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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Does Fire Trigger Seed Germination in the Neotropical Savannas? Experimental Tests with Six Cerrado Species

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Author(s):
Fichino, Betania Santos [1] ; Dombroski, Julia R. G. [1] ; Pivello, Vania R. [1] ; Fidelis, Alessandra [2]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Dept Ecol, Rua Matao, Travessa 14, 321, BR-05508900 Sao Paulo - Brazil
[2] Univ Estadual Paulista, UNESP, Dept Bot, Av 24-A, 1515, BR-13506900 Rio Claro - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Biotropica; v. 48, n. 2, p. 181-187, MAR 2016.
Web of Science Citations: 12
Abstract

The Cerrado (Brazilian savanna) is a biodiversity hotspot with a history of fire that goes back as far as 10million years. Fire has influenced the evolution of several aspects of the vegetation, including reproduction and life cycles. This study tested how fire by-products such as heat and smoke affect the germination of six species common to two Cerrado open physiognomies: wet grasslands and the campo sujo (grassland with scattered shrubs and dwarf trees). We subjected seeds collected in northern Brazil to heat shock and smoke treatments, both separately and combined, using different temperatures, exposure times, and smoke concentrations in aqueous solutions. High temperatures and smoke did not break seed dormancy nor stimulate germination of the Cerrado study species. However, seeds were not killed by high temperatures, indicating that they are fire-tolerant. Our findings differed from those of other fire-prone ecosystems (mostly of Mediterranean vegetation), where fire stimulates germination. Moreover, we provide important information regarding germination strategies of non-woody Cerrado plants, showing the importance of considering the tolerance of seeds to high temperatures when evaluating fire-related traits in fire-prone ecosystems. ResumoO fogo e um importante fator ecologico que influencia a dinamica populacional das plantas. Consequencias imediatas do fogo sAo o aumento da temperatura acima do solo e producAo de fumaca, que podem afetar a germinacAo de diversas especies. O Cerrado (savana brasileira) e um hotspot de biodiversidade, cuja evolucAo esta atrelada a influencia do fogo ha mais de 10 milhoes de anos. Diversos aspectos da vegetacAo, incluindo a reproducAo e os ciclos de vida de diferentes especies, estAo relacionados a coexistencia com o fogo. ObjetivosEsse estudo tem como objetivo elucidar o efeito do calor e da fumaca na germinacAo de seis especies comuns em duas fisionomias abertas do Cerrado: campo umido e campo sujo. MetodosSementes das seis especies foram coletadas na regiAo do JalapAo, Tocantins, Brasil, e submetidas a choques de temperatura e tratamentos de fumaca, separadamente e combinados, em diferentes temperaturas, tempos de exposicAo e concentracoes de solucAo aquosa de fumaca. Resultados ImportantesAltas temperaturas e fumaca nAo quebraram a dormencia nem estimularam a germinacAo das especies de Cerrado estudadas. Entretanto, as sementes nAo foram mortas pelas altas temperaturas, indicando sua tolerancia ao fogo. Nossos resultados se diferenciam daqueles de realizados em outros ecossistemas pirofiticos (especialmente sobre a vegetacAo mediterranea), nos quais o fogo estimula a germinacAo. Alem disso, o estudo prove informacoes importantes sobre estrategias de germinacAo de plantas nAo lenhosas do Cerrado e mostra a importancia de se considerar a tolerancia de sementes a altas temperaturas para o estabelecimento de estrategias de manejo em ecossistemas sujeitos a queimadas. (AU)

FAPESP's process: 08/10049-9 - Effects of fire on herbaceous vegetation dynamics of Cerrado at the Parque Estadual do Jalapão: a functional approach
Grantee:Alessandra Tomaselli Fidelis
Support type: Scholarships in Brazil - Post-Doctorate