Influence of mediterranean shrub species on soil chemical properties in typical mediterranean environment

The influence of two Mediterranean shrub species (Rosmarinus officinalis an d Ulex parviflorus) on soil chemical properties in a typical pine (Pinus ha lepensis) forest hillside was studied. This study was conducted also in the adjacent openings of these plants. The seasonal evolution of the selected soil chemical properties was monitored during one-year period. Ammonium-N ( N-NH4+) and available phosphorus showed similar values under shrub cover th ose in openings. However, the highest levels on electric conductivity, orga nic matter, total nitrogen and nitrate-N (N-NO3-) were observed in soil und erneath canopies, whereas, soil pH was lower in the first 5 cm of soil surf ace under shrubs than in openings. The differences are statistically signif icant and indicate strong differentiation of surface soil conditions at the scale of individual plants. The results obtained suggest that the studied shrubs bring about an important function in to improving soil conditions un der their canopies. The short-term fluctuation of some important soil chemi cal properties shows a clear difference between wet and dry seasons.