4.5. Respondents awareness and perceptions of the D’MOSS programme
4.6.2. Tree crops
112
113 Table 4.36: Comparison of the quality of green spaces within selected tree crop sites using the eThekwini and Adapted typologies
Sit e No.
eThekwini typology
Adapted typology Classification
and area (m2)
Classification Area (m2) and percentage (%) relative to total site
area
Habitat, vegetation type and ecosystem threat status
Infringement
1 Degraded
(65,951.59) Degraded 65,951.59 100*
Habitat type: Functional Vegetation type: KwaZulu- Natal Hinterland Thornveld Ecosystem threat status:
Least threatened
Considerable
2 Transformed
(28,875.50) Transformed 28,875.50 100*
Habitat type: Functional Vegetation type: KwaZulu- Natal Coastal Belt Grassland Ecosystem threat status:
Critically endangered
Considerable
3 Transformed (11,667.44)
Degraded 4,513.60 38.7* Habitat type: Functional Vegetation type: KwaZulu- Natal Coastal Belt Grassland Ecosystem threat status:
Critically endangered
None Transformed 7,153.84 61.3*
4 Transformed
(29,042.82) Transformed 29,042.82 100*
Habitat type: Functional Vegetation type: KwaZulu- Natal Coastal Belt Grassland Ecosystem threat status:
Critically endangered
None
5 Transformed
(36,163.48) Transformed 36,163.48 100*
Habitat type: Functional Vegetation type: KwaZulu- Natal Coastal Belt Grassland Ecosystem threat status:
Critically endangered
None
*𝑸𝒖𝒂𝒍𝒊𝒕𝒚 𝒃𝒂𝒔𝒆𝒅 𝒍𝒂𝒏𝒅 𝒄𝒐𝒗𝒆𝒓 𝒑𝒆𝒓𝒄𝒆𝒏𝒕𝒂𝒈𝒆 = (𝑨𝒓𝒆𝒂 𝒅𝒆𝒈𝒓𝒂𝒅𝒆𝒅/𝒈𝒐𝒐𝒅/𝒊𝒏𝒕𝒆𝒓𝒎𝒆𝒅𝒊𝒂𝒕𝒆/𝒕𝒓𝒂𝒏𝒔𝒇𝒐𝒓𝒎𝒆𝒅
𝑻𝒐𝒕𝒂𝒍 𝒂𝒓𝒆𝒂 𝒐𝒇 𝒔𝒊𝒕𝒆 ) × 𝟏𝟎𝟎
Terminologies: ‘Habitat’ - habitat type of the site according to Swanwick et al. (2003) typology; ‘Vegetation’
- vegetation type of the site according to SANBI KwaZulu–Natal vegetation type classification (2011);
‘Ecosystem threat status’ - ecosystem threat status of the site according to the National Biodiversity Assessment (2011); ‘Infringement’ - the level of infringement on site from land-use activities.
When the quality of the five tree crop sites displayed above (Figure 4.9 and Table 4.36) was compared between the Adapted and eThekwini typologies, the quality classification only differed between typologies for site 3. The quality classification for the remaining sites (1, 2, 4 and 5) was in agreement between the typologies. However, it should be noted that the use of the Adapted typology resulted in the identification of more degraded land; a degraded micro- environment was identified in site 3.
114 Table 4.37: Statistics incorporated into the Adapted typology calculated for all five tree crop sites cumulatively
Land cover characteristic and categorisation Percentage land cover associated with specific habitat and vegetation type, threat status, and infringement categories*
Habitat type Functional habitats 100
Vegetation type KwaZulu-Natal Coastal Belt Grassland vegetation 61.6 KwaZulu-Natal Hinterland Thornveld vegetation 38.4 Threat status Critically endangered land 61.6
Least threatened land 38.4
Infringement Land with considerable infringement 55.2
Land with no infringement 44.8
*Calculated as a percentage of the cumulative area of all the sites considered for this particular green space type (i.e. sum of the areas of the five sites sampled for tree crops which was equivalent to
171,700.83 m2)
The quality based land cover percentages calculated for the five tree crop sites as part of the Adapted typology (Table 4.36) should be interpreted in combination with the statistics shown in Table 4.37. In terms of habitat type, the eThekwini Municipality classified all five of the selected tree crop sites as artificial habitats (eThekwini Municipality, 2012), whilst the Adapted typology classified the tree crops sites investigated as functional habitats. It should be noted that these tree crop sites (Figure 4.9 and Table 4.36) have been designated by the eThekwini typology as plantations (Source for raw data: eThekwini Municipality, 2012). In addition, findings in the literature indicate that green spaces associated with farming, plantations or horticultural practices are usually classified as functional habitats (Dunnet et al., 2002;
Swanwick et al., 2003). This statement was further validated by the Adapted typology, which showed that the five tree crop sites investigated all consisted of functional habitats (Table 4.36 and Table 4.37).
Furthermore, the Adapted typology showed that two different vegetation types occurred within this green space type: sites 2, 3, 4 and 5 consisted of KwaZulu-Natal Coastal Belt Grassland covering the majority of land (61.6%), while 38.4% of the land comprised of KwaZulu-Natal Hinterland Thornveld (site 1). The results (Table 4.36 and Table 4.37) also showed that the predominant vegetation type, viz. KwaZulu-Natal Coastal Belt Grassland, found in the selected tree crop sites was classified as critically endangered. This is in agreement with findings by the
115 Municipality which indicate that this vegetation type has been/ is being subjected to high levels of transformation by settlements and cultivation practices (eThekwini Municipality, 2007).
In terms of the ecosystem threat status (Table 4.36 and Table 4.37), four sites (2, 3, 4 and 5) were classified as critically endangered covering the majority of land (61.6%), with site 1 only classified as least threatened covering 38.4% of the land. With regard to infringement (Table 4.36 and Table 4.37), two of the sites assessed (1 and 2) were subject to considerable infringement constituting 55.2% of the land, while the remaining sites (3, 4 and 5) were not encroached upon, collectively leaving 44.8% of the land undisturbed.
With the above in place, it is also important to interrogate the quality based land cover and infringement status for the selected tree crops sites (Table 4.36) in order to adequately assess integrity of the land. The assessment of the data obtained from the orthophotos for these sites (Figure 4.9) revealed that tree crops in close to settlements were more prone to degradation (for example, site 1) than those situated further away (for example, site 4 and 5). This resonates with findings described for settlements in the previous section, which also showed that green areas located nearby to settlements were exposed to higher levels of infringement and where characterised by areas that were evidently degraded (Figure 4.8). Furthermore, this reinforces the assertion in the literature that increasing urban pressures have resulted in the degradation of green spaces (Zhou and Wang, 2011).
Another interesting result showed that the majority of sites (2, 3, 4 and 5) comprised of land that was classified as transformed. However, it should be noted that in this green space type if a site was classified as transformed, this was not necessarily indicative of a poor quality based land cover. Tree crops are commercial entities of land (Sanchez and Leakey, 1997; Verlarde and Tomich, 2006), inferring that the land has been transformed to grow vegetation.
Furthermore, even though tree crops may have a low ecological value, in some cases research has found that these environments have a high environmental importance as they can significantly aid in carbon sequestration (Verlarde and Tomich, 2006).
116 Table 4.38: Deviation index for selected tree crop sites: how much the quality of these green spaces differed between the Adapted and eThekwini typologies
0- No deviation, 1- Minimal deviation, 2- Moderate deviation, 3- High deviation
Site No. Deviation index
1 0
2 0
3 2
4 0
5 0
Cumulative percentage deviation* 13.3%
*C𝑢𝑚𝑚𝑢𝑙𝑎𝑡𝑖𝑣𝑒 𝑝𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑑𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝐴𝑑𝑎𝑝𝑡𝑒𝑑 𝑡𝑦𝑝𝑜𝑙𝑜𝑔𝑦 𝑞𝑢𝑎𝑙𝑖𝑡𝑦 𝑓𝑟𝑜𝑚 𝑒𝑇ℎ𝑤𝑒𝑘𝑖𝑛𝑖 𝑡𝑦𝑝𝑜𝑙𝑜𝑔𝑦 𝑞𝑢𝑎𝑙𝑖𝑡𝑦 𝑓𝑜𝑟 𝑡𝑟𝑒𝑒 𝑐𝑟𝑜𝑝𝑠 = ( 𝑆𝑢𝑚 𝑜𝑓 𝑠𝑖𝑡𝑒 𝑑𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛 𝑠𝑐𝑜𝑟𝑒𝑠 (2)
𝑀𝑎𝑥𝑖𝑚𝑢𝑚 𝑝𝑜𝑠𝑠𝑖𝑏𝑙𝑒 𝑑𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛 (3) × 𝑁𝑜. 𝑜𝑓 𝑠𝑖𝑡𝑒𝑠 (5)) × 100
The deviation indices calculated for the tree crop sites investigated (Table 4.38) revealed that only one site deviated from the classification defined by the eThekwini typology. There was moderate deviation evident in site 3, while sites 1, 2, 4 and 5 exhibited no deviation from the eThekwini typology. In summary, the quality of the five tree crop sites assessed using the eThekwini typology collectively deviated by approximately 13.3% from that assessed using the more discriminatory Adapted typology. This is a relatively minor deviation and can be attributed to the identification of more degraded land as evidenced in Figure 4.9.
Overall, it was evident that quality based land cover differed minimally when sites were compared using the eThekwini and Adapted typologies. However, a few degraded micro- habitats were potentially misclassified as transformed when using the eThekwini typology; the implication of this misclassification is that these micro-habitats could possibly be inadequately/
inappropriately prioritised for conservation and/ or restoration. More importantly, it should be noted that transformed tree crop habitats potentially hold environmental importance within an urban setting. These environments can significantly aid in carbon sequestration, particularly in rapidly developing cities such as eThekwini, whilst simultaneously contributing to commercial activities.
117