Related Experiment Video
Updated: May 31, 2026
06:56
Tree Core Analysis with X-ray Computed Tomography
Published on: September 22, 2023
Analyzing tropical forest tree species abundance distributions using a nonneutral model and through approximate
1Laboratoire Evolution et Diversité Biologique, Centre National de la Recherche Scientifique, Université Paul Sabatier, Bâtiment 4R3, 31062 Toulouse, Cedex 4, France. franck.jabot@m4x.org
The American Naturalist
|July 14, 2011
Summary
Neutral theory in ecology is challenged by new findings in tropical forests. Deviations from neutrality are common, especially at smaller scales, suggesting other factors influence species distribution.
Area of Science:
- Ecology
- Biodiversity research
- Community ecology
Background:
- The neutral theory of biodiversity posits functional equivalence among species, contrasting with niche-based community assembly.
- While functional equivalence is often disproven, some tropical tree community patterns align with neutral predictions.
- This raises questions about neutral theory's applicability and the information content of species abundance data.
Purpose of the Study:
- To test the predictions of neutral theory using species abundance distributions in ecological communities.
- To develop and validate a more generalized nonneutral model incorporating frequency dependence.
- To investigate the prevalence and drivers of deviations from neutrality in tropical forests.
Main Methods:
- Developed a novel statistical test for ecological neutrality based on species abundance distributions.
- Constructed a generalized nonneutral model extending Hubbell's dispersal-limited neutral model with a frequency-dependence parameter.
- Employed approximate Bayesian computation for parameter inference from empirical data.
Main Results:
- Deviations from neutral theory are more frequent in tropical forest trees than previously recognized, particularly at smaller spatial scales.
- The newly developed nonneutral model provided a better fit to empirical data than the neutral model in over half of the studied permanent tree plots.
- Observed deviations suggest potential roles for environmental filtering in shaping tropical tree species abundance distributions.
Conclusions:
- Neutral theory may be an oversimplification for many tropical forest communities.
- A nonneutral model incorporating frequency dependence offers a more accurate representation of community assembly.
- Environmental filtering is a plausible mechanism driving observed deviations from neutrality in tropical tree species.
Related Concept Videos
01:19Survival Tree
Survival trees are a non-parametric method used in survival analysis to model the relationship between a set of covariates and the time until an event of interest occurs, often referred to as the "time-to-event" or "survival time." This method is particularly useful when dealing with censored data, where the event has not occurred for some individuals by the end of the study period, or when the exact time of the event is unknown.
Building a Survival Tree
Constructing a survival tree begins...
Building a Survival Tree
Constructing a survival tree begins...
01:06Model Approaches for Pharmacokinetic Data: Distributed Parameter Models
Pharmacokinetic models are mathematical constructs that represent and predict the time course of drug concentrations in the body, providing meaningful pharmacokinetic parameters. These models are categorized into compartment, physiological, and distributed parameter models.
The distributed parameter models are specifically designed to account for variations and differences in some drug classes. This model is particularly useful for assessing regional concentrations of anticancer or...
The distributed parameter models are specifically designed to account for variations and differences in some drug classes. This model is particularly useful for assessing regional concentrations of anticancer or...
02:54Evolutionary Relationships through Genome Comparisons
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
01:14Analysis Methods of Pharmacokinetic Data: Model and Model-Independent Approaches
Drug disposition in the body is a complex process and can be studied using two major approaches: the model and the model-independent approaches.
The model approach uses mathematical models to describe changes in drug concentration over time. Pharmacokinetic models help characterize drug behavior in patients, predict drug concentration in the body fluids, calculate optimum dosage regimens, and evaluate the risk of toxicity. However, ensuring that the model fits the experimental data accurately...
The model approach uses mathematical models to describe changes in drug concentration over time. Pharmacokinetic models help characterize drug behavior in patients, predict drug concentration in the body fluids, calculate optimum dosage regimens, and evaluate the risk of toxicity. However, ensuring that the model fits the experimental data accurately...
01:26Distributions to Estimate Population Parameter
The accurate values of population parameters such as population proportion, population mean, and population standard deviation (or variance) are usually unknown. These are fixed values that can only be estimated from the data collected from the samples. The estimates of each of these parameters are sample proportion, the sample mean, and sample standard deviation (or variance). To obtain the values of these sample statistics, data are required that have particular distribution and central...
03:21Phylogenetic Trees
Phylogenetic trees come in many forms. It matters in which sequence the organisms are arranged from the bottom to the top of the tree, but the branches can rotate at their nodes without altering the information. The lines connecting individual nodes can be straight, angled, or even curved.