ICAR AIEEA-PG Forestry Research Methods & Experimental Design: practice questions

1 · Field experiments with trees: plot size, borders, replication · easy

Border rows around a measured plot in a spacing or fertiliser trial are used to:

1. Increase the number of trees measured in each plot
2. Absorb competition from neighbouring treatments
3. Mark the plot so that it can be found later
4. Provide spare trees for destructive sampling only

2 · Field experiments with trees: plot size, borders, replication · medium

In a long-term trial, dead seedlings in the first season are replaced. Good practice requires:

1. Replacements of any vigorous seedlot that happens to be available
2. Replacing dead trees only in the control plots
3. Replacements of the same seedlot, with the replacement recorded
4. Removing the plot from the analysis

3 · Field experiments with trees: plot size, borders, replication · easy

Uniformity trials, in which one treatment is applied to a whole field and small units are harvested separately, are used to:

1. Compare the yields of several new clones
2. Study variability and choose plot size and shape
3. Measure the effect of fertiliser rates on tree growth
4. Estimate the cost of field operations

4 · Mixed-effects models and repeated measures · easy

In a provenance trial replicated in blocks, blocks are usually treated as:

1. Fixed effects of interest
2. Random effects
3. Response variables
4. Covariance structures

5 · Mixed-effects models and repeated measures · easy

A model in which each tree has its own intercept and growth rate, varying around the population average, uses:

1. Fixed intercepts only
2. Random intercepts and random slopes
3. A completely randomised design with subsampling
4. Principal component scores

6 · Multivariate methods: PCA, cluster analysis, ordination · easy

PERMANOVA is used to test:

1. Whether a single response variable is normally distributed
2. Differences in multivariate composition among groups
3. The number of principal components to keep
4. The correlation between two tree heights

7 · Long-term experiments and permanent sample plots · easy

Why are permanent sample plots preferred to temporary plots for estimating forest growth?

1. Permanent plots are cheaper to establish than temporary ones
2. Temporary plots cannot measure tree diameter
3. Permanent plots never need to be remeasured
4. Remeasuring the same trees estimates change precisely

8 · Meta-analysis and systematic reviews · easy

A systematic review differs from a narrative review mainly in that it:

1. Includes only studies with significant results
2. Is written by a single expert, without any protocol at all
3. Covers only one study in great detail
4. Uses explicit, reproducible search and selection methods

9 · Research ethics, data management and reproducible analysis · easy

Preregistering an analysis plan before collecting data mainly protects against:

1. Equipment failure in the field
2. Loss of data from a hard drive
3. p-hacking and HARKing
4. Mortality of trees in the experiment

10 · Scientific writing, peer review and research proposals · easy

Objectives in a research proposal are best written to be:

1. Broad enough to cover any result
2. Specific, measurable and time-bound
3. Identical to the title of the proposal
4. Free of any reference to methods