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12 AT 8 Kowie Thicket: Dense Euphorbia triangularis-dominated thicket on slopes facing the Settlers Dam in the Thomas Baines Nature Reserve (near Grahamstown, Eastern Cape).
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... Thus defined, our Strandveld concept excludes the vegetation termed Strandveld by Rebelo et al. (2006) that is associated with granite, calcarenite and Pleistocene sands on the west coast but includes the vegetation on Holocene sands (Witsand Formation of the Sandveld Group). Being floristically dominated by fynbos taxa, and thus belonging to the Fynbos Biome, the concept also excludes vegetation of the Holocene dunes north of Elands Bay (where succulent karoo taxa replace fynbos lineages) (Rebelo et al., 2006) and east of Algoa Bay (where thicket prevails and where depauperate fynbos is confined to ecologically demanding sites, such as dune slipfaces and excessively-drained ridges) (Hoare et al., 2006;Taylor & Morris, 1981). This vegetation is best placed in the Succulent Karoo and Subtropical Thicket biomes, respectively. ...
... Our focus is on South Coast Strandveld, vegetation associated with poorly weathered, calcareous sands of Holocene age that comprises a matrix of closed-canopy thicket and asteraceous (ericoid shrub-dominated) fynbos (Cowling et al., 1988) that occurs along the Cape south coast. It corresponds to Rutherford, Mucina & Powrie's (2006) Mucina et al.'s (2006a) and Mucina et al.'s (2006b) map as Algoa Dune Strandveld, part of their azonal Eastern Strandveld vegetation group. Following Moll et al. (1984) and Rutherford, Mucina & Powrie (2006), we propose two strandveld bioregions for the Cape Floristic Region: West Coast Strandveld and South Coast Strandveld. ...
... It corresponds to Rutherford, Mucina & Powrie's (2006) Mucina et al.'s (2006a) and Mucina et al.'s (2006b) map as Algoa Dune Strandveld, part of their azonal Eastern Strandveld vegetation group. Following Moll et al. (1984) and Rutherford, Mucina & Powrie (2006), we propose two strandveld bioregions for the Cape Floristic Region: West Coast Strandveld and South Coast Strandveld. Justification for this delimitation is provided later in this section. ...
The vegetation of calcareous coastal dunes of Holocene age along the south coast of South Africa’s Cape Floristic Region is poorly described. This vegetation comprises a mosaic of communities associated with two biomes, Fynbos and Subtropical Thicket. Previously, expert knowledge rather than quantitative floristic analysis has been used to identify and delimit vegetation units. In many areas, mapped units conflate vegetation on Holocene sand with that on unconsolidated sediments of late Pleistocene age, despite pronounced species turnover across this edaphic boundary. Despite dominance by Cape lineages and fynbos vegetation, dune vegetation in the eastern part of the region has been included in the Subtropical Thicket Biome rather than the Fynbos Biome. The high levels of local plant endemism associated with this dune vegetation and the small and fragmented configuration of these habitats, makes it an urgent conservation priority especially when placed in the context of rising sea levels, increasing development pressures and numerous other threats. Here we provide a quantitative analysis of 253 plots of the 620 km ² of Holocene dune vegetation of the study area using phytosociological and multivariate methods. We identified six fynbos and two thicket communities based on the occurrences of 500 species. Following a long tradition in Cape vegetation typology, we used the Strandveld (beach vegetation) concept as our first-order vegetation entity and identified six units based on the fynbos floras. These were, from east to west, Southeastern Strandveld, St Francis Strandveld, Goukamma Strandveld, Southwestern Strandveld and Grootbos Strandveld. Each unit was differentiated by a suite of differential species, most being Holocene dune endemics. The two thicket communities—Mesic and Xeric Dune Thicket—showed limited variation across the study area and were subsumed into the Strandveld units. We discussed our findings in terms of vegetation–sediment relationships, emphasizing the need for a greater geographical coverage of sediment ages to facilitate a better understanding of deposition history on vegetation composition. We also discussed the role of soil moisture and fire regime on structuring the relative abundance of fynbos and thicket across the Holocene dune landscape. Finally, we address the conservation implications of our study, arguing that all remaining Holocene dune habitat should be afforded the highest conservation priority in regional land-use planning processes.
... The South African Albany Thicket biome (see Chap. 5, Sect. 5.3.2; also Hoare et al. 2006) might be an example of such a situation. ...
Biomes are large-scale biotic communities (ecosystems) distinguished by specific ecological functionality and evolutionary origins. They can be studied and delimited using functional variables but also using physiognomic and vegetation-textural surrogates. Biomes are spatially explicit units, and as such, they can be seen as complexes of biotic communities at various hierarchical levels, including zonobiomes, global biomes, continental biomes, and regional biomes. Each of these categories has its characteristic own set of ecological drivers. Walter's zonobiome system is possibly the most common biome system coined to explain the diversity of large-scale biotic communities on Earth. It is a bioclimatic approach, recognising the role of climatic factors driving the zonal biome patterns at large scales. It also provides for biomes driven by other factors, such as soils and hydrology, called azonal biomes. This chapter aims to revisit the usefulness of the zonal/azonal conceptual framework in the ocean-dominated Southern Hemisphere. It puts significant emphasis (at the large-scale biome levels) on the climato-genetic drivers, modern tools of bioclimatology, and sources of bioclimatic data. By doing so, this chapter is also a prelude to the formulation of a new zonobiome system, serving as a basis for a Global Hierarchical Biome System.KeywordsAzonalityContinental biomeEcotoneGlobal biomeGlobal hierarchical biome systemRegional biomeSouthern hemisphereSpatial climatic diagramZonalityZonobiome
... It was eroded from the shales and mudstones of the Beaufort Group, which is part of the Karoo Supergroup (Matike, Ekosse, & Ngole, 2011). The indigenous flora consists primarily of Albany thicket, specifically the Kowie thicket (Hoare, et al., 2006); however, small amounts of fynbos are found in nutrient-poor sandy loams (Hodson, Vijver, & Peijnenberg, 2011). Thicket species thrive in clay-rich soil (Hoare, et al., 2006) and are concentrated in the valleys. ...
... The indigenous flora consists primarily of Albany thicket, specifically the Kowie thicket (Hoare, et al., 2006); however, small amounts of fynbos are found in nutrient-poor sandy loams (Hodson, Vijver, & Peijnenberg, 2011). Thicket species thrive in clay-rich soil (Hoare, et al., 2006) and are concentrated in the valleys. However, they do also occur in areas of moderate topography where clearing for farmland has not happened. ...
The aim of the study described in this article was to investigate the vegetation health and drought response of naturally occurring Albany thicket and neighbouring farmland vegetation, that appears in an area of the Eastern Cape, South Africa. Google Earth Engine was used to manipulate Landsat 5, 7 and 8 datasets to produce a 30-year temporal dataset, after which the normalized difference vegetation index (NDVI) and the normalized difference water index (NDWI) were then applied to create a time series analysis. The Mann-Kendall and Spearman correlation statistical tests were used on the time series to observe trends and correlations between the NDVI and the NDWI datasets. The Spearman correlation test results showed that there were high correlations between the NDVI and the NDWI datasets (all above 0.805). Furthermore, the Man-Kendall test showed that all the datasets had positively increasing trends, while the NDVI datasets all had monotonic positive trends. Large differences in the NDVI and the NDWI were seen for the different vegetation types during times of drought, and farmland was the most severely affected with an average of 19% decrease in the NDVI and an average of 71% decrease in the NDWI.
... In Eastern Cape Province, especially around the Gqeberha-Kariega metropolitan area, but also farther north toward Steytlerville and Graaff-Reinet, Kalanchoe rotundifolia occurs in large numbers, particularly in the undergrowth of what is popularly referred to as Valley Bushveld, which, when pristine, is a dense, often impenetrable, type of thicket vegetation (see Hoare et al., 2006: 542 on the Albany Thicket Biome). Virtually the entire region falls within the Albany Centre of Endemism (Van Wyk & Smith, 2001: 102-109). ...
The recent reinstatement of Kalanchoe decumbens Compton as well as the description of K. waterbergensis van Jaarsv. (Crassulaceae subfam. Kalanchooideae) necessitate a reassessment of the circumscription of K. rotundifolia (Haw.) Haw., thus far the morphologically most diverse kalanchoe indigenous to southern Africa. Material with bright green, generally orbicular to slightly obovate leaves that hitherto has been included in K. rotundifolia is here split off from the latter. The name K. klopperae Gideon F. Sm. & Figueiredo is published for this material.
... The Kat River, a major tributary of the Great Fish River system, drains the Amathole-Winterberg freshwater ecoregion. Deciduous broad-leafed forests and grasslands dominate the natural vegetation in this ecoregion (Hoare et al., 2006). Vachellia karroo (Hayne) Banfi & Galasso and succulent thicket, comprising Euphorbia spp. ...
Headwater streams in Afromontane ecoregions harbour locally adapted aquatic communities. However, across many regions in Africa, these ecosystems and their unique aquatic biodiversity have been severely impacted by unsustainable land use practices. We tested the hypothesis that land use disturbances were the primary drivers of community dynamics by comparing spatial and temporal dynamics together with trait-environment relationships of macroinvertebrate communities in three headwater streams influenced by different land use practices. The three headwater streams were distinguished based on high conductivity, total dissolved solids and alkaline pH in the agriculture-disturbed stream, and low temperature in a stream whose riparian zone was invaded by non-native vegetation compared to a near-natural stream. Macroinvertebrate taxonomic diversity was, nevertheless, comparable among these three streams. Constrained canonical ordination revealed that seasonality was a major driver of macroinvertebrate dynamics that was reflected mostly by the abundances of six macroinvertebrate taxa (Baetis, Dicentroptelum, Afronurus, Tricorythus, Simulium and Cheumatopsyche), whereas land use contributed a small but significant difference. Trait-environment relationships reflected seasonal changes that included the importance of benthic substratum in winter, the occurrence of collector-gatherer invertebrates in spring and aerial breathing traits in summer. Land use-related traits were, nevertheless, reflected by gill respiration and grazer feeding traits represented by Afronurus in the near-natural stream, predator traits represented by Aeshna and Lestes in the invaded stream, and aerial respiration represented by Enithares, Orectogyrus and Rhagovelia in the agriculture-disturbed stream. Our results suggest that environmental variability associated with seasonality probably played a deterministic role within which land use disturbances operated. Overall, our study suggest that importance of using multiple metrics to unpack the patterns associated with land use disturbances in headwater streams.
... In contrast, Tropical Dry Forests (see below), embedded in the savanna biome within the confines of our study area, experience a pronounced winter-drought period. Delimitation of the subtropical Albany Thickets (AT; see Hoare et al. 2006) is also very clear in bioclimatic and structural terms. The units of the AT experience two precipitation-rich and two drier periods. ...
... Albany Thickets receive bimodal rainfall, while TDFs are limited to a seasonal climate characterised by one prolonged dry season. For further discussion on the matter, consult Hoare et al. (2006). ...
The forests of South Africa and the neighbouring countries, including Lesotho, eSwatini, Namibia, Botswana, Zimbabwe, and Mozambique (south of the Zambezi River), were mapped and classified according to the global system of biomes. The new four-tier hierarchical biome system suggested in this paper includes zonobiome, global biome, continental biome (all recognised earlier), and regional biome – a novel biome category. The existing spatial coverages of the forests were revised and considerably improved, both in terms of forest-patch coverage and mapping precision. Southern Africa is home to three zonal forest types, namely Subtropical Forests (Zonobiome I), Tropical Dry Forest (TDF; Zonobiome II) and Afrotemperate Forests (Zonobiome X). These three biomes are characterised by unique bioclimatic envelopes. Five, two, and eight regional biomes, respectively, have been recognised within these zonal biomes. Recognition of the Zonobiome I and the global biome Tropical Dry Forests in southern Africa is novel and expands our knowledge of the biome structure of African biotic communities. The system of the azonal regional biomes is also new and comprehensively covers the variability of the azonal helobiomes (riparian woodlands and swamp forests), mangroves, and azonal coastal forests. In total, 11 azonal regional biomes have been recognised in the study area. The forest biomes in southern Africa were captured in our electronic map in the form of more than 60 000 polygons, covering 42 416 km² (1.27% of the study area). No less than 83% of these forests occur in the territory of southern Mozambique.
Abbreviations: for the abbreviation of the biome units, see Table 1; CE: centre of endemism; IOCB: Indian Ocean Coastal Belt; MBSA: the area of the Map of Biomes of Southern Africa; VegMap2006 and VegMap2018: Vegetation Map of South Africa, Lesotho and Swaziland (as released in respective years); for the meaning of the codes of the biome units see Table 1, and for the meaning of the abbreviations of climatic characteristics see Appendix S1
... The Albany Thicket Biome has characteristics closely related to the Mediterranean forests, woodlands and scrubs category of the global vegetation classification (Hoare et al. 2011). The vegetation consists mainly of dense, woody, semi-succulent and thorny plants such as the Vachellia (formerly Acacia) species. ...
Climatic factors such as rainfall and temperature play a vital role in the growth characteristics of vegetation. While the relationship between climate and vegetation growth can be accurately predicted in instances where vegetation is homogenous, this becomes complex to determine in heterogeneous vegetation environments. The aim of this paper was to study the relationship between remotely-sensed monthly vegetation indices (i.e. Normalized Difference Vegetation Index and Enhanced Vegetation Index) and climatic variables (temperature and precipitation) using time-series analysis at the biome-level. Specifically, the autoregressive distributed lag model (ARDL1 and ARDL2, corresponding respectively to one month and two month lags) and the Koyck-transformed distributed lag model were used to build regression models. All three models estimated NDVI and EVI fairly accurately in all biomes (Relative Root-Mean-Squared-Error (RMSE): 12.0–26.4%). Biomes characterized by relative homogeneity (Grassland, Savanna, Indian Ocean Coastal Belt and Forest Biomes) achieved the most accurate estimates due to the dominance of a few species. Comparisons of lag size (one month compared to two months) generally showed similarities (Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC) and log-likelihood) with quite high comparability in certain biomes – this indicates the utility of the ARDL1 and ARDL2 model, depending on the availability of appropriate data. These findings demonstrate the variation in estimation linked to the biome, and thus the validity of biome-level correlation of climatic data and vegetation indices.
... Endemic to the Eastern Cape, centered around Port Elizabeth and including the Albany district ( Fig. 9). Found in a wider variety of vegetation types than other Chondrocyclus species: Algoa Dune Strandveld, Albany Coastal Forest, Southern Mistbelt Forest, Great Fish Thicket (von Maltitz et al. 2003;Hoare et al. 2006;; in leaf-litter. ...
... Eastern Cape, Baviaanskloof (Fig. 9). Indigenous forest patches in narrow ravines (Western Cape Afrotemperate Forest of von Maltitz et al. 2003) and Albany subtropical thicket (Groot Thicket group) (Hoare et al. 2006), in leaf-litter; also in subtropical thicket/fynbos transition, under stones and amongst leaf litter. COLE M.L., Revision of cyclophorid snails Chondrocyclus s.l. ...
... Amathole Mistbelt forest (Southern Mistbelt Forest group) (von Maltitz et al. 2003) and Great Fish Thicket (Kap River) (Hoare et al. 2006); in leaf-litter. ...
Chondrocyclus Ancey, 1898 is a genus of nine species of African operculate land snails restricted to indigenous forest and mesic thicket. Worn specimens (i.e., without a periostracum or operculum), on which some species descriptions and records were based, appear to be indistinguishable morphologically. A comprehensive revision of Chondrocyclus s.l. is provided here based on comparative morphological examinations of the shell, protoconch, periostracum, operculum, radula and penis, and on mitochondrial genes cytochrome c oxidase subunit I and 16S rRNA. Two genus-level lineages are recognised, Chondrocyclus s.s. and Afrocyclus gen. nov. Revised species descriptions are given for seven species. Two species, C. meredithae Bruggen, 1983 and C. chirindae Bruggen, 1986 both from north of South Africa, are removed from Chondrocyclus. Twelve new species are described: C. herberti sp. nov., C. silvicolus sp. nov., C. amathole sp. nov., C. pondoensis sp. nov., C. devilliersi sp. nov., C. pulcherrimus sp. nov., C. cooperae sp. nov., C. langebergensis sp. nov., C. kevincolei sp. nov., A. oxygala gen. et sp. nov., A. potteri gen. et sp. nov. and A. bhaca gen. et sp. nov. This is the first detailed systematic revision of an Afrotropical cyclophorid group to include morphological and molecular data. This study complements research on other taxa of low-vagility forest-dwelling habitat specialists by providing comparative distribution data for an independent, widespread group. Such evidence is urgently needed for conservation of South Africa’s threatened forest biome.
... E), located approximately 11 km south of Grahamstown in the Eastern Cape, South Africa. The vegetation within the reserve is diverse, with different regions consisting of Kowie thicket (Hoare et al. 2006), Zuurberg quartzite fynbos (Rebelo et al. 2006) and Bhisho thornveld . Predation experiments were confined to areas with low vegetation height (<50 cm), with no closed or semiclosed canopy. ...
Predation risk may be high in small snakes and most small snakes are thought to avoid certain behaviours, such as basking in open areas to reduce predation risk. The extent to which this concealment limits predation during basking is not known, but available data suggests that such concealment may significantly reduce predation attempts. Using model snakes placed in the field, predation rates on small model snakes were tested, specifically whether attack rates differ between partially concealed model snakes and model snakes placed in open unconcealed positions. Results from the current study support previous studies that predation pressure was high (average = 22.15%), but was not significantly reduced by semi-sheltered basking. An important new finding of this study was the high number of model snakes that experience trampling by wild ungulates (average = 12.72%.) This suggests that snakes basking in open and sheltered areas are also at risk of being killed or injured through trampling by larger animals. This study makes an important contribution to understanding predation pressure in African snakes and highlights other threats that snakes are exposed to during basking and thermoregulation.
... Another GCFR vegetation type with common, mainly facultative, CAM plants that may have colonized the cave area is subtropical thicket. The main difference between the climatic and environmental conditions of subtropical thicket and fynbos is the frequency of fires, which is much lower in thicket (Hoare et al., 2006;Rebelo et al., 2006). Low fire frequencies are found where rainfall is plenty and occurs year-round. ...
Highly resolved, well-dated paleoclimate records from the southern South African coast are needed to contextualize the evolution of the highly diverse extratropical plant communities of the Greater Cape Floristic Region (GCFR) and to assess the environmental impacts on early human hunter-gatherers. We present new speleothem stable oxygen and carbon isotope ratios (δ18Oc and δ13C) from two caves at Pinnacle Point, South Africa, covering the time between 330 and 43 ka. Composite δ18Oc and δ13C records were constructed for Staircase Cave and PP29 by combining all stable isotope analyses into a single time series and smoothing by a 3-point running mean. δ18Oc and δ13C values record changes in rainfall seasonality and the proportions of C3 and C4 plants in the vegetation, respectively. We show that in general increased summer rainfall brought about a wider spread of C4 grasses and retreat of the C3 plant–dominated GCFR communities. The occurrence of summer rainfall on the southern coast of South Africa was linked to total rainfall amounts in the interior region through tropical temperate troughs. These rainfall systems shifted the southern coastal climate toward more summer (winter) rainfall when precession was high (low) and/or the westerlies were in a northern (southern) position.
