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Many savannas are experiencing increased cover of trees and shrubs, resulting in reduced herbaceous productivity, shifts in savanna functional structure and potential reductions in ecotourism. Clearing woody plants has been suggested as an effective management strategy to mitigate these effects and restore these systems to an open state with higher rates of grass production and herbivory. This study investigated the effectiveness of repeated shrub clearing as a tool to mitigate bush encroachment in a semi‐arid savanna in southern Africa.We present data from a 7‐year experiment in the Mthimkhulu Game Reserve bordering Kruger National Park, South Africa. Colophospermum mopane stems and resprouting shoots were basally cut 2–3 times per year (2015–2022) in three pairs of treatment and control plots of 60 × 60 m. We monitored changes in soil moisture, grass biomass and herbivore activity via dung counts. We assessed C. mopane physiological responses to repeated cutting using non‐structural carbohydrates and stable water isotopes to infer changes to energy storage and functional rooting depth, respectively.The cleared treatment had higher soil moisture and grass biomass than the control treatment. Dung counts showed impala and buffalo visited the cleared treatment more frequently than the control treatment.Repeated cutting had limited effects on C. mopane survival in the first 2–3 years after initial clearing, but 80% of individuals were dead after 7 years. Repeatedly cut C. mopane had lower belowground starch concentrations and used water from shallower soil depths than C. mopane in control plots.Synthesis and applications. Repeated cutting increased soil moisture availability and grass biomass, and attracted charismatic grazing herbivores. While more costly than once‐off clearing methods, this practice created more employment opportunities for a neighbouring rural community. Transforming portions of the ecosystem to a grass‐dominated state may increase ecotourism potential through improved game viewing in open systems. [ABSTRACT FROM AUTHOR]

Fire‐herbivory feedbacks strongly influence the formation of grazing lawns in savanna ecosystems. Preliminary findings suggest that small‐scale (<25 ha) fires can engineer grazing lawns by concentrating herbivores on the post‐burn green flush; however, the persistence of such grazing lawns over the longer term and without repeated fire is unknown.We used high‐resolution Light Detection and Ranging (LiDAR) to investigate the long‐term effects of fire manipulation on short grass structure (height, cover, volume and spatial continuity) and grazing lawn establishment in Kruger National Park, South Africa. We analysed the effects of fire exclusion and experimental burns applied over a 7‐year period (2013–2019) followed by a 1‐year cessation of burning at varying spatial scales during the early and late dry seasons.Fires contributed a fourfold increase in short grass cover, regardless of fire season or size. The distribution of grass height differed significantly between fire‐induced grazing lawns and recently unburnt parts of the landscape where controlled fires were excluded over the experimental period. The volume (corresponding to bulk density) of short grass on the landscape responded strongly to fires, with grass volume <20 cm in height increasing with both early and late dry season fires.Early dry season fires caused larger and more homogeneous short grass patches. Furthermore, early dry season fires were more influential in increasing the cover of the shortest grass height class (1–5 cm).Synthesis and applications. Our results demonstrate that fire‐induced grazing lawns can persist over the longer term, even when fires are no longer applied, leading to the creation of vertical and horizontal heterogeneity in the grass layer. Small‐scale fires, therefore, represent a feasible management approach to expanding grazing lawn extent, potentially benefiting grazer coexistence and diversity. [ABSTRACT FROM AUTHOR]

Mountainous grassland landscapes are severely threatened by the proliferation of shrub encroachment. So far, it remains unclear though how slope aspect coupled with land disturbances linked to the proximity of homesteads to communal grazing sites affects the distribution, density and structure of the encroaching shrubs in these grassland ecosystems. In this study, we investigated the role that slope aspect plays in determining the density and structure of an encroaching shrub species Euryops floribundus N.E. Br in three communal grazing sites located at varying distances from rural homesteads in a semi-arid mountainous grassland in the Eastern Cape Province of South Africa. Three sites were strategically chosen in Cala communal grazing lands in an encroached mountainous grassland landscape that depicted north and south-facing slope aspects. The selected sites were Tsengiwe; a site located in close proximity to homesteads at a distance of less than 100 m, Upper Mnxe situated at an intermediate distance ranging from 200 to 800 m away from homesteads and Manzimdaka, which was located furthest from homesteads at a distance greater than 1600 m. In each site and corresponding slope aspect, the density and structure of the shrub E. floribundus were evaluated on 36 randomly distributed plots, yielding a total of 108 plots across all sites. We found that shrub density was significantly higher (50%) on the north-facing slope compared to the south-facing slope in Tsengiwe, the site located near homesteads. Shrub height was significantly higher (53 and 17%) on the north-facing slope compared to the south-facing slope at Upper Mnxe and Manzimdaka, which were located at intermediate and furthest distances from the homesteads. Notably, shrub height was significantly lower (37%) in the north-facing slope compared to the south-facing slope in Tsengiwe. Following a similar pattern to shrub height, total stem number was significantly higher (20 and 85%) in the north-facing slope compared to the south-facing slope at Upper Mnxe and Tsengiwe, respectively. Shrub crown area was higher (33 and 11%) in the north-facing slope compared to the south-facing slope at Upper Mnxe and Manzimdaka, respectively. A strong positive relationship was established between the height of shrubs and their longest crown diameter, shortest crown diameter and shrub crown area across all sites, suggesting that the investigated shrub species E. floribundus employs its structural characteristics to survive, and thrive and this was more evident in the north-facing slope. The results highlight the importance of considering the proximity of homesteads into account in ecological studies, and puts emphasis on improved understanding of the vegetation patterns shaped by shrub encroachment in mountainous grasslands, which is crucial in the development of effective land management strategies. [ABSTRACT FROM AUTHOR]

Savannas are characterized by the co-occurrence of two different plant life forms: grasses and trees. Herbivory plays a major role in the balance between grasses and trees in savanna ecosystems. The present study aimed to investigate the impact and interactions between long-term (i.e. 20 years) herbivory and/or its exclusion and plant life form on the soil biochemistry of a protected semi-arid savanna ecosystem in the Kruger National Park (KNP), South Africa. To study the effects of herbivory on soil properties, herbivore exclosures (fully fenced areas, partially fenced areas, and an unfenced area) were used in conjunction with plant life form (trees and grasses) were considered. Interaction effects of herbivory and plant life form on soil pH, electrical conductivity (EC), total nitrogen (TN), total carbon (TC), available phosphorus (available P), exchangeable cations (K+, Na+, Mg2+ and Ca2+) cation exchange capacity (CEC), organic matter (OM) and total microbial activity were determined on savanna soils in the Nkuhlu exclosures, KNP. Exclosures where herbivores were present had significantly higher soil pH, The presence of herbivores caused an increase in soil pH, EC, exchangeable Na, CEC, and OM. The influence of the tree canopy was significantly more pronounced in elevating total C and N, exchangeable K+, Mg2+ and Ca2+, CEC and OM than observed in the open grassland zones across all exclosures. The two-way interaction between herbivory and plant life form resulted in significant decreases in TN, TC, exchangeable K, Na and Mg in open grassland areas outside of herbivore exclosures where large animals had direct access, as compared to areas within the exclosures which was protected from animal entry herbivory. This data can be used by national parks as an indicator to increase their knowledge of environmental issues relating to maintaining and preserving landscape features of savannas. [ABSTRACT FROM AUTHOR]

Short-duration overnight kraaling has been suggested as a tool for restoring degraded rangelands. However, the response of different plant functional types and communities to such intense livestock impact may vary depending on local context. We thus examined the effects of short-duration overnight kraaling on soil and vegetation characteristics in a mesic montane grassland in South Africa using paired kraal and control sites, as part of a low intensity grazing approach. Kraaling increased soil P and S, as well as soil organic matter (except when initial values were over 12%). The effect of kraaling on vegetation was strongly dependent on initial condition. Basal cover of grasses and forbs increased by approximately 50 and 15%, respectively, if sites had very low initial basal cover, but decreased by up to 15% if initial values were over 50% and 10%, respectively. Kraaling always decreased herbaceous biomass, but especially when initial values were over 2 000 kg ha−1. In mesic grasslands, short-duration overnight kraaling is promising as a tool for rehabilitating degraded sites or fertilizing abandoned cropland, but should be avoided where the grass sward is intact. We recommend that the suitability of kraaling be evaluated per vegetation type and local context. [ABSTRACT FROM AUTHOR]

In the past, rangelands were managed in a semi-nomadic manner, where pastoralists would distribute livestock to different parts of the rangeland depending on the availability of forage. However, understanding how livestock use rangelands has not been a subject of many studies as the devices to monitor livestock were not available. The objective of this study was to assess livestock grazing distribution in communal rangeland of the Eastern Cape in South Africa in order to improve livestock grazing. The study used Global Positioning Systems (GPS) that were placed on six animals including three sheep and three cattle, selected randomly from participating households. The GPS collars recorded the geographic position of the areas where animals were grazing, at five-minute intervals during the wet and dry season. Grass species composition was surveyed using line transects on areas where livestock grazing occurred. The study further identified three production domains, which were separated by bound polygons on Google Earth Pro to extract MODIS EVI where livestock grazing occurred. Livestock grazing distribution was analysed using T-LoCoH installed in R. The results revealed that both sheep and cattle spent most of their time grazing in areas associated with human features. The dominant grass species were Hyperrenia hirta and Eragrostis plana, suggesting a negative impact of the current livestock grazing distribution. Possible explanations of the current grazing distribution might be that these areas are close to homesteads and provide grazing lawns that contain a high nitrogen content. This study will help in providing an informed basis for the development of South African communal rangeland policies for effective livestock management. [ABSTRACT FROM AUTHOR]

The Gamka Karoo is a low-lying vegetation type in the semi-arid Nama Karoo in the south-western part of South Africa with extensive rangelands used for livestock ranching and wildlife. Although the Nama Karoo is generally resilient to grazing and most responsive to variable rainfall, chronic overstocking, particularly in the driest regions and around water points, could degrade vegetation and soils. The interactive effects of rainfall (MAP) and grazing (stocking rate, percentage overstocking, resting system) on plant species composition and soil chemical characteristics were examined on 36 farms across a regional rainfall gradient (120–300 mm y−1) and around water points (n = 3) on farms. Multivariate direct gradient analyses revealed regional species compositional differences were related most strongly to MAP (r = 0.736), but not to grazing, with no MAP × grazing interaction. On a smaller scale, grazing intensity (1/distance from water point) had a weak negative impact on the vegetation (r = 0.36) and soil chemistry (r = 0.49) with nutrient enrichment around water points in paddocks. Our findings suggest that the Karoo is responsive to rainfall, but loosely coupled to grazing. Adaptive management with livestock numbers matched to rainfall and forage supply is recommended to sustain animal production, vegetation and soils. [ABSTRACT FROM AUTHOR]

Communal Property Associations (CPAs) rangeland users need more knowledge on the state of their respective grazing lands and also the interaction of soil properties with grazing management implemented. This study aimed to investigate the effect grazing has on the physical and chemical properties of four different soil types found in selected CPAs of the Bela-Bela municipality, they are as follows: Mawela (Hutton-clay loam: HCL), Bela-Bela (Hutton-clay: HC), Moretele (Hutton-loamy sand: HLS) and Ramorula (Ecca sand-clay loam: ESCL). The macro and micro minerals, pH, nitratenitrogen, ammonium-nitrogen, organic carbon, soil particle size distribution, acidity and resistance were all measured. All data were subjected to two-way factorial analysis of variance (SAS, 2010). The topsoil was sampled at a depth of 300 mm at an interval of 100 m (100 and 200 m) from the same transect used for woody species data collection resulting in a total of 18 samples per CPA. In each CPA, three camps were selected. In each camp, three transects 200mapart at the length of 200mwere set. In each transect, soils were drawn at 0, 100 and 200 m making a total of nine soil samples per each camp. The highest (P <0.05) pH (7.14) recorded on the sub-soil was in HLS. Nitrate nitrogen (2.4 mg/kg) concentration on the topsoil was high (P <0.05) in HC soil type. Soil organic carbon for both topsoil (0.66%) and subsoil (0.41%) was significantly lower (P <0.05) in HLS soil type and ESCL soil type respectively. Phosphorus concentration was significantly high (P <0.05) in ESCL soil type for both topsoil (12.86 mg/kg) and sub-soil (1.59 mg/kg). Iron concentration was high in both topsoil (11.8 mg/kg) and sub-soil (7.3 mg/kg) in ESCL soil type. Sub-soil manganese concentration was found to be higher (P <0.05) in ESCL soil type (7.58 mg/kg). Soil resistance (2880Ω) measured in topsoil was high (P <0.05) in HCL soil type compared to other soil types. Moreover, for the sub-soil the highest (P < 0.05) resistance (least salts) (3640Ω) was recorded in ESCL soil type. For most of the soil types, the mineral concentration was higher in topsoil than in sub-soil, this trend explains that the uptake of these minerals by plants took place due to the inconsistencies of grazing management employed in these selected CPA farms. It is of colossal significance to properly manage rangelands, to allow a fair-to-good herbaceous layer in the presence of minerals in the soils and farmer should prioritize having enclosures and keeping N-fixing tree species in the rangelands to achieve the above mentioned conditions. [ABSTRACT FROM AUTHOR]

Frequent grazing can establish high forage value grazing lawns supporting high grazer densities, but can also produce overgrazed grass communities with unpalatable or low grass basal cover, supporting few grazers. Attempts to create grazing lawns via concentrated grazing, with a goal to increase grazer numbers, are thus risky without knowing how environmental conditions influence the likelihood of each outcome. We collected grass species and trait data from 33 frequently grazed grass communities across eastern South Africa (28 sites) and the Serengeti National Park, Tanzania (five sites), covering wide rainfall (336–987 mm year−1) and soil (e.g., 44%–93% sand) gradients. We identified four grass growth forms using hierarchical clustering on principal components analyses of trait data and assessed trait–environment and growth form–environment relationships using fourth corner and principal components analyses. We distinguished two palatable grass growth forms that both attract yet resist grazers and comprise grazing lawns: (1) "lateral attractors" that spread vegetatively via stolons and rhizomes, and (2) "tufted attractors" that form isolated tufts and may have alternate tall growth forms. By contrast, (3) tough, upright, tufted "resisters," and (4) "avoiders" with sparse architectures or that grow appressed to the soil surface, are of little forage value and avoided by grazers. Grazing lawns occurred across a wide range of conditions, typically comprising lateral attractor grasses in drier, sandy environments, and tufted attractor grasses in wetter, low‐sand environments. Resisters occurred on clay‐rich soils in mesic areas, while avoiders were widespread but scarce. While grazing lawns can be established under most conditions, monitoring their composition and cover is important, as the potential for overgrazing seems as widely relevant. Tufted attractor‐dominated lawns appear somewhat more vulnerable to degradation than lateral attractor‐dominated lawns. Increased avoider and resister abundance both reduce forage value, although resisters may provide better soil protection. [ABSTRACT FROM AUTHOR]

In the Kruger National Park (KNP), the lower slopes of catenas have open patches referred to as sodic patches. Fire and herbivores are dominant mediators of vegetation in sodic patches. The effect of fire and herbivores on soil properties of sodic patches remains largely understudied. Moreover, the co-existence of trees and grasses and how they influence savanna soils is an important but poorly understood phenomenon in ecology. Therefore, the present study aimed to determine the influence of 20 years of fire, herbivores, vegetation type, and their interaction on soil biochemistry of sodic patches on the Nkuhlu exclosures in the Kruger National Park, South Africa. We found a higher main effect of fire on available phosphorus, cation exchange capacity, and soil organic matter. The presence of herbivores caused an increase in soil exchangeable cations (K+, Ca2+, Na+, and Mg2+), organic matter, cation exchange capacity, and microbial activity. Tree canopies had a higher effect on total nitrogen, exchangeable Ca and Mg, soil organic matter, and cation exchange capacity than open grassland zones. Our results indicate that changes in vegetation structure due to fire and herbivores and their secondary impact on soil properties should be taken into consideration in managing savannas. Moreover, fire and herbivores play an important role in the maintenance of vegetation type (trees and grasses) in sodic patches. [ABSTRACT FROM AUTHOR]

Woody‐plant encroachment is an under‐recognized consequence of land degradation. This phenomenon is common in rangeland ecosystems, where woody plants outcompete grasses, resulting in a shift to more wooded ecosystems. The consequences of this for livelihoods are most often damaging. Case studies at a local scale have shown negative consequences for ecosystem services and livelihoods, though few have considered these impacts over greater scales to find more generalizable patterns that are useful for governance structures at actionable levels.Here we make use of census data on household income and use of provisioning ecosystem services together with remote‐sensed woody‐plant encroachment data to perform the first country‐wide assessment at the municipal level across South Africa investigating correlations between woody cover change and (1) household income and (2) the use of provisioning ecosystem services use.We show that woody‐plant encroachment is greatest in municipalities with low income and a higher reliance on provisioning ecosystem services, specifically when woody cover was low. This reinforces a poverty trap by creating a positive‐feedback loop. For example, encroached landscapes with lower grass cover are more prone to overgrazing, decreasing fuel loads and further driving encroachment. This places more pressure on the remaining grass cover and decreases the provisioning of ecosystem services.Furthermore, our results allow us to rank the most affected municipalities based on income, reliance on provisioning ecosystem services and rates of woody cover change. We identify 16 municipalities requiring much‐needed interventions due to the risk of woody‐plant encroachment to natural resource‐reliant livelihoods.We suggest that interventions to reduce woody‐plant encroachment be targeted in low‐income communities, providing a win–win scenario for livelihoods and biodiversity. We recommend that woody‐plant encroachment be recognized as major form of land degradation and that restoration of encroached landscapes be prioritized within the UN Decade of Ecological Restoration 2021–2030. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Throughout much of the Quaternary, lower sea levels in the southern Cape of South Africa exposed a different landscape to what we see today, the Palaeo‐Agulhas Plain (PAP). The PAP was dominated by large‐bodied and gregarious grazing species contrasting with the small‐bodied predominantly solitary species we find in the region today. The distribution of these herbivores would likely have been driven by similar drivers we see in contemporary herbivore ecology. Importantly, the occurrence of early humans and their associated technology would have also influenced the probability of herbivores occurring in an area. Here we create a predictive model for large herbivores using probability of occurrence of functional grouping in relation to environmental drivers and humans. We show how early humans influenced the distribution of large herbivores on the PAP alongside other environmental drivers. In the fynbos biome, probability of occurrence was highest for the medium‐sized social mixed feeders' functional group in the thicket for small non‐social browsers, large browsers, and non‐ruminants and in grasslands for water‐dependent grazers. In our models, human influence affected functional groups to varying degrees but had the strongest effect on medium‐sized social mixed feeders. [ABSTRACT FROM AUTHOR]

Bijlia dilatata (Prince Albert Vygie) is a red-listed succulent (Aizoaceae) endemic to a single valley in the Western Cape and restricted to disjunct sites in quartzite pavements. Populations of this species were surveyed in 2002 during above-average rainfall and again in 2020 and 2021 during drought, and in June 2023 following drought-breaking rains. We found that populations declined over the two low-rainfall decades, that declines differed significantly among sites, that mortality was greater among smaller plants and that recruitment had failed. Our hypothesis that elevation provides a refuge from heat-induced mortality was supported by data that showed decreasing population decline along a 300 m elevation gradient. Factors significantly influencing population structure included landuse (grazing intensity), microsites and initial population density. Shaded microsites beneath living shrubs and adjacent to large rocks were significantly cooler and stayed moister longer after rain and B. dilatata plants in such microsites were larger than those in open sites or beneath dead shrubs. Grazing and climate change, including reduced winter rainfall, and increased ambient and soil surface temperatures, appear to be contributing to declines in endemic, habitat specialist dwarf succulents already threatened by land transformation and poaching in the biodiverse, Succulent Karoo region of South Africa. • Populations of an endemic dwarf succulent plant declined by 74% during drought. • Survival was better but seed production was poorer in shade below small shrubs. • Drought killed small plants and decline was greater where land was heavily grazed. • Populations on elevated parts of the landscape (330 m above lowlands) declined less. • Species threatened by climate change, grazing and poaching need protection. [ABSTRACT FROM AUTHOR]

Rangeland monitoring aims to determine whether grazing management strategies meet the goals of sustainable resource utilization. The development of sustainable grazing management strategies requires an understanding of the manner in which grazing animals utilize available vegetation. In this study, we made use of livestock tracking, in situ observations and Sentinel-2 imagery to make rangeland scale observations of vegetation conditions in a semi-arid environment, to better understand the spatial relationships between vegetation conditions and sheep movement patterns. We hypothesized that sheep graze more selectively under low stocking rates—resulting in localized overgrazing. We also assessed the importance of image spatial resolution, as it was assumed localized effects of grazing will be best explained by higher resolution imagery. The results showed that livestock tend to congregate along drainage lines where soils are deeper. The findings demonstrate how the spatial analysis of remotely sensed data can provide a landscape-scale overview of livestock movement patterns. This study illustrates that high-resolution normalized difference vegetation index (NDVI) data can be used as a grazing management tool to determine the spatial variability of productive areas across the semi-arid Upper Karoo rangelands and identify preferred grazing areas. [ABSTRACT FROM AUTHOR]

Restoration of degraded grasslands through improved management is among the possible sustainable solutions to compensate for anthropogenic soil carbon (C) emissions. While several studies have shown a positive effect of rehabilitation on soil C, the impact on soil CO2 emissions is still uncertain. Therefore, this study aimed at quantifying the impact of grassland rehabilitation on soil CO2 emissions in a degraded grassland, South Africa. Commonly used rehabilitation practices were considered, that is rotational grazing (RG), livestock exclosure with fertilizer application (EF) and annual burning (AB), all being compared with traditional free grazing (FG). A total of 2880 in situ measurements of CO2 emissions were performed over 2.5 years under field conditions simultaneously with aboveground biomass, soil temperature, water content and soil organic C (SOC) to understand the changes in C fluxes. The RG performed the best under degraded grasslands by decreasing net CO2 emissions (per g of C) by 17% compared to FG, while EF increased emissions by 76% and AB had similar emissions to FG. The lower net emission under RG is associated with an increase in SOC stocks by 50% and aboveground biomass by 93%, after three years of implementation. Soil CO2 emissions were correlated positively to aboveground biomass and topsoil temperature (r = 0.91 and 0.60, respectively), implying a high effect of grass cover on soil microclimate and microbial activity. These results suggested RG as a potential cost‐effective nature‐based soil management strategy to increase SOC stocks into degraded grassland. However, long‐term trials replicated in different environments are still required. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to determine acaricide resistance in Rhipicephalus decoloratus ticks collected from grazing cattle between November 2018 and May 2019 in Elundini, Senqu, and Walter Sisulu Local Municipalities in the northeastern region of the Eastern Cape Province. Materials and Methods: A sample of 20-30 adult engorged female R. decoloratus ticks were collected from at least 10 randomly selected cattle (highly tick-infested) at each dip tank and placed into the labelled plastic collection bottles containing absorbent paper and with a perforated lid at a constant room temperature of ±28°C and >70% relative humidity until resistance testing commenced. The Shaw larval immersion test method was used to determine R. decoloratus larvae resistance to various acaricide concentration levels [amidines, organophosphate (OP), and synthetic pyrethroids (SPs)]. Results: This study found that most ticks were susceptible to exposure to different acaricide field concentrations of amidines (49% at 250 ppm), OPs (33% and 47% at 300 ppm and 500 ppm, respectively), and SPs (44% and 23% at 150 ppm and 300 ppm, respectively). The resistance testing results showed no resistance to amidines at any localities and no resistance to OP in the Senqu region. However, resistance development of the larvae to amines, OPs, and SPs was extensively observed in Senqu (18%, 6%, and 7%), Elundini (15%, 15%, and 17%), and Walter Sisulu (13%, 19%, and 9%) regions, respectively. Conclusions: The larvae's resistance is a cause for worry. Hence, the continuous monitoring of tick resistance to commonly used acaricides will help mitigate widespread acaricidal resistance and sustain livestock productivity. [ABSTRACT FROM AUTHOR]

Islands of fertility (IOF) emerge when vegetation exerts such a considerable influence on soil properties that sub‐canopies become significantly more fertile than inter‐canopies. How confounding phenomena such as grazing patterns, seedbank dynamics and temporal changes impact IOF, has not been thoroughly examined. Soil and vegetation characteristics of 43 IOF in the Tankwa Karoo were surveyed along a rainfall gradient spanning three plant communities. Sixteen were in the Tankwa Karoo (TK) plant community, 14 in the Tankwa Wash (TW) and 13 in the Tankwa Escarpment (TE). The IOF were identified from aerial photos as clumps of shrubs separated by bare patches. Soils were described in 2014 and the seedbank composition in 2014 and 2015. Concentrations of nutrients, carbon and sodium were measured in IOF less than 5 years, 5–15 years and 30 years liberated from livestock grazing. Electrical conductivity, clay, nitrogen and carbon were the only soil properties that were significantly different from IOF to bare patch. The seedbank in IOF was identical to that in the bare patches. There was no significant difference in IOF versus bare patch nutrient concentrations in the three sampling locations. The soil in IOF was richer, more fertile and had a better structure than the soil in bare patches between IOF. There was a sharp turnover in seedbank composition in the two, drought‐ridden years. Longer grazing exclusion did not influence the nutrient concentrations. Findings here suggest that IOF are dynamic in space and time and are essential elements of landscape heterogeneity with critical ecosystem services. They should hence be managed and monitored to sustain them in landscapes to reverse their degradation, despite being the result of degradation. [ABSTRACT FROM AUTHOR]

Lebeckia ambigua is a perennial legume endemic to rangeland South Africa that is adapted to dry (< 400-mm annual rainfall), infertile and acidic (below pH 5.5Ca) soils. Although it is considered that the legume was grazed by mammalian ungulates during its evolution, little is known about its production, nutritive value for grazing animals or optimal management in an agricultural context, in either its centre of the origin or in Australia. Experiments were conducted to test the hypotheses that sheep would graze L. ambigua in autumn without adverse effects on either the animal or the plant. Lebeckia ambigua was established at two sites in Western Australia. In experiment 1, three grazing intensities were imposed by exclusion cages introduced during a single intensive grazing period, to provide differing residual pasture heights. The metabolisable energy and crude protein content of L. ambigua were more than 11.4 MJ/kg dry matter and 21%, respectively for all treatments. Un-grazed L. ambigua produced 1740 kg DM/ha while a single moderate or severe grazing reduced total biomass production by about 50% over 10 weeks post-grazing (P < 0.001). In experiment 2, continuous grazing of L. ambigua for 64 days had no negative impacts on biochemical health indicators of merino wethers. Grazing had no effect on plant density in either experiment indicating that L. ambigua is adapted to substantial grazing pressure in autumn. Lebeckia ambigua could become a valuable plant for sustainably increasing livestock production on infertile soils in rain-fed agro-ecosystems where other legumes fail. [ABSTRACT FROM AUTHOR]

We tested the response of algal epifauna to the direct effects of predation and the indirect consequences of habitat change due to grazing and nutrient supply through upwelling using an abundant intertidal rhodophyte, Gelidium pristoides. We ran a mid‐shore field experiment at four sites (two upwelling sites interspersed with two non‐upwelling sites) along 450 km of the south coast of South Africa. The experiment was started in June 2014 and ran until June 2015. Four treatments (predator exclusion, grazer exclusion, control, and procedural control) set out in a block design (n = 5) were monitored monthly for algal cover for the first 6 months and every 2 months for the last 6 months. Epifaunal abundance, species composition, algal cover, and algal architectural complexity (measured using fractal geometry) were assessed after 12 months. Predation had no significant effect on epifaunal abundances, while upwelling interacted with treatment. Grazing reduced the architectural complexity of algae, with increased fractal dimensions in the absence of grazers, and also reduced algal cover at all sites, though the latter effect was only significant for upwelling sites. Epifaunal community composition was not significantly affected by the presence of herbivores or predators but differed among sites independently of upwelling; sites were more similar to nearby sites than those farther away. In contrast, total epifaunal abundance was significantly affected by grazing, when normalized to algal cover. Grazing reduced the cover of algae; thus, epifaunal abundances were not affected by the direct top‐down effects of predation but did respond to the indirect effects of grazing on habitat availability and quality. Our results indicate that epifaunal communities can be strongly influenced by the indirect consequences of biotic interactions. [ABSTRACT FROM AUTHOR]

The concept of the piosphere is important in rangeland management, wildlife management, desertification. Piosphere research describes the changes in soil, biota and fauna as a function of distance from water sources utilized by grazing animals. Piosphere research has provided a better understanding of how grazing pressure can affect local environments. We conducted a bibliometric analysis to describe the progress of piosphere knowledge between 1915 and 2018. This is the first comprehensive bibliometric analysis of piosphere research, and it provides insights on future challenges, research challenges, and knowledge gaps. Google Scholar was used to identify 875 publications from 68 countries and 10 different languages. Our analyses showedthat research article was the most frequent publication type and piosphere was the most frequent keyword. Australia was first in the number of publications followed by South Africa and USA. Ivan Thrash is the most contributed author with 11 publications. The most frequently cited article is 'Responses of Mediterranean grassland plants to grazing and protection' in The Journal of Ecology. Herbivores, vegetation, soil, livestock, wildlife, and ecological were the most frequent research areas of piosphere investigations. English was the major and dominant language of piosphere publications. Rapid growth was found in piosphere research since the 1990s, enlivened by advances in statistics, remote sensing, GIS, and programming. We recommend that future research should investigate knowledge gaps such as grazing system relationships to piosphere patterns, economic analysis of watering point development and closure, and the implications of climate change and new piospheres. [ABSTRACT FROM AUTHOR]

Purpose: Cover crops can provide multiple agroecosystem services to crops produced in conservation agriculture systems. South African grain producers in the Mediterranean climate region are reluctant to integrate cover crops in rainfed systems since cover crops replace cash crops leading to financial losses. Using cover crops as fodder can help cover input costs, while providing a range of advantageous services to the cropping system. The aim of this study was to investigate how cover crop mixtures and the utilisation of cover crops affect soil quality, the quality and quantity of the mulch as well as wheat (Triticum aestivum L.) produced in the subsequent year. Methods: A two-year study was conducted in the Western Cape Province of South Africa. In Year 1, diverse legume and cereal-based cover crop mixtures were partially grazed, cut and material removed for haymaking, or left unutilised as a mulch. In Year 2, spring wheat (Triticum aestivum L.) was planted to investigate the effects of cover crop mixtures and utilisation method on subsequent spring wheat yield. Results: Cover crops used as hay or for grazing did not affect (P < 0.05) grain yield of wheat that followed in rotation. Legume-based cover crop mixtures increased (P < 0.05) wheat grain protein content regardless of utilisation method. Soil quality and nitrogen content improved (P < 0.05) when cover crops were grazed. Conclusions: Cover cropping can be used by South African grain producers as an important agronomic tactic to improve system productivity and support sustainable intensification of rainfed cropping systems. [ABSTRACT FROM AUTHOR]

Rainfall and stocking densities are key drivers of vegetation functioning and productivity in semi-arid regions. Below-average rainfall is of particular importance in the agricultural sector as it limits fodder availability for livestock in the short term, and can influence potential agricultural productivity through inducing the mortality of palatable perennial plant species in the long term. Changes in rainfall trends are not equal for all regions and must be quantified locally to sustainably manage natural grazing resources. The Upper Karoo has experienced considerable fluctuations in rainfall for many thousands of years, with relatively wetter and drier phases. This study analysed farm records from the past eight decades at eight sites in the Upper Karoo. The aim was to provide detailed and comparable descriptions to generate a more general understanding of rainfall at a spatial scale over this entire bioregion and to assess recent farming conditions within a historical rainfall context. A steadily increasing trend in rainfall of approximately 10 mm per decade has been observed in the Upper Karoo over the past eight decades, and the 30-year period from 1989 to 2018 was generally characterised by above-average rainfall. Presently, the farming conditions are more favourable compared to historical rainfall recorded before the year 1989. [ABSTRACT FROM AUTHOR]

In savannas, ruminant herbivores can have divergent impacts on tree recruitment and subsequent woody cover. Whereas heavy grazing by cattle results in woody thickening, intensive grazing by wildlife instead tends to be associated with lower woody cover.To disentangle why woody cover is low in areas heavily grazed by wildlife, we investigated (a) whether grazing lawns attract indigenous mammalian browsers, and if a preference for short‐grass habitat decreases with browser body mass as predator susceptibility decreases; and (b) whether browser attraction to grazing lawns translates into the suppression of woody plants, including seedlings and saplings, thus maintaining the openness of heavily grazed short‐grass areas.In Kruger National Park, South Africa, we contrasted browser abundance (using dung counts) on grazing lawns and on low‐herbivory sites characterised by tall grass. Additionally, a herbivore exclosure experiment was set up to investigate the combined impact of browser removal and grass height habitat type on seedling survival and sapling growth of a dominant woody plant species. Finally, in Hluhluwe‐iMfolozi Park (HiP), we examined the long‐term (10 years) impact of browser removal on the growth rates of a range of woody species, monitored across ten sites along a gradient of herbivory ranging from grazing lawn to tall grass.Steenbok and impala selected short‐ over tall grass as preferred browsing sites, while elephant preferred tall grass. Browser abundance on short grass decreased with browser body mass, indicating that predator avoidance might be a key factor driving mesoherbivores to utilise grazing lawns.Seedling survival was lowest on grazing lawns when browsers were present, with mortality occurring in two out of every three seedlings. Similarly, sapling growth was lowest on grazing lawns, although browser removal had no significant effect. Evidence for increased browser impact on grazing lawns was clearest from our long‐term herbivore exclosure experiment in HiP, which demonstrated that browsers strongly modify the growth rates of woody plants in short‐grass habitats.Synthesis. These results provide support for the hypothesis that browsers, particularly browsing mesoherbivores and mixed feeders, are attracted to short‐grass habitats, and that they help maintain grazing lawn openness by suppressing seedling survival and woody plant growth where grass is kept short by grazers. [ABSTRACT FROM AUTHOR]

Holstein cows on a farm in the Humansdorp district, Eastern Cape province, South Africa, developed reddened, painful teat skin 3 days after grazing a mixed forage crop dominated by bulb turnip (Brassica rapa , Barkant cultivar). The crop was grazed 45 days after planting and 10% of the herd developed symptoms. More characteristic non-pigmented skin lesions started manifesting 1–2 days after the appearance of the teat lesions. Affected cows had elevated serum activities of gamma-glutamyl transferase, glutamate dehydrogenase and aspartate aminotransferase. These blood chemistry findings confirmed a secondary (hepatogenous) photosensitivity. As a result of the severity of the teat and skin lesions, seven cows were slaughtered and tissue samples from five of them were collected for histopathological examination. Liver lesions in cows that were culled 3 or more weeks after the onset of the outbreak showed oedematous concentric fibrosis around medium-sized bile ducts and inflammatory infiltrates in portal tracts. Characteristic lesions associated with other known hepatobiliary toxicities were not found. No new cases were reported 5 days after the cattle were removed from the turnips. The sudden introduction of the cows, without any period of transitioning or adaptation to grazing turnips, as well as the short latent period, clinical signs of photosensitisation, blood chemistry and histopathology, confirmed a diagnosis of Brassica -associated liver disease, a condition seen in New Zealand but not previously described in South Africa. Brassica forage crops are potentially toxic under certain conditions and farmers must be aware of these risks. [ABSTRACT FROM AUTHOR]

Nematodes and coccidia are major pathogens causing parasitic infections in livestock production. This study aimed to determine the prevalence and seasonality of gastrointestinal helminths and coccidia in communal sheep grazing in humid, semi-humid and arid zones of the Eastern Cape Province. A total of 3299 faecal samples were collected from sheep between January 2012 and December 2015. Of the collected roundworm species (faecal eggs and faecal cultures), Haemonchus contortus was the only species found. The prevalence of gastrointestinal parasites was significantly higher in the humid zone (H. contortus 81% and coccidia 37%), followed by a semi-humid zone (H. contortus 75% and coccidia 22%) and the arid zone was the lowest (H. contortus 71% and coccidia 14%). Haemonchus contortus had significantly higher faecal egg counts (FEC) during spring (1465.73 ± 143.56) and summer (1418.73 ± 160.73) and the lowest during autumn (496.67 ± 219.13) and winter (352.05 ± 164.44) in all agro-ecological zone. The humid zone had significantly higher FEC in seasonal occurrence of H. contortus and coccidia compared with other agro-ecological zones (P < 0.05). There was no significant difference (P > 0.05) observed in the seasonal occurrence of H. contortus species in arid zone. Surprisingly, higher coccidia counts (352.17 ± 43.58) during 2012 winter season in humid zone and in summer season (0.00 ± 559.72) of 2013 in the semi-humid zone than other agro-ecological zones. However, agro-ecological zone differences and seasonal variations had an influence on H. contortus and coccidia distribution and abundance. This study confirms that helminths and coccidia are major causative agents causing parasitic infections in livestock production, and therefore, good animal health management practices including proper hygiene should be followed to prevent parasitic infection in small ruminants. [ABSTRACT FROM AUTHOR]

Background: Bone consists of Ca and P deposited within an organic collagen matrix. The highly porous nature of this matrix provides bone with an extensive surface area, making bone a highly labile source of both Ca and P and serves as metabolic reservoir for Ca, P and other minerals. Phosphorus in the skeleton provides large reserve, which may be mobilized when the diet is deficient in phosphorus, the measurement of bone minerals is important to evaluate bone reserves such as bone volume, bone specific gravity and bone thickness. Methods: Ten male mix breed cattle between the ages of 6 and 12 months therefore, were randomly selected from a herd feeding exclusively on communal grazing and receiving no supplements and were used to determine the role of bone phosphorus, calcium and magnesium on bone reserves in cattle grazing natural pasture. Bone samples were analysed for P through the FASPac II Version R2MI Auto-Analyzer and were analysed for Ca and Mg through an Atomic Absorption Spectrometer. Results: Bone volume, bone specific gravity and bone thickness were reacting with same pattern almost throughout research. Grass phosphorus was positively correlated to bone Mg (r²= 0.466) with the P value of 0.053. Concentration of Ca in the grass was positively correlated to bone Mg (r²= 0.524) and bone specific gravity (r²= 0.593) with the P values of 0.051 and 0.048 respectively. The rainfall measured during the research shown to have positive correlation on the concentration of P in the grass r²= 0.690) and of Mg (r²= 0.848) with the P values of 0.04 and 0.001 respectively. [ABSTRACT FROM AUTHOR]

Rainfall and herbivory shape savannah herbaceous communities, but these disturbances are being altered globally. To assess potential consequences of such alterations, we evaluated herbivore effects on species and functional diversity during an episodic drought in a sodic savannah using data collected from long‐term herbivore exclosures in the Kruger National Park, South Africa. Herbaceous life forms are rarely acknowledged as distinct functional entities. Moreover, the functional ecology of forbs remains elusive. Here, we present disturbances–responses by forbs separately from grasses. We hypothesised that combinations of intense utilisation and drought would be associated with low diversity and high dominance at species and functional levels for both life forms. Contrary to our hypothesis, low forb and grass diversity was associated with long‐term herbivore exclusion, which exceeded expected undesirable effects of intense utilisation and drought. Grasses responded less sensitively, suggesting that forbs respond dynamically to changes in herbivore assemblage when these alterations are combined with drought. Consistent with patterns in savannah systems, forbs contributed significantly to species and functional trait diversity. High forb diversity is suggested to enhance resilience of this nutrient‐rich ecosystem against declines in its functioning when subjected to drought and alterations in herbivory. [ABSTRACT FROM AUTHOR]

In the Nama-Karoo, South Africa, rainfall and grazing by livestock are two important drivers of botanical composition. Summer rains are advantageous particularly to the grass layer, whereas the characteristic dwarf shrubs survive better than grasses during drought, and benefit from rainfall during cool months. Heavy grazing by livestock during summer reduces the abundance of grasses, whereas winter grazing increases it. This study examined the influences of season of grazing (summer vs winter) and rainfall on botanical composition at two long-term grazing trials at Grootfontein in the eastern Karoo from 1949 to 1967. Severe summer grazing strongly reduced grass abundance and slightly increased the abundance of both palatable and unpalatable dwarf shrubs. High previous-season rainfall strongly promoted short-lived grasses. Dwarf shrubs and grasses declined in response to a decline in annual rainfall over the study period, except for the creeping grass Tragus koelerioides that increased in abundance, possibly in response to decreased competition and an increase in available gaps in the vegetation layer. Results indicate that grazing systems that exclude repeated summer-only grazing maintain ecological health, and that rainfall is the main driver of composition unless extreme grazing systems are employed. [ABSTRACT FROM AUTHOR]

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Large herbivores, particularly wide‐ranging species, are extensively impacted by land use transformation and other anthropogenic barriers to movement. The adaptability of a species is, therefore, crucial to determining whether populations can persist in ever smaller subsets of their historical home ranges. Access to water, by drinking or from forage moisture, is an essential requirement, and surface water provision is thus a long‐established, although controversial, conservation practice. In the arid Kgalagadi Transfrontier Park (KTP), South Africa, surface water provision in the 1930s facilitated the establishment of a sedentary wildebeest (Connochaetes taurinus) population in a region historically accessed only in the wet season, via now collapsed long‐distance movements. Here, we investigate the behaviour and diet of this wildebeest population, and how these relate to water in the landscape, to better understand the process of transitioning from a mobile to sedentary population. Data from 26 monthly surveys reveal that wildebeest distributions are shaped by water availability and salinity, shade, forage, season and possibly predator detectability. Areas with saline or no water are used predominantly in the wet season when forage moisture is high. Wet season movements beyond the study area mean the timing of wildebeest grazing in these regions matches historical timing. Grass utilization field data suggest that the KTP grazer population experiences forage deficits during the dry season, when ~80% of grass tufts are grazed and C:N and crude protein levels decline. Nonetheless, dung isotope data show that wildebeest meet their crude protein intake requirements during the dry season, likely by consuming unprecedentedly high levels of browse (>33%). While restoring the full historical range and movements of most large herbivore populations is not possible, these findings highlight that understanding the behavioural and dietary adaptability of a species can augment 'next best' efforts to conserve viable populations while home ranges contract. [ABSTRACT FROM AUTHOR]

Grazing lawn and flammable-tussock grass communities are contrasting resource pools for mammalian grazers in terms of forage quantity and quality. Drought events fundamentally alter forage availability within these communities and therefore should alter herbivore use with repercussions for the recovery and functioning of ecosystems after drought. During and after an intense El Niño drought (2014–2017) in Kruger National Park, South Africa, we addressed two questions: (1) how does herbivore use of different grass types change during a drought and (2) how do these changes affect grass productivity post-drought? We monitored grazer use of three different grass communities (lawn, tussock and burned-tussock) at a landscape scale and measured primary productivity monthly during and post-drought. For the first drought year, grazer numbers were highest on grazing lawn communities. This pattern continued into the second dry growing season, until herbivores finally left the study area. Both lawns and tussock grasslands recovered rapidly after the first good rainfall (productivity > 150 g m−2 per month). However, grazers did not return to feed on the same patches they had frequented pre-drought resulting in grazing lawn grasses self-shading and senescing. Longer droughts have the potential to decouple grazers and grazing lawns with negative impacts on lawn productivity and persistence that could drive the loss of lawns in savanna landscapes and impact mesoherbivore populations. It is clear from our results that grazer effects need to be incorporated into drought frameworks to understand the consequences of droughts for grassland function. [ABSTRACT FROM AUTHOR]

Projected increases in the frequency and severity of drought events are expected to impose changes in the ecology of native forb communities in semi-arid ecosystems. We examined the state of forb communities during, and directly after an extreme drought event across two contrasting land-use types, which included a protected area (high diversity of free roaming wild herbivores) and communal rangeland (long history of intensive cattle grazing) in a semi-arid Lowveld savanna of the Gazankulu area, South Africa. Forb floristic data were collected towards the end of the drought and repeated after the drought release a few months later. Forb community composition was significantly different among land-use types. Community changes were not induced by annual forb emergence alone, but through species-specific dominance shifts, which differed among land-use types. Forb richness, diversity and biomass were equally low at both land-use types and increased significantly after the drought release, although the magnitude of response was much stronger in the protected area, whereas drought contributed to a directional change in the protected area with a complete post-drought turnover in both annual and perennial forb species, much less variability was observed in the communal rangeland, which may suggest long-term effects imposed by land-use history. [ABSTRACT FROM AUTHOR]

The adaptation of Zulu (Nguni) sheep (Ovis aries) to environmental stress and survival under extensive conditions makes them uniquely important to rural Nguni farmers of South Africa. Here, the faecal bacterial community of five Zulu sheep populations managed under extensive conditions across summer and winter seasons was investigated in order to understand the influence of prevailing seasonal factors. Bacterial operational taxonomic units (OTUs)/species (at 97% 16S rRNA gene similarity) in Zulu sheep faeces were more diverse in winter than in summer at most (80%) sites and varied between seasons at specific sites. Firmicutes was the most abundant phyla in both summer and winter seasons, while the relative abundance of Actinobacteria reduced in 80% of sites from summer to winter. The genera (or family) such as Akkermansia, Eubacterium coprostanoligenes group, Intestinibacter, R-7 group (family Christensenellaceae), Ruminococcus, Ruminoclostridium, Treponema and UCG-005 (family Ruminococcaceae) were relatively more abundant and belonged to a ‘core microbiome’ of Zulu sheep faeces. Between seasons, Acinetobacter, Jeotgalicoccus, Methanobrevibacter, Phascolarctobacterium and Planomicrobium were differentially abundant. Overall, results suggest increased richness and diversity of bacteria from summer to winter which may be related to spatio-seasonal variations in grazing management, forage types and availability. This observation serves as baseline evidence, justifying further controlled studies investigating, amongst other factors, effects of forage type and availability across seasons on ruminal microbiota of Zulu sheep grazing in communally managed rangelands. [ABSTRACT FROM AUTHOR]

This study investigated indigenous goat production on kikuyu at Cedara Research Station, KwaZulu- Natal, South Africa. Three stocking rates were used (30, 45 and 60 goats/ha) to evaluate goat production on kikuyu. Does with kids grazed kikuyu for a total of seven months under a four camp rotational grazing system. Kid and doe mass were monitored. The results show that does lost weight to weaning at all stocking rates, with significant differences between the years. Does were able to regain some of the weight lost during lactation once the kids were weaned. Stocking rate affected kid growth rates, with higher weight gains at the lower stocking rates. Evaluation of doe performance showed that the light stocking rate had higher production per animal but lower production per hectare. Therefore, to maximise production per hectare a heavy stocking rate should be used, but to maximise weight gain per animal, a low stocking rate should be implemented. [ABSTRACT FROM AUTHOR]

Rangelands of arid ecosystems are driven by internal and external environmental controls. Grazing pressure is an important anthropogenic driver, but stochastic environmental events such as rainfall variability and prolonged drought can have profound effects on arid vegetation. We investigated the effect of a prolonged drought and initial high grazing pressure on range condition, perennial vegetation cover, life form cover, vegetation composition and vegetation diversity at five monitoring sites in a conservation area in arid Succulent Karoo vegetation. The response of the rocky mountainous vegetation to drought and grazing differed notably from the response of the sandy plains vegetation. Range condition and perennial vegetation cover reduced drastically in all habitats, although the extent of deterioration was less in the mountainous habitats. Annual vegetation cover was associated with inter-annual rainfall variability. Species richness decreased at three of five sites, whereas species evenness increased at three of five sites. Shannon-Wiener index of diversity and Simpson's diversity index trends were inconsistent. Vegetation composition changed directionally from a quasi-stable state in all five monitoring sites as the drought persisted. The extent of the change was less in mountainous habitats indicating potentially higher resilience than in plains habitats, though grazing pressure was lower in the mountains than on the plains over the study period. The existence of quasi-stable states, together with the observed directional changes in vegetation composition in response to both drought and grazing, indicated that both equilibrium and non-equilibrium vegetation dynamics apply. [ABSTRACT FROM AUTHOR]

We tested whether holistic planned grazing (HPG) and four-camp grazing (FCG) rotational grazing approaches influence beef cattle parasites counts compared with continuous, season-long (SLG) grazing. We expected that parasite counts would increase linearly with increasing camp occupancy by cattle from 1 d (70-camp, HPG) to 21–28 d (four-camp, FCG) to 180 d (one-camp per season, SLG). Tick and faecal egg counts were observed across seasons on 30 steers raised on a private farm in Cedarville, South Africa. Tick species identified were Rhipicephalus evertsi evertsi, Rhipicephalus (Boophilus) decoloratus, Hyalomma spp. and Amblyomma hebreaum with respective prevalences of 32%, 29%, 20% and 19%. Unidentified roundworms had the highest faecal worm egg counts (81.2%) followed by Coccidia (16.4%), Nematodirus (1.2%) and strongyles (1.2%). Overall, prevalence and mean counts for ticks and faecal worm eggs were highest in the hot wet season, with the SLG having greater (P≤ 0.05) values than either of the rotational approaches. However, increasing camp number and animal densities above four camps did not reduce (P > 0.05) parasite loads compared with HPG. Current results suggest that rotational grazing is a potential strategy to reduce livestock losses caused by high tick and worm loads in cattle, especially in the hot wet season. [ABSTRACT FROM AUTHOR]

Large‐scale environmental changes create challenges for conservation of wildlife, particularly in fenced, insular protected areas where many wildlife populations persist. Moreover, large mammalian herbivores inhabiting spatially and temporally heterogeneous environments face the challenge of securing highly variable forage resources. Mixed feeders like the eland (Taurotragus oryx) can switch between browse and grass, but the cues that elicit that switch are not well understood. We investigated the seasonal diet shift of eland confined to a small fenced reserve and the role of greenness to elicit that shift. Eland changed from a diet in the wet season, consisting of grasses and browse found in woodland and grassland vegetation types, to a diet in the dry season dominated by the greenest browse species still available in woodland vegetation types, as greenness of dry season forage decreased. Our results suggest that eland switch from browsing to grazing in response to phenophase of the grass sward, which could explain the varying selection of grasses versus browse observed across the species range. [ABSTRACT FROM AUTHOR]

Vegetation degradation has been identified as a serious environmental problem, around the communal villages of South Africa. An investigation of the relationship between vegetation condition and local grazing management systems was undertaken across the communal villages of the central Keiskamma Catchment, Eastern Cape Province. The hypothesis that "differences in grazing management strategies may explain the variations in vegetation condition within these communal villages" was tested. Landsat TM imagery of 1984 and 1999, in conjunction with SPOT‐4 imagery of 2011, was used to assess the spatial and temporal trends in vegetation. Structured interviews were administered among communal village authorities to obtain information regarding the functionality of local grazing management structures. Using the logistic regression in IDRISI Selva remote sensing software, relationships between vegetation condition and grazing management systems were analysed. Spatial and temporal trends in vegetation cover revealed a drastic reduction in fair vegetation, an increase in extremely degraded vegetation and bare/eroded surfaces, particularly in villages with ineffective rangeland management practices. The hypothesis was accepted; a distinct relationship between the respective grazing practices and vegetation condition was identified. Variations in the functionality of local grazing management structures in the communal villages account for the vegetation condition disparities observed. A revitalisation of these structures is key in vegetation restoration endeavours. [ABSTRACT FROM AUTHOR]

Abstract The common springbok (Antidorcas marsupialis), with its characteristic dorsal fan and stotting movement is the national animal of South Africa. In the Pleistocene, this species shared the subcontinent with the extinct Bond's springbok (Antidorcas bondi), and differences in their ecological relationship has been of long-standing interest to palaeontologists. Brink (1987) proposed that Bond's springbok, as a characteristic species for the Florisian Land Mammal Age, was an essential part of a Pleistocene grazing community that likely occupied open grasslands in the interior. This niche contrasts markedly with the flexible browsing habits of the extant springbok, which can tolerate arid habitats. Here we revisit the dietary ecological history of A. bondi by means of published species distribution data through time, and carbon stable isotope data. The results suggest that its specialist grazing ecology remained stable from the Mid-Pleistocene onwards until its extinction in the early Holocene (c. 8-10ka). The results are discussed in the context of Pleistocene palaeoenvironmental change in southern Africa. [ABSTRACT FROM AUTHOR]

Abstract The purpose of this paper is to give an ecological description of the vegetation of the Jurisdam-Seekoegat section of the Mountain Zebra National Park in the Eastern Cape Province, South Africa. The effect of different land use practices on the vegetation composition was also investigated. Vegetation classifications and descriptions are of immense value to scientists and land managers and provide information on the composition, structure, diversity and effect of management on the different ecosystems present. The Braun-Blanquet approach was used to classify the different plant communities, while the veld condition was determined using the Ecological Index Method. Plant community data was analysed using the JUICE software package while diversity of the different plant communities was determined using the Shannon–Wiener and Gini–Simpson Indices. From a TWINSPAN analysis eight plant communities that can be grouped into six major communities were identified. Two plant communities not previously described for the Park were identified. The different plant communities can all be related to topography and effect of previous land use. Grasses and dwarf shrubs are the most prominent species. The plant communities of the rocky midslope areas achieved the highest species richness and diversity for the study area. The areas least affected by heavy grazing had a higher veld condition score than those heavily grazed by domestic animals in the past. The results of this study also emphasises the importance of resting overgrazed veld, while it seems that heavily grazed areas will not recover without further human intervention. A vegetation map of the different plant communities was produced using ArcGIS. Highlights • Vegetation classification improves our knowledge and understanding of complex ecosystems. • Rocky hilly areas act as refuge areas for vegetation with the highest diversity of plant species. • Resting of overgrazed veld in arid areas assists in veld condition recovery. • Wildlife has less of an impact on veld condition than domestic animals with continued grazing. • Overgrazing seems to alter nutrient structure of soil thereby altering vegetation composition. [ABSTRACT FROM AUTHOR]

As changes in the environment have brought wild and domestic animals into closer proximity, cross-species disease transmission has become a major concern in wildlife conservation. The worldwide impacts of tick-borne diseases require an understanding of pathogen transmission dynamics across different host species. Livestock are often kept near protected areas and frequently share habitat with wild animals. The influence of host community composition on tick-borne pathogen transmission remains poorly understood, making it difficult to determine whether sharing habitats with domestic livestock increases tick-borne disease in wildlife populations. We used network analysis to analyse 35,349 collections of 54 tick species in South Africa, treating hosts as nodes and shared tick species as links. Across all life stages, 93 mammalian species were connected by a total of 3105 links. Sheep, goats, and dogs were particularly important domestic species for network connectivity; and for wild animals, soft-skinned, smaller mammals such as the scrub hare. Although South African ticks exhibit some specialization on wild animals, network analysis showed that opportunistic feeding on domestic hosts can lead to shortened transmission pathways and facilitate pathogen spread between mammal species. Mammal species are highly interconnected through the tick species that they share, and domestic mammals significantly increase the risk of disease transmission. These findings support conservation measures that limit contact between domestic and wild mammals to reduce tick-borne disease transmission. Grazing in protected areas must be evaluated in light of disease risks to both domestic and wild animals, and potentially also to people. [ABSTRACT FROM AUTHOR]

As the primary land use in the Karoo, extensive small-stock farming contributes significantly towards the agricultural economy of the region. However, the sustainability of this practice has been questioned for many years. This led to the establishment of a long-term stocking-density trial in 1988 at the Carnarvon Research Station. The trial was designed on a three-camp rotational grazing system under four stocking densities (8, 7, 5.5 and 4 ha SSU-1). Following continuous treatment over 28 years, the results from a once-off assessment in February 2016 portrayed no significant differences between treatments with regard to plant height, cover, species diversity, ecological and grazing index scores. Animal production varied among treatments where the mean production per hectare was found to be the highest under the high stocking-density treatment. Due to the absence of historical data, the results from this study are not conclusive with regards to changes in the vegetation dynamics over time and therefore does not lend itself to making conclusions concerning stocking densities. It can, however, be concluded that the vegetation of the Western Upper Karoo is remarkably resilient to the perceived higher stocking densities set at the time, on condition that an appropriate grazing management strategy is applied. [ABSTRACT FROM AUTHOR]

Biogenic volatile organic compounds (BVOCs) play an important role in the chemistry of the troposphere, especially in the formation of tropospheric ozone (O3) and secondary organic aerosols (SOA). Ecosystems produce and emit a large number of BVOCs. It is estimated on a global scale that approximately 90% of annual BVOC emissions are from terrestrial sources. In this study, measurements of BVOCs were conducted at the Welgegund measurement station (South Africa), which is considered to be a regionally representative background site situated in savannah grasslands. Very few BVOC measurements exist for savannah grasslands and results presented in this study are the most extensive for this type of landscape. Samples were collected twice a week for 2 h during the daytime and 2 h during the night-time through two long-term sampling campaigns from February 2011 to February 2012 and from December 2013 to February 2015, respectively. Individual BVOCs were identified and quantified using a thermal desorption instrument, which was connected to a gas chromatograph and a mass selective detector. The annual median concentrations of isoprene, 2-methyl-3-butene-2-ol (MBO), monoterpene and sesquiterpene (SQT) during the first campaign were 14, 7, 120 and 8 pptv, respectively, and 14, 4, 83 and 4 pptv, respectively, during the second campaign. The sum of the concentrations of the monoterpenes were at least an order of magnitude higher than the concentrations of other BVOC species during both sampling campaigns, with -pinene being the most abundant species. The highest BVOC concentrations were observed during the wet season and elevated soil moisture was associated with increased BVOC concentrations. However, comparisons with measurements conducted at other landscapes in southern Africa and the rest of the world that have more woody vegetation indicated that BVOC concentrations were, in general, significantly lower for savannah grasslands. Furthermore, BVOC concentrations were an order of magnitude lower compared to total aromatic concentrations measured at Welgegund. An analysis of concentrations by wind direction indicated that isoprene concentrations were higher from the western sector that is considered to be a relatively clean regional background region with no large anthropogenic point sources, while wind direction did not indicate any significant differences in the concentrations of the other BVOC species. Statistical analysis indicated that soil moisture had the most significant impact on atmospheric levels of MBO, monoterpene and SQT concentrations, whereas temperature had the greatest influence on isoprene levels. The combined O3 formation potentials of all the BVOCs measured calculated with maximum incremental reactivity (MIR) coefficients during the first and second campaign were 1162 and 1022 pptv, respectively. -Pinene and limonene had the highest reaction rates with O3, whereas isoprene exhibited relatively small contributions to O3 depletion. Limonene, α-pinene and terpinolene had the largest contributions to the OH reactivity of BVOCs measured at Welgegund for all of the months during both sampling campaigns. [ABSTRACT FROM AUTHOR]

The Succulent Karoo, one of two arid biodiversity hotspots in the world, is known for its high plant species richness, but little is known about the influence of topography and how it mediates the potentially deleterious effects of grazing. Changes in vegetation species composition, cover and species diversity were examined along piosphere gradients on northerly slopes, bottomlands and low-lying plains on 45 farms. Landscapes differed in the plant speciesand life-form composition, species richness and cover, with the more species-rich, heterogeneous grassy northerly slopes distinct from the plains and bottomlands, which were dominated byPteronia pallens,Psilocaulon junceumandDrosanthenumspp. with more annual and ephemeral species. Overall, species richness declined linearly with decreasing rangeland condition. A weak grazing effect was detected only on the north-facing slopes, where shrubs and grass decreased with intense grazing. Years of overgrazing have resulted in the widespread dominance ofP. pallens, especially on the plains and bottomlands, rendering them insensitive to grazing. The current condition of the northern slopes should be maintained and managed such that palatable species can spread to more degraded areas of the landscape. [ABSTRACT FROM PUBLISHER]

Southern Africa’s grassland biodiversity is threatened by habitat transformation such as commercial forestry. Ecological networks (ENs) have been instigated to alleviate the pressure of habitat transformation on local biodiversity. ENs are large scale webs of corridors and patches of natural vegetation criss-crossing production landscapes that can simulate conditions in protected areas (PAs). Many ENs have lost many native large mammal species, which have been replaced by domestic livestock to retain natural grazing dynamics, which could have an impact on the long-term value of ENs for insects. Here we compared dung beetle, butterfly and grasshopper diversity in ENs across a landscape mosaic of timber plantations, where 1) wild megaherbivores were maintained, 2) in ENs where these herbivores were replaced by livestock and, 3) in a nearby World Heritage PA which retained its natural complement of megaherbivores. Sites in the PA far from any plantation were similar in composition to those in the wild grazed EN. Presence of the wild grazers improved the alpha- and beta-diversity of all focal insect taxa when compared to domestic grazing. Furthermore, species composition shows significant differences between the two grazing systems indicating that an assemblage of native large mammals facilitates insect diversity conservation. We support the maintenance or introduction of large native mammals in ENs or similar conservation areas in production landscapes to simulate the ecological conditions and natural heterogeneity in nearby PAs. [ABSTRACT FROM AUTHOR]

Moist high-altitude grasslands in South Africa are renowned for high avifaunal diversity and are priority areas for conservation. Conservation management of these areas conflicts with management for other uses, such as intensive livestock agriculture, which requires annual burning and leads to heavy grazing. Recently the area has become target for water storage schemes and renewable electricity energy projects. There is therefore an urgent need to investigate environmental factors and habitat factors that affect bird species richness in order to optimise management of those areas set aside for conservation. A particularly good opportunity to study these issues arose at Ingula in the eastern South African high-altitude grasslands. An area that had been subject to intense grazing was bought by the national power utility that constructed a pumped storage scheme on part of the land and set aside the rest for bird conservation. Since the new management took over in 2005 the area has been mostly annually burned with relatively little grazing. The new management seeks scientific advice on how to maintain avian species richness of the study area. We collected bird occurrence and vegetation data along random transects between 2006 and 2010 to monitor the impact of the new management, and to study the effect of the habitat changes on bird species richness. To achieve these, we convert bird transect data to presence only data to investigate how bird species richness were related to key transect vegetation attributes under this new grassland management. First we used generalised linear mixed models, to examine changes in vegetation grass height and cover and between burned and unburned habitats. Secondly, we examined how total bird species richness varied across seasons and years. And finally we investigated which habitat vegetation attributes were correlated with species richness of a group of grassland depended bird species only. Transects that were burned showed a larger decrease in vegetation cover compared to transects that were not burned. Grass height increased over time. Bird species richness was highest in summer compared to other seasons and increased over time. Overall bird species richness increased over the three summer surveys but species richness of birds that prefer heavily grazed habitat showed little change over the three years. Changes in bird species richness were best explained by the model with grass height for combined species richness of grassland depended birds but also for birds that prefer heavy grazing when treated alone. On one hand birds that prefer moderate grazing were best explained by a null model. However, overall bird species richness was better positively correlated to grass height than grass cover or dead grass. We conclude that frequent burning alone with relatively reduced grazing led to higher but less dense grass, which benefited some species and disadvantaged others. We suggest that management of this grassland use combination of fire and grazing and leave some areas unburned to accommodates birds of various habitat needs. [ABSTRACT FROM AUTHOR]

Tropical savannas and grasslands are estimated to contribute significantly to the total primary production of all terrestrial vegetation. Large parts of African savannas and grasslands are used for agriculture and cattle grazing, but the carbon flux data available from these areas is limited. This study explores carbon dioxide fluxes measured with the eddy covariance method for three years at a grazed savanna grassland in Welgegund, South Africa. The tree cover around the measurement site, grazed by cattle and sheep, was around 15%. The night-time respiration was not significantly dependent on either soil moisture or soil temperature on a weekly temporal scale, whereas on an annual time scale higher respiration rates were observed when soil temperatures were higher. The yearly carbon dioxide balances of the growing seasons 2010-11, 2011-12 and 2012-13 were -85, 67 and 139 g C m-2 yr-1, respectively. The yearly variation was largely determined by the changes in the early wet season fluxes (September to November) and in the mid-growing season fluxes (December to January). Early rainfall enhanced the respiratory capacity of the ecosystem throughout the year, whereas during the mid-growing season high rainfall resulted in high carbon uptake. This study underlines the difficulty in establishing a functional relation between the total ecosystem respiration and the environmental drivers in savanna ecosystems. Furthermore, the high inter-annual variation of carbon balance in savanna ecosystems is difficult to relate to environmental drivers. [ABSTRACT FROM AUTHOR]

Aim Some regions donate more invaders from particular taxonomic and functional groups than they receive. We demonstrate a particularly striking donor-recipient asymmetry in invasion ecology in grasses. Specifically, we explore whether low numbers of invasive grasses in South Africa can be explained by sampling biases, introduction dynamics, species traits or invasibility of ecosystems. Location South Africa, Australia, Chile, Europe and the USA. Methods We tested for a donor-recipient asymmetry using lists of native and non-native grasses in five regions across the globe. Then, using distribution, trait and environmental data, we tested whether regions differed in: (1) herbarium sampling effort; (2) introduction dynamics of non-native grasses (primary uses, area of origin and minimum residence time of non-native grasses); (3) traits of native and non-native grasses (leaf size, height, life history, growth form, C3:C4 ratio and taxonomic placement); and (4) fire frequency. Results South Africa has fewer invasive grasses, and fewer widespread invasive grasses, than other regions; while grasses native to South Africa are much more likely to be invasive elsewhere than other grasses. This asymmetry cannot be explained by sampling biases, historical trade links or minimum residence time. Rather it is likely to be due to a combination of: (1) the massive scale of the introduction of South African grasses around the world; (2) specific traits that make South African grasses successful competitors; and (3) the high fire frequency of many South African ecosystems to which many native grasses are adapted, but introduced grasses are not. Main conclusion South Africa has a high diversity of grasses that possess specific traits to cope with fire, grazing and disturbance. This makes them more competitive. Moreover, the high diversity of certain grass lineages in South Africa acts as a reservoir of potential invaders and possibly helps limit invasions in South Africa by promoting fire. [ABSTRACT FROM AUTHOR]

Grazing and fire are disturbances integral to the evolution and maintenance of savanna grasslands. Humans are altering or completely eliminating these disturbance regimes at a global scale, with important consequences for savanna ecosystem structure and function. It is unknown whether the alteration of these disturbance regimes will have similar effects on grass communities of savanna grasslands in different geographic regions that vary in their biogeographic and evolutionary histories, as well as in the diversity of extant grazers., Here, we examined the effects of large herbivore loss on different aspects of grass community structure - taxonomic, phylogenetic and functional - across a range of fire frequencies in C4-dominated mesic savanna grassland sites of North America (Konza Prairie Biological Station, Kansas, USA) and South Africa (Kruger National Park). The goal of the study was to determine whether the loss of large herbivores exerted a consistent effect on the grass communities of two physiognomically similar grasslands with different biogeographic and grazing histories., The removal of large herbivores resulted in divergent responses in the grass communities at Konza and Kruger that was consistent across fire treatments. At Konza, there was a rapid and significant response to grazing exclusion while the response was muted and transient at Kruger. Functional syndromes associated with grazing resistance were generally conserved across sites, and it was the functional strategies of the dominant species at each site that drove the divergent responses. Further, our study supports the hypothesis that grazing and aridity may be selective forces that act in parallel as those species that were grazing resistant also occupied drier niches., Synthesis. Our study demonstrates that savanna grassland communities with different biogeographic and grazing histories respond differently to the removal of large herbivores and that climate, fire and grazing are interactive forces in maintaining savanna grassland diversity and function. We show that the functional attributes of the dominant grasses, which are in part driven by the biogeographic and grazing history experienced, are the most relevant in predicting the response of savanna ecosystems to the loss of large herbivores. [ABSTRACT FROM AUTHOR]

Questions Vegetation change in arid regions with a coefficient of rainfall exceeding 33% usually displays non-equilibrium dynamics, where abiotic factors override internal biotic controls. Irreversible changes have nonetheless also been described for arid regions. What are the contributions of internal/equilibrium vs external/non-equilibrium factors to vegetation dynamics and can degradation due to overstocking be reversed after removal of livestock? Location Goegap Nature Reserve, Namaqualand, South Africa. Methods The descending point method was conducted annually from 1974 at two transects. Vegetation change was assessed in terms of vegetation cover, species composition, life-form composition, range condition, species richness and diversity. Principal coordinates analysis was used to illustrate the trajectories in floristic data, and the effects of stocking density and rainfall were examined with redundancy analysis. Results Vegetation cover, species richness and Shannon-Wiener index of diversity showed an increase and range condition improved with time. These positive changes could be related to the removal of high numbers of livestock and low wildlife numbers in the first years of survey. A gradual decline in the rate of increase in some of these parameters could be related to high grazing pressure during the later monitored years. There was a notable increase in non-succulent chamaephytes, but the initial increase in succulent chamaephytes was not sustained. The directional change evident in perennial species composition, supports the equilibrium concept, whereby the negative changes induced by heavy grazing were partially reversed. Within the directional change, four quasi-stable states could be distinguished, which could be reconciled with the state-and-transition model. The annual component showed no directional change, but displayed event-driven, non-equilibrium dynamics by fluctuating in reaction to the timing and quantity of rainfall. Conclusions The vegetation change displayed elements of both equilibrium and non-equilibrium dynamics, and demonstrated that the effects of heavy grazing in the Succulent Karoo were reversible. Overall, the recovery process proceeded slowly and was primarily detected in the perennial component of the vegetation. The increase in wildlife numbers in the later studied years and decline in perennial vegetation cover stress the need for active management of animal numbers to avoid vegetation degradation. [ABSTRACT FROM AUTHOR]