Endemic flora biodiversity in the south of the Iberian Peninsula: altitudinal distribution, life forms and dispersal modes

Abstract

The south of the Iberian Peninsula, with an altitudinal range varying from sea level to 3482 m and annual average rainfall ranging from 206 to 2223 mm, has 516 vascular endemic species or subspecies, that is, an endemicity rate of 13%. This survey deals with parameters such as species richness, originality, life forms and dispersal modes of these plants, in relation to altitudinal and rainfall gradients. Although most of the endemic plants occur between 600 and 1400 m a.s.l. and in the range of 600-1000 mm annual average rainfall, floristic originality (rate of endemic taxa per area unit) increases exponentially with altitude. The biological spectrum of this endemic flora does not follow the usual patterns observed either in local floras in the south of the Iberian Peninsula or in other regions of the Mediterranean Basin. Chamaephytes (46.08%) and hemicryptophytes (31.37%) are very abundant, whereas therophytes (11.96%) and phanerophytes (0.98%) are comparatively rare. There is a statistically significant correlation between life form and both altitudinal and rainfall gradients. Chamaephytes reach their highest density rates within 1400-2000 m a.s.l., but these records tend to decrease as rainfall rates increase. Abundance of hemicryptophytes is directly dependent on rainfall rates and inversely dependent on temperature. The altitudinal distribution pattern of therophytes is opposite to that of hemicryptophytes, but there is no clear correlation as far as rainfall gradient is concerned. Considering both the endemic plants as a whole and each of the life form groups, the relationships between the dispersal modes used and the altitudinal and rainfall gradients are analysed. Up to 44.51% of the endemic plants do not present evident adaptations to promote the dispersion of their diaspores. However, only in the group of therophytes, whose occurrence is positively related to areas of minor altitude, does this difficulty of dispersion play a significant role in the maintenance of stenochory.

Alpine–subalpine species richness of the Romanian Carpathians and the current conservation status of rare species

“…An analysis of endemic species distribution, related to grid cell altitude and SR shows that the number of these species increases with altitude (R 2 = 0.33, P \ 0.001), similarly to the results recorded in the southern Europe (Giménez et al 2004). There is also a strong relation to the total number of taxa per grid cell-R 2 = 0.82 (Kull et al 2002).…”

Plant Species Diversity along Road Reserve in Kisumu County- Kenya

“…For instance, most tropical ecosystems (Batalha and Martins, 2004;Koulibaly et al, 2006;Ouedraogo et al, 2011;Schmidt et al, 2005) have ascertained that the phanerophytes are the most dominant life form especially in the forested regions. In most savannas ecosystems however, the therophytes (Aghaei et al, 2013;Medvecka et al, 2013;Turki and El Shayeb, 2005), chamaephytes (Gimenez et al, 2004) and hemicryptophytes (Amjad, 2012;Dimopoulos and Georgiadis, 1992;Klimes, 2003) have been reported to dominate different regions depending on how well they interact with their environment (Zarezade et al, 2007). From our study, phanerophytes grouped together constituted 48.9%, which implied that they were the most dominant, however, there was need to delimit the groups (Govaerts et al, 2000) for ease of understanding, given the floral diversity of the study area.…”

Vegetation of temporary ponds in cold holes in the Taurus mountain chain (Turkey)

“…More hemicriptophytes, which are associated with a cold and humid environment (Raunkiaer 1934), can be found at higher altitudes, which has already been noticed in other mountains (Klimeš 2003;Naqinezhad et al 2009). On the other hand, the situation with therophytes is the opposite; they are the dominant life forms in regions with a Mediterranean climate (Giménez et al 2004) and are therefore more common at lower altitudes.…”