Should managed populations be monitored every year?
Should managed populations be monitored every year?
复制标题
是否应该每年对管理的种群进行监测？
DOI：
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发表时间：
2006
影响因子：
5
通讯作者：
H. Possingham
中科院分区：
文献类型：
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作者：
Cindy E. Hauser;A. Pople;H. Possingham
我们经常需要估计野生种群的规模，以确定适当的管理行动，例如设定收获配额。监测通常是在假设必须在设定收获配额之前定期（通常每年）进行的假设下进行计划的。然而，监控的成本可能非常昂贵，我们应该权衡监控的成本和监控对决策的改进。每年监测的成本较低的替代方案是使用人口模型和以前调查的信息来预测人口规模。在本文中，监测频率问题是在决策理论框架内提出的。我们发现，根据系统状态而变化的监控机制可以优于固定间隔监控。使用南澳大利亚红袋鼠 (Macropus rufus) 种群的数据说明了这一想法。某一年是否应该进行监测取决于上一年的人口密度估计、人口估计的不确定性以及过去的降雨量。我们发现，当基于模型的人口密度预测非常不确定时，监测就很重要。如果几年没有进行监测，或者降雨量高于平均水平，则可能会发生这种情况。当先前信息表明种群数量接近种群丰度的临界阈值时，监测也很重要。然而，当新信息不会改变最佳管理行动时，监控就不那么重要了。
We often need to estimate the size of wild populations to determine the appropriate management action, for example, to set a harvest quota. Monitoring is usually planned under the assumption that it must be carried out at fixed intervals in time, typically annually, before the harvest quota is set. However, monitoring can be very expensive, and we should weigh the cost of monitoring against the improvement that it makes in decision making. A less costly alternative to monitoring annually is to predict the population size using a population model and information from previous surveys. In this paper, the problem of monitoring frequency is posed within a decision-theory framework. We discover that a monitoring regime that varies according to the state of the system can outperform fixed-interval monitoring. This idea is illustrated using data for a red kangaroo (Macropus rufus) population in South Australia. Whether or not one should monitor in a given year is dependent on the estimated population density in the previous year, the uncertainty in that population estimate, and past rainfall. We discover that monitoring is important when a model-based prediction of population density is very uncertain. This may occur if monitoring has not taken place for several years, or if rainfall has been above average. Monitoring is also important when prior information suggests that the population is near a critical threshold in population abundance. However, monitoring is less important when the optimal management action would not be altered by new information.