Grassroots Vol 20 No 3 | Page 20

FEATURE % Total N 0,6 0,5 0,4 0,3 0,2 0,1 0 Thicket transformed boundary Transformed 40m Transformed 20m Thicket 20m Thicket 40m Vegetation type Figure 6: Total nitrogen in the soil in the thicket and transformed patches. which, allow water infiltration as well as the establishment of seedlings. Higher total nitrogen in the soil produces high forage nitrogen in the thicket areas. This forms a valuable resource for herbivores when the soil moisture levels drop during the dry season and the transformed patches stop producing leaves with a resultant drop in the quality and quantity of the forage these areas. This is especially relevant during the ever-frequent inter-annual droughts in the Albany thicket Biome, and where annual evaporation is nearly 4-fold the precipitation (Jury & Levey 1993). Figure 7: The number of individuals and number of species in the thicket and transformed areas. This preliminary study indicates that a mosaic of transformed grassland and thicket patches may be the best outcome for both production and biodiversity, allowing animals to forage in the cleared patches in the wet season and to be able to find quality forage in the thicket in the dry season. We do not yet know what the patch sizes and distribution should be to achieve this goal. We also still need to understand the ecosystem services that thicket patches provide much better to understand the best way to approach the management of the thicket to gain the most benefit in terms of ecosystem services. Figure 8: Average height and width in cm of woody plants in the thicket and transformed areas. These preliminary results also indicate that restoration of transformed areas to thicket will be a challenge. Soils in the cleared areas are more compacted and have lower nutrients than soils in thicket areas. Without improving the soil condition to a state that is closer to that found in the thicket vegetation, it will be exceedingly difficult to establish young plants. The presence of animals will further limit the success of restoration as many animals prefer to forage in these open areas utilizing young woody plants extensively. REFERENCES Cowling RM & Mills A J 2011. A preliminary assessment of rain throughfall beneath Portulacaria afra canopy in subtropical thicket and its implications for soil carbon stocks. South African Journal of Botany 70: 236-240. Grant CC & Scholes MC 2006. The importance of nutrient hot-spots in the conservation and management of large wild mammalian herbivores in semi-arid savannas. Biological Conservation 130: 426-437. Grant CC, Botha J, Grant TC, Peel MJS & Smit IPJ 2019. "When less is more: Heterogeneity in grass patch height support herbivores in counter-intuitive ways. African Journal of Range and Forage Science 36: 1-8. Haschick SL & Kerley GIH 1997. Factors influencing forage preference of bushbuck and boer goats for Subtropical Thicket plants. African Journal of Range & Forage Science 14: 49-55. Jury MR & Levey K 1993. The climatology and characteristics of drought in the Eastern Cape of South Africa International Journal of Climatology 13: 629-641. SANParks, 2015. Addo Elephant National Park Management Plan (2015 - 2025) (Draft). South African National Parks. http:// (accessed 29.04.20.). Sigwela AM, Kerley GIH, Mills AJ & Cowling RM 2009. The impact of browsing-induced degradation on the reproduction of subtropical thicket canopy shrubs and trees. South African Journal of Botany 75: 262-267. 19 Grassroots Vol 20 No 3 September 2020