Nature Is Not Nice

"Nature is fucking hardcore".

—The 5 Most Horrifying Bugs in the World, Cracked

You've found yourself alone in the woods. No big deal, nature is a perfectly fine place to spend some time, wandering around. But now you can't see the edge of the forest anymore. And you realize that you can't see the sun, either, so you can't tell which direction to go in to get out. Let's add some scary strange noises. Watch yourself randomly running in some direction, looking for a way out, screaming for help, as the sun goes down and afternoon turns into dusk, which turns into a moonless night. You are so screwed.

The truth is, nature isn't cruel; it just doesn't care about you. The forest is a big scary place in which you can get lost, or killed by wild and ferocious animals. The desert has only about a hundred ways for you to be injured or die. The jungle is even worse. Even a lake or a river is a dangerous place for a person who isn't prepared. This trope comes into play when a work's creator chooses to use that fact, rather than romanticizing it or portraying nature as harmonious or maternal. The focus is on the horror, danger, and ruthlessness of untamed nature.

Subtropes include Thirsty Desert, Swamps Are Evil, and Hungry Jungle. Contrast Ghibli Hills; inversely related to All-Natural Snake Oil.

Examples of Nature Is Not Nice include:

Film

Werner Herzog appears to be of this opinion, as can be seen in several of his films. His ending narration to Grizzly Man perhaps puts it best.

Literature

In The Girl Who Loved Tom Gordon, the only real enemy the protagonist faces is the cruelty of nature. Or it could be an evil forest spirit.
To Build A Fire is a particularly poignant Jack London short story about a man desparately seeking to make the eponymous fire in subzero weather. He doesn't.
Hatchet by Gary Paulsen - Nature is the antagonist here as the protagonist has only the titular hatchet to avoid dying in the Canadian wilderness after an airplane crash.
Into Thin Air, both book and film vs. This is about a guided tour of Mount Everest gone terribly wrong. The book is nonfiction, the film based on it.

Live-Action TV

The Life and Times of Grizzly Adams uses this trope as a primary source for action as Adams and his friends often have to rescue visitors who learn the hard way that the wilderness is a dangerous place to be in if you don't know what you're doing.

Video Games

In some ways, this is the heart of early gameplay in Minecraft. There is no real enemy or driving plot; it's just your struggle to survive in a hostile wilderness where the wild animals happen to be monsters.