The death that occurs at the end of the Cherry Orchard -- that of the serf-turned-servant, Fiers -- is far more comic than the death of Konstantin, however, and that is why this death occurs onstage rather than out of sight of the audience. Much of the Cherry Orchard is focused on the inability of many of the characters to see beyond the ends of their own noses and immediate interests; with better foresight and acknowledgement of others, many of the bad things that befall the characters could have been averted. This is definitely a dark form of comedy, but the repeated nature of this trope throughout the play makes it ultimately comedic. The idea that Fiers decides to curl up on a couch in an old house and die, having been forgotten by his family and former masters, is the final punch-line of the play and must be seen onstage.
Other examples of what is seen and what is unseen as elements of both forestalling true tragedy and embracing full comedy can be seen in both plays. The actual chopping down of the cherry orchard in the Cherry Orchard takes place offstage because, like Konstantin's death, this would become the full focus of the audience's experience if it were actually shown rather than merely suggested through offstage action and sounds. Nina's brief and largely inexplicable appearance in the final act of the Seagull actually allows her breakdown and degradation to become more comedic, as it is seen to be more nonsensical than a truly tragic loss -- she is flighty, disconnected, and an ultimately comedic character because the tragedies in her life occur offstage, while her brief triumphs are directly exposed to the audience as empty and meaningless to everyone except her. The fact that Nina isn't in on the joke again makes this very dark yet very humorous comedy.
Gaps in Time
Putting Chekov's plays in a context that includes more literary and dramatic history, there is another striking element in the narrative development and the progression of action in the Seagull and the Cherry Orchard that adds to their comedy and detracts from their level of tragedy. Plays that were part of a similar trend towards realism and a true dissection of interpersonal issues such as the major plays of Ibsen and Strindberg had an immediate quality, taking place over only a few days or sometimes even a single day at the culmination of the tragedy. Chekov's plays include long gaps in time that show the monotony of this tragedy.
Anything loses its edge once it has reached the state of boredom, and the many months that intervene between scenes in the Cherry Orchard and the two-years' gap in the Seagull demonstrate that the same situations have been allowed to persist for so long that they have essentially reached this state of boredom. Though events occur in these periods, of course, and though the audience even learns of some of these events through the dialogue of the play, these events do little other than sustain the status quo of the characters and they remain largely unchanged when the audience views them again directly. This is comic because rather than directly observing these characters going through their ups and downs, the audience only sees that their ups and down don't ultimately matter a great deal. When such meaninglessness is juxtaposed against the level of meaning and the depth of emotion that these characters attach to the same meaningless developments, the result can be nothing other than comedy -- again, very dark and cynical comedy, but comedy nonetheless.
Modern theatre -- most modern disciplines in the arts as well as the sciences, for that matter -- has become obsessed with categorization. Determining whether Chekov's plays should be classified as tragedies or comedies is a perennial debate amongst theatre practitioners and scholars, and the case certainly hasn't been settled here. The above makes it clear, however, that the comedic aspects of the Seagull and the Cherry Orchard are at least as strong as the elements of tragedy traditionally seen in these plays.