Timing of seed dispersal and seed dormancy in Brazilian savanna: two solutions to face seasonality

Autor(es)

Escobar, Diego F. E. ^[1] ; Silveira, Fernando A. O. ^[2] ; Morellato, Leonor Patricia C. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Inst Biosci, Phenol Lab, Av24A, 1515, BR-13506900 Rio Claro, SP - Brazil

^[2] Univ Fed Minas Gerais, Dept Bot, BR-30161970 Belo Horizonte, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANNALS OF BOTANY; v. 121, n. 6, p. 1197-1209, MAY 11 2018.
• Citações Web of Science: 4

Resumo

Background and Aims The relationship between fruiting phenology and seed dispersal syndrome is widely recognized; however, the interaction of dormancy classes and plant life-history traits in relation to fruiting phenology and seed dispersal is understudied. Here we examined the relationship between fruiting season and seed dormancy and how this relationship is modulated by dormancy classes, dispersal syndromes, seed mass and seed moisture content in a Brazilian savanna (cerrado). Methods Dormancy classes (non-dormancy and physical, morphological, morphophysiological, physiological and physiophysical dormancy) of 34 cerrado species were experimentally determined. Their seed dispersal syndrome (autochory, anemochory, zoochory), dispersal season (rainy, dry, rainy-to-dry and dry-to-rainy transitions), seed mass and moisture contents, and the estimated germination date were also determined. Log-linear models were used to evaluate how dormancy and dormancy classes are related to dispersal season and syndrome. Key Results The proportions of dormant and non-dormant species were similar in cerrado. The community-estimated germination date was seasonal, occurring at the onset of rainy season. Overall, anemochorous nondormant species released seeds during the dry-to-rainy transition; autochorous physically dormant species dispersed seeds during the dry season and rainy-to-dry transition; zoochorous species dispersed non-dormant seeds during the dry and rainy seasons, while species with morphological, morphophysiological or physiological dormancy dispersed seeds in the transitional seasons. Seed mass differed among dispersal seasons and dormancy classes, but seed moisture content did not vary with dispersal syndrome, season or dormancy class. Conclusions The beginning of the rainy season was the most favourable period for seed germination in cerrado, and the germination phenology was controlled by both the timing of seed dispersal and seed dormancy. Dormancy class was influenced by dispersal syndrome and season. Moreover, dormancy avoided seed germination during the rainy-to-dry transition, independently of dispersal syndrome. The variability of dormancy classes with dispersal syndrome allowed animal-dispersed species to fruit all year round, but seeds germinated only during the rainy season. Conversely, seasonally restricted wind-dispersal species dispersed and germinated their non-dormant seeds only in the rainy season. (AU)

• Processo FAPESP: 14/21430-6 - Fenologia da dispersão e estratégias de germinação de sementes de plantas lenhosas e herbáceas no cerrado
• Beneficiário: Diego Fernando Escobar Escobar
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 10/51307-0 - Diversidade florística e padrões sazonais dos campos rupestres e cerrado
• Beneficiário: Leonor Patricia Cerdeira Morellato
• Modalidade de apoio: Auxílio à Pesquisa - Parceria para Inovação Tecnológica - PITE
• Processo FAPESP: 13/50155-0 - Combining new technologies to monitor phenology from leaves to ecosystems
• Beneficiário: Leonor Patricia Cerdeira Morellato
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - PITE
• Processo FAPESP: 07/59779-6 - Estudo comparativo da diversidade e da fenologia reprodutiva e vegetativa entre borda e interior num fragmento de cerrado em itirapina, sao paulo.
• Beneficiário: Leonor Patricia Cerdeira Morellato
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 09/54208-6 - EMU: Laboratório Multiusuário Centralizado do Núcleo de Estudos em Biodiversidade da UNESP
• Beneficiário: Célio Fernando Baptista Haddad
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários