*3.4. Research Theme*

As noted in Table 3, of the 52 articles included in this review, 297 keywords were used to describe the main themes of the research. Of these keywords, 104 did not directly address a research theme (e.g., names of study locations, methods that could be applied to a range of themes). Thus, we removed these terms from the total count, leaving 193 keywords addressing a research theme. In total, 91 keywords (47.2%) focused on human experience, 57 (29.5%) on management, 37 (19.2%) on physicality, and eight (4.1%) on valuation. Two articles did not use keywords: an introduction to a special journal issue [8]; and a longitudinal study on the effects of new urban greenways on transportation energy use and greenhouse gas emissions [44]. For the latter, we added one term to the physicality classification code, making a total of 194 total terms reviewed.

