Natural regeneration of forest after disturbance, depends from many factors, as environmental conditions of affected area and organisms that potentially could grow in those sites. It is important to know the regenerative patterns after some disturbance, for that reason in this study we evaluated the natural regeneration from two groups (conifers and oaks) in Sierra Norte of Oaxaca, Mexico in relation with edaphic, biological and disturbance factors. Edaphic factors that we analyzed were: temperature; moisture; percentage of sands, silts and clays; nitrate and potassium concentration; compaction level; infiltration time; litter depth; pH. Biological factors were: number of species and individuals per species; average heights; average basal areas; percentage of vegetation cover; number of seeds produced by each group. Types of disturbance that we included were: forest harvesting; sanitation by plague; fire. We did correlations between different variables with information of natural regeneration (individuals ≤2.5 cm of DHP, diameter at breast height). The variables with any significant correlation (R2= ≥0.25) were applied to different generalized linear models. We also compared the regeneration from each group according to the different types of vegetation of the study area (conifer, oak and mixed forests).
Results/Conclusions:
According to the models that we got, the natural regeneration of conifers is explained until a 95.56% (D2, deviance) by variables as average temperature to 5 cm and 10 cm of depth, average moisture to 5 cm of depth, number of conifer species and the presence/absence of forest harvesting. For models that included disturbance as fire and sanitation by plague, their deviance values were lower, 82.61% and 79.71% respectively. The natural regeneration of oaks is explained until a 96.14% by variables as average temperate to 10 cm of depth, percentage of silts in the soil, number of oaks species, number of individuals of oaks and presence/absence of sanitation by plague. The model that included forest harvesting obtained a lower deviance value (79.60%). We do not find significant differences in natural regeneration of oaks between the different types of vegetation of study area, but in the regeneration of conifers was higher in conifer forests dominated by Abies hickelii. We observed that natural regeneration of conifers and oaks depends of type of disturbance and vegetation. Knowing what factors are important for the natural regeneration of vegetation in any site it is fundamental to apply that knowledge in the conservation of biological resources.