title: Phylogeny strongly drives seed dormancy and quality in a climatically buffered hotspot for plant endemism.
abstract: Models of costs and benefits of dormancy (D) predict that the evolutionarily stable strategy in long-term stable environments is for non-dormancy (ND), but this prediction remains to be tested empirically. We reviewed seed traits of species in the climatically buffered, geologically stable and nutrient-impoverished campo rupestre grasslands in Brazil to test the hypothesis that ND is favoured over D. We examined the relative importance of life-history traits and phylogeny in driving the evolution of D and assessed seed viability at the community level.
  
  
  
  Germination and viability data were retrieved from 67 publications and ND/D was determined for 168 species in 25 angiosperm families. We also obtained the percentage of embryoless, viable and dormant seeds for 74 species. Frequencies of species with dormant and non-dormant seeds were compared with global databases of dormancy distribution.
  
  
  
  The majority of campo rupestre taxa (62·5 %) had non-dormant seeds, and the ND/D ratio was the highest for any vegetation type on Earth. Dormancy was unrelated to other species life-history traits, suggesting that contemporary factors are poor predictors of D. We found a significant phylogenetic structure in the dormancy categorical trait. Dormancy diversity was highly skewed towards the root of the phylogenetic tree and there was a strong phylogenetic signal in the data, suggesting a major role of phylogeny in determining the evolution of D versus ND and seed viability. Quantitative analysis of the data revealed that at least half of the seeds produced by 46 % of the surveyed populations were embryoless and/or otherwise non-viable.
  
  
  
  Our results support the view that long-term climatic and geological stability favour ND. Seed viability data show that campo rupestre species have a markedly low investment in regeneration from seeds, highlighting the need for specific in situ and ex situ conservation strategies to avoid loss of biodiversity.
authors: Departamento de Botânica, ICB/UFMG, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, Minas Gerais 31270-110, Brazil.
authors: Roberta L C
authors: RL
authors: Dayrell
authors: Departamento de Botânica, ICB/UFMG, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, Minas Gerais 31270-110, Brazil.
authors: Queila S
authors: QS
authors: Garcia
authors: Instituto de Ciências Biológicas e Saúde, Centro Universitário UNA, Rua Guajajaras 175, 30180-100 Belo Horizonte, MG, Brazil.
authors: Daniel
authors: D
authors: Negreiros
authors: Department of Biology, University of Kentucky, Lexington, KY 40506, USA.|Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA.
authors: Carol C
authors: CC
authors: Baskin
authors: Department of Biology, University of Kentucky, Lexington, KY 40506, USA.
authors: Jerry M
authors: JM
authors: Baskin
authors: Departamento de Botânica, ICB/UFMG, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, Minas Gerais 31270-110, Brazil faosilveira@icb.ufmg.br.
authors: Fernando A O
authors: FA
authors: Silveira
mesh_terms: D004463:Ecology; D019684:Magnoliopsida / Q000502:physiology*; D010802:Phylogeny; D057445:Plant Dormancy / Q000502:physiology*; D012639:Seeds / Q000502:physiology*
keywords: Campo rupestre; Cerrado; OCBIL; P-deficient soils; community; ecophylogenetics; embryoless seeds; evolutionarily stable strategy; refugia; regeneration ecology; rupestrian grassland; seed viability