摘要：

The importance of shrub formations in the Mediterranean area both in terms of area occupied and carbon sequestered by them is currently being recognized. However, due to the lack of suitable models to estimate biomass accumulation and growth rate in this region, the carbon sequestered by these formations is not included when computing the total carbon stocks in aboveground biomass in Mediterranean forest ecosystems, according to the IPCC guidelines. The aim of the present study is to develop equations to predict biomass accumulation and growth rate for the main shrub formations in the region of Andalusia (Southern Spain), using the fraction of canopy cover (FCC (m) ) and the average height of the shrub formations (H (m) ) as predictors. To build these models, more than 800 plots were inventoried using destructive sampling; the mean value found in the region for biomass accumulation and annual growth rate being 16.73 Mg ha(-1) and 1.14 Mg ha(-1) year(-1), respectively. Heathers and big-size Cistaceae formations were the ones that presented the highest values of biomass accumulation (24.99 and 21.01 Mg ha(-1), respectively), while the highest values for annual growth rate were achieved by Leguminous gorse shrubs and, again, big-size Cistaceae bushes (1.49 and 1.64 Mg ha(-1) year(-1), respectively). The carbon content for the main shrub species and formations in the area was also obtained. The developed models provide the opportunity to estimate shrub carbon stocks in Mediterranean forest management from easy-to-obtain variables, namely FCC (m) and H (m) . Moreover, the used shrub formations classifications and model structure allow their applicability to compute biomass accumulation and growth rate at regional and national level using as input data from the Spanish National Forest Inventory.

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