Reproductive behavior and root system of Agave fourcroydes Lem. and A. sisalana Perr. (Agavaceae) in invaded ecosystems of the Natural Park Cabo de Gata-Níjar (Almería).
María del Mar Sánchez Sánchez
In the 1950s two Agave species, henequen (Agave fourcroydes Lem.) and sisal (A. sisalana Perr.), were introduced in the coastal plain of Parque Natural de Cabo de Gata-Níjar (Almería), with the aim of producing textile fibers. At present, both species are growing in this area and they are invading the natural vegetation. Their effective mechanisms of vegetative reproduction, their nature CAM and the existence of contractile roots, like adaptative strategy to drought, give to Agaves a high invader potential. To know the flowering phenology, the contribution of different mechanisms of vegetative reproduction, and the radical system of these species, will allow us to develop strategies for the management of these invasive species. In this study, we monitored the individuals of Agave species for the phenology description and the analysis of bulbils produced in the flowering scape; furthermore, we selected individuals of both species to make a description of radical system and estimate the production of new shoots produced by rhizomes. Finally, we sampled the bulbils randomly with the aim of discovering their origin. Results showed that the main mechanisms of propagation in this area are the shoots produced by rhizomes and the ones produced from the rosette; furthermore, we observed that, agaves ́s phenology and their radical system are similar between species but there are some significant differences that can affect in their invader potential.
Keywords: Agave fourcroydes Lem., Agave sisalana Perr., reproductive strategy, plant invasions, vegetative multiplication, bulbils, contractile roots, rhizomes.