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.
Light response curves of fully current-year Pinus cembra needles at 2 180 m a.s.l. (krummholz belt; top), 2 100 m a.s.l (tree line; middle), and 1 950 m a.s.l. (forest limit; bottom) assessed in fall (open symbols) and in summer (closed symbols). Measurements were made in situ at ambient CO2, 15 °C, and 70% of relative humidity.
