Total N and C analyses
Total foliar N and C content was determined in foliage collected in late
August 2016, and early June and late August 2017 (n= 5-6). The tissue
was dried for 72 h at 70°C, ground
using a mini Wiley Mill (Thomas
Scientific, Swedesboro, NJ) and passed through a 0.85 mm sieve (#20
mesh). The samples were dried at 70°C for additional 16 h before
aliquots of 3 to 5 mg dry weight were sealed in tin capsules. The
material was sent to the Stable Isotope Mass Spectrometry Laboratory at
Kansas State University in 2016 and to the Stable Isotope Core
Laboratory at Washington State University in 2017 for analysis following
the methods of Nippert et al. (2013) and Révész et al.(2012), respectively. Briefly, the samples were run through an elemental
analyzer using glutamic acid and acetanilide as standards, respectively,
to determine N and C content.