Trying to Link Vegetation Units with Biomass Data: The Case Study of Italian Shrublands

Although their carbon stock is relevant in assessing the baseline for the negotiation of future agreements with respect to carbon balance, there still are few available studies concerning the biomass and the net ecosystem exchange capacity of Mediterranean shrublands. In this chapter a preliminary overview on the biomass values concerning Italian shrubland communities and/or their dominant/ characteristic woody species is provided. Many useful data on above- and belowground biomass issued from investigations carried out in other Mediterranean countries and concerning plant communities, which share the same ecological, floristic and structural traits of Italian shrublands. A preliminary finding of this research is the uneven degree of knowledge concerning the different non-forest woody communities. For example, there is still no literature on the biomass of some 2/3 of all the considered phytosociological units. Besides, both the above and the below-ground biomass of many Mediterranean shrubs show a very wide range of variation as they are strongly influenced by progressive succession processes and by the nature, the intensity and the frequency of disturbance factors. Thus, direct measuring of these values for each vegetation unit and dominant woody species should be encouraged and intensified. Monitoring activities concerning biomass increase are recommended as well: as a matter of fact, at present reference data on this topic are so limited and variable that it is not possible to confidently estimate the annual growth of shrubland communities.