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ESA Certified Ecologist Research Methods in Environmental & Sustainability Science: practice questions

ESA Certified Ecologist (Ecologist-in-Training, Ecologist, Senior Ecologist) · USA · Ecological Society of America

Original practice questions written to the published syllabus · not past papers
10worked here, free
18written to this exam in this subject
8syllabus units

What this subject covers

Designing, analysing and publishing environmental research: hypotheses, field and laboratory designs, long-term experiments, mixed methods, meta-analysis, reproducibility and ethics.

In the exams: UGC NET Paper 1 (research aptitude) and Unit 9; ICAR AICE-JRF/SRF; PhD coursework

Where the 18 questions fall

How our questions for ESA Certified Ecologist spread across the units of Research Methods in Environmental & Sustainability Science. Difficulty: 5 easy, 10 medium, 3 hard.

Before-after-control-impact designs5
Field, plot and landscape-scale experimental designs3
Qualitative and participatory methods3
Long-term experiments and monitoring plots2
Systematic review and meta-analysis2
Research questions and hypotheses1
Mixed-effects models and repeated measures1
Open data, reproducibility and research ethics1

10 practice questions, worked

Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.

1 · Research questions and hypotheses · medium

Soil moisture affects both nitrogen fertiliser uptake and crop yield, and wetter plots were also fertilised more heavily. In a study of fertiliser and yield, soil moisture is acting as a:

  1. Confounding variable
  2. Mediating variable
  3. Dependent variable
  4. Moderating variable
Answer and working

A. Confounding variable

A confounder is associated with both the explanatory variable (fertiliser rate) and the response (yield) and can create a spurious association. A mediator lies on the causal path; a moderator changes the strength of an effect.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

2 · Field, plot and landscape-scale experimental designs · hard

For a two-sided test at α = 0.05 with power 0.8, n per group ≈ 2(1.96 + 0.84)² σ²/δ². If σ = 8 kg and the difference worth detecting is δ = 8 kg, about how many units per group are needed?

  1. 8
  2. 4
  3. 16
  4. 63
Answer and working

C. 16

n = 2 × 2.8² × (8/8)² = 15.7, rounded up to 16. 63 would follow from δ = σ/2 (halving δ quadruples n); 4 and 8 are arithmetic slips.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

3 · Field, plot and landscape-scale experimental designs · medium

Why are guard rows or buffer zones left around field plots?

  1. To raise the number of replicates without adding more experimental units
  2. To keep drift and root foraging from crossing between plots
  3. To allow the treatments to be assigned to plots without randomisation
  4. To supply subsamples that add degrees of freedom to the error term
Answer and working

B. To keep drift and root foraging from crossing between plots

Measurements come from the inner net plot so neighbouring treatments do not contaminate results. Buffers do not create replicates or degrees of freedom.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

4 · Long-term experiments and monitoring plots · medium

For detecting change in tree basal area over 20 years, why are permanent plots usually more powerful than new random plots at each survey?

  1. Each plot is its own control, removing between-plot variation in change
  2. Permanent plots are always larger, so they contain more trees in total
  3. New random plots must be measured with less accurate instruments
  4. Permanent plots remove the need to account for any serial correlation
Answer and working

A. Each plot is its own control, removing between-plot variation in change

Paired remeasurement cancels between-plot differences, so change is estimated with less error. Serial correlation still needs attention.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

5 · Long-term experiments and monitoring plots · medium

In adaptive monitoring as described by Lindenmayer and Likens, what remains fixed while questions and designs evolve?

  1. A core set of consistently measured variables
  2. The original hypotheses and their statistical tests
  3. The list of sites, which may never be changed
  4. The staff team who first established the programme
Answer and working

A. A core set of consistently measured variables

Adaptive monitoring lets questions and methods evolve but keeps key measurements consistent so long-term records remain comparable.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

6 · Before-after-control-impact designs · medium

What is the most common practical obstacle to using BACI for development projects?

  1. BACI cannot be analysed with mixed-effects or generalised linear models
  2. Control sites are not allowed by most environmental regulators
  3. Baseline data must be collected before construction begins
  4. BACI requires the impact to be randomly assigned to the impact site
Answer and working

C. Baseline data must be collected before construction begins

Baseline data at impact and control sites must exist before the impact, so monitoring must be planned and funded early.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

7 · Qualitative and participatory methods · hard

During participatory mapping of village forest use, older men dominate the discussion. What is good practice?

  1. Record only the dominant view because it represents local authority
  2. Replace the mapping with a satellite image to avoid any bias
  3. Hold separate sessions for women, young people and other groups
  4. Ask the men to speak on behalf of their households' members
Answer and working

C. Hold separate sessions for women, young people and other groups

Separate groups by gender, age or wealth so less powerful voices are heard; their resource uses (fuelwood, fodder, medicinal plants) often differ.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

8 · Qualitative and participatory methods · medium

Before collecting traditional ecological knowledge from an indigenous community, a researcher must obtain:

  1. Free, prior and informed consent
  2. A signed confidentiality waiver
  3. Permission from a journal editor
  4. A random sample of all households
Answer and working

A. Free, prior and informed consent

FPIC, together with agreements on ownership and use of the knowledge, is the accepted standard; Nagoya Protocol obligations may also apply.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

9 · Systematic review and meta-analysis · medium

Why should a systematic review protocol be published before the review is carried out?

  1. To allow the journal to calculate an impact factor in advance
  2. To prevent methods from being changed after the results are seen
  3. To show that the search will be limited to one database
  4. To replace the need for screening by two reviewers
Answer and working

B. To prevent methods from being changed after the results are seen

A pre-published protocol reduces bias from post-hoc choices; it is standard in CEE guidelines.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

10 · Open data, reproducibility and research ethics · easy

Which of the 3Rs is served by using a power analysis to set the minimum number of animals needed in a field study?

  1. Reduction
  2. Replacement
  3. Refinement
  4. Reproduction
Answer and working

A. Reduction

Reduction means using the fewest animals that give valid results. Replacement substitutes non-animal methods; refinement minimises pain and distress.

Further reading: See the manual sources: Hurlbert 1984; Quinn and Keough; Zuur et al.; Legendre and Legendre; Underwood 1994; CEE Guidelines; Koricheva et al.

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Read the subject

Research Methods in Environmental & Sustainability ScienceThe full study manual, free ESA Certified EcologistFormat, sections and how it has changed

More ESA Certified Ecologist practice

Ecosystem Services & Pollinators in Agricultural LandscapesLandscape Ecology, Protected Areas & Human-Wildlife InteractionsBiodiversity Science & Conservation

Research Methods in Environmental & Sustainability Science for other exams

UGC NET · IndiaICAR AICE-JRF/SRF · India

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