The word bucolic comes from the ancient Greek word boukolikos (βουκολικός), meaning "rustic" or "pertaining to herdsmen".  It combines boûs (βοῦς) meaning "ox" or "cow" (which also gives us words like bovine) and -kolos (-κολος) meaning "tending" or "keeper", and together they form boukólos (βουκόλος) meaning a "cowherd" or "oxherd".  The Greek term passed into Latin as būcolicus, keeping its association with herdsmen and pastoral themes.    

According to the Oxford English Dictionary (OED), the word bucolic first entered the English language in the 16th century.  It originally appeared in English literature in the 1520s in its longer form, bucolical. The shorter, modern variant bucolic became established slightly later, with its earliest recorded use dating back to circa 1609 or 1610. When it first appeared in English, the term specifically referred to pastoral poetry or things relating to shepherds and herdsmen before broadening to mean "rural or rustic" in the 19th century.  

In storytelling, a bucolic setting—defined by idyllic, rural, and pastoral landscapes—serves as a powerful narrative tool that goes far beyond simple background decoration.  Writers and filmmakers use bucolic elements to manipulate pacing, contrast character growth, and ground abstract themes in tangible visuals,  

Here is why bucolic settings are so important in storytelling: 

The Archetype of the "Safe Haven":  Bucolic settings often represent the ultimate emotional anchor or the "Status Quo" at the beginning of a hero's journey. It establishes a sense of peace, innocence, and safety before the conflict begins.  
The Shire in The Lord of the Rings: J.R.R. Tolkien uses the rolling green hills of Hobbitsville to represent everything worth fighting for. It gives both the characters and the audience a clear picture of what will be lost if evil wins.  
District 12 (The Seam/Meadow) in The Hunger Games: Though impoverished, the natural world outside the fence represents freedom and survival, contrasting sharply with the artificial, suffocating Capitol.  
 

A Catalyst for Psychological Contrast:  Placing a character in a serene, rustic environment can heighten internal or external turmoil. This technique uses environmental juxtaposition to make a story's darker elements hit harder.
Disrupting Peace: Introducing violence or a threat into a peaceful pasture creates immediate shock value (e.g., the opening farmhouse scene in Inglourious Basterds).  
Isolation and Claustrophobia: A beautiful, open countryside can ironically feel incredibly isolating if a character is trapped there against their will, turning a paradise into a prison.  

Structural Pacing and "Breathing Room":  Stories cannot sustain high-octane action indefinitely. Pastoral settings act as a narrative exhale, offering characters and audiences a chance to process trauma, build relationships, and regroup.  
The Farmhouse in Avengers: Age of Ultron: After facing devastating defeats, the heroes retreat to Hawkeye’s hidden, rustic family farm. This bucolic interlude allows for quiet dialogue, character development, and a reset before the final act.  

Symbolic and Thematic Weight:  Bucolic landscapes frequently mirror a character's internal state or ground the story's core themes.

Just the facts:

BUCOLIC Definition & Meaning - Merriam-Webster

BUCOLIC Synonyms: 22 Similar and Opposite Words | Merriam-Webster Thesaurus

BUCOLIC Synonyms: 372 Similar Words & Phrases