Disturbance By Grazing


For the ELZ, these two facets of landuse, grazing and burning, dominate. However within the ILZ, and particularly along the boundaries of the two zones, grazing, and to a much lesser extent, burning, assume dominance over clearing as disturbance agents. Therefore even though the assessment was notionally reported only for the ELZ, the condition of the uncleared grazing land on the outer margins of the ILZ was taken into account.

Tenure as well as landcover type boundaries were used in the assessment. By definition, the disturbance status of all Unused land was assessed as the lowest class, slight.

This assessment was reported simply as a table of the absolute and relative areas in the four disturbance classes: slight (little or no detectable impact); substantial (detectable but localised impact); significant (widespread significant landscape change); indeterminate (unable to interpret).

These four classes were assigned disturbance ratings of 0, 1, 2, and 0, respectively. A numeric measure was calculated as the sum of the products of the proportional distribution of areas and the respective disturbance ratings above and has a potential range of 0-200. The rating and score were then assigned thus: 0-50 was low (*); 50-100 was moderate (**); >100 was high (***).


Table 14: The distribution of relative area (%) of the four disturbance levels for all landcover types within the ELZ. The score was based on the sum of the products of the percentage areas and the disturbance ratings, slight (0) to significant (2), and assigned 0-50 was low (*); 50-100 was moderate (**); >100 was high (***).

Landcover Slight  Substantial    Significant    Indeterminate  Score         
type                                                                         
_____________________________________________________________________

xTML4     100     0              0              0              *             

eTML3     75      25             0              0              *             

wTML3     100     0              0              0              *             

xTML3     100     0              0              0              *             

eM2       100     0              0              0              *             

xM2       100     0              0              0              *             

eL2       100     0              0              0              *             

wL2       100     0              0              0              *             

xL2       44      56             0              0              **            

eM1       65      0              0              35             *             

eL1       100     0              0              0              *             

wL1       24      0              76             0              ***           

xL1       58      42             0              0              *             

wS3       66      0              0              34             *             

xS3       97      0              0              3              *             

eS2       100     0              0              0              *             

wS2       37      0              63             0              ***           

xS2       12      0              88             0              ***           

eS1       65      35             0              0              *             

wS1       68      0              32             0              **            

xS1       25      0              75             0              ***           

xZ3       44      0              0              56             *             

xZ2       34      66             0              0              **            

wZ1       3       0              97             0              ***           

xH2       100     0              0              0              *             

xG4       81      19             0              0              *             

xG3       5       95             0              0              **            

xG2       3       0              97             0              ***           

Littoral  100     0              0              0              *             

xG1       21      79             0              0              **            

xF1       16      0              84             0              ***