Fig 6.
Number of highly cited articles for each (a) type of ecosystem, (b) ecosystem service, (c) research focus, and (d) case study site.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.