At the reciprocal transplant gardens (CF, TL, SG), single transplant tussock per plot were repeatedly measured through the season. This was normally (but not always) the tussock closest to the boardwalk (normally tussock A. This dependent on whether enough leaf area could be inserted into the clip (see later). Measurements from non-transpant (NT) tussock were also taken. These can be found in a line approximately 10-20 m from the transplant gardens, East of the gardens in Coldfoot and Toolik Lake and North of the garden at Sagwon.

An optisciences OS5P chlorophyll fluorometer was used to measure quantum yield of PSII, using the 'Yield' mode.  A custom made handle which combines the metal clip that the fibreoptic cable sits in and a LICOR LI 190 Quantum sensor connected to a LICOR LI 250 light meter was used to take the measurements. The fibreoptic cable head was held in place about 1 cm from the leaves. As much green leaf material as possible (this varied between tussocks and seasons) was put into the clip for the leaf, making sure to:

1. not shade the leaf material from the sun

2. not shade the PAR sensor (which is on the same plane as the leaves).

Scans were taken when Fs was high enough according to the the machine (normally about 90-100).

Directly after the measurement, an infrared thermometer was used to measure leaf surface temperature. The leaves that were taken for fluorescence  were held on the same plane and light conditions as for the fluorescence measurement and a temperature measurement was taken from approximately 5-10 cm away from the leaves.

On some occastions measurements were not taken on some plots due to time constraints on the day or the tussock was being used for the demography study. Sometimes measurements were not taken if not enough leaf material could be gathered to get a high enough fluorescence reading.