The challenges of effective model scoping: A FLORES case study from the mafungautsi forest margins,Zimbabwe

This paper explores the challenge of defining the scope of a systems model, emphasising three aspects: boundary, granularity and conceptual scope. The significance of these is illustrated by reference to a model of land-use decisions made in villages bordering on the Mafungautsi forest in Zimbabwe. The purpose of this model was to help policy players (Forestry Commission staff, non-governmental organisations, researchers and local people) to understand the impact of policy interventions on local people’s livelihoods. Scoping decisions that were made in building the Mafungautsi model were deliberately liberal, to encompass the interests of all participants in the modelling process. These decisions now present a range of serious challenges: the difficulty of model calibration, the computational expense of running simulations, and the difficulty for new users to understand the model. Facilitators of modelling teams need to consider the serious implications of giving everyone what they want and including all participants’ ideas in a model. In the long run, it may be better to be tough and reject many suggestions at the outset. The former approach is unlikely to lead to a tractable model, while the latter may ultimately offer greater satisfaction for all. We are grateful to the UK’s Department for International Development (DFID) and the European Community for financial support of this project. Thanks also to all of the ACM team who have contributed ideas on the process and content of the modelling work and who make it fun to undertake collaborative research. Thanks also to the participants in the Zimbabwe FLAC workshops for their input into the specification of the Mafungautsi model. Finally thanks to Robert Muetzelfeldt, Jasper Taylor, Jonathan Massheder, Fergus Sinclair and Jerry Vanclay for helping us to ride on the FLORES bandwagon.     

ZimFlores: A model to advise co-management of the mafungautsi forest in Zimbabwe

ZimFlores (version 4) is the outcome of a participatory modelling process and seeks to provide a shared factual basis for exploring land-use options for the communal lands surrounding the Mafungautsi forest. The ZimFlores experience underscores the importance of a sharing a common problem and a common location in which all participants have an interest. Participatory modelling has proved an effective way to consolidate a diverse body of knowledge and make it accessible. Results demonstrate the importance of model outputs that are diagnostic, and which offer insights into the issues under consideration. Many people contributed in many ways to help realize ZimFlores. Some of the people who contributed include Elias Ayuk, Ivan Bond, Ephraim Chabayanzara, Muyeye Chambwera, Vijay Datadin, Wil de Jong, Peter Frost, James Gambiza, Jode Garbe, Peter Gondo, Emmanuel Guveya, Chiedza Gwata, John Hansell, Gideon Kamumvuri, Godwin Kowero, Dominic Kwesha, Chris Legg, Tim Lynam, Hilton Madevu, Simba Mandota, Everisto Mapedza, Frank Matose, Gutura Matoso, Chipo Mlambo, John Mudekwe, Maxwell Mukwekwerere, Dorcas Mungwari, Tendayi Mutimukuru, Mkhululi Ngwenya, Richard Nyirenda, Bill Ritchie, Lizwelabo Sibanda, Manasa Sibanda, Fergus Sinclair, Jivas Sithutha, Jasper Taylor, Michael Thomas, Zivanai Tsvuura and Steve Twomlow. We are grateful to the UK’s Department for International Development (DFID) and the European Community for financial support of this project.     

Utilization of created wetlands to upgrade small municipal wastewater treatment systems

Created wetlands offer a low cost, low maintenance, and practical alternative for upgrading secondary municipal wastewater treatment systems. The removal efficiencies, effects of seasonal temperature variations, and effects of increased loading rates on contaminant removal within such a system was studied by Auburn University researchers at a created wetland site in Hurtsboro, Alabama. The 0.16 ha system consisted of a two cell wetlands planted with cattails (Typha latifolia), bulrush (Scirpus validus), arrow duck potatoes (Sagitaria latifolis), burr reeds (Spargaminum eurycarpun), water pennywort (Hydrocotyl ranunculoides), and parrotfeather (Myriophyllum brasiliense). Testing occurred from January through September of 1988 at hydraulic loading rates of 169, 289, and 345 m³ ha^?1 d^?1. The monthly average total suspended solids influent: effluent mg L^?1 concentration ratio during the study period was 135:19 while the monthly average total BOD₅ influent: effluent mg L^?1 concentration ratio was 38:8. Once the system stabilized, the monthly average total BOD₅ effluent concentration remained essentially constant over the range of average BOD₅ loading rates employed in this study. Total Kjeldahl N removal was more effective at loading rates of 2.6 kg ha^?1 d^?1. The monthly average influent: effluent TKN mg L^?1 concentration ratio was 15:4.     

Monitoring and action threshold determination for the obscure mealybug Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) using pheromone-baited traps

The absence of effective pest monitoring has resulted in an increase in populations of the obscure mealybug Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) in pome fruit orchards in the Western Cape Province of South Africa recently. The sex pheromone for P. viburni was recently identified and synthesized. Flight activity of adult male P. viburni was monitored by placing and servicing three, evenly spaced pheromone-baited traps per orchard in three pome fruit growing regions used for the study. Fortnightly fruit sampling was done by randomly picking three fruits per tree for the duration of each fruit season, dissecting and noting mealybug infestation. The biweekly male P. viburni trap catch information and fruit infestation data collected over two seasons were correlated. There was a positive and significant relationship between the fruit infestation and number of P. viburni adult males caught in pheromone-baited traps (r² = 0.454, P < 0.001). The action threshold level was estimated to be 2.5 male P. viburni caught per trap per fortnight at an economic threshold of 2% fruit infestation. This monitoring method was less labor intensive, more accurate and quicker than the current visual sampling and monitoring techniques.     

Prevalence of obesity in dogs examined by Australian veterinary practices and the risk factors involved

A study was undertaken to determine the prevalence of obesity in dogs examined by veterinary practices across Australia, and to determine the risk factors involved; 1700 practices were asked to complete a veterinarian opinion survey, and of the 428 practices that responded, 178 were selected to complete an RSPCA Australia Pet Obesity Questionnaire, together with additional practices selected by Australian State and Territory RSPCA societies. This questionnaire was sent to a total of 209 practices which were asked to record details of eligible dogs, and the reason why they had been examined during the previous month. Fifty-two (24.9 per cent) of the practices responded and provided data on 2661 dogs, of which 892 (33.5 per cent) were overweight and 201 (7.6 per cent) were obese. A further 112 dogs (4.2 per cent) were classified as thin or very thin, but these were excluded from subsequent analyses. Of the remaining 2549 dogs, approximately half were female and 1905 (74.7 per cent) were neutered. The dogs' weight category was influenced by several factors. Breed influenced the importance of sex and neutering as risk factors. The prevalence of overweight and obese dogs combined was 41 per cent; the prevalence increased with age up to about 10 years old, and then declined. Rural and semirural dogs were more at risk of obesity than urban and suburban dogs.     

Infectious ideas: Modelling the diffusion of ideas across social networks

Will the practice of collecting wild honey wearing no clothes become a widespread practice in Zimbabwe? Or will beekeeping take over as the main way that people acquire honey? Both practices impact on forest resources; how can the foresters influence the uptake of these ideas? This paper describes an exploratory modelling study investigating how social network patterns affect the way ideas spread around communities. It concludes that increasing the density of social networks increases the spread of successful ideas whilst speeding the loss of ideas with no competitive advantage. Some different kinds of competitive advantage are explored in the context of forest management and rural extension.