It could be that whatever the cause, maybe a mix of a drought and maybe the leaf gobblers only effected that area, with the other areas not touched by the drought, or leave gobblers if one wants to add in multiple reasons.
Doesn't it seem odd that they are ready to sing the praises of Cera in that episode, even before her dad made her out to be something great, yet no they've never sang the praises of the amazing longneck boy? The one who acts and gets things done while we grown ups just stand around and argue?