INVESTIGADORES
ASHWORTH Lorena
congresos y reuniones científicas
Título:
Reproductive and genetic consequences of habitat fragmentation in plant populations: What do we know after two decades of research?
Autor/es:
AGUILAR, A.; QUESADA, M.; ASHWORTH, L.; HERRERIAS-DIEGO, Y.
Lugar:
Cape Town, Sudáfrica
Reunión:
Conferencia; Diversitas Open Science Conference II; 2009
Resumen:
The loss and fragmentation of natural habitats by human activities are pervasive phenomena in
terrestrial ecosystems across the Earth and the main current driving forces behind biodiversity
loss. Fragmentation studies in plant populations have mostly focused on sexual plant
reproductive dynamics. More recently, plant population genetic parameters have also been
thoroughly investigated in fragmented habitats. By means of meta-analyses we reviewed the
results of 20 years of fragmentation studies around the world and tested whether reproductive
output and genetic diversity decreases in fragmented habitats, and whether fragmentation has
differential effects depending on certain life history and ecological traits of plants. We also tested
whether certain methodological approaches used by authors influence the ability to detect
fragmentation effects. Overall, fragmentation has large and negative effects on pollination, plant
reproduction, genetic diversity and outcrossing rates but no effects on inbreeding coefficients.
The mating system of plants, which reflects both the degree of dependence on pollinator
mutualism and also the distribution of genetic diversity within and among populations, explained
most of the variation among the species effect sizes. Outcrossing, self-incompatible plants
showed strong negative fragmentation effects on reproduction and allelic richness. The rarity
status of plants also determined differential susceptibility to genetic erosion, where common and
recently rare plants were more negatively affected. Higher inbreeding coefficients in fragmented
habitats were only observed in studies analyzing progenies. The time elapsed in fragmentation
conditions significantly influenced the results. Our results suggest that fragmentation is shifting
mating patterns towards increased selfing. We conclude that animal-pollinated self-incompatible
plants are exceptionally vulnerable to fragmentation as a consequence of both, ecological and
genetic mechanisms.