• Covariance;
  • Eigenanalysis;
  • Pattern;
  • Sampling;
  • Spatial process;
  • Understory;
  • Variance
  • Scoggan (1978)

Abstract. We examine the effects of changing plot size on parameter estimation efficiency in multivariate (community-level) ecological studies, where estimation efficiency is defined in terms relating to the statistical precision of estimates of all variables (e.g. species) in a data set. Three ‘efficiency criteria’ for multivariate estimation are developed, and the relationship between estimation efficiency and plot size examined using three field data sets (deciduous understory, coniferous understory, and mire vegetation) from central Canada.

For all three communities, estimation efficiency was found to increase monotonically with increasing plot size. However, relative gains in efficiency at larger plot sizes were offset by substantial increases in sampling effort (enumeration time per plot). Our results indicate that the largest plot size possible, given the constraints of time, should be used for parameter estimation in plant communities. Also, plots that are larger than the mean patch size should be utilized when sampling heterogeneous vegetation.