Chance in plant communities: a new approach to its measurement using the nugget from spatial autocorrelation

Brownstein, Gretchen, Steel, John B., Porter, Stefan, Gray, Abraham, Wilson, Craig, Wilson, Padarn G. and Wilson, J. Bastow (2012) Chance in plant communities: a new approach to its measurement using the nugget from spatial autocorrelation. Journal of Ecology, 100 4: 987-996. doi:10.1111/j.1365-2745.2012.01973.x

Author Brownstein, Gretchen
Steel, John B.
Porter, Stefan
Gray, Abraham
Wilson, Craig
Wilson, Padarn G.
Wilson, J. Bastow
Title Chance in plant communities: a new approach to its measurement using the nugget from spatial autocorrelation
Journal name Journal of Ecology   Check publisher's open access policy
ISSN 0022-0477
Publication date 2012-07
Year available 2012
Sub-type Article (original research)
DOI 10.1111/j.1365-2745.2012.01973.x
Volume 100
Issue 4
Start page 987
End page 996
Total pages 10
Place of publication Oxford, United States
Publisher Wiley-Blackwell Publishing
Collection year 2013
Language eng
Formatted abstract
1. The unpredictable component of community structure – chance/randomness/stochasticity – is increasingly discussed, recently in terms of Neutral Theory, but is never directly measured. We show that a direct estimate of chance can be made from spatial autocorrelation, and demonstrate this usage.

2. The dissimilarity between two patches of vegetation was plotted against the distance between the patches, and a curve fitted. We argue that the y-intercept of the curve, i.e. the ‘nugget’, represents the amount of chance variation in species composition, because when distance is zero all dispersal limitation and spatially correlated environmental differences are excluded, and only chance remains.

3. The method estimated that in 16 sites around the South Island of New Zealand, 0–71% of the variation in plant community composition was due to chance, with a mean of 34%.

4. Synthesis. The new analysis method provides information on the amount of randomness in community species composition and could be applied to the many dissimilarity/distance studies in the literature. The amount of randomness in the 16 study sites was not related to the type of plant community or to the species richness per quadrat. However, randomness was positively correlated with whole-community species richness, supporting previous suggestions of a relationship between chance, the size of the species pool and redundancy.
Keyword Distance decay
Plant population and community dynamics
Species pool
Species richness
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Centre for Mined Land Rehabilitation Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 5 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 4 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Fri, 08 Mar 2013, 09:37:27 EST by Gretchen Brownstein on behalf of Centre For Mined Land Rehabilitation