Background:

In tropical pines forest, fire favors the maintenance of biodiversity.

Hypotheses:

Fires favor tree regeneration; the increase in fire severity and topography affect forest structure, composition, and tree regeneration.

Study site and dates:

A tropical pine forest in El Fresno, Morelos, one year after a fire.

Methods:

Forest structure, composition and tree regeneration were evaluated in 13 plots in an unburned forest and in 45 of 500 m2 plots affected by low, medium, and high fire severity.

Results:

We registered 4,727 trees, 1,134 dead trees and 2,130 resprouts from 11 species in eight families: three species were seeders, and seven species were resprouters. The highest abundance of recruits was registered in the low fire severity: > 98 % were Pinus pringlei (Pinaceae) seedlings. The highest abundance of resprouters was registered in the high severity: > 72 % were Quercus spp (Fagaceae) resprouts. With the increase in fire severity, basal area and tree cover decreased. At higher altitudes, there was a higher density of adult trees and juveniles while at places with higher slopes, a higher basal area of dead trees was registered.

Conclusions:

The fire event increased regeneration and changed forest composition. In medium fire severity, the density of pine seedlings increased while high fire severity favored oak resprouts.