Growth rings and age in Vella pseudocytisus pseudocytisussubsp. subsp. paui paui(Brassicaceae Brassicaceae)

Abstract

Age characterises the population structure and determines its dynamics. The most accurate age estimation of woody plants can be obtained through dendrochronological techniques when the rings are well marked and constitute a reliable record of each annual growing season. Our work has focused on Vella pseudocytisus subsp. paui Gómez Campo, an endemic shrub which grows in a continental semiarid climate in the center of the Iberian Peninsula (Community of Aragón) (Figure 1), with only two extant populations and recently enlisted as Endangered in the Spanish Red Data List (Moreno, 2008). The objjective of this work is to supppport with dendrochronologgical data the demog p graphic monitoring carried out over the last ten years (Domínguez et al., in press), in order to assess the study of its demographic performance (vital rates, population dynamics, survival trends). Due to the fact that the species is strictly protected under the Aragonian law, we were able only to collect individuals known to be dead or removed by agricultural practices from both populations over the last ten years. After checking the existence of defined boundaries between rings, we have measured them in 126 trunk sections corresponding to 61 individuals (see Table 1