Yes, land creatures will have summoning sickness.
Every one of your creatures that you didn't control all the time since your most recent turn began have summoning sickness, even if they weren't creatures all the time. Since a land's mana ability requires tapping, that ability can't be used in that case.
302.6. A creature’s activated ability with the tap symbol or the untap symbol in its activation cost can’t be activated unless the creature has been under its controller’s control continuously since his or her most recent turn began. A creature can’t attack unless it has been under its controller’s control continuously since his or her most recent turn began. This rule is informally called the “summoning sickness” rule.
Also note the ruling on Gatherer, which explicitely answers your question:
Forests that enter the battlefield while Life and Limb is on the battlefield will enter the battlefield as creatures. They’ll have summoning sickness.