain the proximate mechanisms of sex expression.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF02347656
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