title: Altitude affects the reproductive performance in monoicous and dioicous bryophytes: examples from a Brazilian Atlantic rainforest.
abstract: OBJECTIVE
  Short life cycles and trade-offs linked to breeding systems make bryophytes good models for the study of plant reproductive strategies. Our aim was to test if differences in sexual reproductive performance of bryophytes in tropical rainforests are driven by the breeding system of the species (monoicous or dioicous) or are mainly affected by the habitat.
  
  
  METHODS
  The reproductive performance (sexual branches, gametangia (sex organs), fertilization and sporophyte production) of 11 species was repeatedly monitored and analysed from populations at sea-level and montane sites of a Brazilian Atlantic rainforest over 15 months.
  
  
  RESULTS
  Monoicous species had the highest reproductive performance, particularly for sexual branches, fertilized gametangia and sporophyte production. Species at the sea-level site produced more sexual branches and had more female-biased sex ratios of gametangia than species in the montane site. Fertilizations were more frequent at the montane site, but sporophyte frequency was similar between the two sites. Fertilization tended to occur mostly in the periods of heavy rain (October to December).
  
  
  CONCLUSIONS
  Breeding system is not the only major influence on the reproductive performance of bryophytes. We show that habitat is also an important factor determining life-history differentiation. Female-biased sex ratios and low rates of fertilization are seen to be compensated for by high production of reproductive structures at the initial phases of the reproductive cycle.
authors: Departamento de Biologia Vegetal ,  Instituto de Biologia, CP 6109, Universidade Estadual de Campinas - UNICAMP ,  Campinas, SP 13083-970 ,  Brazil.
authors: Adaíses S
authors: AS
authors: Maciel-Silva
authors: Ivany F
authors: IF
authors: Marques Valio
authors: Håkan
authors: H
authors: Rydin