Document


Title

Ecophysiology of seed germination of wild Dahlia coccinea (Asteraceae) in a spatially heterogeneous fire-prone habitat
Document Type: Journal Article
Author(s): S. Vivar-Evans; V. L. Barradas; M. E. Sanchez-Coronado; A. G. de Buen; A. Orozco-Segovia
Publication Year: 2006

Cataloging Information

Keyword(s):
  • ash
  • ash
  • Asteraceae
  • cold stratification
  • fire intensity
  • fire management
  • germination
  • gibberellic acid
  • heat
  • herbaceous vegetation
  • laboratory fires
  • light
  • Mexico
  • Mexico City
  • moist and dry heat
  • precipitation
  • seed dormancy
  • seed germination
  • seeds
  • shrubland in a lava field
  • shrublands
  • temperature
Topic(s):
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 49198
Tall Timbers Record Number: 25521
TTRS Location Status: Not in file
TTRS Call Number: Not in File
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

Dahlia coccinea grows on fire-prone xerophilous shrubland, on a lava field located in Mexico City. Two kinds of experiments were performed to test the role of fire and environmental heterogeneity on germination. The first experiment tested the effect of environmental conditions (constant and alternating temperatures, cold stratification and light). The second one tested the effects of fire and high temperatures (dry and moist heat) on germination. Seeds of Dahlia were indifferent to light. The seeds showed physiological dormancy which was lost by after-ripening or by gibberellins. During simulated fires, dry seeds tolerated high temperatures of short duration and also withstood prolonged exposure to 60ºC. Dry heat treatment reduced the mechanical restriction for embryo growth in dormant seeds. Ash and prolonged exposure to moist heat inhibited germination. Exogenous gibberellins reversed the deleterious effects of prolonged exposure to moist heat. The effect of cold stratification was related to the seeds' physiological stage and to light conditions; stratification in the dark reduced germination. Seeds of D. coccinea could tolerate, evade, or be slightly favored by the effects of low intensity fires occurring in their habitat. Seed responses to treatments suggest that the spatially heterogeneous lava field could provide a wide variety of micro-sites where physiological dormancy could be broken and during fires seeds could maintain their viability and subsequently germinate and/or develop a seed bank. © 2006 Elsevier SAS. All rights reserved.

Citation:
Vivar-Evans, S., V. L. Barradas, M. E. Sanchez-Coronado, A. G. de Buen, and A. Orozco-Segovia. 2006. Ecophysiology of seed germination of wild Dahlia coccinea (Asteraceae) in a spatially heterogeneous fire-prone habitat. Acta Oecologica, v. 29, no. 2, p. 187-195. 10.1016/j.actao.2005.10.001.