FEATURE
Thicket patches in the Eastern
Cape: do they have any value?
Rina C Grant 1,2 , Michael Powell 1 , Kamva Zenani 1
and Putuma Balintulo 1
Current Addresses: 1 Rhodes Restoration Research Group and 2 Nelson Mandela University
E-mail Address: [email protected]
I n the savannas of the Kruger National
Park, the open grassland and sodic
patches are favoured by grazers. They
prefer these patches because of higher
nitrogen concentrations in the grass
blades that are kept short and growing
by continuous grazing (Grant et al.
2019). Termite mounds also seem to
act as islands of higher nutrient content
that influence the nutrients in its surroundings
(Grant et al. 2006).
In the Albany Thicket of the Eastern
Cape large patches of thicket have
been cleared to provide forage for
cattle and sheep and to improve visibility
for tourism operations. In Addo
Elephant National Park (AENP) some of
these opened patches are still clearly
visible after 40 years, and all species,
even elephant (Loxodontha africana)
seem to utilize these areas extensively
(SANParks 2015).
We were interested to find out:
1. Why these cleared patches have
not been invaded by the surrounding
woody species as happens in
the savannas?
2. Whether the thicket species are
present in the grassland patches,
but just utilised intensely?
3. Do thicket areas provide ecosystem
services in the form of nutrients or
moisture to the adjacent cleared
areas?
In a preliminary study in early May 2019,
we looked at five sites in the main camp
of AENP where there was a distinct
boundary between the thicket patch and
the adjacent cleared and transformed
area. Surveys were done in fifteen 100 m
transects with three transects in each of
the five sites. Transects stretched from
thicket to transformed area with 50 m
in each. We collected a total of 36 soil
samples at 20 and 40 m from the thicket
– transformed boundary into the thicket
and at 20 and 40 m into the transformed
area. The vegetation surveys were done
Figure 1: A typical sodic patch in Southern Kruger National Park with the insert
illustrating a well-utilized termite mound
Figure 2: A cleared patch adjacent to the thicket in AENP.
Figure 3: Typical study area with transformed areas next to well-utilized thicket.
17 Grassroots Vol 20 No 3 September 2020