When have we looked hard enough? A novel method for setting minimum survey effort protocols for flora surveys
Article first published online: 30 OCT 2008
© 2008 The Authors. Journal compilation © 2008 Ecological Society of Australia
Volume 33, Issue 8, pages 986–998, December 2008
How to Cite
GARRARD, G. E., BEKESSY, S. A., McCARTHY, M. A. and WINTLE, B. A. (2008), When have we looked hard enough? A novel method for setting minimum survey effort protocols for flora surveys. Austral Ecology, 33: 986–998. doi: 10.1111/j.1442-9993.2008.01869.x
- Issue published online: 30 OCT 2008
- Article first published online: 30 OCT 2008
- Accepted for publication December 2007.
- impact assessment;
- statistical power;
- survey effort;
- type II error
There is now a substantial body of literature documenting the detectability of plants and animals under standard survey conditions. Despite the evidence that many flora and fauna species have detection probabilities of less than one, it is still the default assumption of most environmental impact assessment processes that if a species is present, it will be detected. Here we briefly review a number of existing studies that have estimated the survey effort necessary to detect animal species, based on what is known about their detection rates in standard surveys. We then propose a novel method, based on failure-time analysis, for quantifying the detectability of and determining appropriate survey effort for plant species during flora surveys. We provide computer code for implementing the method in the Bayesian freeware WinBUGS. Methods for estimating detectability can be used to inform minimum survey requirements and have important applications in environmental impact assessment and monitoring.