Relaciones florísticas y características regenerativas en Apurimacia dolichocarpa (Fabaceae), especie endémica del centro de Argentina
[Floristic relations and regenerative traits in Apurimacia dolichocarpa (Fabaceae), an endemic species of central Argentina]
Funes, Guillermo; Cabido, Marcelo
Apurimacia dolichocarpa (Griseb.) Burkart is a narrow endemic species, restricted to rock outcrops in the western slope of Co´rdoba Mountains in central Argentina. The aim of this paper is to study the main characteristics of the sites where the species occurs, its phytosociology, the germination and the seedling morpho-functional traits in A. dolichocarpa. Floristic surveys were performed and some physical factors (altitude and size of the outcrops) measured in 18 stands dominated by this species. Imbibition and germination experiments were designed including four temperature regimes (15/5, 20/10, 30/15 and 35/20°C) in light (12/12 h daily photoperiod) and in continuous darkness. Additionally, morpho-functional traits were described in seedlings grown under laboratory conditions for that purpose. A. dolichocarpa was highly restricted to rock outcrops where it generally dominates saxicolous species arrangements. The seeds did not show physical dormancy, and germinated under different temperature regimes, both under light and darkness. Seedlings of A. dolichocarpa belong to the Cryptocotylar-hypogeal-reserve type. Taking into account that A. dolichocarpa is the dominant species in the outcrop communities where it occurs and that the germination of the seeds is not constrained by temperature nor by light/dark conditions, the species would be able to maintain viable populations and even expand its range; nevertheless, this range expansion is likely to be constrained by the low competitive ability exhibited at the seedling stage.