Seasonal timing of pseudoviviparous reproduction of Leiothrix (Eriocaulaceae) rupestrian species in South-eastern Brazil.
OBJECTIVE
Pseudovivipary is an asexual reproductive strategy. Leiothrix spiralis and L. vivipara (Eriocaulaceae) are pseudoviviparous and occur in rupestrian grasslands, a habitat that has a predominance of sandy and shallow soil, with low water retention. This study aims to investigate the seasonal variation effect of moisture availability on L. spiralis and L. vivipara pseudoviviparous reproduction, and to compare their life history attributes, on rupestrian grasslands in Southeastern Brazil.


METHODS
A field study was conducted, including observations concerning pseudoviviparous reproduction and measurement of demographic variables in both L. spiralis and L. vivipara. Soil moisture measurements were also performed to study its effect on the pseudoviviparous reproduction of L. spiralis and L. vivipara.


RESULTS
Flower head and plantlet production in L. spiralis were highly correlated with soil moisture. All scapes split off in the drier period, indicating that this is a splitter ramet species. Plantlet mortality was positively correlated with scapes splitting off. The L. vivipara phenophases were not synchronized to the variation in soil moisture, since flower heads and plantlets were produced throughout the year. Moreover, the splitting off of scapes was not observed. In addition, plantlets were formed early, as soon as the flower heads appeared, and remained suspended. Therefore, this species was called 'canopy forming'.


CONCLUSIONS
Seasonal timing of pseudoviviparous reproduction can be a vital component of the successful establishment of plantlets in L. spiralis, considering that in this species the plantlets are formed only after the flower head touches the ground. In contrast, in L. vivipara, the plantlets are formed early, without touching the ground. Moreover, L. spiralis is a splitter ramet species, while L. vivipara is a canopy-forming species. The pseudoviviparous canopy-forming strategy appears to be more advantageous than the splitter ramet strategy, because even under similar soil moisture conditions, the survival of L. vivipara plantlets was greater than that of L. spiralis.
Coelho
Flávia F
FF
Departamento de Biologia Geral, Universidade Federal de Minas Gerais ICB, Caixa Postal 486, cep 30161-970, Belo Horizonte, MG, Brazil. flaviafcoelho@yahoo.com.br
Capelo
Christina
C
Neves
Ana Carolina O
AC
Martins
Rogério P
RP
Figueira
José Eugênio C
JE
D001938:Brazil; D039262:Eriocaulaceae / Q000145:classification* / Q000502:physiology*; D035264:Flowers / Q000502:physiology; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D012987:Soil / Q000032:analysis; D014867:Water / Q000737:chemistry
D012987:Soil; D014867:Water