A World on a Branch Perched on a branch, I get to work investigating the rich, green world around me. My passion is epiphytes—plants that grow on other plants. A surprising variety of epiphytes can grow on a single tree branch here. I find mosses, lichens, ferns, orchids, and bromeliads. Bromeliads are plants with stiff leaves shaped like a pineapple top. Even woody shrubs grow on the branches of cloud forest trees. Trees provide epiphytes with a place where


they can reach sunlight. Epiphytes make their own food and take in nutrients from the air. T eir leaves and roots absorb moisture and minerals from rainwater and clouds. T ey find everything they need in the canopy. Over time, the roots and stems of the


epiphytes grow together to form a mat on the branch. T e bodies of epiphytes break down when they die. T is forms a type of soil called humus. Like peat moss in a garden, the spongy humus can hold a huge amount of water and nutrients. T e soil in the mat provides even more nutrients to the growing epiphytes. You might think that the epiphytes’ thick


mats would hurt the trees. But just the opposite is true. I discovered that tiny roots grow from the mat-covered tree branches. T e rootlets grow into the epiphyte mat. T e rootlets take in water and nutrients that help the tree grow.


Miniature Forests T e epiphytes and humus around them form a tiny treetop ecosystem. It’s like a miniature forest with soil, plants, animals, and even their predators. When I peek in between the leaves and


humus, I see an enormous variety of creatures that creep and crawl. I find earthworms, snails, slugs, millipedes, beetles, and ants—lots of ants. As many as 4,000 kinds of ants live only in the Costa Rican canopy. One is named aſt er me! Other animals crawl, fly, and slither in the


canopy, looking for food. I see centipedes and spiders as well as birds, lizards, snakes, and tree-dwelling mammals.


20 NATIONAL GEOGRAPHIC EXPLORER


Teeming With Life Many kinds of birds hunt for food among the epiphytes. T e hummingbirds are some of my favorites. T ey hover over bromeliads, sipping nectar from the flowers. Other birds eat fruit or insects off the epiphytes’ leaves. Oſt en I see shimmering pools of water in


“tank epiphytes.” T e thick leaves of some bromeliads and ferns overlap tightly. T ey form tanks that hold rain and dew. T ese tiny pools house small insects and amphibians. Some kinds of tree frogs lay their eggs in them. When the eggs hatch, the tadpoles stay in the pool until they become adult frogs. Predators that gobble up fat tadpoles can’t reach these pools. T e more I explore the canopy, the more


connections I find among the organisms living there. T e cloud forest is a wonderful, interconnected web of life.


This colorful stinkbug is one of many insects that live in the cloud forest canopy.


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