Figure 2.
Map of Northeastern United States. Most field studies considered are from this region. Locations referenced in the text are labelled in black.
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.