| Abstract: | A long-term field experiment was conducted in a semiarid Mediterranean site to determine the effect of the application of several doses (6·5, 13, 19·5 and 26 kg m−2) of urban solid refuse (USR) on the plant colonization, plant cover and biomass production. The plant species richness did not increase in all the treated plots with respect to the control except immediately after the treatment was applied. This increase was only maintained after three years in the lowest dose of USR and the control. The addition of USR slowed floristic change and the lowest percentages of change corresponded to those plots receiving the highest doses. The plot receiving the lowest doses behaved in a similar way to the control plot. Plant cover increased substantially in the plots treated with USR compared with the control plot, even the lowest doses increasing the cover by 500 per cent. Plant biomass also significantly increased in all the amended plots compared with the control, although such increases were not directly proportional to the doses of USR added. USR can be considered an effective organic amendment to regenerate the plant cover of degraded soils. © 1997 John Wiley & Sons, Ltd. |
