Track 2-03: Ecological Succession, Management and Restoration of Grasslands
Description
The decline of traditional pastoral systems has highlighted the problem of managing shrub encroachment in shrublands of the Mediterranean region, especially in marginal habitats. Ephemeral grasslands appear after fire in Mediterranean shrub communities on phosphorus-deficient soils, but natural successional processes rapidly led to their dominance. In a study, aimed at reducing the rate of successional change and extending the period of grassland dominance, phosphorus was applied after fire to improve herbaceous growth and two years later the regenerating Sarcopoterium spinosum shrubs were controlled with selective herbicide. Subsequently, the vegetation in the treated areas was monitored for more than 20 consecutive years. The vegetation was undisturbed during the winter/spring growing season but was grazed during the dry summer of each year by beef cattle. In control plots, the shrubs returned to pre-fire dominance of shrubs within five years. With phosphorus and herbicide, shrub dominance was reduced by the vigorous herbaceous vegetation for more than 20 years. It is shown that appropriate management of grazing, periodic control of the shrub component, and occasional soil nutrient amelioration can lead to the development of attractive open woodland with a productive herbaceous understory. The practical feasibility of this management option depends on the relation between costs and benefits. Preliminary economic analysis indicated that management may be cost effective.
Included in
Role of Fires, Herbicides and Fertilizer in Manipulating Shrub/Grass Balance in Mediterranean Grasslands
The decline of traditional pastoral systems has highlighted the problem of managing shrub encroachment in shrublands of the Mediterranean region, especially in marginal habitats. Ephemeral grasslands appear after fire in Mediterranean shrub communities on phosphorus-deficient soils, but natural successional processes rapidly led to their dominance. In a study, aimed at reducing the rate of successional change and extending the period of grassland dominance, phosphorus was applied after fire to improve herbaceous growth and two years later the regenerating Sarcopoterium spinosum shrubs were controlled with selective herbicide. Subsequently, the vegetation in the treated areas was monitored for more than 20 consecutive years. The vegetation was undisturbed during the winter/spring growing season but was grazed during the dry summer of each year by beef cattle. In control plots, the shrubs returned to pre-fire dominance of shrubs within five years. With phosphorus and herbicide, shrub dominance was reduced by the vigorous herbaceous vegetation for more than 20 years. It is shown that appropriate management of grazing, periodic control of the shrub component, and occasional soil nutrient amelioration can lead to the development of attractive open woodland with a productive herbaceous understory. The practical feasibility of this management option depends on the relation between costs and benefits. Preliminary economic analysis indicated that management may be cost effective.
