Sylvan Empathy (General)
The witch is able to commune empathetically with nature.
Liber Mysterium
The Netbook of Witches and WarlocksBy Timothy S. Brannan and The Netbook of Witches and Warlocks Team
Prerequisite: Knowledge; Nature: 4 ranks
Benefit: With a successful Knowledge: Nature check (DC 15), the witch are able to understand basic things about the local ecosystem. This ability does not grant the ability to Speak with Plants, as per the spell, but can tell general things about how the plants are feeling. These things would include fear (possibly of lumbering or an approaching forest fire), happiness (a new ranger is in the area) or anger (humans have been needlessly abusing the forest).
In addition, with this feat you can use your Animal Empathy skill as if it were Diplomacy to get aggressive plants to back down.