Could ecologists be more random? Straightforward alternatives to haphazard spatial sampling

Abstract

When conducting field studies, it is common for ecologists to choose the locations of sampling units arbitrarily at the time sampling occurs, rather than using a properly randomised sampling design. Unfortunately, this ‘haphazard’ sampling approach cannot provide formal statistical inference from the sample to the population without making untestable assumptions. Here, we argue that two recent technological developments remove the need for haphazard sampling in many situations. A general approach to simple randomised sampling designs is outlined, and some examples demonstrate that even complicated designs can be implemented easily using software that is widely used among ecologists. We consider that more rigorous, randomised sampling designs would strengthen the validity of the conclusions drawn from ecological studies, to the benefit of the discipline as a whole.