| Summary: | A thesis submitted to the Faculty of Science, University of the
Witwatersrand, Johannesburg, in fulfillment of the requirements for
the degree of Master of Science. === This work describes the coastal grasslands of Mkambati Game Reserve
and their suitability for the present large herbivore complement.
The initial description makes use of both field survey and
quantitative sampling and multivariate analysis which facilitated
the production of soil and vegetation maps at tre scale of 1:
10 000. Suitability of these grasslands for herbivores is assessed
in terms of both quantity and quality of food available and the
present herbivore impact.
Local variation in soil type was considerable. Eight standard soil
forms were distinguished as well as severaI others previously
undescribed. Most of the soils were dystrophic although nutrient
'hot-spots' were common. This determined floristic composition of
the various communities to some extent.
Three grassland communities and four subcommunities were recognized
which contributed 81, 5% to the total area of the reserve. The
remaining area comprised forest. wetlands. exposed rock and
accommodation camps. Each grassland community was associated with
particular ranges of the measured environmental variables.
The standing crop of the three communities was high relative to
other areas of Southern Africa. Absolute amounts varied seasonally
being highest in summer and lowest in winter Partitioning between
the phytomass, necromass and litter components also varied
seasonally. Total standing crop increased with increasing interval
since the last fire. Litter breakdown rates differed between
communities and species.
Forage quality was poor being lowest in autumn and winter and
declining with age. This was probably a result of the dystrophic
soils. Crude protein and phosphorus were limiting for several
months of the year. Total forage quantity was in excess of the
present herbivore needs although availability declined with age and
during the non-growing season. However, the poor quality reduced
the amount available such that present herbivore impact was low, at
all times being less than 9%.. Removal by herbivores was highest
several months after a fire when absolute amounts of various
nutrients were at a maxinum per unit area. Thereafter it declined
to less than 1% with aging of the sward.
The implications of the results for management are discussed and
future research needs identified. === AC 2018
|
|---|
