Decision thresholds for management actions

A NERP Workshop (University of Melbourne, May 2014)

By Carly Cook (MU), Kelly Hunt de Bie (UoM), and Prue Addison (UoM) 

Managing natural environments involves difficult decisions about when to intervene to prevent undesirable changes. Intervening too early may result in unnecessary management actions, while intervening too late may lead to much greater costs or irreversible outcomes. Managers, therefore, need to be able to identify the most appropriate point to take action, and this is often referred to as a decision threshold (see Figure 1 for two examples).

Developing decision thresholds to guide management requires a good ecological understanding of the system, along with knowledge of the social, political and economic drivers at play. Striking the appropriate balance between these factors needs an active dialogue between scientists and managers to ensure appropriate decision thresholds are developed that take into account the constraints faced by management agencies.

Protected area management agencies within Australia (and several other countries) are working toward developing and implementing decision thresholds to guide management action. However, progress has been slow because there is little information sharing, virtually no coordination of effort, and ad hoc engagement between managers and scientists about how to identify and define decision thresholds. With this in mind we sought to bring together managers from across Australia and New Zealand to share ideas and accelerate progress toward the development of decision thresholds for protected area management. Researchers at the University of Melbourne and Monash University facilitated a workshop funded by the NERP ED Hub with 14 managers from 10 different government and non-government protected area management agencies across Australia and New Zealand. The diverse participation by agency staff reflects the broad interest in this topic.

The workshop started with representatives from all of the agencies sharing their current progress towards developing and implementing decisions thresholds. We found widespread support for the idea of decisions thresholds as a management tool. However, agencies have different objectives for developing thresholds and are using different approaches. Some are only just beginning to explore the concept while others are implementing thresholds in specific cases. Some agencies were focussed on supporting day-to-day management decisions, others on building decision thresholds into existing monitoring, evaluation and reporting programs that would improve management outcomes and the transparency of management decisions.

The discussion revealed that decision thresholds can take many different forms (eg, a quota for sustainable harvest or culling over-abundant species) and that management agencies have developed decision thresholds for a least one management issue, generally in relation to managing threats to biodiversity rather than focussed on important species or ecosystems.

“The most exciting development of the workshop was broad agreement on a general framework that sets out the keys elements required to set decision thresholds.”

During the workshop, there was fruitful discussion around the internal obstacles faced by agencies in developing and implementing decision thresholds within their management context. Many useful suggestions were made about how to overcome some of these operational barriers. There were also numerous scientific knowledge gaps identified that need to be addressed to assist agencies develop decision thresholds grounded in the best available science. The similarity between the knowledge gaps faced by different agencies was striking, suggesting targeted research could make a significant difference to overcoming many of the obstacles. There was broad support for a collaborative research agenda to develop an approach to identifying decision thresholds that could be applied in a wide range of different contexts.

Click to see larger image

CLICK FOR LARGER IMAGE Figure 1: Two examples of what a decision threshold might look like. Each tracks the population size of a species of concern over time (geckoes up top, the seaweed Neptune’s necklace in the lower graph). The dotted line in each graph represents a decision threshold. When a decline in the species of concern results in it crossing the threshold, a specific management action is triggered. (For background on the Neptune’s necklace example, see Decision Point #74).

The most exciting development of the workshop was broad agreement on a general framework that sets out the key elements required to set decision thresholds. This framework would fit within the monitoring, evaluation and adaptive management frameworks already in place within the agencies. The next step will be developing a series of questions that need to be addressed at each step and a range of decision support tools that will assist agencies in answering those questions. There was strong support for testing this framework for establishing decision thresholds through a range of case studies, targeting issues of current concern to Australian and New Zealand protected area management.

All the participants agreed that the workshop was a great success and very timely for their management agencies. The opportunity to share progress, challenges and possible solutions was extremely valuable and will form the basis of major progress in developing decision thresholds to guide protected area management. We would like to thank all of the agencies and their representatives for making the time to contribute and for their productive contribution to this important topic. The workshop provided an exciting way forward for an issue that could make a significant contribution to the effectiveness of protected area management.

More info: Kelly Hunt de Bie 

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