like the quote marks around the word 'heartbeat' in the title
indicating an analogy, and not a literal heart beat with a literal heart
but to each his/her own
like the quote marks around the word 'heartbeat' in the title
indicating an analogy, and not a literal heart beat with a literal heart
but to each his/her own
you obviously missed the link to the science paper, posted as a comment, noting a periodic change in trees over the basis of 2 to 4 hours, not related to sunlight or circadian rhythms, and not related to respiration.