Year: 2013
Type: article
Abstract: Patterns that resemble strongly skewed size distributions are frequently observed in ecology. A typical example represents tree size distributions of stem diameters. Empirical tests of ecological theories predicting their parameters have been conducted, but the results are difficult to interpret because the statistical methods that are applied to fit such decaying size distributions vary. In addition, binning of field data as well as measurement errors might potentially bias parameter estimates. Here, we compare three different methods for parameter estimation--the common maximum likelihood estimation (MLE) and two modified types of MLE correcting for binning of observations or random measurement errors. We test whether three typical frequency distributions, namely the power-law, negative exponential and Weibull distribution can be precisely identified, and how parameter estimates are biased when observations are additionally either binned or contain measurement error. We show that uncorrected MLE already loses the ability to discern functional form and parameters at relatively small levels of uncertainties. The modified MLE methods that consider such uncertainties (either binning or measurement error) are comparatively much more robust. We conclude that it is important to reduce binning of observations, if possible, and to quantify observation accuracy in empirical studies for fitting strongly skewed size distributions. In general, modified MLE methods that correct binning or measurement errors can be applied to ensure reliable results.
Source: PLoS ONE
Language: English
Subfield: Forestry
Domain: Life Sciences
SDG: Life on land
Open Access status: gold
Estimated APC paid: $2,382
Awards: G1198279745, LTREB: Long-Term Studies of Seedling and Small Sapling Community Dynamics in a Neotropical Forest, What Causes Large Local-Scale Variation in Tree Diversity in a Neotropical Forest? An Experimental Approach, Habitat Variation in the Demography and Life History of Tropical Trees, G3772627221, Dynamics of a Neotropical Forest: The First Decade, Demographic Analysis of a Tropical Forest in Panama, The Structure and Dynamics of a Tropical Forest, G6242140455, The Neutral Theory of Biodiversity and Biogeography: "New Theoretical Approaches", The Dynamics of a Neotropical Forest: The 1995 Recensus Including Seedling and Small Sapling Populations, The Dynamics of a Neotropical Forest: the 2005 Recensus and the Annual Seedling and Small Sapling Census, Theoretical and Empirical Studies of Seed and Pollen Dispersal in Tropical Trees, Impact of Logging on the Demography and Population Genetics of Mahogany in Bolivia
OpenAlex ID: W2016826530