Publication: Fire cues and germination of invasive and native grasses in the Cerrado
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Date
2020-01-01
Advisor
Coadvisor
Graduate program
Undergraduate course
Journal Title
Journal ISSN
Volume Title
Publisher
Soc Botanica Brasil
Type
Article
Access right
Acesso aberto
Abstract
Fire-related cues may enhance seed recruitment in flammable ecosystems and differences in fire-germination responses of invasive vs. native species can drive the invasion process. We evaluated the effects of heat shock and smoke water solution treatment on seed germination of invasive (Melinis minutiflora, Urochloa decumbens, U. brizantha) and native grasses (Axonopus pressus, Aristida setifolia, Gymnopogon foliosus) of the Cerrado. The effect of fire temperature was tested by exposing seeds to heat shock treatments of 60, 100, and 200 degrees C for one minute, comparing them to untreated seeds. The effect of smoke was tested by soaking seeds for 24-h in an aqueous smoke comparing them to seeds soaked in distilled water. Differences among treatments were evaluated by ANOVA and randomization tests. None of the tested species had germination stimulated by the temperature or smoke. Both species of Urochloa experienced decreased viability with increasing temperature, while seeds of native species and M. minutiflora tolerated heat shock up to 200 degrees C. The invasive grasses usually germinated faster than the native grasses. Germination time is therefore a crucial trait driving the invasion process, irrespective of fire-related cues. Other seed traits (e.g. dormancy) and higher resprouting capacity may help invasive species to persist in frequently burned savannas.
Description
Language
English
Citation
Acta Botanica Brasilica. Sao Paulo Sp: Soc Botanica Brasil, v. 34, n. 1, p. 185-191, 2020.
