Question: How does competition by grasses, grazing by indigenous large herbivores, and their interaction affect the establishment, growth and survival of transplanted native woody and herbaceous seedlings on an abandoned agricultural field?
Location: West Coast Renosterveld, Cape Floral Region, South Africa.
Methods: Indigenous shrub seedlings were planted in different treatments, where either grass competition or herbivory or both were manipulated. Survival, growth and canopy cover of the seedlings were measured on a monthly basis over 14 months, and compared between treatments.
Results: Experimental transplanting of indigenous shrubs into an old field showed that most of the plants investigated competed for resources with grasses on the field, and competition negatively affected the seedlings throughout the experiment. Mortality was higher, and growth was reduced for seedlings exposed to grass competition. Herbivory alone had no significant impact on the target species with the exception of Olea europaea ssp. africana. There was no significant interaction between competition and herbivory.
Conclusion: Reduction of herbaceous competition significantly accelerates shrubland recovery on abandoned agricultural fields in renosterveld.
Abbreviations: NPNW = Not protected from herbivory and not weeded; NPW = Not protected from herbivory and weeded; PNW = Protected from herbivory and not weeded; PW = Protected from herbivory and weeded.
Nomenclature: Germishuizen and Meyer (2003).