Influence Of Fire Recurrence On CO2 Sink And Soil Composition In Holm Oak Forests
Free (open access)
321 - 330
F. R. López-Serrano, J. De las Heras, D. Moya, F. A. García-Morote & E. Rubio
During the last few decades thousands of hectares of Holm oak (Quercus ilex subsp. ballota) forests have burned in Spain due to the increase in the number of large forest fires. This species is able to resprout after disturbance, so a high density coppice stand regenerates naturally after a fire. In SE Spain, a wildfire affected a Holm oak forest in August, 1993, and another fire occurred in July, 2001. A study was carried out to assess the influence of fire recurrence on the CO2 sink capacity of this forest but also the influence on the soil composition. For this research, several plots were defined and set in the burned area. All resprouts within plots were measured (diameter at 30 cm above ground) and selected individuals were subjected to destructive tests to estimate biomass (above and below ground). By applying allometric relationships to all resprouts, the biomass of the different plots was estimated. To estimate the annual CO2 sink in the study plots, the dry biomass obtained was multiplied by determined conversion factors. A large resprouting event occurred 3 months after the last fire and the estimated biomass suggested that recurrent fires could be negatively related to the vitality of the Holm oak shoots. Results also showed the important contribution of these coppice forests as a CO2 sink. However, fire recurrence decreased the presence of the main soil components and it was not significantly affected by treatments. These results allowed us to establish that the CO2 sink capacity is negatively affected by successive fires. This tendency could be changed by silvicultural treatments aimed to improve growth, vitality and adequate reproduction. Management models of coppice Holm oak stands are needed in order to improve CO2 sink capacity. Keywords: resprouting, quercus ilex, coppice forest.
resprouting, quercus ilex, coppice forest.