Cloud forests are unique ecosystems found in tropical and subtropical mountainous regions around the globe. They are defined by the consistent presence of low-lying cloud cover at the canopy level, creating a misty, humid environment. Also known as “water forests” or “fog forests,” they comprise only about 1% of global woodland. This persistent atmospheric moisture shapes a distinct habitat, fostering a rich array of life specifically adapted to these cool, damp conditions.
Defining Cloud Forest Environments
Cloud forests typically occur at elevations ranging from approximately 850 to 4,000 meters, though most are found between 1,000 and 2,500 meters above sea level. Their defining characteristic is the frequent or persistent low-level cloud cover that envelops the forest canopy.
Clouds form as warm, moist air rises up mountain slopes, cools, and condenses into mist and fog. This constant cloud presence reduces direct sunlight, leading to cooler temperatures (8°C-20°C) and high humidity (often exceeding 90%).
Beyond rainfall, water enters these ecosystems through “fog drip,” where cloud moisture condenses on leaves and branches, dripping to the forest floor. This process can contribute significantly to the total water input, sometimes accounting for more than half of the annual precipitation. Soils are often saturated, acidic, and rich in organic matter due to slow decomposition in cool, moist conditions.
Life Thrives in the Mist
The constant moisture and unique microclimate of cloud forests support an extraordinary diversity of life, much of which is found nowhere else. Plants adapt to humid, low-light, and nutrient-poor conditions.
Epiphytes, plants growing on others without rooting in soil, are abundant and diverse, including orchids, bromeliads, ferns, mosses, and lichens. These “air plants” absorb water and nutrients from the mist and debris, forming thick blankets on tree trunks and branches. Cloud forest trees are often shorter, gnarled, and densely covered in these epiphytes, contributing to the forest’s unique appearance.
This dense vegetation and high humidity create many microhabitats. Many specialized animal species also call cloud forests home, showcasing high endemism. Examples include amphibians, such as frogs relying on constant moisture, and birds like the Resplendent Quetzal.
Why Cloud Forests Matter
Cloud forests provide ecological services extending beyond their misty borders. They act as natural “water factories,” intercepting moisture from clouds and slowly releasing it into rivers and streams. This hydrological function maintains steady water supplies for millions in downstream communities, preventing soil erosion and reducing landslide risk.
They are also biodiversity hotspots, containing a disproportionately high number of plant and animal species, many of them endemic. While not always as species-rich as lowland rainforests, their high endemism makes them irreplaceable reservoirs of genetic diversity.
Cloud forests contribute to global climate regulation by storing carbon in their biomass and soils, as cool, moist conditions slow organic matter decomposition. Despite their importance, cloud forests face threats from climate change, which can shift cloud cover to higher elevations, and human activities like deforestation and logging. Protecting these unique ecosystems is essential for safeguarding their water provisioning, biodiversity, and climate regulation roles.