NEWS
Coming up with new solutions
for yellow thatch grass
René de Klerk (for Safari News)
Reprinted From: http://bit.ly/2NDiuEX
Y
ellow thatch grass (Hyperthelia
dissoluta) has been a problem in
the Waterberg region of Limpopo
for years. This fire-dominant perennial
species grows up to 3m tall and oc-
curs naturally in the Highveld region of
South Africa. New growth is extremely
nutritious and palatable during its early
growth stages, but once mature, wildlife
no longer shows interest.
While much debate has been ongoing
over the best solution for the grass that
is taking over the reserve’s open plains,
management at Mabula Game Reserve
is now experimenting with different
methods. It is still early days, but they
are hoping to find the best solution for
their grassy problem.
“There is a lot we can do about the
grass, but not much to stop it from
growing back,” says Mabula reserve
manager Kobus Havemann. The grass
occurs in high densities on most of the
open plains in the reserve. These plains
are great areas for game viewing, but
the thatch grass that dominates is not
palatable once mature, and it reaches
this about two months after new growth
starts. It also competes with other grass
species as nothing else is as aggressive
and quick to grow. “Plenty of animals
will use the thatch grass on the plains,
but to be a food source we have to keep
it short,” says Havemann.
Figure 1: Invasive grassland species:
Yellow thatch grass
crobes were introduced at a third site.
Microbes and seeds were combined in
another plot. The last two plots were
aggravated (the top soil disturbed) with
one seeded, and another microbes and
seeds added.
After three years of surveys, which will
be towards the end of 2019, Human will
be able to reveal what the effects of fire,
slashing and microbes are on the thatch
grass.
“Only then will we find the best man-
agement practises,” says Human. Part
of it also includes watching ungulates
to see whether they actively seek the
microbe sites – the reason why they are
next to each other.
Keeping it short is where the challenge
lies. Thatch grass has numerous uses,
including roofing, but continuously
harvesting in an area with dangerous
game is not viable. Burning the grass is
a short-term solution, but it returns even
thicker. Even slashing the grass does
not solve the problem. A local farmer has recently been con-
tracted to rake and bale thatch grass in
a n attempt to take away the seed bed
that naturally forms when you cut grass
but leave the stalks on the ground. This
provides the ideal medium for new
seeds to germinate and flourish and it
is felt that this may aggravate the thatch
grass problem on Mabula.
Management has chopped and burned
for the last 20 years, but they are hop-
ing research will provide better solu-
tions. Research ecologist Preller Human
is now searching for possible answers
and has set up experimental sites of
50m x 50m next to one another in an
area that was previously burnt. One site
will be left untouched. Another plot is
seeded with beneficial grass, while mi- This is a very exiting experiment and we
may just have stumbled across a solu-
tion to control thatch grass effectively in
the long term. Havemann says Mabula’s
open plains are extremely important
for tourism as sightings are guaranteed
with the shorter grass. The vital informa-
tion gained from the research will assist
the reserve in adapting its management
plan and inform important decisions.
13
Figure 2: Yellow thatch grass in Mabula
Private Game Reserve
Grassroots
Vol 19
No 1
March 2019