Answer: According to john Muir, the only one who can save trees is Uncle Sam and also God himself he is the creator of all these beautiful species of trees. The "Uncle Sam" here refers to the common person, and by referring to him as Uncle Sam, John Muir is expecting the common person to have enough wisdom and sense to protect something that sustains us (wisdom and sense being things one would commonly associate with an uncle figure).
Step-by-step explanation: