Effect of habitat disturbance on pollination biology of the columnar cactus Stenocereus quevedonis at landscape-level in central Mexico
Por:
Rodríguez-Oseguera A.G., Casas A., Herrerías-Diego Y., Pérez-Negrón E.
Publicada:
1 may 2013
Resumen:
Stenocereus quevedonis (pitire') is a columnar cactus endemic to central
Mexico, grown for its edible fruit. Phenology, pollination biology and
behaviour of flower visitors of this species were compared in six
conserved and disturbed sites, hypothesising that: (i) pitire
pollination is self-incompatible, requiring animal vectors; (ii) higher
incidence of radiation on plants in cleared forest may lead to a higher
number of flowers per pitire plant and longer blooming season, and
disturbing and differential spatial availability of flower resources may
determine differential attraction of pollinators to conserved and
disturbed areas; (iii) if pitire pollination system is specialised,
reproductive success would decrease with pollinator scarcity, or other
species may substitute for main pollinators. In all sites, pitire
reproduction started in January, flowering peak occurring in April,
anthesis duration was 15h and predominantly nocturnal (9h), pollen was
released at 23:00h, nectar was produced throughout anthesis, and
breeding system was self-incompatible. Flower production per plant was
similar in disturbed and conserved sites, but flower availability was
higher (because of higher tree density) and longer in disturbed sites.
Pollination is nocturnal, the most frequent legitimate pollinator being
the bat Leptonycteris yerbabuenae; diurnal pollination is rare but
possible, carried out by bee species. Fruit and seed set in control and
nocturnal pollination treatments at disturbed sites were higher than in
conserved sites. Frequency of L.yerbabuenae visits was similar among
site types, but more visits of complementary nocturnal and diurnal
pollinators were recorded in disturbed sites, which could explain
differences in reproductive success.
Filiaciones:
Rodríguez-Oseguera A.G.:
UNAM, Ctr Invest Ecosistemas, Morelia 58190, Michoacan, Mexico
Casas A.:
UNAM, Ctr Invest Ecosistemas, Morelia 58190, Michoacan, Mexico
Herrerías-Diego Y.:
Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Mexico
Pérez-Negrón E.:
UNAM, Ctr Invest Ecosistemas, Morelia 58190, Michoacan, Mexico
|