Plants thrive all over the planet, despite the fact that many animals love to snack on them. Various hypotheses account for all those plants. One is that predators kill enough plant-eating animals to give vegetation a chance. Another is that plants develop physical and chemical means to defend themselves.
Now researchers have teased out some of these factors in an East African savannah.
And as a result, the thorn-free, vulnerable acacia are more plentiful in woody areas with plenty of predators. But the thorny acacia are more numerous on the open savannah, where they need to defend themselves. The study is in the journal Science. [Adam T. Ford et al,Large carnivores make savanna tree communities less thorny]
The researchers say their findings show that both plant defenses and carnivorous predators help plants thrive. They also say that when humans influence – in part by eliminating large predators – we disrupt longstanding, complex systems. And that we should really try to better understand such systems, and our effects on them.