The Question and Answer section for The Cherry Orchard is a great resource to ask questions, find answers, and discuss the novel.
Yasha says this.
Again, the Cherry Orchard shows the demise of the Russian aristocracy, and the ensuing rise of those in the lower classes (serfs). Social change revolves around the emancipation of these serfs due to reforms put in place by political change.
1) The end of serfdom
2) The arrival of the railroad