Have you guys ever heard of High Altitude Weed? Whatever stress is increased by altitude causes major resin production...
Hardly surprising considering cannabis first evolved in the mountains of Kazakhstan. Resin is the plant's sunscreen against UV light, and there is increased UV at altitude. Therefore plants at altitude would have increased resin production as a natural defense. Lovely garden, thanks for sharing.
source: http://www.sciencedirect.com/science/article/pii/S1011134496000188Since 1981, broad-band measurements have been made at Jungfraujoch, Switzerland (3576 m above sea-level (a.s.l.)) and Innsbruck, Austria (577 m a.s.l.), where daily totals of erythemal effective irradiance, UVA irradiance and total irradiance have been compared. Under clear sky conditions, the observed increases in irradiance with altitude (altitude effect) of the daily totals of global irradiance are 8%±2% per 1000 m (total irradiance), 9%±2% per 1000 m (UVA irradiance) and 18%±2% per 1000 m (erythemal effective irradiance) during the summer.