Plant growth analysis

Published sources of information on plant growth analysis

A free, undergraduate-level course on plant growth analysis, resource capture and resource allocation 

Lecture 1    Growth of individuals, growth analysis, rates of growth, transformations, calculations

Lecture 2    Relative growth rate, unit leaf rate, leaf area ratio, subdivisions, interrelations, allometry

Lecture 3   Formulae and tools for the classical approach, replication and statistics

Lecture 4    Growth of populations, plant density, leaf area index, crop growth rate

Lecture 5   Functional approach to individual and population growth

Lecture 6    Population growth functions, dynamics of biomass and leaf production

Lecture 7    Plant functional types: theory, practice, models.

Resources from this website

  • Classical plant growth analysis made easy
    Many studies have only one, or very few, harvest intervals and must therefore use the classical (non-curve-fitting) form of plant growth analysis. However, most studies of this type neglect the rigorous, but necessary, mathematical and statistical calculations that this approach involves. A 2002 Annals of Botany paper describes a state-of-the-art spreadsheet tool which does all of the hard work for users who paste-in appropriate raw data.

    • You can download a .pdf version of the paper here, and the Excel spreadsheet tool here Warning: these items are both copyright material for personal and private study only.

  • Functional plant growth analysis made easy
    If you have a series of successive harvests in your growth experiment there are good reasons for using fitted plant growth curves to derive your growth parameters.

    • If you have a moderate number of harvests (perhaps five to ten) you should consider using stepwise polynomial growth curves. A 1974 paper in the Journal of Applied Ecology described a method which has been successfully used hundreds of times. There is now a Windows-based tool which you can use to apply this method. Go here to download all the necessary files.

    • If you have more than about ten harvests you should consider using B-splined polynomial growth curves. There is a DOS-type application available for obtaining plant growth parameters from spline curves: go here to download all the necessary files. This application also delivers second derivatives from the fitted splines (the rates of change of the rates of change).

    • Later work shows that the methods of cubic spline smoothers and loess smoothers represent versatile and accurate ways of form-free curve fitting that have the added advantage of being able to estimate smoothly changing first derivatives with less subjectivity than B-splines.