If the trees are randomly distributed, then no. But if there is dispersion or aggregation, then yes. So you need to take this into account when placing traps. You can place traps in transects through the landscape. Random placement isn't always best because if a trap is not placed near an invertebrate, you won't catch any!

Pitfall traps should be at least 50 meter to each other to represents independent traps.

Thank you very much for these answers