Fast regeneration of the tussock grass Ampelodesmos mauritanica after clearing

Abstract

Disturbance by clearing is common in Mediterranean shrublands of NE Spain as a fire prevention technique to reduce juel loads. We compared the regeneration of the vegetation in grass-dominated communities in cleared stands with adjacent non-cleared stands. We especially focussed on the response of the expansive perennial grass Ampelodesmos mauritanica in a 6 month (recently cleared), two year old (once cleared) stands and in a one-year-old stand cleared in two consecutive years (twice cleared). Cleared plots recovered quickly from clearing due to the dominance in the community of species that resprout from belowground organs after disturbance. The number of species was not significantly different between cleared and adjacent non-cleared plots. Total plant cover was lower in recently cleared plots than in adjacent non-cleared plots, but not significantly different in once and twice cleared plots. Clipped Ampelodesmos mauritanica plants had high survival and vigorous resprouting after clearing. Although in cleared plots Ampelodesmos mauritanica plants were smaller than in adjacent non-cleared plots, cover was not significantly different. Seedling recruitment was higher in recently cleared plots than in adjacent non-cleared plots. Our results suggest that clearing is not a very effective management tool for reducing Am pelodesmos mauritanica abundance and as a fire-prevention technique because this dominant grass shows no mortality after clearing and accumulates fuel loads very fast after aboveground biomass removal.