End trees for Dearth Day - D real reasons... 

De-forestation nation: The one currently ranked #1 in the world, as the culprit, celebrated at other times as providing the materials...

End treaties: Well, that, based on my deductive reasoning, which was in turn influenced by a major Influencer..."This news update from the British Broadcasting Company..." which first discovers, covers, and then...provides their own commentary..."Nothing's out of the question, is within reach..." All those cease fires, controlled burns, treaties, being discussed but where else...

Add a Leaf: Was the conclusion I came to after..."nothing's off the table...heavy discussion around the table...elbows, leaning on...(given the mostly male come-panions here)...lack of manners exposed..." 

Dearth, un-Earthed...The real reason for the season...Arbor days, why we need to supplant so many that have been allegedly been cut down, in order to "table that..." Let alone the chairing section...and whole matter of table tennis, that left a huge...

Hole new reason:  Planting a seed to make you want to go out and supplant, what trees and other greenery you (don't) see...as in "Germin-nation..." In case you get tired of hearing about plain old deforesting...

Breath of fresh air: For all of us, while simply a sigh, of relief, for them, the few trees left standing, in hopes of reinforcements. 

A natural following: Groaning season, as in “Sad Sap”