METHOD
Pine cones were collected in eight natural populations of Pinus oocarpa in Mexico.
Fire forest conditions were simulated by heating cones inside an oven using three temperatures (100, 200 and 250ºC) and three times of exposure (5,10,20 min) based on the model shown before. Two cones per population were heated, and overall, 16 cones per combination of time and temperature were used.
Cone opening (discrete variable) was measured in response to these treatments using the next formula:
Opening=(diameter after heating-diameter before heating)/diameter before heating
Predictor variables are Temperature and Time (Categorical). Since no considerable variation was found between Populations, it was considered as a covariate.
Fire forest conditions were simulated by heating cones inside an oven using three temperatures (100, 200 and 250ºC) and three times of exposure (5,10,20 min) based on the model shown before. Two cones per population were heated, and overall, 16 cones per combination of time and temperature were used.
Cone opening (discrete variable) was measured in response to these treatments using the next formula:
Opening=(diameter after heating-diameter before heating)/diameter before heating
Predictor variables are Temperature and Time (Categorical). Since no considerable variation was found between Populations, it was considered as a covariate.