A Simplified Method to Assess the Impact of Sediment and Nutrient Inputs on River Water Quality in Two Regions of the Southern Coast of South Africa.

Many rivers in the southern coastal region of the Western Cape Province, South Africa, are known to be in a poor state. Since the 1990s, the river water quality of this coastal region has been affected by increasing populations and by intensifying land use activities. Simplified risk assessment approaches are critical to identify in a timely manner areas where land use activities may impact water quality, particularly for regions with limited data.

A framework for engaging stakeholders on the management of alien species.

Alien species can have major ecological and socioeconomic impacts in their novel ranges and so effective management actions are needed. However, management can be contentious and create conflicts, especially when stakeholders who benefit from alien species are different from those who incur costs. Such conflicts of interests mean that management strategies can often not be implemented.

An assessment of the effectiveness of a long-term ecosystem restoration project in a fynbos shrubland catchment in South Africa.

The long-term effectiveness of ecological restoration projects is seldom reported in the scientific literature. This paper reports on the outcomes of ecosystem restoration following the clearing of alien Pinus plantations and associated alien plant invasions over 13 years from an 8000 ha mountain catchment in the Western Cape Province, South Africa. We examined the goals, methods and costs of management, and the ecological outcomes in terms of reduced alien plant cover and native vegetation recovery.

Stakeholder perceptions and practices regarding Prosopis (mesquite) invasions and management in South Africa.

Invasive alien trees impact the environment and human livelihoods. The human dimensions of such invasions are less well understood than the ecological aspects, and this is hindering the development of effective management strategies. Semi-structured interviews were undertaken to investigate the knowledge and perceptions of Prosopis between different stakeholder groups.

Prosopis: a global assessment of the biogeography, benefits, impacts and management of one of the world's worst woody invasive plant taxa.

Invasive species cause ecological, economic and social impacts and are key drivers of global change. This is the case for the genus Prosopis (mesquite; Fabaceae) where several taxa are among the world's most damaging invasive species. Many contentious issues ('conflicts of interest') surround these taxa, and management interventions have not yet sustainably reduced the negative impacts.

Natural hazards in a changing world: a case for ecosystem-based management.

Communities worldwide are increasingly affected by natural hazards such as floods, droughts, wildfires and storm-waves. However, the causes of these increases remain underexplored, often attributed to climate changes or changes in the patterns of human exposure. This paper aims to quantify the effect of climate change, as well as land cover change, on a suite of natural hazards.

Comment on "Climatic niche shifts are rare among terrestrial plant invaders".

Petitpierre et al. (Reports, 16 March 2012, p. 1344) conclude that niche shifts are rare for terrestrial plant invaders and that this justifies the use of correlative modeling to project species geographic ranges for biological invasions and climate change.

Alien plant invasions--incorporating emerging invaders in regional prioritization: a pragmatic approach for Southern Africa.

Plant invasions are a serious threat to natural and semi-natural ecosystems worldwide. Most management-orientated research on invasions focuses on invaders that are already widespread and often have major impacts. This paper deals with "emerging" invaders-those alien species with the potential to become important problems without timely intervention.

Trading water for carbon with biological carbon sequestration.

Carbon sequestration strategies highlight tree plantations without considering their full environmental consequences. We combined field research, synthesis of more than 600 observations, and climate and economic modeling to document substantial losses in stream flow, and increased soil salinization and acidification, with afforestation. Plantations decreased stream flow by 227 millimeters per year globally (52%), with 13% of streams drying completely for at least 1 year.