Ecological information from spatial patterns of plants: insights from point process theory

Richard Law, Janine Barbel Illian, David Francis Robert Philip Burslem, Georg Gratzer, C. V. S. Gunatilleke, I. A. U. N. Gunatilleke

Research output: Contribution to journalLiterature review

235 Citations (Scopus)

Abstract

1. This article reviews the application of some summary statistics from current theory of spatial point processes for extracting information from spatial patterns of plants. Theoretical measures and issues connected with their estimation are described. Results are illustrated in the context of specific ecological questions about spatial patterns of trees in two forests.

2. The pair correlation function, related to Ripley's K function, provides a formal measure of the density of neighbouring plants and makes precise the general notion of a 'plant's-eye' view of a community. The pair correlation function can also be used to describe spatial relationships of neighbouring plants with different qualitative properties, such as species identity and size class.

3. The mark correlation function can be used to describe the spatial relationships of quantitative measures (e.g. biomass). We discuss two types of correlation function for quantitative marks. Applying these functions to the distribution of biomass in a temperate forest, it is shown that the spatial pattern of biomass is uncoupled from the spatial pattern of plant locations.

4. The inhomogeneous pair correlation function enables first-order heterogeneity in the environment to be removed from second-order spatial statistics. We illustrate this for a tree species in a forest of high topographic heterogeneity and show that spatial aggregation remains after allowing for spatial variation in density. An alternative method, the master function, takes a weighted average of homogeneous pair correlation functions computed in subareas; when applied to the same data and compared with the former method, the spatial aggregations are smaller in size.

5. Synthesis. These spatial statistics, especially those derived from pair densities, will help ecologists to extract important ecological information from intricate spatially correlated plants in populations and communities.

Original languageEnglish
Pages (from-to)616-628
Number of pages13
JournalJournal of Ecology
Volume97
Issue number4
Early online date3 Jun 2009
DOIs
Publication statusPublished - Jul 2009

Keywords

  • forest
  • heterogeneous environment
  • mark correlation function
  • marked point process
  • pair correlation function
  • plant's-eye view
  • point pattern process
  • Ripley's K function
  • spatial pattern
  • Lankan dipterocarp forest
  • asymmetric competition
  • edge-correction
  • K-function
  • associations
  • population
  • statistics
  • vegetation
  • inference
  • growth

Cite this