https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:49977 Wed 31 Aug 2022 16:22:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49976 Wed 31 Aug 2022 15:12:45 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49989 Wed 31 Aug 2022 12:31:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56779 Wed 28 Sep 2022 10:25:53 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:53640 Wed 27 Jul 2022 14:16:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:53638 Wed 27 Jul 2022 10:32:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56843 Wed 26 Oct 2022 15:54:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56774 Wed 26 Oct 2022 10:32:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56775 Wed 26 Oct 2022 10:14:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56776 Wed 21 Sep 2022 19:37:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50173 Wed 20 Jul 2022 09:15:38 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49981 Wed 20 Jul 2022 09:01:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50038 Wed 20 Apr 2022 08:42:45 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56072 Wed 14 Sep 2022 15:55:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56075 Wed 14 Sep 2022 14:24:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56077 Wed 14 Sep 2022 14:24:19 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56076 Wed 14 Sep 2022 14:24:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56071 Wed 14 Sep 2022 14:24:13 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56079 Wed 14 Sep 2022 14:17:20 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50128 Wed 12 Jul 2023 19:15:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49970 Wed 12 Jul 2023 09:51:26 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:57006 Wed 09 Nov 2022 09:09:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56068 Wed 07 Sep 2022 13:34:48 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56069 Wed 07 Sep 2022 13:07:02 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56818 Tue 27 Sep 2022 16:36:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56816 Tue 27 Sep 2022 12:52:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56808 65%) occurred in more recent decades. Canopy cover of ~ 50% was found to be rare in each decade. This suggests that ~50% canopy cover maybe a transient, unstable state. The period with the highest rate of canopy cover increase was 2002-2013, and this increase coincided with a high mean annual rainfall 10 years prior to 2002 and a high mean annual rainfall in most years between the 20022013 period. The period between 2002 and 2013 also had the highest number of sites transitioning from lower to higher tree canopy cover classes, indicating that rainfall may have been a factor driving bush encroachment during the past several decades. An increase in canopy cover (a decrease in light transmittance) was accompanied by changes in woody species composition during thicket formation. The low canopy cover (high light transmittance) sites were dominated by Vachellia karroo and Scutia myrtina trees, while high tree cover sites had fewer V. karroo and S. myrtina trees and were rather characterised by an abundance of thicket tree species. Species proportion, NMDS and dendrogram plots indicated that sites with a light transmittance range between 50-100% had similar tree species compositions, different from sites with light transmittances <50%. An increase in tree density was strongly correlated to an increase in canopy cover (from 2019 satellite imagery), density of trees > 3m, maximum height reached by trees, diversity of trees, total canopy volume, total canopy area and leaf area index (LAI), and a decrease in light transmittance. A structural equation model (SEM) was used to explore the relationships between canopy characteristics (maximum canopy area, canopy volume, tree diversity, density of trees, density of trees >3m, individual trees and maximum canopy height), aerial canopy cover in 2019, and light transmittance. The model explained 73% of the variation in light transmittance, mostly via the direct effect of canopy characteristics. Canopy characteristics had a strong influence on both aerial cover in 2019 and directly on light transmittance, but canopy cover in 2019 had a weak influence on light transmittance. The herbaceous layer was rich and dominated by C4 grasses such as Eragrostis plana, Sporobolus fimbriatus, Themeda triandra and Digitaria eriantha) and forbs including Hibiscus aethiopicus, Helichrysum dregeanum, Helichrysum nudifolium and Gerbera viridifolia at low canopy cover sites with high light transmittance. In contrast, high tree cover sites had fewer herbaceous species in general. Grass and forb species characteristic of these sites high canopy cover sites were Panicum maximum, Loudetia flavida, Pellaea viridis and Cyperus spp. Different sites with low light transmittance (<50%) had similar herbaceous species composition. Basal cover, richness, abundance and diversity of herbaceous plants decreased significantly with an increase in tree density, density of trees >3 m, canopy volume, canopy area, canopy cover, LAI, and increased significantly with increasing light transmittance. Most grasses had their highest densities at LAI <0.5, which was estimated to correspond to ~75% light transmittance and ~38% canopy cover and then started to decline thereafter. Herbaceous species basal cover was also highest at LAI <0.5. An SEM model indicated that herbaceous diversity, basal cover and richness responded both to light availability and to the structure of the woody vegetation directly (R2 = 0.53). While the effect of light transmittance on herbaceous communities was strong (0.41), there was little difference between the effect of light transmittance and canopy characteristics (-0.35) on herbaceous communities. Two possible threshold points, relating to two types of transitions in vegetation structure, could be deduced from this study. The first threshold occurred at canopy cover ~ 40% (LAI < ~ 0.5, light transmittance ~ 75%), at which point many of the common herbaceous species, including the dominant C4 grasses, began to decline in abundance while the composition remained characteristic of the savanna state. A canopy cover of less than ~ 40% at a site provides a suitable state for a high abundance of grass and forb species which help maintain an open system by facilitating fires. The second threshold marked a compositional shift between savanna and closed-canopy vegetation states. Savanna species (trees, grasses and forbs) dominated at high light transmittances (>50%) and were significantly reduced at low light transmittances (< 50%), indicating a possible species composition threshold at ~50% light transmittance at which a savanna state switches to a thicket (LAI ~ 1 and canopy cover ~70%). This point indicated the point where there was a significant difference in both tree and herbaceous plant compositions, with a marked reduction in the occurrence of C4 grasses at light transmittance <50%. Fire is supressed when the C4 grass layer is lost, and further thicket encroachment will take place causing complete canopy closure. Land managers in this system should start becoming concerned about a reduction in grass biomass when canopy cover reaches about 40% and would have to reduce tree cover before the threshold of 50% light transmittance (70% canopy cover from aerial photos) is reached to maintain a savanna system.]]> Tue 27 Sep 2022 11:00:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56806 Tue 27 Sep 2022 09:15:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56841 Tue 25 Oct 2022 14:23:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56839 Tue 25 Oct 2022 11:29:01 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49985 Tue 19 Jul 2022 09:37:26 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49975 Tue 19 Jul 2022 09:14:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49992 Tue 19 Jul 2022 09:10:34 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49973 Tue 19 Jul 2022 07:43:58 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56782 Tue 11 Oct 2022 09:36:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49983 Tue 06 Sep 2022 19:46:27 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50943 Tue 06 Sep 2022 19:12:42 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49990 Tue 06 Sep 2022 18:57:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56823 Thu 29 Sep 2022 15:26:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56820 Thu 29 Sep 2022 12:17:42 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:46470 50%) of each EI category is stable, but there are areas showing signs of degradation, including 43% of grasslands degraded and 39% of wetlands, cultivated lands, and riparian zones also degraded. Degradation is dominant in the upper (T35B and T3C) and lower (T35K, T35L and T35M) parts of the catchments. The three criteria used by the stakeholders in the prioritisation process of the key EI were assigned 12 spatial attributes (the catchment characteristics about the study area in relation to the criteria) to indicate relevant information needed for selecting suitable restoration areas to enhance flow regulation. The AHP analysis results identified approximately 63% (17,703 ha) of wetlands, 88% (235,829 ha) of grasslands, 78% (13,608 ha) of abandoned cultivated fields and 93% (3,791 ha) of the riparian zones as suitable areas for restoration to mitigate drought impact through flow regulation. Also, the suitability results showed 63% (17,703 ha) of wetlands, 58% (2,203 ha) of riparian zones, 68% (11,745 ha) of abandoned cultivated fields and 46% (122,285 ha) of grasslands as suitable restoration areas for improving ecosystem services for community livelihoods. The AHP analysis identified more than 39-43% (of the degraded EI indicated by the Trends.Earth analysis) areas that are suitable for restoration, because key EI plays a significant role in flow regulation and people’s livelihoods, especially when they are managed, maintained, and restored to good health conditions. Therefore, the prioritized EI areas should be either maintained, managed, rehabilitated or restored. The major distinct causes of land degradation are woody encroachment in grasslands, invasion of alien plants on abandoned cultivated fields and soil erosion in the catchment. The most suitable EI areas recommended for restoration are those natural resources near local communities, which provide essential ecosystem services to sustain their livelihood. Therefore, degraded EI in the T35 catchments should be restored and maintained to improve livelihood and mitigate drought impacts. The study pointed out how the key selected ecological infrastructure can help mitigate the impacts of droughts and improve human livelihood. The study contributes towards the important concept of investing in ecological infrastructure to improve the social, environmental, and economic benefits.]]> Thu 22 Sep 2022 12:27:12 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56795 Thu 22 Sep 2022 11:14:34 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50009 Thu 21 Jul 2022 16:08:30 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50172 Thu 21 Apr 2022 17:46:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56073 Thu 15 Sep 2022 12:52:58 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56078 Thu 15 Sep 2022 12:10:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56074 Thu 08 Sep 2022 11:28:46 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56801 Mon 26 Sep 2022 11:56:53 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56789 Mon 26 Sep 2022 11:21:46 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56783 Mon 26 Sep 2022 09:58:04 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56838 Mon 10 Oct 2022 08:20:01 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50131 Mon 05 Sep 2022 12:59:57 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56834 Fri 30 Sep 2022 11:21:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56777 Fri 30 Sep 2022 10:25:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49994 Fri 22 Jul 2022 09:08:31 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:57007 Fri 11 Nov 2022 08:55:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56070 Fri 09 Sep 2022 12:53:04 SAST ]]>