Literature search and Filtering
Criteria
For this review, a literature search was performed on the core
collection of the Web of Science data base for the years 2018 to 2024,
in order to keep the focused on the recent and relevant advances in what
is a rapidly developing field. One search was conducted for
biodiversity, and one for each of the six selected functional traits.
The search terms used in Figure 2A produced the first round of results,
ranging from 685 for biodiversity and 14 for leaf dry matter, and a
total of 1504 results. The first filter, row B in Figure 2, selected
just research articles and reviews, which reduced the total by 2.2%.
The third filter, row C in Figure 2, examined the abstracts to ensure
that the papers were directly related to the search theme. This removed
77.4% of the original total. The final filter, row D in Figure 2,
involved examination of the papers to ensure they represented a
development or advancement in the remote sensing methods, or an
analysis/assessment of the remote sensing methods. Furthermore, papers
that exclusively used proximal sensors, such as handheld spectrometers,
rather than remote sensors, were also excluded. This brought the total
number of papers down to 125, with a final total of 112 after duplicates
were removed.