Scientific Method in Action – Group Task Group members : Mabandi Mnisi Moses Shitlhelani Christopher Shai

Consider the following aerial photo of the SAWC / Welverdiend area Scientific Method in Action – Group Task Observe / Idea Question & expected answer Answer Protected area, wildlife (natural grazers) Communal land, cows only Group members - Mabandi Mnisi, Moses Shitlhelani and Christopher Shai

Who eats more - Wildlife or Cows? Chris, Maband, Moses (and Dave) – the Professors Introduction Background: Different land uses affect biodiversity in different ways. For example, protected savannas will look and function differently to communally utilized savannas. Observation revealed that communal areas seemed to have less vegetation and more grazing by only a single herbivore – the cow. Alternatively, a protected area seemed to have more vegetation and a diversity of herbivores (natural wildlife). Hypothesis: Cows have a greater impact on vegetation than natural grazers do.

Materials and Methods Counts 25m North Choose 1 point in Welverdiend (communally grazed area) and 1 point in the SAWC (protected savanna). Mark this central point with a flag. Using a compass and a tape measure, set up 4x25 m transects running north, east, south and west way from your flag. Biomass – At every 5 m along each of your 4 transects (5, 10, 15, 20 and 25m), use the disc pasture meter to measure the ‘bulk’ of vegetation. Record this in cm. Species composition / Vegetation structure – At every 1m (~large step) along each of your 4 transects (1-25m), record whether the plant closest to your foot is either a grass (G), a forb (F) or bare soil (S).

Data collection sheet TRANSECT Distance (m) NESW VegBioVegBioVegBioVegBio

Results Table 1: Frequency of vegetation and biomass for naturally and unnaturally grazed areas. Vegetation %Grass%Forb%Soil%MixedBiomass (range), mean SAWC821800(3-16), 9.27 Welver (0-11), 3.33 The dominant grass species found in the 2 areas were Urochloa and Eragrostis for Welverdiend and Urochloa, Panicum and Chloris for the SAWC.

Figure 1: Average biomass in naturally and unnaturally grazed areas.

Figure 2: Frequencies of vegetation components for naturally and unnaturally grazed areas.

Discussion Hypothesis: Cows have a greater impact on vegetation than natural grazers do. Our results showed that communally grazed areas have, on average, 3x less biomass and a lower grass frequency, meaning that less of the community is made up of grass. Also, the dominant grass species were different between the two sites. Therefore, we accept our hypothesis. Cows do have a higher impact on vegetation than do natural grazers. Reasons for higher impact: Restricted area of cattle Seasonal movement / migration prevented (concentration of grazing) No stock control / stocking densities Type of grazers (mixed feeders in natural area sharing resources, but bulk grazers – cows – in communal area) Heavy trampling (links to size and high number of cows)