Flowering pattern of biodiesel plant Jatropha in frost- and drought-prone regions of Botswana

Jatropha has gained interest as a potential biodiesel feedstock. Nevertheless, its oil production decreases significantly in frost- and drought-prone regions. In this study, we characterized the flowering pattern of Jatropha in Botswana in the 2014/2015 season. Extensive springtime pruning synchronized Jatropha regrowth in summer and effectively stimulated growth after frost damage. Flowering started in February 2015 and peaked in April and May. Wide variations in flowering frequency were observed among different Jatropha accessions. Trees flowering in February and March produced fruit in May, but most trees only flowered in April and May and did not yield fruit because of cold snaps. These observations suggested that harvesting seed before wintertime is the key to improve Jatropha production in the Botswana climate. This study highlighted the importance of inducing early flowering by developing new agricultural managements. These may include frost cover and sun shades to prevent stress-induced damage, canopy control by pruning, optimization of fertilization practice, and/or introduction of superior Jatropha varieties.     

Should all disaster risks be reduced? A perspective from the systems concept of the edge of chaos

The field of disaster risk reduction (DRR) has risen to prominence since the declaration of the International Decade of Disaster Risk Reduction between 1990 and 2000. This decade provided the impetus for a change from the predominant paradigm of disaster response to that of disaster risk reduction as a means of addressing the underlying drivers that lead to disasters. In an effort to promote risk reduction, the UNISDR (the principal agency for disaster risk reduction within the UN structure) formulated policies and strategies to provide both conceptual and practical guidance as to how risk should be reduced. However noble the efforts, this paper contends that the current approach to and understanding of risk within the international community might not be cognisant of complex adaptive systems (CAS) concepts such as the edge of chaos. Specifically, this concept argues that risk (or chaos) within a system is actually a fundamental requirement to the functioning of all resilient socio-ecological systems. Therefore, the reduction of risk without an understanding of the role of that risk within the larger socio-ecological system might actually end up reducing the system’s overall level of disaster resilience. This paper aims to explore the concept of edge of chaos through a literature review of key theoretical works on the topic, followed by a discussion on its implications for the predominant paradigm of risk reduction within disaster risk management policy and practice.     

A botanical importance rating system for estuaries

In many semi-arid areas, estuaries are threatened because of freshwater impoundment. Estuaries are important sites for ecological diversity and, increasingly, for recreation. A system has been developed which rates estuaries according to their botanical importance. A formula allows a single numerical importance score to be calculated. The area cover of each estuarine plant community type (i.e. intertidal salt marsh, submerged macrophytes, reed/sedge swamps and supratidal salt marsh) and its importance in the estuary forms the basis of the score. The ‘ecological condition’ of the plant community and the community richness within the estuary are incorporated into the formula. The formula is effective in determining the botanical importance of estuaries. Further methods to determine the zoological, physical and socio-economic importance of estuaries need to be developed to allow the overall importance of estuaries to be determined.     

Faecal pollution loads in the wastewater effluents and receiving water bodies: a potential threat to the health of Sedibeng and Soshanguve communities,South Africa

The discharge of untreated or inadequately treated effluents has been identified among the activities responsible for the spread of a wide range of potentially infectious agents. The aim of this study was to determine whether inadequate treatment of wastewater and the faecal pollution load of effluents and receiving water bodies in Sedibeng District and Soshanguve peri-urban area of the Tshwane Metropolitan Municipality could be a potential threat to the health of the surrounding communities. Variations in the counts of faecal indicator bacteria and pathogenic microorganisms and compliance of the effluents and receiving water bodies with South African and World Health Organization standards were assessed between August 2011 and May 2012 using culture-based methods and molecular techniques. The overall quality of effluents did not comply with the South African special standard of no risk for unrestricted irrigation (zero?Escherichia coli/100 ml). The quality of the receiving water bodies did not comply with South African regulatory limits set for domestic purposes (zero?E.?coli/100 ml, <30 faecal enterococci/100 ml and <1 somatic coliphages/100 ml), for full contact recreation (<20 somatic coliphages/100 ml) and aquaculture (<10?E.?coli/100 ml) and WHO standards for full and intermediate contact recreational use (<1?E.?coli/100 ml and <40 faecal enterococci/100 ml, respectively). The PCR results revealed the prevalence of pathogenic microorganisms; between 0 and 60 % of samples tested positive for Salmonella Typhimurium and Shigella dysenteriae, and between 20 and 60 % of samples tested positive for Vibrio cholerae. These findings demonstrated that potential health risks might be associated with the use of the target river waters for domestic, recreational and irrigation purposes. This study calls for a prompt intervention to improve wastewater management.     

A botanical importance rating system for estuaries

In many semi-arid areas, estuaries are threatened because of freshwater impoundment. Estuaries are important sites for ecological diversity and, increasingly, for recreation. A system has been developed which rates estuaries according to their botanical importance. A formula allows a single numerical importance score to be calculated. The area cover of each estuarine plant community type (i.e. intertidal salt marsh, submerged macrophytes, reed/sedge swamps and supratidal salt marsh) and its importance in the estuary forms the basis of the score. The ‘ecological condition’ of the plant community and the community richness within the estuary are incorporated into the formula. The formula is effective in determining the botanical importance of estuaries. Further methods to determine the zoological, physical and socio-economic importance of estuaries need to be developed to allow the overall importance of estuaries to be determined.     

Monitoring in adaptive co-management: Toward a learning based approach

The recognition of complexity and uncertainty in natural resource management has lead to the development of a wealth of conceptual frameworks aimed at integrated assessment and complex systems monitoring. Relatively less attention has however been given to methodological approaches that might facilitate learning as part of the monitoring process. This paper reviews the monitoring literature relevant to adaptive co-management, with a focus on the synergies between existing monitoring frameworks, collaborative monitoring approaches and social learning. The paper discusses the role of monitoring in environmental management in general, and the challenges posed by scale and complexity when monitoring in adaptive co-management. Existing conceptual frameworks for monitoring relevant to adaptive co-management are reviewed, as are lessons from experiences with collaborative monitoring. The paper concludes by offering a methodological approach to monitoring that actively seeks to engender reflexive learning as a means to deal with uncertainty in natural resource management.     

Commercial trials evaluating the novel use of ethyl formate for in-transit fumigation of shipping containers

Sediment samples from 25 sites in 17 rivers of the Pantanal (Brazil) were analyzed with the objective of evaluating pesticide contamination in sediments. Samples were extracted with an acetone, ethylacetate, and water mixture 2:2:1 (v/v/v). The extract was purified by flash chromatography with aluminum oxide and florisil. A multiresidue gas chromatography-mass spectrometry method was applied to monitor 23 pesticides of different chemical classes (organochlorine, organophosphorus, triazines, anilides and pyrethroids) with some of their degradation products. Compounds identified in sediment samples included λ -cyhalothrin (1.0 to 5.0 μ g kg^{? 1}), p,p′-DDT (3.6 μ g kg^{? 1}), deltamethrin (20.0 μ g kg^{? 1}) and permethrin (1.0 to 7.0 μ g kg^{? 1}).