Search

The article explores the concept of "rurality" in South Africa and its significance. It highlights the diverse and complex nature of rural areas in the country, which encompass both commercial agricultural lands and scattered settlements on communal lands. The article emphasizes the need for nuanced approaches to rural development and policymaking that take into account the varied rural experiences within South Africa. It also discusses the challenges faced by rural areas, such as limited economic opportunities, financial constraints, and barriers to service delivery. The article concludes by emphasizing the economic, cultural, environmental, and governance implications of defining and addressing rural areas in South Africa. [Extracted from the article]

With water quality deteriorating rapidly at a global scale, river sections suited to serve as reference sites are being increasingly lost. It thus becomes critical to develop rapid methods to confirm that previously monitored sites continue meet the requirements of reliable reference sites. In the absence of pristine sites, 9 near-natural sites, as defined by the Kleynhans (1996) classification, were used as reference sites for the Luvuvhu River catchment to compare the quality of physico-chemical factors against a biological metric. Baetid mayfly community structure at a site was chosen as an index of water quality, since this family is common in all types of freshwaters, highly diverse and adapted to unpolluted running water. Baetid larvae were sampled monthly from stones-in-current biotopes across 9 sites for over 1 year, between December 2016 and January 2018. A Spearman’s correlation test was used to evaluate the relationship between physicochemical factors and identify redundant variables. Water quality standards were measured against the national water quality guidelines for aquatic ecosystems. We used a generalized linear model to determine the effect of physico-chemical variables on baetid species, and canonical correspondence analysis to show the relationships between baetid species, sites, and physico-chemical variables. A total of 3 039 individuals belonging to 12 mayfly species were recorded. Our findings indicated that while the physico-chemical factors were highly variable, they were within favourable ranges to reflect reference site conditions. While water temperature was the most important driver of baetid community structure in general, as it negatively affected their abundances, a subset of species (Pseudoponnota sp., Pseudocloeon sp., Acanthiops varius and Demoulinia crassi) showed clear responses to changes in TDS and stream width. We conclude that specific baetid species show good potential as biological indicators of reference sites and chronic water temperature stress, making assessment of reference sites easier. [ABSTRACT FROM AUTHOR]

The argument over fiscal decentralization and carbon dioxide emission (CO2) reduction has received much attention. However, evidence to back this claim is limited. Economic theory predicts that fiscal decentralization affects environmental quality, but the specifics of this relationship are still up for debate. Some scholars noted that fiscal decentralization might lead to a race to the top, whereas others contended that it would result in a race to the bottom. In light of the current debates in environmental and development economics, this study aims to provide insight into how this relationship may function in South Africa from 1960 to 2020. In contrast to the existing research, the present study uses a novel dynamic autoregressive distributed lag simulation approach to assess the positive and negative changes in fiscal decentralization, scale effect, technique effect, technological innovation, foreign direct investment, energy consumption, industrial growth, and trade openness on CO2 emissions. The following are the main findings: (i) Fiscal decentralization had a CO2 emission reduction impact in the short and long run, highlighting the presence of the race to the top approach. (ii) Economic growth (as represented by the scale effect) eroded ecological integrity. However, its square (as expressed by technique effect) aided in strengthening ecological protection, validating the environmental Kuznets curve hypothesis. (iii) CO2 emissions were driven by energy utilization, trade openness, industrial value-added, and foreign direct investment, whereas technological innovation boosted ecological integrity. Findings suggest that further fiscal decentralization should be undertaken through further devolution of power to local entities, particularly regarding environmental policy issues, to maintain South Africa's ecological sustainability. South Africa should also establish policies to improve environmental sustainability by strengthening a lower layer of government and clarifying responsibilities at the national and local levels to fulfill the energy-saving functions of fiscal expenditures. [ABSTRACT FROM AUTHOR]

The extant literature has produced mixed evidence on the relationship between financial development and ecological sustainability. This work addresses this conundrum by investigating financial development's direct and indirect consequences on ecological quality utilizing the environmental Kuznets curve (EKC) methodological approach. Our empirical analysis is based on the novel dynamic autoregressive distributed lag simulations approach for South Africa between 1960 and 2020. The results, which used five distinct financial development measures, demonstrate that financial development boosts ecological integrity and environmental sustainability over the long and short terms. In the instance of South Africa, we additionally confirm the validity of the EKC theory. More importantly, the outcomes of the indirect channels demonstrate that financial development increases energy usage's role in causing pollution while attenuating the detrimental impacts of economic growth, trade openness, and foreign direct investment on ecological quality. Moreover, the presence of an inadequate financial system is a requirement for the basis of the pollution haven hypothesis (PHH), which we examine using trade openness and foreign direct investment variables. PHH for both of these variables disappears when financial development crosses specified thresholds. Finally, industrial value addition destroys ecological quality while technological innovation enhances it. This research provides some crucial policy recommendations and fresh perspectives for South Africa as it develops national initiatives to support ecological sustainability and reach its net zero emissions goal. [ABSTRACT FROM AUTHOR]

Free‐flowing rivers (FFRs) are important surrogates for freshwater biodiversity as there are increasingly fewer rivers that reflect intact habitat and species diversity from source to sea. The status and changes in the ecological condition or protection of FFRs is not explicitly reported on in global biodiversity targets. Indices are proposed for reporting such changes to the Sustainable Development Goals (SDGs) 6 and 15, Aichi Target 11, and the post‐2020 global biodiversity framework.FFRs were identified at a countrywide scale in South Africa for protection, planning, monitoring, and assessing changes in their ecological condition and protection status. They were selected and prioritized using criteria co‐produced with national, provincial, and local river managers and policy makers. Given the high competition for water resources and the unlikely possibility for strictly protecting all FFRs, a subset of FFRs, termed 'flagship FFRs', was identified.Methods for reporting changes in the protection levels of prioritized FFRs at a countrywide scale were developed, which included indices of FFRs related to global targets: the loss of the extent of FFRs in a natural and largely natural ecological condition for SDG 6; changes in the connectivity of FFRs included in the post‐2020 global biodiversity framework targets; and changes in protection levels of FFRs for Aichi Target 11 and SDG 15.1.2.Flagship FFRs attracted targeted management initiatives and thus maintained their connectivity and ecological condition. This was not true when all FFRs were considered; in the broader set of FFRs, longitudinal fragmentation increased and ecological condition declined from 2011 to 2018.Considering the increasing pressures rivers are likely to experience from human and climate change impacts, particularly in semi‐arid to temperate environments, urgent prioritization and monitoring of FFRs is called for so that a targeted set of protection and management strategies can be applied. [ABSTRACT FROM AUTHOR]

In open-canopied temperate rivers, periphyton plays a pivotal role by converting dissolved nutrients into food for biota. International research suggests that periphyton is particularly responsive to flow and nutrient alterations and therefore ideally suited to aiding the prediction and monitoring of the effects of altered flow regimes. Given that one of South Africa's key focus areas for river management has been the provision of flows to sustain aquatic ecosystems, this study aimed to quantify the relative importance of potential environmental drivers of periphyton, particularly flow, under different nutrient conditions in rivers of the south-western Cape. The study focused on two perennial rivers, the Berg and Molenaars Rivers. Quantitative monthly samples of periphyton biomass were collected from four sites, representative of different flow and nutrient regimes, over a 21-month sampling period between September 2007 and May 2009. The frequency of flood disturbance over the wet season was found to be the single most important driver of periphyton communities. It accounted for almost 75% of the total variation in periphyton biomass under natural flow and nutrient-poor conditions and it was therefore identified as the primary driver of periphyton communities. Its role was smaller under moderately enriched conditions and accounted for 45% of the total variation. These findings suggest that periphyton in south-western Cape rivers has great potential as a tool for predicting and monitoring the effects of altered flow regimes under different nutrient enrichment regimes. Together with some insight into community structure, the next step is to develop periphyton indicators that reflect different aspects of ecosystem integrity, for use in scenario modelling and other management aspects. [ABSTRACT FROM AUTHOR]

Beach-based recreation is an important ecosystem service. Its management relies on balancing human needs and the integrity of coastal ecosystems. Management, however, can be unbalanced in favor of the former, for example, through bather safety programs that are lethal to sharks and other marine species. The promotion of eco-friendlier shark control strategies is underpinned by an understanding of human engagement with shark hazard mitigation (SHM). This study used a questionnaire survey to assess beach visitors' (N = 843) perceptions of SHM at locations implementing lethal and nonlethal shark control in South Africa. Perceptions were dependent on demography, water use, attitudes towards sharks, and local contexts. Elements requiring attention encompassed the role of fear in shaping perceptions, limited awareness of local SHM, misunderstanding of the ecological harm of some mitigation types, and personal responsibility in mitigating risks. Strategies to garner support for pro-shark beach-based recreation are discussed. [ABSTRACT FROM AUTHOR]

Invasive alien species such as Bellyache bush (Jatropha gossypiifolia L.) pose immense threats to global food security, biodiversity, ecosystem integrity and provision of ecosystem services. The Bellyache bush has generally been naturalised in Africa but poses vast management challenges in the African Savannah, yet there is little knowledge of its spatial distribution and future potential invasion risk. In this study, we modelled the spatial distribution of Bellyache bush in South Africa as a function of key biophysical factors using maximum entropy (MaxEnt) and estimated its potential invasion risk into native environments because of climate change. Results show that temperature seasonality, mean annual temperature range and mean temperature of the coldest month are the key factors explaining Bellyache bush distribution in South Africa. The response of the occurrence of Bellyache bush to the temperature variables demonstrated that the suitable habitat for Bellyache bush ranged between 10° and 30 °C while the tolerance to precipitation range is very wide (400 mm – > 2500 mm/year−1). The total area suitable for Bellyache bush propagation in South Africa is ∼129 034 km2 (10% of the total land area of South Africa) in the current and will increase because of climate change to ∼510 914 km2 (40% of the total land area of South Africa). Our results suggest that we can estimate the spatial distribution and Bellyache bush invasion risk areas in South Africa. This implies that policies and management strategies for further Bellyache bush invasions in South Africa can now informatively be targeted to high priority areas. [ABSTRACT FROM AUTHOR]

The Eastern Cape Province harbours 46% of South Africa's remaining indigenous forest cover, and is one of the country's poorest and least developed provinces. Forest resources thus represent a vital component of rural livelihoods in this region. Consequently, forest management policies aim to balance the needs of resource users with the ecological integrity of forest ecosystems. In a recent study, forest bird ranges were shown to have declined in the Eastern Cape over the past 20 years, despite increases in forest cover over the same time period, indicating that habitat degradation may be driving forest bird losses. Given that harvesting of forest products represents the primary human disturbance in forests in the Eastern Cape today, insight is needed regarding the link between resource use and habitat modification. We report on effects of harvesting of three key forest products -- poles, timber and medicinal bark -- on habitat structure at the ground, understorey and canopy layers in indigenous forests in the province. Harvest activities had considerable impacts on habitat structure, depending on the nature and extent of harvesting. Bark and timber harvesting resulted in canopy gaps, whereas pole harvesting reduced tree density, resulting in understorey gaps. Overall, harvest activities increased the frequency of canopy disturbance, and density of understorey layer foliage. Unsustainable bark harvesting practices increased the mortality rate of canopy trees, thereby increasing dead wood availability. By providing insight into human-mediated habitat modification in forests of the Eastern Cape, this study contributes to the development of ecologically informed sustainable resource management policies. Significance: * Unregulated harvesting of forest products in state-managed indigenous forests of the Eastern Cape results in habitat modification. * The nature and extent of habitat modification is dependent on the type and intensity of resource use, indicating that resource use may be sustainably managed. * Timber and medicinal bark harvesting activities result in canopy disturbances, thereby altering natural canopy gap dynamics, with concomitant impacts on understorey habitat structure. * Changes in forest habitat structure associated with high levels of resource use are likely to have ramifying effects on forest biodiversity. [ABSTRACT FROM AUTHOR]

Researchers increasingly consider the systematic integration of green infrastructure (GI) concepts in urban planning as an essential approach to tackle significant current and future challenges. Cities in sub-Saharan Africa (SSA) face rapid urbanization, unregulated land-use practices, and poor enforcement of policies. These cities struggle to address the depletion and degradation of existing GI that increases their vulnerability to climatic hazards that threaten ecosystem integrity, and compromise human health. This paper draws on a review of policy documents, semi-structured interviews with metro officials, and cross-sector focus group discussions to explore ways to operationalize GI spatial planning and design on the ground. Through a case study of the City of Tshwane Metropolitan Municipality, South Africa, which takes a public-private co-development approach, we investigate the uptake of GI planning principles, the challenges, and local proposals for GI applications. In conjunction with the literature, we discuss the alternatives at hand. The local policy documents reflected many planning principles anchored in the Global North literature. Together with public and private partners, we co-developed four locally informed GI objectives: environmental protection, safety, joint ownership, and collaborative governance. We co-identified local planning principles and three strategies for operationalizing GI planning, including working with conventional planning, greater flexibility and creativity, and cross-sectoral collaboration. The findings suggest that collaborative strategies that allow greater access and the active, diverse use of GI could provide much-required cross-sectoral care and management. The real challenge is the establishment of such participatory partnerships as mechanisms to consolidate diverse priorities and co-develop technical and financial alternatives. • Adapt and advance green infrastructure for sub-Saharan African cities. • Develop novel GI planning principles and objectives for the Global South context. • Co-creation workshop for planning principles held across-sectors. • Green infrastructure planning and operationalization issues are distinguished. • Green infrastructure operationalization strategies are proposed. [ABSTRACT FROM AUTHOR]

Fluvial geomorphology affects river character, behaviour, evolution, trajectory of change and recovery potential, and as such affects biophysical interactions within a catchment. Water bodies in South Africa, in common with many other water-stressed parts of the world, are generally under threat due to increasing natural and anthropogenic influences including aridity, siltation and pollution, as well as climate and environmental change. This study reports on a case study to characterise the geomorphology of different river systems in South Africa, with the aim of better understanding their properties, controls, and implications for biophysical interactions including water quality, biodiversity (aquatic and riparian), and human activity within the catchment. The approach adopted is based on the River Styles ® framework (RSF), a geomorphology-based approach developed for rivers in New Zealand and Australia, but applied here for the first time to South Africa. Based on analysis of remote sensing imagery, SRTM-2 digital topographic data and field observations on sites through the entire river system, six geomorphic elements were identified along the Sabie River, northeast South Africa (gorge, bedrock-forced meander, low-moderate sinuosity planform controlled sand bed, meandering sand bed, low sinuosity fine grained sand bed, and floodouts), using the RSF classification scheme and based on the RSF procedural tree of Brierley and Fryirs (2005). Previous geomorphological studies along the Sabie River have shown that different reaches respond differently to episodic floods; we use these data to link river geomorphological character (as defined by the RSF) to the hydrodynamic conditions and processes giving rise to such character. This RSF approach can be used to develop a new management approach for river systems that considers their functional biophysical behaviour within individual reaches, rather than considering them as homogeneous and uniform systems. [ABSTRACT FROM AUTHOR]

South Africa's infamous apartheid policies were not based on social, political, and economic injustice alone. They were also instituted environmentally with consequences that continue to scar the land and its people today. We offer the term environmental apartheid to refer to the use of the rural environment to deliberately marginalize racially defined groups, as well as the subsequent consequences of that marginalization. In the case of South Africa, the paradigmatic example of apartheid, environmental apartheid was largely instituted through rural marginalization , the use of rural space as an environmental means of marginalization. Although legal apartheid is over, environmental apartheid and its consequences continue to oppress Black South Africans, with devastating implications for their health, livelihoods, and ecological integrity. We illustrate these rural injustices through a case study of KuManzimdaka, a community of smallholder farmers on communal land in South Africa's Eastern Cape Province. [ABSTRACT FROM AUTHOR]

Developing innovative monitoring systems for biodiversity outcomes in protected areas (PAs) are important to enable effective adaptive management. Here we show how to quantitatively detect and monitor temporal and spatial patterns in environmental heterogeneity, an important indicator of ecological integrity and biodiversity patterns. We used a 28-year time series (1991–2018) generated from freely available Landsat satellite imagery and Rao's quadratic index to calculate relative heterogeneity and trends in heterogeneity for 41 PAs across South Africa. We selected PAs where mega-herbivore assemblages were similar and where management objectives were broadly aligned with South African legislation to protect biodiversity. There was a three-fold difference in heterogeneity among PAs, mainly linked to variation in topography and rainfall. Heterogeneity decreased in 12 (29%), increased in three (7%) and remained stable in 26 (64%) PA's. These trends were not explained by overall heterogeneity, PA size, or rainfall – i.e., PAs that were smaller, drier, and more homogenous were not more likely to show decreasing trends than PAs that were larger, wetter, and generally more heterogenous. Rather trends in heterogeneity are likely the result of interactions between regional process (e.g., rainfall) and local factors such fire regimes, megaherbivore densities, and park management. The framework presented here can be extended to include every PA nationally, or even globally, and the data product fully automated. This presents an opportunity for conservation management to incorporate this important biodiversity indicator in PA monitoring programs as well as other large-scale ecological monitoring initiatives. • We quantify temporal and spatial patterns in environmental heterogeneity in protected areas. • Heterogeneity differed among PAs, driven by variation in topography and rainfall. • Heterogeneity increased (7%), decreased (29%), and remained stable (64%) in 41 PAs. • Trends likely driven by interactions between regional processes and local factors. • The framework and methodology presented here can support adaptive management in PAs. [ABSTRACT FROM AUTHOR]

Biological invasions threaten ecosystem integrity and biodiversity, with numerous adverse implications for native flora and fauna. Established populations of two notorious freshwater invaders, the snail Tarebia granifera and the fish Pterygoplichthys disjunctivus, have been reported on three continents and are frequently predicted to be in direct competition with native species for dietary resources., Using comparisons of species' isotopic niche widths and stable isotope community metrics, we investigated whether the diets of the invasive T. granifera and P. disjunctivus overlapped with those of native species in a highly invaded river. We also attempted to resolve diet composition for both species, providing some insight into the original pathway of invasion in the Nseleni River, South Africa., Stable isotope metrics of the invasive species were similar to or consistently mid-range in comparison with their native counterparts, with the exception of markedly more uneven spread in isotopic space relative to indigenous species. Dietary overlap between the invasive P. disjunctivus and native fish was low, with the majority of shared food resources having overlaps of <0.26. The invasive T. granifera showed effectively no overlap with the native planorbid snail. However, there was a high degree of overlap between the two invasive species (˜0.86)., Bayesian mixing models indicated that detrital mangrove Barringtonia racemosa leaves contributed the largest proportion to P. disjunctivus diet (0.12-0.58), while the diet of T. granifera was more variable with high proportions of detrital Eichhornia crassipes (0.24-0.60) and Azolla filiculoides (0.09-0.33) as well as detrital Barringtonia racemosa leaves (0.00-0.30)., Overall, although the invasive T. granifera and P. disjunctivus were not in direct competition for dietary resources with native species in the Nseleni River system, their spread in isotopic space suggests they are likely to restrict energy available to higher consumers in the food web. Establishment of these invasive populations in the Nseleni River is thus probably driven by access to resources unexploited or unavailable to native residents. [ABSTRACT FROM AUTHOR]

Built environment design professionals balance competing requirements for human comfort, aesthetics and ecological integrity in their projects. Among them, landscape designers play an important role in optimising the benefits derived from urban green spaces. This study critically considers value dimensions and domains that impinge on professionals' decision making and environmental values that are applicable to built environment design. It specifically identifies the dominant group-based value domains and environmental values in local practice and examines how landscape designers determine the relative importance of competing values in urban South Africa. The study made use of semi-structured interviews with long-standing figures in the industry. The findings indicate that the political change, the economy and the varied climate and landscape character are contextual influences that strongly shape regional social constructions of urban nature. These constructions emphasise instrumental utility values that juxtapose fundamental values and overshadow less urgent eudemonistic and intrinsic environmental values. In the design process, designers trade off artistic pursuits for utility values, with implications for aesthetics and quality. The contextual influences undermine value pluralism. Current trade-offs arguably perpetuate a local legacy of the uneven distribution of quality green spaces. Promisingly, designers show environmental concern and value for sustainability, indigenous plants, utility, quality and safety. The potential for designers to strengthen bonds with urban nature lies in the creation of aesthetic experiences that build on existing local affinities to landscape character and indigenous species. Professional bodies have an important task to assist built environment designers in creating cities that preserve human-nature relationships. • Contextual influences strongly shape landscape design values in the Global South. • These influences undermine value pluralism. • There is an over-emphasis on instrumental utility values. • Unique local environmental values are identified. • Environmental care is illustrated as emergent from social-ecological relations. [ABSTRACT FROM AUTHOR]

The article compares the recovery of vertebrate faunas from the Permian-Triassic (P-T) mass extinction in Russia and South Africa. Definitions of recovery from the PT crisis are presented. It notes that the difference in findings on ecosystem recovery in Russia and South Africa can be attributed to recovery definition, sampling and sedimentary environments. It points out the possibility of a paleobiogeographical difference between the two regions.

Environmental Water Assessments (EWAs) aim to protect the ecological integrity of rivers amidst increasing anthropogenic pressures on freshwater resources, and fish communities are the ecosystem component most commonly included. The Fish Response Assessment Index (FRAI) was developed to assess the integrity of fish communities in South African rivers and is commonly applied in EWA studies. This paper reports on the suitability of the FRAI for the non-perennial Seekoei River and discusses some of the challenges faced. Our relatively long and thorough study on the Seekoei River confirmed the concerns that earlier, snapshot, fish integrity assessments in the Orange River system raised: that the existing fish indices are not ideally suited for these rivers with their naturally low species richness and hardy, generalist fish communities. Other difficulties with the use of a score-based method include prediction of the expected species, calculation of a frequency of occurrence rating, selection of the right sampling times for comparative purposes, loss of habitats and sampling points under different flow conditions, and problems experienced when using accumulated data to try to correct for a situation of having too few sampling points. At this stage a more generalised approach is suggested for the Seekoei River, and ultimately other similar non-perennial systems. This could include a number of community characteristics, such as abundance, species richness, species diversity and evenness, recruitment, fish health and the presence/absence of exotic species. [ABSTRACT FROM AUTHOR]

The Grassland Biome is currently one of the most threatened biomes in South Africa and is in dire need of a biomonitoring protocol. The components of ecological integrity in these ecosystems are, however, too diverse and time-consuming to measure scrupulously. It is therefore necessary to develop a set of grassland indicators that are efficient and rapid in their assessment of grassland ecosystem integrity. The South African Grassland Scoring System (SAGraSS), based on the grassland insect community, is such a suggested indicator. The present study is the first to investigate the applicability and rapidity of this proposed method. Although SAGraSS scores correlated significantly with Ecological Index values (the most commonly used index by which veld condition is evaluated in central South Africa), the method proved to be tedious and the identification of insects taxing. We offer a number of changes to make the SAGraSS method a more rapid method of assessment. [ABSTRACT FROM AUTHOR]

Many existing parks are currently experiencing difficulties in achieving their conservation aims, yet they remain an important option for maintaining and enhancing the conservation of biological diversity and ecosystem processes. Critics have claimed that many national parks cannot continue to protect the biological resources within their borders, and the sustainability of these areas over the long-term is in question. Ways need to be found to strengthen those that are failing, and to understand and replicate those that are succeeding. This paper presents the empirical results from a systematic evaluation of how effectively six case study national parks and national park reserves in Canada and South Africa have been protecting ecological integrity. Several parks were effective at addressing the priorities for which they had monitoring data, however the effectiveness rating of each park decreased when all indicators, including those identified as priorities but lacking monitoring data, were analysed. This indicates that the parks had generally identified more priority indicators than they were actually able to address (for many reasons, including lack of budget or trained staff, managerial challenges). Overall, a systematic approach to evaluating ecological integrity in national parks is recommended as the managers of protected areas cannot be expected to conserve the biological diversity and ecosystem processes within their borders if they are unaware of the ecological status of the park’s biodiversity. The paper concludes with several practical recommendations for monitoring ecological integrity in national parks. [Copyright &y& Elsevier]

Recently, conservation estate in South Africa's Eastern Cape Province has increased 10-fold resulting in large predators being increasingly reintroduced to restore ecological integrity and maximize tourism. We describe the reintroductions of large carnivores (>10 kg) that have occurred in the Eastern Cape and use various criteria to assess their success. Lion Panthera leo reintroduction has been highly successful with a population of 56 currently extant in the region and problems of overpopulation arising. The African wild dog Lycaon pictus population has increased to 24 from a founder population of 11. Preliminary results for spotted hyaenas Crocuta crocuta also indicate success. Wild populations of leopards Panthera pardus exist on several reserves and have been supplemented by translocated individuals, although deaths of known individuals have occurred and no estimate of reproduction is available. Cheetah Acinonyx jubatus reintroduction has also been less successful with 36 individuals reintroduced and 23 cubs being born but only 41 individuals surviving in 2005. Criteria for assessing the success of reintroductions of species that naturally occur in low densities, such as top predators, generally have limited value. Carrying capacity for large predators is unknown and continued monitoring and intensive management will be necessary in enclosed, and possibly all, conservation areas in the Eastern Cape to ensure conservation success. [ABSTRACT FROM AUTHOR]

Three data sources (physico-chemistry, bio-monitoring and eco-toxicology) are currently used in South Africa to establish environmental water quality conditions. Environmental water quality in turn is key information required for the "ecological reserve determination" of river reaches. Bio-monitoring in South Africa has been limited in recent times mostly to the use of the SASS procedure which relies on invertebrates only. This paper describes the re-introduction of a diatom-based water quality assessment as an added-value bio-monitoring tool. A specific example is discussed citing the response of diatom assemblages to diffuse pollution from acid mine drainage and how effective diatoms are as indicators of ecological integrity and river recovery measured downstream of the area of impact. The advantages of applying this bio-monitoring technique over other biological measures are presented in the context of technological advances in rapid image processing, species identification and software applications of diatom-based water quality indices. The valuable records of the diatom assemblages of the past, held in the South African Diatom Collection at the CSIR (KwaZulu-Natal), can now be accessed and interpreted as historical environmental water quality reference points for several rivers in South Africa. [ABSTRACT FROM AUTHOR]

Climate induced drought is a prominent threat to natural saline aquatic ecosystems by modifying their hydrology and salinity, which impacts the biodiversity of these ecosystems. Lake Nyamithi is a naturally saline lake in South Africa that experienced the effects of a two-year supra-seasonal drought (2015–2016). This study aimed to determine potential effects of the drought and accompanying increased salinity (between 9.8 and 11.5 g L−1) on aquatic invertebrate communities of Lake Nyamithi, and assess their potential recovery following the drought. Aquatic invertebrates and water were collected for biodiversity and chemical assessments during predrought conditions (2014), the peak of the drought (2016) and after the site had received water (2017). Taxon richness was considerably reduced during the peak of the drought as many biota could not tolerate the increased salinity. Ecological resilience and recovery was evident in the lake since numerous biota (re)colonized the lake promptly after the site received water and salinity decreased (<8 g L−1). By the end of 2017, invertebrate biodiversity exceeded that of predrought conditions. Although some biota may be able to temporarily cope with extreme weather conditions, frequent or prolonged periods of drought and increased salinity pose a threat to naturally saline lakes such as Nyamithi and dilution with fresh water is vital for the persistence of species diversity and ecological integrity. [ABSTRACT FROM AUTHOR]

Landscape transformation and subsequent habitat loss locally extirpate populations and threaten ecosystem health. Timber plantations are a major threat to grassland ecosystems globally. An effective mitigation measure is the instigation of webs of large conservation corridors as ecological networks in plantation mosaics. These ecological networks incorporate natural water courses along with their matrices of natural grassland. Dragonflies are highly sensitive to habitat condition and are effective bioindicators of water quality. Here, we compare dragonfly diversity in conservation corridors, with nearby protected areas as controls, to determine the effectiveness of ecological networks for maintaining river ecosystem integrity, in the KwaZulu-Natal Midlands, South Africa. We also investigate the effect of ecological network corridor width on dragonfly assemblages. Lastly, we explore the importance of 18 environmental variables as drivers of dragonfly diversity. Dragonfly abundance, species richness, and Dragonfly Biotic Index scores (a scoring system based on dragonfly range of extent, threat status, and environmental sensitivity) did not differ between ecological network and protected area sites. Dragonfly abundance and species richness were positively correlated with ecological network corridor width. Landscape and water variables were the most important drivers of dragonfly assemblage composition in both ecological networks and protected areas. Management variables and those related to anthropogenic disturbance were not as important. This highlights the conservation success of these well-managed ecological networks for maintaining dragonfly biodiversity in forestry plantations, provided that corridors are wide enough. Implementation of ecological networks as a mitigation measure for plantation forestry is highly effective for lotic systems, and should be implemented more widely in environmental protection plans for transformed landscapes. [ABSTRACT FROM AUTHOR]

Temporarily closed estuaries require seasonal opening to tidal flows to maintain normal ecological processes. Each estuary has specific environmental flow (EFlow) requirements based on the relationship between freshwater inflow, coastal dynamics, rate of sandbar formation, and the open/closed state of the mouth. Key abiotic processes and ecosystem services linked to mouth state were highlighted. We reviewed completed EFlow requirement studies for temporarily closed estuaries in South Africa and found that the formulation of these requirements should consider the timing and magnitude of flows in relation to the morphology of an estuary, its mouth structure, catchment size, and climate. We identified ten key principles that could be adapted to similar systems in equivalent climatic settings. Principle 1 recognizes that each estuary is unique in terms of its EFlow requirements because size, scale, and sensitivity of core elements to freshwater inflow are specific for each system; EFlows cannot be extrapolated from one estuary to another. Principle 2 highlights the importance of baseflows in keeping an estuary mouth open because a small reduction in flow can cause the mouth to close and alter essential ecological processes. Principle 3 outlines the role of floods in resetting natural processes by flushing out large volumes of sediment and establishing the equilibrium between erosion and sedimentation. Principle 4 emphasizes the need for open mouth conditions to allow regular tidal flushing that maintains water quality through reducing retention times and preventing the onset of eutrophic conditions. Principle 5 advises artificial breaching to be practiced with caution because execution at low water levels encourages sedimentation that reduces the scouring effect of flushing. Principle 6 holds that elevated inflow volumes from wastewater treatment works or agricultural return flows can increase the frequency of mouth opening and cause ecological instability. Principle 7 states that water released from dams to supply the environmental flow cannot mimic the natural flow regime. Principle 8 specifies the need for short- and long-term data to increase the confidence levels of EFlow assessments, with data to be collected during the open and closed mouth states. Principle 9 advocates the implementation of a monitoring program to track the achievement of EFlow objectives as part of a strategic adaptive management cycle. Finally, Principle 10 recommends the adoption of a holistic catchment-to-coast management approach underpinned by collaboration with regulatory authorities and stakeholders across a range of sectors. These principles can be used to guide the formulation and management of EFlows, an essential strategy that links the maintenance of estuarine ecological integrity with social well-being. [ABSTRACT FROM AUTHOR]

Forest management in many developing nations aims to balance the needs of resource users and the ecological integrity of indigenous forests, in terms of both biodiversity conservation and ecosystem services, particularly carbon sequestration. While South Africa has legislated management policies to achieve this, implementation has been lacking, resulting in concern that unregulated resource use is compromising forest biodiversity. However, there is little information regarding resource use since these regulations were promulgated a decade ago. This study reports on the current nature and extent of forest product harvesting in the Eastern Cape, South Africa, which contains just under half of the country's indigenous forests. Extraction rates and target species of key products, namely poles, timber and bark, were assessed across six forests, representing five forest types. Harvest intensities indicated low to moderate levels of use, but there was considerable variation in levels of resource use at the forest-scale, illustrating the importance of site-specific assessments. Furthermore, resource use was species-specific, indicating that sustainability is dependent on the ecology of preferred species. Of concern was widespread commercial-scale bark harvesting; and relatively high timber extraction from a Pondoland scarp forest, a threatened forest type. We urge implementation of existing regulations, which distinguish between subsistence and commercial use; and commensurate capacitation of the new Department of Environment, Forestry and Fisheries. In the case of timber and bark, we recommend licencing of the de facto commercial harvesting taking place in order to promote regulation. • Resource use from indigenous forests in South Africa is largely unregulated. • Harvest rates of poles, timber and medicinal bark were site- and species-specific. • Unsustainable methods of bark harvesting, driven by market demand, were widespread. • Commercial-scale timber harvesting was recorded in a threatened coastal forest type. • Implementation of existing regulations through institutional capacitation is urged. [ABSTRACT FROM AUTHOR]