Im afraid it is outside of your comprehensive range. If you had read my message with a little more attention you will have noted that, I discerned against 'no forests' which is a theory that suggests the earth was covered by giant trees, which, through a process not really explained,breaks down and mineralises into rock. I could break it down to an audience no problem. But I'm sure my common sense answers will baffle your tiny pea brain jk I love you dude, let's kiss and make up.
For your humour, giant trees would create giant canopies,which would block out the light and leave the undergrowth barren, what about top soil? The deepest recorded is 20 metres or so, just not deep enough to support the required root mass.... I could literally find arguments for it all day, but wouldn't that take the fun out of you bunch of dummies learning?