Part of my fieldwork with Brosimum alicastrum (see The Curious Case of Brosimum alicastrum and Gas Exchange) involved climbing trees to get a closer look at their flowers. I opted for rope, ascenders, and a sit harness, rather than the metal spikes used to climb telephone poles, because I had to climb the same trees several times during the flowering season and I didn't want to damage them or effect flower production.
Was a wonderful way to get away from the mosquitos, although I did fall asleep (briefly) on my observation platform one time (I was roped in). [NOTE: It wasn't so much that I was worried about snakes in the canopy. I just forgot to take off my leggings before going up the rope when this picture was taken (thx, Lauro)].