What symbol from Nature does the poet invoke to say that there can be life under apparent stillness?

The poet doesn't want us to confuse stillness with total inactivity. The poet says that nature has lessons to teach us. There can be live under Apparent stillness. The poet invokes the earth as a living example of the statement and proves his point. Winter is the season when all appears to be dead and inactive but it is really not so everything gets silent and calm and in spring, which follows winter, everything comes alive again.