Reproductive biology of five native plant species from Monte desert of Argentina

TADEY, M.; TADEY, J. C.; TADEY, N.

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

Blackwell Publishing

Lugar: London; Año: 2009 vol. 161 p. 190 - 201

0024-4074

The knowledge of plant breeding systems allows evaluating if seed production depends on pollination agents and also helps to understand gene flow mechanisms within and among populations, both important for conservation of natural areas. The reproductive biology of Monte desert vegetation is mostly unknown and the diversity of this habitat is being threatened by desertification as a result of human impact. The objective of this study was to determine the reproductive biology of the most abundant plant species of Monte desert, Patagonia, Argentina and discuss their ecological importance. Mating systems, flowering phenology and pollinators network were studied for five representative plant species of Monte desert (Gutierrezia solbrigii, Grindelia chiloensis, Larrea divaricata, L. cuneifolia and Atriplex lampa). Several mating systems were represented in these five plant species. Starting from anemophilous pollen dispersion in Atriplex lampa, to a gradient of dependence on pollinators; from the less dependent Gutierrezia solbrigii and both Larrea species (facultative self-compatible) to the most dependent, Grindelia chiloensis (self-incompatible). Flowering phenology was restricted to spring season and synchronized with pollinators’ abundance. The four insect-pollinated species were moderately generalist but all of them maintained their own pollinators’ assemblage. Pollinators’ assemblage was mainly composed by solitary bees; beetles, flies and butterflies were also present. Coleopterans depended more on Grindelia chiloensis, dipterans on Gutierrezia solbrigii, lepidopterans on Gutierrezia solbrigii and Larrea divaricata and hymenopterans on Larrea divaricata and Larrea cuneifolia. These four plant species are ecologically very important because of their relative abundance and as food resource for a wide range of pollinators’ species. Solitary bees play a critical role in pollination services on Monte desert. This habitat is very disturbance-sensitive and vegetative regeneration is difficult due to drought conditions; therefore sexual reproduction is essential for the maintenance of plant species. The knowledge presented in this work is useful for understanding plant species responses to disturbance in arid habitats and to generate conservation and managements regulations.