Hemispherical photos were taken from above and below the shrubs found in the TSQS in the BEF-China experiment. These were used to calculated the amount of light that penetrates through the tree canopy, to the understory shrubs, and then through the understory to the ground. This openness was calculated, using the WinSCANOPY software, which differentiates between sky and canopy (in the photos), and thereafter calculates the percentage of each; where the percentage of sky= openness.

Photographs were taken using a Nikon D100 camera with a fisheye lens (Nikon 10.5mm f/2.8 DX Fisheye, made in Japan). Camera setting was kept at S (automatic aperture), 250 shutter speed and lens set to manual. The camera was held horizontally with the top/flash showing North. All photos were taken above the shrub apex, and the height was measured. For shrubs that were too high, the camera was placed in the shrub centre at the heighest point within reach. Photos of the shrubs were also taken with a smartphone

BEF-China experiment, located near Xingangshang, Dexing City of Jianxi Province - Site B

Indirectly: Plants (Shrubs)- Distylium buxifolium (DiBu) and Viburnum setigerum (ViSe)

The hemispherical photos were grouped by the dates on which they were taken and then further divided into light and dark (subgroup). To analyse the Hemispherical photos, the WinSCANOPY 2009a (Regent Instruments Inc., Canada) software was used. The lens.cal was removed from the software folder (this is the software’s default camera and lens) as different models were used. In the WinSCANOPY program, new colour classes were created for each subgroup of each date folder. During this process, a diverse amount of colours from different photos in the folder were selected and defined as either ‘sky’ or ‘canopy’. The ‘Edit Classes’ tool was selected to ensure the colours were correctly defined and that the ‘Sky’ was selected for the openness calculation. For the first image, after the photo was uploaded, the analysis mode was selected and under ‘Hemisphere’ – ‘Camera and Lens’, the interactive mode was used to manually create a circular radius around the centre of the image, to ensure the top and bottom of the radius touch the top and bottom of the image respectively. For all the following images, the colour class created for the subgroup the image belongs to was loaded prior to analysis, the image was selected from the folder and finally ‘Hemisphere’ was set as ‘Duplicate Last’ to ensure the circular hemisphere for each image is identical (the same size, location and orientation). This was done individually for all images in order to ensure the openness value was realistic. If it was uncertain, the image was changed to black and white mode to better see what was classified as sky and canopy. Finally, the openness value of the output was noted with the corresponding image number (belonging to a particular shrub).