भागवत - वरं जन्म तरूणाम्

अहो एषां वरं जन्म सर्वप्राण्युपजीवनम् ।
सुजनस्येव येषां वै विमुखा यान्ति नार्थिनः ॥

- भागवत

Oh!! these (trees) have a very noble life by supporting life of many beings (birds and animals). Like a virtuous person, they never disappoint any one who seeks their help.

- Bhagavata

याज्ञवल्क्य - तरुहानि दमः

प्ररोहिशाखिनां शाखास्कन्दसर्वविदारणे |
उपजीव्यद्रुमाणां च विंशतेर्द्विगुणो दमः ||

- याज्ञवल्क्य

One must be punished severely if he cuts the branches and trunk of a tree that was growing well (freely and happily). The punishment must be doubled if the tree was being useful to people.

- Yajnavalkya