Blindness and encephalopathy caused by Helichrysum argyrosphaerum DC (Compositae) in sheep and cattle

An outbreak of amaurosis and paresis was observed amongst sheep, and occasionally cattle, which had been grazing on pastures consisting mainly of Helichrysum argyrosphaerum DC. A similar syndrome was produced by feeding the suspect plant to sheep, thereby providing proof of its toxicity. Although none of the sheep became blind and only one developed paralysis, typical spongy lesions were detected in the brains and optic fasciculi of all the experimental animals. The lesion had specific predilection sites, such as the white matter around the lateral ventricles, the optic tracts plus chiasm, the pyramidal tracts and the brachium pontis. Enlargement of the optic fasciculi furthermore gave rise to malacia, papilloedema and retinal changes. Some aged sheep developed cataracts approximately 2-3 months after the initial outbreaks of amaurosis had occurred. Circumstantial and histopathological evidence suggests that the cataracts may be due to chronic Helichrysum poisoning, but this could not be confirmed in the present investigation.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acroabt XI was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Changes in forest cover and carbon stocks of the coastal scarp forests of the Wild Coast, South Africa

Land-use intensification and declines in vegetative cover are considered pervasive threats to forests and biodiversity globally. The small extent and high biodiversity of indigenous forests in South Africa make them particularly important. Yet, relatively little is known about their rates of use and change. From analysis of past aerial photos we quantified rates of forest cover change in the Matiwane forests of the Wild Coast, South Africa, between 1942 and 2007, as well as quantified above- and belowground (to 0.5 m depth) carbon stocks based on a composite allometric equation derived for the area. Rates of forest conversion were spatially variable, with some areas showing no change and others more noticeable changes. Overall, the net reduction was 5.2% (0.08% p.a.) over the 65-year period. However, the rate of reduction has accelerated with time. Some of the reduction was balanced by natural reforestation into formerly cleared areas, but basal area, biomass and carbon stocks are still low in the reforested areas. The total carbon stock was highest in intact forests (311.7 ± 23.7 Mg C ha−1), followed by degraded forests (73.5 ± 12.3 Mg C ha−1) and least in regrowth forests (51.2 ± 6.2 Mg C ha−1). The greatest contribution to total carbon stocks was soil carbon, contributing 54% in intact forests, and 78% and 68% in degraded and regrowth forests, respectively. The Matiwane forests store 4.78 Tg C, with 4.7 Tg C in intact forests, 0.06 Tg C in degraded forests and 0.02 Tg C in regrowth forests. The decrease in carbon stocks within the forests as a result of the conversion of the forest area to agricultural fields was 0.19 Tg C and approximately 0.0003 Tg C was released through harvesting of firewood and building timber

How to halt the global decline of lands

The assessment of land degradation and restoration by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services shows that land degradation across the globe is a wide and severe issue and is showing no signs of slowing down. This trend must be halted and reversed

Institutions and governance of communal rangelands in South Africa

The creation of local institutions with a mandate over land access and control is seen as a prerequisite for successful decentralisation of land tenure and effective local resource management in sub-Saharan Africa. However, with land tenure reform in South Africa currently at a state of legislative impasse, real uncertainty now exists over land rights and governance of rangeland in many communal areas. This paper draws on case study material from Eastern Cape province to illustrate how this ongoing uncertainty has resulted in the operation of a range of traditional authority and civil society institutions in different communal areas with varying degrees of legitimate authority over land administration and highly variable performance in managing rangeland resources. Collective management of rangeland resources seems most difficult in environments where land rights are contested because of the coexistence of traditional leaders and civil society institutions. On this basis an approach to tenure reform is advocated, which vests all powers over local land administration in democratically elected and accountable civil society institutions. Some successful examples of this already exist and might serve to guide policy formation, which must be flexible enough to accommodate collective management approaches that emphasise cooperation both within and between communities.Keywords: common property, land tenure, natural resource management, traditional leadersAfrican Journal of Range & Forage Science 2013, 30(1&2): 77–8

Institutions for sustainable land management: reflections on institutional aspects of implementing the UNCCD in South Africa

By its nature, combating desertification is a complex, multidisciplinary activity that requires coordinated responses at a multitude of levels spanning both scientific disciplines and government departments. In the final analysis, it is at the level of the land user where the bulk of activities take place, and where the greatest impact is to be gained. Providing access to knowledge, a supportive environment and, in some instances, financial assistance that allows the land user to counter  desertification is important. However, the nature of desertification processes is such that, in many instances, they extend beyond the domain of control of a single land user and require a coordinated response from multiple land users. This is especially true of situations where resources are used and managed communally as is the case in much of southern Africa. Though global and national institutional structures may facilitate implementation, it is proposed that sound local-level institutions are one of the most important components for successful sustainable land management interventions. The need to differentiate between private and communal land in terms of the nature of structures and forms of incentives to promote the combating of desertification is highlighted.Keywords: communal land use; community-based natural resource management; desertificationAfrican Journal of Range & Forage Science 2009, 26(3): 159–16

Maintaining Biodiversity during Biofuel Development

This chapter focuses on four key issues: • Understanding the opportunities and threats biofuels pose to biodiversity. • Understanding how impacts can be predicted and modelled as a component of multi-criteria decisions surrounding strategic decision making on whether to undertake a biofuels programme or not. • Operational planning at the biofuel plantation level to minimise negative biodiversity impacts. • Minimising the risk of invasive alien species (IAS) resulting from biofuel production. Most of this chapter is focussed on the impact of feedstock plantations for liquid biofuels. However, the same techniques can usually be applied to feedstock for other types of bioenergy. This is illustrated in some of the provided examples