Important factors for local ecotype selection in restoration applications
Keywords: Veldagteruitgang, veldherstel, hersaai, ekotipe spesies
AbstractThe type of restoration application in degraded natural rangelands will depend on the degree of degradation. Degraded areas that are beyond the threshold of natural recovery normally need active restoration interventions. This includes the disturbance of the soil surface or the removal of undesired and alien species to reduce the competitive effect on the existing vegetation. One of the main goals of restoration in degraded arid and semi-arid rangelands is to increase the grazing capacity for livestock production. Active restoration interventions include re-seeding or re-vegetation with local ecotype selected species, adapted to the speciﬁc soil and climatic conditions of the area. To facilitate seed germination and seedling establishment, the restoration practice should also include protection measures such as brush packing or any cover by other organic matter. The timing of re-seeding is dependent on the seasonality and precipitation, especially in areas where rainfall events are erratic and unpredictable. Re-seeding of large degraded areas with speciﬁc ecotype selected species greatly depends on the availability of seed. This is a major limiting factor as most seed available from seed merchants are used for cultivated pastures, and do not include seed of local ecotype species that are adapted to a certain environment. To collect large quantities of seed represented by a speciﬁc habitat is very labor intensive and often not cost effective. Furthermore, if local ecotype selected seed is used, the quality, viability and purity are often not of a high standard, leading to poor restoration results. Although the economic implication and short term results of a restoration application are often regarded as determining factors, the ecological importance and improvement in the range condition should not be underestimated. Restoration applications have to be implemented according to a predetermined plan and should include monitoring and sound long-term management principles.