The role of resource economics in the control of invasive alien plants in South Africa

The recognition of the economic consequences of alien invasive plants in terms of water-supply costs was pivotal in the establishment of the Working for Water programme, which has spent over R3 billion in dealing with the problem while simultaneously addressing poverty relief. Given competition from other social development projects for future funding, however, there is a need to justify further alien control programmes and to maximize efficiency within the programme. This requires valuing the biodiversity benefits of alien control and improving of the evaluation methods used. The concept of ecological goods and services has been a useful political tool, but the resource-economics concept of the Total Economic Value of biodiversity forms a more useful analytical framework. Studies on the impacts of alien invasive plants in South Africa initially concentrated on water losses, but more recently have included values of direct consumptive and non-consumptive use, option and existence value, and other indirect measures. Secondary effects such as downstream changes in aquatic ecosystem functions have not been assessed. Studies have varied in their scale and scope, as well as in the 'currency' of evaluation (such as financial or economic). Several approaches have been used for valuing water losses, with initial estimates having been the most conservative. Estimates of non-water benefits have frequently involved extrapolation from site-specific investigations within the study area, or been estimated from estimates at the regional level. None of the contingent valuation studies used has been applied following internationally accepted guidelines. In water-yielding catchments, alien control programmes are easy to justify in economic terms. In other areas, this may be more difficult. Cost-benefit analyses to date have tended to include the full financial costs of clearing, whereas, in reality, the opportunity cost of labour is close to zero, and economic costs are therefore much smaller. Benefits, which accrue later, tend to be underestimated from lack of information on biodiversity values and by high discount rates. A revised approach would favour the outlook for control programmes. If this fails to secure funding, what alternatives are there? New regulations are considered suboptimal and likely to fail. Opportunities for creating incentives to clear aliens from private lands are extremely limited, and there are no incentives that can reduce future invasions. Government-funded control programmes are thus the most efficient option. Future studies will need to address the right questions using the appropriate methods, incorporate both ecological and economic dynamics, express values in the right 'currency', and use a discount rate that reflects the rights of future generations. The quality of this research will depend on relevant ecological enquiry

Comparative foraging ecology of two broad-ranging migrants, grey plover Pluvialis Squatarola and whimbrel Numenius Phaeopus (Aves: Charadrii), in tropical and temperate latitudes of the Western Indian Ocean

Bibliography: leaves 186-205.A seasonal study of the nonbreeding foraging ecology of Grey Plovers and Whimbrels was undertaken at the Zwartkops estuary, South Africa, and additional data were collected from a variety of sites in tropical and south temperate latitudes during the premigratory period. The main objective of the study was to provide comparative data on shorebird foraging ecology in the southern hemisphere, in order to contribute to the general understanding of shorebird foraging behaviour and migration patterns

Evaluating the cost-effectiveness of ecosystem-based adaptation: Kamiesberg wetlands case study

Ecosystem-based adaptation (EbA) is increasingly being promoted as a cost-effective means of adaptation to climate change. However, in spite of considerable international press, there is still little evidence to substantiate this claim. This study proposes a method through which the cost-effectiveness of EbA strategies can be evaluated against alternative adaptation options, and contributes to South African literature on the subject. The potential cost-effectiveness of wetland restoration is assessed as a means of securing the carrying capacity of land for pastoralist communities of the Kamiesberg communal area in South Africa under projected future climate conditions. The conventional alternatives would be to respond to increasingly dry conditions by drilling boreholes and using supplemental feed for livestock. It was assumed that the EbA interventions would occur upfront, whereas the alternatives are more likely to be implemented in reaction to droughts over a longer time period. The study found the implementation of conventional alternatives to be more cost-effective than EbA as a means to sustaining livestock stocking rates, with EbA being twice as costly. However, this is framed from the perspective of those directly affected (the landowners), and does not include the benefits to broader society

Assessing, quantifying and valuing the ecosystem services of coastal lagoons

The natural conservation of coastal lagoons is important not only for their ecological importance, but also because of the valuable ecosystem services they provide for human welfare and wellbeing. Coastal lagoons are shallow semi-enclosed systems that support important habitats such as wetlands, mangroves, salt-marshes and seagrass meadows, as well as a rich biodiversity. Coastal lagoons are also complex social-ecological systems with ecosystem services that provide livelihoods, wellbeing and welfare to humans. This study assessed, quantified and valued the ecosystem services of 32 coastal lagoons. The main findings of the study are: (i) the definitions of ecosystem services are still not generally accepted; (ii) the quantification of ecosystem services is made in many different ways, using different units; (iii) the evaluation in monetary terms of some ecosystem service is problematic, often relying on non-monetary evaluation methods; (iv) when ecosystem services are valued in monetary terms, this may represent very different human benefits; and, (v) different aspects of climate change, including increasing temperature, sea-level rise and changes in rainfall patterns threaten the valuable ecosystem services of coastal lagoons.DEVOTES project, from the European Union's Seventh Framework Programme for research, technological development and demonstration [308392]; networks and communities of Eurolag; Future Earth Coasts; SCOR; Fundacao para a Ciencia e a Tecnologia (FCT) Investigador Programme [IF/00331/2013]; Fundacao para a Ciencia e a Tecnologia [UID/MAR/04292/2013]; CESAM by FCT/MEC national funds (PIDDAC) [UID/AMB/50017/2013 - POCI-01-0145-FEDER-007638]; FEDER; European Commission, under the 7th Framework Programme through the collaborative research project LAGOONS [283157]; FCT [SFRH/BPD/107823/2015, SFRH/BPD/91494/2012

A synthesis of three decades of socio-ecological change in False Bay, South Africa: setting the scene for multidisciplinary research and management

Over the past three decades, marine resource management has shifted conceptually from top-down sectoral approaches towards the more systems-oriented multi-stakeholder frameworks of integrated coastal management and ecosystem-based conservation. However, the successful implementation of such frameworks is commonly hindered by a lack of cross-disciplinary knowledge transfer, especially between natural and social sciences. This review represents a holistic synthesis of three decades of change in the oceanography, biology and human dimension of False Bay, South Africa. The productivity of marine life in this bay and its close vicinity to the steadily growing metropolis of Cape Town have led to its socio-economic significance throughout history. Considerable research has highlighted shifts driven by climate change, human population growth, serial overfishing, and coastal development. Upwelling-inducing winds have increased in the region, leading to cooling and likely to nutrient enrichment of the bay. Subsequently the distributions of key components of the marine ecosystem have shifted eastward, including kelp, rock lobsters, seabirds, pelagic fish, and several alien invasive species. Increasing sea level and exposure to storm surges contribute to coastal erosion of the sandy shorelines in the bay, causing losses in coastal infrastructure and posing risk to coastal developments. Since the 1980s, the human population of Cape Town has doubled, and with it pollution has amplified. Overfishing has led to drastic declines in the catches of numerous commercially and recreationally targeted fish, and illegal fishing is widespread. The tourism value of the bay contributes substantially to the country’s economy, and whale watching, shark-cage diving and water sports have become important sources of revenue. Compliance with fisheries and environmental regulations would benefit from a systems-oriented approach whereby coastal systems are managed holistically, embracing both social and ecological goals. In this context, we synthesize knowledge and provide recommendations for multidisciplinary research and monitoring to achieve a better balance between developmental and environmental agendas.https://www.elementascience.orgam2020Mammal Research Institut

The value of flower tourism on the Bokkeveld Plateau - a botanical hotspot

The Bokkeveld Plateau is situated at the interface between the Cape Floristic Region and the Succulent Karoo and has high levels of endemism and plant biodiversity. During spring, the area attracts tourists to view the wildflowers in bloom. Wildflower tourism has been suggested as a means to protect the plant biodiversity of the region. A questionnaire survey was used to estimate the value of flower tourism and to explore visitors' preferences for different attributes of their experience. The travel-cost method, conjoint modelling and direct questions were used. It was estimated that R2,35 million is spent annually in the area. According to the travel-cost analysis, the average consumer surplus was R28 per person. On average, 37 per cent of visitor enjoyment came from seeing expanses or carpets of flowers and 26 per cent from seeing the variety of flowers. The average length of stay would be reduced to 37 per cent of its original length if there were no flowers present. The conjoint analysis showed that seeing carpets of flowers contributed by far the most to the scores given to scenarios, as compared with seeing a variety of species of flowers or bulbs. Biodiversity conservation will therefore depend on marketing the biodiversity and other attributes of the area rather than relying on the visual displays that are highly weather dependent.