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Table 2 Results of the logistic regressions predicting probability of a cactus to burn, canopy type and growth strategy as explanatory variables. The analysis was conducted with and without Leptocereus quadricostatus and Harrisia portoricensis data. Data were collected in 2014-2015 at El Faro, Puerto Rico. Odds ratio is the probability of being killed by the fire versus surviving the fire (e.g., burned cacti were more than 62 times as likely to die as unburned cacti); Z-value is the regression coefficient divided by its standard error; P-value represents the probability of a Type I error

From: Effects of fire on native columnar and globular cacti of Puerto Rico: a case study of El Faro, Cabo Rojo

Parameter Odds ratio (±SE) Z-value P-value
Intercept 0.983 (1.20) −0.092 0.927
Open Canopy (Grasses and shrubs) 4.807 (1.46) 4.141 <0.001
Globular Cactus 2.542 (2.39) 1.089 0.276
Open Canopy x Globular Cactus 0.577 (2.61) −0.574 0.566
Without Leptocereus quadricostatus and Harrisia portoricencis
Intercept 0.967 (1.21) −0.186 0.853
Open Canopy (Grasses and shrubs) 4.792 (1.54) 3.626 <0.001
Globular Cactus 2.588 (2.36) 1.109 0.267
Open Canopy x Globular Cactus 0.579 (2.66) −0.556 0.578