Assessing, with limited resources, the ecological outcomes of wetland restoration: a South African case

Resources for evaluating the ecological outcomes of ecosystem restoration projects are often limited, especially within government-funded programs. In order to rapidly assess the ecological outcomes ofwetland restoration, an improved approach has been developed, which was applied in the assessment of the ecological outcomes at nine restoration sites of South Africa’s Working forWetlands program. The sites encompass a diversity of restoration problems and land use contexts. The approach begins by distinguishing hydrogeomorphic (HGM) units, for which ecological condition is assessed and reported for hydrology, geomorphology, and vegetation pre- and post-restoration. These three components are closely linked but, as demonstrated at some of the sites,may respond differentially to restoration interventions. For mostHGMunits, overall ecological condition was improved by between 10 and 30%, with the greatest contribution of restoration generally being to the hydrology component. Having determined the integrity and costs of the interventions, cost-effectiveness is then reported in South African Rands per hectare equivalent restored, which was found to vary by more than an order of magnitude across the HGM units assessed. Cost-effectiveness must be interpreted in the light of the long-term integrity of the interventions, the site’s landscape context, and the contribution of restoration to ecosystem services provision. Some sites may be considerably less cost-effective than others, but the cost may nonetheless be justified if the sites make key contributions to ecosystem services provision. The study was conducted in the context of a formative evaluation and the findings are envisaged to improve wetland restoration practice

Analysis of spinocerebellar ataxia types 1, 2, 3, and 6, dentatorubral-pallidoluysian atrophy, and Friedreich's ataxia genes in spinocerebellar ataxia patients in the UK

Accurate clinical diagnosis of the spino-cerebellar ataxias (SCAs) can be diffcult because of overlap in phenotype with other disorders and variation in clinical manifestations. Six SCA loci have been mapped and four disease causing genes identified, in addition to the causative gene for Friedreich's ataxia (FA). All of the identified mutations are expansions of trinucleotide repeat tracts. The SCA2 and SCA6 genes were published recently. The extent of the normal CAG size ranges at these loci and the relative frequencies of the known causes of SCA in the UK are not known. This study first investigated the normal size ranges of the SCA2 and SCA6 loci by genotyping control populations of West African and South African subjects, since African populations generally show the greatest allelic diversity. We found one allele larger than the previously determined normal range for SCA2, and our results at the SCA6 locus agreed with the previously reported normal range. The second component of the study assessed the relative frequencies of the SCA1, 2, 3, and 6, DRPLA, and FA trinucleotide repeat mutations in 146 patients presenting with SCA-like symptoms referred to genetic diagnostic laboratories in the UK. We detected mutations in 14% of patients referred with a diagnosis of autosomal dominant SCA, and in 15% of patients referred with spinocerebellar ataxia where we did not have sufficient family history data available to allow categorisation as familial or sporadic cases. Friedreich's ataxia accounted for 3% of the latter category of cases in our sample, but the most common causes of SCA were SCA2 and SCA6.Articl

An assessment of the effectiveness of a large, national-scale invasive alien plant control strategy in South Africa

This paper presents an assessment of a large, national-scale alien plant control program that has operated in South Africa for 15 years. We reviewed data from three national-level estimates of the extent of invasion, records of the costs and spatial extent of invasive species control operations, assessments of the effectiveness of biological control, and smaller-scale studies. The 19 most important invasive taxa, mainly trees, in terrestrial biomes were identified. The effectiveness of control efforts on the extent of invasion of these taxa was assessed. Control costs over 15 years amounted to 3.2 billion rands (US$457 million), more than half of which was spent on 10 taxa, the most prominent being in the genera Acacia, Prosopis, Pinus and Eucalyptus. Despite substantial spending, control operations were in many cases applied to a relatively small portion of the estimated invaded area, and invasions appear to have increased, and remain a serious threat, in many biomes. Our findings suggest that South Africa’s national-scale strategy to clear invasive alien plants should be substantially modified if impacts are to be effectively mitigated. Rather than attempting to control all species, and to operate in all areas, a more focused approach is called for. This would include prioritising both the species and the areas, and setting goals and monitoring the degree to which they are achieved, within a framework of adaptive management. A greater portion of funding should also be directed towards biological control, where successes have been most notable

Biological invasions in the Cape Floristic Region: history, current patterns, impacts, and management challenges

The Cape Floristic Region (CFR) is the most invaded terrestrial area in South Africa in terms of: the conspicuous prominence of (mainly woody) invasive plants (Fig 12.1, Plate 12) (Henderson 2007); the area invaded as surveyed (Kotzé et al. 2010); and the numbers of animal invaders (Picker and Griffiths 2011). At the same time its status as a globally important system for the study of plant invasions is firmly established. Tree invasions in the region provide model systems that have been influential in the development of plant invasion ecology; in particular work on pine species (Richardson et al. 1994) and Australian acacias (Richardson et al. 2011). In fact, the observation of alien trees invading pristine fynbos shows that widespread invasions are not, as suggested by Charles Elton, confined to ecosystems markedly altered by human activities (Elton 1958). This provided part of the stimulus for a major international programme on invasions in the 1980s funded by the Scientific Committee on Problems of the Environment