JE003: A Sappy Ending

Synopsis
Ash and co. walk through a leafless forest and wonders what could've happened. They then notice a Heracross on the only living tree and meet a man named Woodruff. He then explains that the forest is out of whack because of a Pinsir. What could cause a Pinsir to hoard all the sap for itself?

Trivia

 * The air date between the Japanese and English versions of this episode were exactly one year apart.