Abstract Detail

Plant life in Neotropical rocky outcrops

Nogales da Costa Vasconcelos, Thais [1], Alcantara, Suzana [2], Andrino, Caroline [3], Forest, Félix [4], Reginato, Marcelo [5], Simon, Marcelo [6], Pirani, José Rubens [7].

Fast diversification through a mosaic of evolutionary histories characterizes the endemic flora of the campo rupestre.

Mountains are among the most biodiverse areas on the globe. In young mountain ranges, exceptional plant species richness is often associated with recent and rapid radiations linked to the mountain uplift itself. In ancient mountains, however, orogeny vastly precedes the evolution of vascular plants, so species richness has been explained by species accumulation during long periods of low extinction rates. Here we evaluate these assumptions by analysing plant diversification dynamics in the campo rupestre, an ecosystem associated with pre-Cambrian mountaintops and highlands of eastern South America, areas where plant species richness and endemism are among the highest in the world. Analyses of 15 angiosperm clades show that radiations of endemics exhibit fastest rates of diversification during the last 5 Myr, a climatically unstable period. However, results from ancestral range estimations using different models disagree on the age of the earliest in situ speciation events and point to a complex floristic assembly. There is a general trend for higher diversification rates associated with these areas, but endemism may also increase or reduce extinction rates, depending on the group. Montane habitats, regardless of their geological age, may lead to boosts in speciation rates by accelerating population isolation in archipelago-like systems, circumstances that can also result in higher extinction rates and fast species turnover, misleading the age estimates of endemic lineages.

1 - University of Arkansas
2 - UFSC-Universidade Federal De Santa Catarina, Depto De Botanica, Campus Universit�rio Trindade, Bairro Trindade, Florianopolis, SC, 88040-900, Brazil
3 - USP
4 - Royal Botanic Gardens, Kew, Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, United Kingdom
5 - UFRGS
6 - Embrapa-Cenargen
7 - USP, Brazil

Keywords:
climatic fluctuations
species pump
speciation
Extinction
Pliocene
Pleistocene.

Presentation Type: Colloquium Presentations
Session: COL08, Plant life in Neotropical rocky outcrops
Location: Virtual/Virtual
Date: Friday, July 31st, 2020
Time: 10:45 AM
Number: COL08003
Abstract ID:325
Candidate for Awards:None