As previously stated in Chapter 1, the SES existing in the rural landscapes practices two different types of land tenure systems namely freehold farms and communal/leasehold areas. The landscapes comprise diverse land cover types inter alia areas of irrigation agriculture, dryland cultivation, residential, extensive rangeland and forest. T35B includes examples of recent commercial afforestation, commercial rangelands and the socio-ecological system associated with communal tenure (Palmer 2014). QC S50E and T12A are exclusively under communal tenure with extensive agricultural practices. No river systems aside small dams and reservoirs are seen in QC T35B and QC T12A, unlike the large Ncora dam with its tributaries quite visible in QC S50E. Grasslands predominated as the natural habitats of the catchments and their replacement or removal ought to augment the cost of event and thus require strong consideration (Vos 2014). Until the early nineteenth century, rural dwellers extensively grazed livestock on the communal rangelands (traditional homelands) of the Eastern Cape as a livelihood strategy (Bennett & Barrett 2007). Since the nineteenth century, livestock farmers have practised seasonal herding where livestock are herded to more productive valleys during dry seasons and open plains in spring. However, such movement is no longer practical within the confines of modern regulatory frameworks (De Wet 1987; Peires 1982). By 1930s, human impacts infringing on the natural resources were more evident and commercialisation defined a new landscape-land use system. During the study period, it has become evident that human development has had increasing impacts on the size of the rangelands and productivity.
In NLC 2000, having a low accuracy, natural grasslands indicate large areas of persistence from the mountainous highlands of Southern Drakensberg Highland and East Griqualand grasslands of T35B to the low-lying flat plains of Tsomo and Drakensberg grasslands of T12A and S50E (DWAF 2004). Significant man-made impacts are not profound at the three QCs. However, commercial afforestation started at a slower rate with higher agricultural cultivation in S50E (Figure 5.9). Alien plants subsumed under FITBs appear to be heavily infested in T35B and T12A
but scantily distributed in S50E, mostly at the low-lying, hilly, slightly inclined flatlands and agrarian regions. Few areas of urban/built-up are distinct in T35B when compared to urban intensity that are visible in T12A and S50E. Mainstream river system (Tsomo River) are seen in S50E, which supplies the Ncora dam by gravitational flow via irrigation vents to designated agricultural lands.
When compared to NLC 2000, by 2014, high FITBs infestation concealed greater fragments of grasslands in T12A and S50E with reverse scenarios occurring in T35B where the infested areas were replaced by commercial afforestation and cultivation. The infestations were seen along the peripheral mountainous escarpment to the central gentle declining flatlands. Extensive commercial afforestation is prominent at the eastern-lowland region and the agrarian activities are maximised at the central-low lying valley bottoms of the QCs. Agricultural cultivation had consolidated its tractions along these sections where it signified a fairly unremitting extensive development incline. The land use pattern under freehold landowners of the T35B seems to be a recent development on land use tenure as unequal afforestation and infestation were clearly distinguished between the two time analyses. Small patches of urban density observable in 2000 appear to be replaced by agrarian activities and grassland in 2014. This activity could be attributed to small landholdings by farmers who might have built shacks or cottages on the farms for shelter but were abandoned or demolished in time. These observations were made during data processing and manipulation. Small irrigation dams and reservoirs were located amidst arable lands and wetlands to obstruct upstream flowing stream and direct water supply to the agricultural stands. Wetlands were however observed to be converted into cultivated lands, commercial afforestation and grasslands. This conversion might have resulted from technological advancement in agricultural mechanisation, which was used to construct ditches and level the land for extensive crop cultivation. Additionally, the conversion of Wetlands could have been as a result of the different frameworks adopted for wetland identification and classification at both time-periods.
Agricultural practises intensified along the landscapes in T12A and S50E with the cultivated areas showing dominance at the foothills of Tsomo river in S50E (Figure 5.8). Grasslands and commercial afforestation were replaced by FITBs in both QCs, where the land tenure systems were of communal ownership and the livestock owners exercised over-exploitation of the rangeland because it was free (Palmer 2014) and this might have aggravated infestation intensity. Development as a product of civilisation was hugely exploited as the rate of urbanisation skyrocketed largely in T12A but fairly intensified in S50E. Built-up regions were interspersed with
FITBs infestation in these catchments. Such symbiotic co-existence may have been as a result of human activities that have placed man as a promotor of such infestation since agrarian practices are also prevalent around the urban zones. Given that wetlands are minuscule in these catchments, their conversion cannot be evidently established.
In ENLC 2000, with an accuracy higher than NLC 2000, grassland distributions similar to NLC 2000 were observed. Unlike the NLC 2000, man-made activities appeared to be apparent at the three QCs in terms of commercial afforestation in T35B, agrarian practices and urbanisation in T12A and S50E. FITBs were found to be less infested in T35B and T12A than in S50E when compared to NLC 2000. Urban/built-up are insignificantly present in T35B but densely seen in T12A and S50E. Wetlands were well pronounced in T35B in both NLC and ENLC 2000, while Tsomo River in close proximity to Ncora dam in S50E was still discernible in ENLC 2000. By 2014, half size of FITBs was reduced in T35B while no significant change was observed in T12A and S50E. Forest plantation was maximally intensified in T35B and intensely deforested in T12A and S50E. No significant change was seen in urban/built-up areas in T35B but civilisation and human development, in terms of urban/built-up areas, were made prominent in T12A and S50E. Conclusively, high degree of land cover change over a 14-year period between NLC 2000 and DLC 2014 appears to be exaggerated when compared to the transitional change between ENLC 2000 and DLC 2000. As a result, and because of the high accuracy of ENLC 2000, subsequent discussion on land use conversion and ET/NPP evaluation will solely reflect on the ENLC 2000 base reference set.
The period of 2000 – 2014, in ENLC 2000, the transformation in LULC initiated by both natural and human factors generally seemed to be marginal, but contributory in causing grassland degradation in the QCs. The grassland conversion to other land uses clearly occurred but persisted over the 14-year period. Waterbodies and wetlands persisted more in T35B as the dominant species of the catchments. While negligible, grassland intensification was observed in T35B. Degradation of grassland to alien plants and FITBs in T12A and S50E necessitates immediate rehabilitation to abate further degradation. Benini et al. (2010) found similar grassland increases and decreases in T35B and T12A/S50E respectively over the 14-year period within successive periods in the Lamone River basin. Although land cover for Lamone river basin is deciduous forest, the Afforestation activities that was seen to increase in Lamone River (Benini et al. 2010), also occurred in T35B where the commercial plantation nearly doubled the original size. The type of landscape tenure system existing in T12A and S50E infringed on the sustainability of commercial
afforestation as no management system was in place to conserve the small areas of forest plantations present at the catchments. Agrarian and urban intensification were partially observed in T12A and S50E and such intensification barely occurred in T35B.
Degradation gradients for deforestation, degradation and abandonment were negligible in the three QCs. The conversion of classes, labelled exceptionality, can be characterised as a degradation gradient where an unexpected conversion took place. While such conversion requires immediate intervention, its occurrence in the QCs is insignificant. As established in the literature, invasive alien plants are known to have affected grassland veld types (Carbutt & Martindale 2014; Carbutt et al. 2011). Though incorporated as FITBs, its persistence and intensification are noticeable in T12A and S50E whereas the reclamation process, where FITBs are replaced by grasslands are more prominent in T35B.
Generally, the assumptions made from the transition analysis between edited reference and derived land cover shows that no significant changes were observed in terms of degradation except FITBs persistence and intensification at catchment scales. These FITBs infestation (including alien plants) were already prevalent prior to the reference year. Anthropogenic intensification may have occurred but at marginal scales. Moreover, rehabilitation strategies directed towards clearing of alien plants (FITBs) by WfW appears to yield no significant results as reclamation rates across the catchments does not equal the size of FITBs infested regions.