Mechanical fuel treatment effects on vegetation in a New Mexico dry mixed conifer forest

Abstract

While the main objective of many silvicultural treatments in the western US is to reduce fire potential, their effects on overstory regeneration, midstory and herbaceous communities is of importance to land managers. To quantify these effects, we measured overstory regeneration, midstory density by species, herbaceous biomass, species richness and cover in commercial and non-commercial treatments with differing slash prescriptions in dry mixed conifer stands of south central New Mexico. Results indicated that overstory regeneration and shrub density were not significantly affected by treatments, although they did increase at one site which appeared to be more mesic than the others. Herbaceous biomass increased 4 years post-treatment in one non-commercial scatter treatment and 3 years post-treatment in the commercial treatment. Species richness was not affected by any of the treatments. Cover of grasses and forbs remained low in all treatments. Soil cover increased in the commercial treatment; however, it decreased each year following treatment.