Trying to identify the title and author of a Science Fiction story about a human boy and girl who are on an alien world. Notable is the teleportation device that only allows non-living material or plant material sent to & from Earth, until the girl, with a telepathic sentient tree determine the problem and successfully shield themselves and make the transport. The aliens have a number of psionic/esp/mental talents and the overall theme of the book was the conflict between human culture, dependent on machines, and the alien culture which was interactive with Nature.
This does sound like Xenocide, by Orson Scott Card.
The girl is probably Jane, a
computer sentient being come to life in the philotic (faster than light) connections between the ansibles.
She is able to transport inanimate objects, more or less by memorizing every detail of all the particles (using any computers across the galaxy in the network of ansibles for storage) and then simply "recreating" the object elsewhere. However, she can't transport living things because there are too many details to recall—not enough storage space in binary memory for the amount of detail and complexity in living beings.
When she discovers the philotic connection with the Piggies' father trees, she is able to contact them and use their organic memory space for storage, thus allowing her orders of magnitude more detail and the ability to transfer living beings.
(Honestly, it doesn't sound so weird in the flow of the story.)
There are a lot of characters, so I'm not sure which boy you're referring to, but it's probably Milo.