Ockie J. H. Bosch

The use of degradation gradients for the assessment and ecological interpretation of range condition

Multivariate procedures were used to subdivide the southern African climatic climax grasslands of the 700–800‐mm rainfall zone into relatively homogeneous grazing areas. A degradation gradient was constructed for each of these areas. This was done by means of centred PCA ordination, using static data representing compositional differences induced mainly by grazing. The first axis of these ordinations represented a gradient of degradation. The second and higher axes were combined in a single value, namely, the Euclidean distance from the first axis. The degradation gradients were then used as a basis for ordinating new sites into the old ordinations, assessing their condition in an objective and quantitative way. The Euclidean distances from the first axis were used to determine the appropriateness of the degradation gradients for the assessment of the condition of a particular site. Knowledge of species response to grazing, community dynamics and recovery potential obtained through the ordination and regr...

A quantitative state and transition model for the Mitchell grasslands of central western Queensland

Concerns of reduced productivity and land degradation in the Mitchell grasslands of central western Queensland were addressed through a range monitoring program to interpret condition and trend. Botanical and eclaphic parameters were recorded along piosphere and grazing gradients, and across fenceline impact areas, to maximise changes resulting from grazing. The Degradation Gradient Method was used in conjunction with State and Transition Models to develop models of rangeland dynamics and condition. States were found to be ordered along a degradation gradient, indicator species developed according to rainfall trends and transitions determined from field data and available literature. Astrebla spp. abundance declined with declining range condition and increasing grazing pressure, while annual grasses and forbs increased in dominance under poor range condition. Soil erosion increased and litter decreased with decreasing range condition. An approach to quantitatively define states within a variable rainfall environment based upon a time-series ordination analysis is described. The derived model could provide the interpretive framework necessary to integrate on-ground monitoring, remote sensing and geographic information systems to trace states and transitions at the paddock scale. However, further work is needed to determine the full catalogue of states and transitions and to refine the model for application at the paddock scale.

An integrative approach to rangeland condition and capability assessment

A comprehensive system has been designed to serve as a basis for rangeland condition and grazing capacity assessment. It is important that research information and knowledge be transferred to land managers in the most usable form. An approach has therefore been developed by which different computer technologies are combined to produce a unique and user friendly package for direct application by the grazing industry. The system can be applied universally, regardless of the pool of quantitative knowledge that exists. This is of special importance for the evaluation and monitoring of the many rangeland systems not yet understood and quantified.

Systemic intervention to tackle the constraints and challenges facing stakeholders and the performance of the agricultural sector in Ghana

Constraints and challenges in Ghanas agricultural industry limit its throughput. A policy constraint is an issue when it comes to agricultural sustainability. A fresh approach to interventions and capacity-building using systems thinking approach; the four levels of thinking and the Evolutionary Learning Laboratory during a stakeholder workshop in Ghana has shown remarkable impact on the ability of the agricultural industry to evolve, improve, and raise its efficacy. With stakeholders interventions, the Bayesian belief network (BBN) models indicated that, agricultural productivity level will rise from 57.5 to 92.2% reducing poverty level from 44.9 to 10.0% below the poverty line. Also farmers yield and profit increased. The BBN revealed the impact of uncertainty on management systems to be accounted for in the decision making process. This means that decision makers can balance the desirability of an outcome against the chance that the management option selected may fail to achieve it.

The influence of rainfall on vegetation composition in different conditional states

The impact of ecological factors such as changes in rainfall could lead to large compositional changes in the diverse indigenous flora of southern Africa. A study was therefore initiated to determine the influence of rainfall conditions on species composition changes, which could serve as a basis for determining the long term influence of rainfall increase (e.g. cloud stimulation) and rainfall decrease (e.g. long term droughts). Certain species were found to occur in all the rainfall zones while others were limited to either the high or the low rainfall area. The reaction of species on the rainfall gradient also differs in vegetation representing different degradation stadia. The predictions of the reactions of key species on rainfall decrease or increase are of special importance for the eventual determination of grazing capacity.

Construction and evaluation of condition assessment and grazing capacity models for use in grazing management in the Eastern Mixed Bushveld of southern Africa

The Integrated System for Plant Dynamics (ISPD) is a comprehensive system in which new and existing data and knowledge are quantitatively or qualitatively used as a basis for range condition and grazing capacity assessments and for denning appropriate management options to maintain or improve the condition and capability of the range. This study was carried out to investigate the degree to which the qualitative approach in ISPD can be implemented, and to determine the amount and availability of data and expert knowledge in a specific area for the purpose of constructing a database in ISPD. Large quantities of information were available for the construction of vegetation condition and grazing capacity models for direct implementation in the grazing industry. The results generated by the models corresponded to the proposed grazing capacity values for the study area. The models furthermore enable any user to assess rapidly and accurately the range condition and grazing capacity for any vegetation unit in any stage of degradation.

R&D Productivity in the Pharmaceutical Industry: Scenario Simulations Using a Bayesian Belief Network

The pharmaceutical industry is in a R&D productivity crisis. Rapidly increasing development costs, decreasing profitability of new medical entities and missing breakthrough innovations are negatively affecting the future of the pharmaceutical industry. This complex problem requires a systems thinking approach to find effective solutions. In this study, a general pharmaceutical R&D productivity system has been modeled as a Bayesian Belief Network BBN. This model is based on a literature review and the mental model of experts in the pharmaceutical field. The model does not only support users to understand the system but is also able to simulate different future scenarios. A blockbuster drug scenario, a generic drug scenario, and a personalized drug scenario has been modeled with three different corresponding outcomes. These simulations enables decision makers to identify the leverage points of the pharmaceutical R&D productivity system. These leverage points could be the foundation of any further strategy development. The R&D productivity system archetype is potentially applicable for other R&D intensive industries.

Environmental stress resistance and propagation studies of six Cynodon Dactylon strains to assess reclamation suitability

Abstract Strains of Cynodon dactylon (L.) Pers. were collected from six different climatic localities in South Africa. Under controlled conditions the strains were submitted to various environmental stress factors. Experiments were conducted to ascertain their sexual and vegetative reproductive potencies. The drought resistance test revealed that the Augrabies strain is best adapted to tolerate severe moisture stress. All strains survived a soil pH (HZO) of 2.7. The average biomass production of the Delareyville strain, at 2096 fertilizer application, was double that of the Klawer strain. Vegetative reproductive faculties of stolon scions outstripped those of rhizomes by an average ratio of 3.6:1. A seed viability ranging from 0 to 3.596 was obtained. The low percentages of seed viability indicate that the best results will be obtained if stolon scions are used to establish C. dactylon strains in denuded areas. The results indicate that no strain is superiorly adapted to resist all environmental stress factors. Consequently, strain selection for reclamation purposes will depend on the specific environmental conditions prevailing at the reclamation site. All results yielded differences between the six strains which are symptomatic of ecotypification. A hypothesis which implies that in situ studies are sufficient to predict ecotype suitability for reclamation is presented.

Special Issue: Systems Education for a Sustainable Planet

We live in a world in which complexity characterizes all human endeavors today, such as healthcare, economic development, environmental protection, gender relationships, poverty, mental health, business management and social responsibility (just to name a few). The issues facing our world have become increasingly complex due to the fact that they are embedded in a global web of ecological, economic, social, cultural and political processes and dynamic interactions. These complex problems and challenges cannot anymore be addressed and solved in isolation and with the single dimensional mindsets and tools of the past.

The Value of Local and Indigenous Knowledge for the Development of Information Systems for Conservation Management

Human and natural interactions in the earth’ s vast drylands have global-scale influences. Dryland ecosystems play a major role in global biophysical processes by reflecting and absorbing solar radiation, maintaining a balance of atmospheric constituents, and sustaining biomass and biodiversity. A continuously increasing human population and demands for food and water, has lead to increasing pressures on the functioning of natural ecosystems and subsequently the maintenance of genetic, species and ecosystem diversity. The development of technologies and practices for the conservation and promotion of sustainable systems to enhance biodiversity requires full consideration of the social, cultural, ecological, political and economic values which different communities place on species and ecosystems (WOCAT 2000). These call for better communication, linkages and coordination between stakeholders at all levels of decision making. However, effective decision making relies on better informed individuals and organizations, which makes the availability of knowledge to achieve different goals, a prerequisite for sustainable management of any system.