Extraction of a weak climatic signal by an ecosystem

The complexity of ecosystems can cause subtle and chaotic responses to changes in external forcing. Although ecosystems may not normally behave chaotically, sensitivity to external influences associated with nonlinearity can lead to amplification of climatic signals. Strong correlations between an El Ni?o index and rainfall and maize yield in Zimbabwe have been demonstrated; the correlation with maize yield was stronger than that with rainfall. A second example is the 100,000-year ice-age cycle, which may arise from a weak cycle in radiation through its influence on the concentration of atmospheric CO2 (ref. 5). Such integration of a weak climatic signal has yet to be demonstrated in a realistic theoretical system. Here we use a particular climatic phenomenon-the observed association between plankton populations around the UK and the position of the Gulf Stream-as a probe to demonstrate how a detailed marine ecosystem model extracts a weak signal that is spread across different meteorological variables. Biological systems may therefore respond to climatic signals other than those that dominate the driving variables.     

Triple Task Method: Systemic, Reflective Action Research

This brief article introduces a new methodology for systemic action research—Triple Task (TT)—and sets out its rationale and initial progress in becoming an embedded method for group working. Arising from the authors previous work with soft systems approaches, the Imagine method for sustainable development assessment and action research in a variety of global locations, TT provides a means for groups to engage together in purposive work and, at the same time, for facilitators to understand how the dynamic of the group influences the groups output. TT is based on an ambitious concept and at the time of writing the results of TT applied in the context of an EU Framework 7 funded project are in their early stages but importantly, significant insights are already arising including the answers to some puzzling questions:

• Do purposeful groups always produce the most insightful outcomes?
• Do conflictual groups produce incoherent results?
• What makes a ‘good’ group?

     

Have national trends in fertility between 1986 and 2006 occurred evenly across England and Wales?

During the past 20 years fertility patterns within England and Wales have changed considerably. The total fertility rate experienced a prolonged decline during the 1990s and hit a record low in 2001. Since then the level of fertility has increased fairly rapidly. Over the two decades, fertility has been constantly increasing at ages above 30, and as a consequence the mean age of motherhood has been rising. This article explores fertility trends within statistical regions and local authorities to improve our understanding of changes in fertility at the subnational level between 1986 and 2006.     

How People Use Rich Pictures to Help Them Think and Act

Groups of all kinds are complex organisations. To understand them and to facilitate them in process terms is a matter of rich and diverse discourse in varied fields from sustainable development to coastal ecology; from bandwidth in rural communities to health service provision. How to allow groups to discourse, problem solve and review their own issues and concerns? Diagrams in general and rich pictures in particular can be great means to allow groups to explore their subconscious, their occult sentiments and conflicted understandings. This paper explores and explains diverse use of pictures and shows how they can be applied and understood in group processes of all kinds.