In Frost's poem, "Mending Wall," does the wall between the neighbors' farms serve a practical purpose?

Robert Frost's poem, "Mending Wall," focuses on the relationship between two neighbors. Every year, the two neighbors meet to repair a wall that exists between their two farms. The speaker of the poem does not seem to see the point of maintaining the wall between his property and that of his neighbor. He states that the wall is not needed where it exists. However, his neighbor sees a value to the wall beyond the practical:

There where it is we do not need the wall:

He is all pine and I am apple orchard.

My apple trees will never get across

And eat the cones under his pines, I tell him.

He only says, "Good fences make good neighbours."

In these lines, the speaker is focusing on the practical use of the wall whereas his neighbor seems to be thinking of what the wall means to them on a more symbolic level. The wall's real purpose is not to keep things in or out, but rather to tie the neighbors together. It not only creates a bond between them, one of shared responsibility for maintaining the wall, but it also gives them a chance to interact yearly, thus helping them maintain their relationship as neighbors, much as they are maintaining the wall.