How to Conduct a Literature Review

BAE/DAS/GENAG 582 - NRES Capstone Spring 2026

Manoj Sharma

What Is a Literature Review?

  • A structured summary and analysis of existing research about a question of interest
  • Shows:
    • What is known (e.g., impacts, mechanisms, trends)
    • What is debated or uncertain
    • Where the knowledge gaps are
  • Helps you:
    • Justify management or policy recommendations
    • Design your own study or monitoring plan

Focusing Your Question

  • Start broad → narrow with the 4 Ws:
    • What (stressor/intervention) – e.g., land retirement, grazing, prescribed fire
    • Where (place/ecosystem) – e.g., Kansas CRP grasslands, Great Plains watersheds
    • Who/what biota – e.g., grassland birds, pollinators, stream invertebrates
    • When (timeframe) – e.g., post‑enrollment, last 20–30 years
  • Example focusing:
    • Broad: “CRP and wildlife”
    • Focused: “Effects of Conservation Reserve Program grasslands on grassland bird richness in north‑central Kansas since 2000”

Literature Review vs Background & Synthesis vs Summary

Literature review

  • Organized by themes (e.g., “effects on water quality”, “effects on wildlife habitat”)
  • Compares and contrasts multiple studies
  • Explicitly identifies gaps and uncertainties

Background paragraph

  • Short, mostly descriptive overview
  • Less critical or systematic

Stronger synthesis

  • Don’t just list: “Smith (2015) found… Jones (2018) found…”
  • Instead:
    • “Most studies find that wider riparian buffers (>30 m) reduce nitrate loads more effectively than narrow buffers (<15 m) (Smith 2015; Jones 2018; Lee 2020), especially in clay‑rich soils. However, in steep catchments, hydrologic bypass can limit their effectiveness (Garcia 2021).”

The Literature Review as a Process

  1. Focus your topic (place, taxa, stressor, time scale)
  2. Search for scholarly and key grey literature
  3. Evaluate what to include (quality, relevance)
  4. Organize sources (reference manager, notes, themes)
  5. Synthesize patterns, contradictions, and gaps
  6. Write & revise the review

Evaluating Sources

For each item, ask:

  • Type & quality
    • Peer‑reviewed article? Technical report? Policy brief?
    • Reputable agency, journal, or NGO?
  • Methods
    • Field experiment, observational study, model, meta‑analysis?
    • Is design appropriate (replication, controls, time span, spatial scale)?
  • Relevance
    • Similar ecosystem, region (e.g., Great Plains vs. other biomes)?
    • Comparable management context (e.g., CRP vs other set‑aside programs)?
  • Recency & coverage
    • Mix of foundational and recent studies

Using a Reference Manager & Taking Notes

Why use Zotero, Mendeley, etc.?

  • Store PDFs and citations in one place
  • Tag and group articles by ecosystem, stressor, method, region
  • Automatically format references (APA, AAG, journal styles)

Basic workflow

  • Save items from Google Scholar/databases with browser connector
  • Attach the PDF
  • Add tags like: CRP, water-quality, grassland-birds, Kansas

Good notes for each study

  • Full citation
  • Research question / objective
  • Study design (field vs. model, temporal & spatial scale)
  • Major findings (direction &, if possible, magnitude of effects)
  • Limitations (short time span, single watershed, etc.)
  • Your comment: How does this inform your CRP question?

Organizing by Themes & Typical Structure

Organize by themes, not by paper

  • By mechanism – e.g., how CRP affects runoff vs. habitat structure
  • By scale – plot‑level vs. watershed‑ or landscape‑scale studies
  • By dimension – land use, water quality, wildlife responses
  • By type of evidence – field experiments, monitoring, modeling, meta‑analysis

Typical structure of an environmental lit review

  • Introduction
    • Define the environmental problem/context
    • Narrow to your specific question
  • Thematic body sections
    • Historical land use / disturbance context
    • Effects on physical environment (soil, hydrology, water quality)
    • Effects on biota (species richness, abundance, key taxa)
    • Management and policy implications
  • Synthesis & gaps
    • Consistent patterns
    • Conflicting results (and possible reasons)
    • Under‑studied ecosystems, taxa, or scales

Common Pitfalls & Quick Checklist

Common pitfalls

  • Topic still too broad (“climate change and biodiversity”)
  • Ignoring key agency/technical reports
  • Ignoring methods and scale when comparing studies
  • Over‑quoting; under‑paraphrasing

Checklist

Assignment Overview & Topic Selection (Step 1)

Literature Review Assignment – Overview

  • Initial phase of your scientific research
  • You will later extend this work in your group project by:
    • Refining a problem statement
    • Collecting and analyzing data
    • Testing hypotheses and developing conclusions
  • For now: Focus on what is already known about your topic

Step 1: Select Your Topic

  • Choose a topic related to your group research project
  • Coordinate with your instuctors, mentors, and team members
  • Good strategy: each student reviews one aspect (e.g., land‑use, water quality, or wildlife dimension of CRP in Kansas)
  • Deliverable: short typed description (≤ 1 page) of your subject area

Steps 2–3: Search & Annotated Bibliography

Step 2: Conduct a Literature Search

  • Goal: find the 10 most relevant scholarly sources on your topic
  • Focus on peer‑reviewed research articles (plus key books/monographs)
  • Use library databases and Google Scholar; most generic web pages are not suitable

Step 3: Prepare Annotated Bibliographies

  • Minimum of 10 articles that you found and read
  • Each annotation (1–3 paragraphs) should include:
    • Purpose and research question
    • Methods and study area
    • Key results and conclusions
    • Your personal comments (connection to your project)

Steps 4–5: Write the Review, Final Product & Citation Style

Step 4: Write the Literature Review

  • Introduction: introduce topic and how you organize the literature
  • Body: organized by themes, concepts, chronology, or methods
  • Summary: brief synthesis plus 2+ possible future research questions linked to your findings

Step 5: Prepare the Final Product

  • Title page
  • Distinct section headings (Introduction, Thematic Sections, Summary/Future Research)
  • Figures/maps if helpful, with proper captions and citations
  • Bibliography including your 10 annotated articles plus any additional key sources

Annotated Bibliography Examples

See examples from past students on Canvas:

Annotated Bibliography Examples

When reviewing the examples, notice:

  • How the citation is formatted at the top
  • The level of detail in the annotation (1–3 paragraphs)
  • How students synthesize purpose, methods, results, and conclusions
  • Personal comments connecting the paper to their research question
  • Use of key graphics or tables (when included)

Citation Style: AAG Format

Read this

Journal Article:
Sellers, P.J., 1985. Canopy reflectance, photosynthesis, and transpiration. International Journal of Remote Sensing 6:1335-1372.

Book:
Shigesada, N. and K. Kawasaki. 1997. Biological invasions: Theory and practice. New York: Oxford University Press.

Book Chapter:
Zwolinski, M.J. 1996. Effects of fire on montane forest ecosystems. In Effects of fire on madrean province ecosystems: A symposium proceedings, ed. P.F. Folliott, L.F. DeBano, and M.B. Baker, 55-63. Fort Collins, CO: U.S. Forest Service.

Citation Style: Additional Formats

Web Page:
North Central Pest Management Center. 2003. 2003 soybean aphid watch – facts. http://www.pmcenters.org/Northcentral/Saphid/Facts.htm (last accessed July 3, 2003).

Personal Communication:
Not included in the reference list; cite in the text only.
Example: Microsoft is the best software company in the world (W. Gates, personal communication, August 20, 2002).

Email Communication:
Doe, Jane. “Thursday’s Lost Lecture.” 15 September 1996. Personal e-mail (15 September 1996).

Newspaper/Magazine Article:
Feder, B.J. (2002, July 18). IBM Beats Forecasts but With Signs of Weakness. The New York Times, p. C1.

Thank You

Questions?