Pastoral literature idealizes life in nature, specifically the life of a shepherd out tending his sheep in the pastor. Pastoral literature typically speaks of love, death, and various social issues. In the sense that A Midsummer Night's Dream primarily deals with the topic of love, we can say that it represents pastoral literature. We can see the reference to the forest, in both the very beginning and the very end of the play, as a happy, ideal state in nature, much like a pastor. We can also see Oberon as symbolizing a shepherd in the fact that he looks after the four Athenian lovers and creates for them an ideal state of love. However, Shakespeare also portrays the forest as a chaotic, even nightmarish place while the city of Athens is the more rational, peaceful state of existence, and in this sense, A Midsummer Night's Dream cannot be referred to as pastoral literature.
In the beginning of the play, Hermia and Lysander run into the woods to escape the harsh social injustices of the city. Hermia is being forced by her father to marry Demetrius upon threat of punishment, either through death or being sent to a convent, in accordance with the ancient law of Athens, referred to as the "ancient privilege of Athens" (I.i.42). Since Duke Theseus is upholding this law, and Duke Theseus represents the court, we can see that escaping into the woods resembles pastoral literature. Escaping into the woods is like escaping into the country and running away from the harsh laws of the court.
However, Shakespeare makes a switch. Suddenly peaceful nature becomes nightmarish when Puck mistakes Lysander for Demetrius, making Lysander fall in love with Helena and out of love with Hermia. The nightmare continues when Oberon attempts to fix Puck's mistake by making Demetrius fall in love with Helena as well, which was Oberon's initial aim. This state is a nightmare for Hermia because suddenly the love of her life now prefers another woman over her. It is a nightmare for Helena because, even though two men now love her when before neither man loved her, she believes they are mocking her and believes her best friend is in on the plot, as we see in her line, "Lo, she is one of this confederacy!" (III.ii.195). The fact that nature has become a nightmare rather than an ideal state shows us that in this manner, the play does not fit in with pastoral literature.
However, the ideal state is recreated in the woods once Puck and Oberon finally unite the lovers as they should be. This ideal state continues when Theseus decrees that both couples should be married. Nevertheless, the couples do not return to the woods but rather return to the city, showing us that ultimately, contrary to pastoral literature, Shakespeare is portraying the city as what can be the ultimate, peaceful, rational state once the unjust laws are overruled.