Effects of fire recurrence in Quercus coccifera L. shrublands of the Valencia Region (Spain): I. plant composition and productivity

Abstract

The purpose of this study was to determine whether fire recurrence modifies the regeneration capacity of Quercus coccifera garrigues in the Valencia region ͑eastern Spain͒. We studied several areas with different fire recurrences ͑1, 2 and 3 fires in 16 years͒, all of which had sustained a common last fire in 1994. Three-and-a-half years after the last fire, differences between the 3 fire recurrences were not detected with respect to total plant cover and Q. coccifera cover, with a mean value between 92 and 76%. On the most frequently burned sites, herbaceous and subshrub species cover showed a tendency to increase, while that of the obligate seeding shrub, Ulex parviflorus, decreased with both fire frequency and shorter last-fire interval. The most recurrently burned areas with the shortest last-fire intervals presented higher species richness, which mainly affected the herbaceous and subshrub species group, and of these, the hemichryptophytes. The major effect of fire recurrence was the significant decrease in stem and total biomass of Q. coccifera in the three studied sites. Three-and-a-half years after the fire, the mean total biomass values were around 1500, 1000 and 700 g. m -2 in the garrigues with 1, 2 and 3 fires respectively. Stem production was more affected than leaf production. Leaf area index values showed the same pattern as leaf biomass. Recurrent fires also caused a decrease in net primary production measured the fourth year after fire. The results point to the fact that fire recurrence can cause depletion in garrigue productivity and recovery capacity in southern areas, in contrast with the high resilience observed in northern Mediterranean garrigues.

A conceptual dynamic vegetation-soil model for arid and semiarid zones

“…Quercus coccifera L. inhabits regions where the edaphic conditions lead to a great aridity and is considered pyrostable, since it shows a high regeneration rate after fire. The latter, seems to be due to the continuity of belowground biomass after fire that plays an important role in determining the optimum tactics to be adopted during succeeding cycles (Abril and Gracia, 1989;Cañellas and San Miguel, 2000;Delitti et al, 2005). The kermes oak is found commonly in Spain in continental vegetation structure in the meso-Mediterranean belt and varied ombrotype climates (dry-humid, semiarid-dry, drysubhumid and dry) reaching up to 2 m in height.…”

The resilience ability of vegetation after different fire recurrences in Provence

“…The same species recolonize the plots after a fire quite quickly. This is called "autosuccession" [4,6,7].…”

Water availability and species identity control shrub colonization in abandoned semiarid steppes

“…In this line, according to field evidences and our own results, future climatic and disturbance regimes may have contrasting effects for the persistence of some patch-forming species leading to changes in the composition of species of the studied system (Delitti et al, 2005;Peñuelas et al, 2001). …”