Why do cloud forests have more flowers than jungles?

A curious thing about the cloud forest of Valle de Cocora was that it, somehow, looked even more like a jungle than actual jungles. It had a similar tangle of vegetation to the rainforest in Soberanía, but whereas Soberanía was mostly a uniform green and brown, Valle de Cocora had near-constant bursts of colour from its huge array of flowers. This was something I would have expected more from jungle, but it was this forest, hundreds of meters into the chilly sky, that had the most colourful display of life.

It doesn’t quite make sense. The most striking difference in the cloud forest was that it was colder than Soberanía. Insects thrive in hotter climes, and flowers are designed to attract insects, so the insects will spread pollen as the visit the flowers and enable the plants to breed. Ergo, the forest with the warmer climate should have more flowers than the colder forest. But like an error in reality, here was a range of flowers far larger and more diverse in a colder environment than a hot one.

To be clear, what we call a “jungle” is properly called a tropical rainforest, which is, quite simply, a hot and wet forest, situated in the tropics around the equator. But once a tropical forest is more than 1200 meters above sea level, it becomes “cloud forest”. The name comes from the frequent mist that permeates it, rendering it constantly damp. Both jungle and cloud forest, with their abundant water and warmth (relative warmth, in the case of the latter), are home to an enormous diversity of both animals and plants.

Trees in jungles, well-watered and with plentiful sunlight, grow broad and towering, creating dense canopies that plunge the rest of the jungle into shadow. The trees of the cloud forest, on the other hand, have to struggle against the wind and rain of the mountains to grow, resulting in shorter forests without the all-encompassing canopy of jungles. This enables sunlight to reach smaller plants known as epiphytes on the forest floor. It’s these plants that develop the flowers. These are then pollinated by not just a range of insects, which is still significant in the cloud forest, even if it is less than in a jungle, but also the many hummingbirds of the Andes.

To be honest, I should have been able to work this out at the time. I had noticed that Soberanía was dark, and I had seen the hummingbirds in Acaíme. I should have been able to use my logic and put two and two together. After all, there was no mystery or magic to it, just a multicoloured forest of hummingbirds in the clouds.

Sources: Monteverde: Ecology and Conservation of a Tropical Cloud Forest by Nalini M. Nadkarni & Nathaniel T. Wheelwright, 2000