This question most commonly comes up in connection with the Netflix documentary series *Our Planet*, narrated by David Attenborough. The series covers seven distinct ecosystem types across its eight episodes, and the one major ecosystem category notably absent is mountains (also called alpine or montane environments). There is no episode dedicated to mountain ecosystems, despite their enormous biodiversity and the unique pressures climate change places on high-altitude habitats.
What Our Planet Covered
Released in April 2019, *Our Planet* devoted each episode to a different environment. The eight episodes and their focal ecosystems are:
- “One Planet” — a broad introduction to Earth’s interconnected systems
- “Frozen Worlds” — Arctic and Antarctic ice environments
- “Jungles” — tropical rainforests, with a focus on South America
- “Coastal Seas” — shallow ocean habitats and coral reefs
- “From Deserts to Grasslands” — arid landscapes and savannas, including Africa
- “The High Seas” — open ocean and deep-sea environments
- “Fresh Water” — rivers, lakes, and wetlands
- “Forests” — temperate and boreal woodlands
The series was praised for weaving humanity’s environmental impact into every episode rather than treating conservation as a separate topic. But even across eight hours of footage, some ecosystems didn’t make the cut.
Why Mountains Stand Out as the Gap
Mountain ecosystems cover roughly 25% of the Earth’s land surface and support an outsized share of the planet’s species diversity. Alpine meadows, cloud forests, and high-altitude plateaus each host plants and animals found nowhere else. Snow leopards, mountain gorillas, Andean condors, and thousands of specialized plant species all depend on these habitats.
Mountains also serve as critical water sources for billions of people downstream, and they are acutely sensitive to rising temperatures. Glacial retreat, shifting tree lines, and species being pushed toward ever-higher elevations are among the most visible signs of climate change on land. Given that the series specifically set out to highlight human impact on ecosystems, the omission of mountains is the most frequently noted gap.
Other Ecosystems Left Out
Mountains aren’t the only environment *Our Planet* skipped. Several other ecosystem types received little or no dedicated coverage:
- Urban environments — Cities are increasingly recognized as ecosystems in their own right, with wildlife adapting to human infrastructure in surprising ways.
- Caves and subterranean systems — Underground habitats harbor highly specialized species that have evolved in complete darkness over millions of years.
- Tundra — While “Frozen Worlds” touched on polar regions, the vast treeless tundra biome and its permafrost-dependent ecology didn’t get a standalone treatment.
Any documentary series has to make choices about scope, and *Our Planet* chose breadth over exhaustive coverage. Still, for quizzes and classroom questions about the series, mountains is the answer that comes up most often as the ecosystem the team did not explore.
Context From Ocean Science
The pattern of leaving certain ecosystems underexplored isn’t unique to documentary filmmaking. The decade-long Census of Marine Life, one of the largest biodiversity surveys ever attempted, acknowledged major gaps in its own coverage. Deep-sea areas, ocean trenches, hydrothermal vents, methane seeps, and ice-bound waters were all flagged as poorly sampled. Coral reefs in the Indian Ocean and intertidal zones across South America and Canada also remained understudied. The census concluded that most undiscovered marine species are likely concentrated in the tropics, the deep sea, and the waters of the Southern Hemisphere, precisely the places that are hardest and most expensive to reach.
Similarly, the ongoing Ocean Census project has identified the Arctic deep ocean as one of the least explored regions on Earth. Much of the Arctic seafloor sits below 1,000 meters and remains largely unmapped, with chemosynthetic ecosystems around hydrothermal vents and cold seeps only recently being documented for the first time. Exploration gaps almost always come down to the same constraints: remote geography, extreme conditions, and limited funding.