Macrophyte, Microphyte & Epiphyte Flora of Costa Rica

Microphytes

Microphytes or microalgae are microscopic algae, typically found in freshwater and marine systems. They are unicellular species which exist individually, or in chains or groups. Depending on the species, their sizes can range from a few micrometers (µm) to a few hundreds of micrometers. Unlike higher plants, microalgae do not have roots, stems and leaves. Microalgae, capable of performing photosynthesis, are important for life on earth; they produce approximately half of the atmospheric oxygen and use simultaneously the greenhouse gas carbon dioxide to grow photoautotrophically.

The biodiversity of microalgae is enormous and they represent an almost untapped resource. It has been estimated that about 200,000-800,000 species exist of which about 50,000 species are described. Over 15,000 novel compounds originating from algal biomass have been chemically determined. Most of these microalgae species produce unique products like carotenoids, antioxidants, fatty acids, enzymes, polymers, peptides, toxins and sterols.

Epiphytes

An epiphyte is a plant that grows non-parasitically upon another plant (such as a tree), and derives its moisture and nutrients from the air, rain, and sometimes from debris accumulating around it instead of the structure it is fastened to. An epiphytic organism that is not a plant is not called an epiphyte; such an organism may be called an epibiont. Epiphytes are usually found in the temperate zone (e.g., many mosses, liverworts, lichens, and algae) or in the tropics (e.g., many ferns, cacti, orchids, and bromeliads). Many houseplants are epiphyte species due to their minimal water and soil requirements. Epiphytes provide a rich and diverse habitat for other organisms including animals, fungi, bacteria, and myxomycetes.

The term epiphytic derives from the Greek epi- (meaning 'upon') and phyton (meaning 'plant'). Epiphytic plants are sometimes called "air plants" because they do not root in soil. However, there are many aquatic species of algae, including seaweeds, that are epiphytes on other aquatic plants (seaweeds or aquatic angiosperms).

Costa Rica Species

Costa Rica is home to a vast array of plants and trees, every species highly adapted to the ecosystems within which they reside. Vivid displays of color surround you in the forests, where the lush green trees and foliage are accented by brightly colored flowers.

The most common class of flowering plants are the heliconia, a large flower of red, orange or yellow. Orchids are common as well, as are many types of ferns. From the lichens and moss below your feet to the ceiba trees that stand more than 20 stories tall, the flora of Costa Rica's rainforests envelop its visitors and overwhelm them with color and vibrance.

Epiphytes, otherwise known as "air plants", are categorized by their rooting behavior - they root themselves onto other plants. Surprisingly, they are not parasitic, or they do not actively harm their host. Water is collected from the run-off of other plants and trees, or is absorbed from the moisture in the air. To fulfill their nutrient requirement, epiphytes photosynthesize their own food and thrive off of decaying plant matter. Throughout all of Costa Rica's forests, epiphytes can be seen clinging to their hosts, covering trees and other ground cover. Orchids, mosses, ferns, lichens, and bromeliads are just a few of the families of epiphytes.

Mosses and Lichens

Among the most diminutive epiphytes are the lichens and mosses that grab onto tree bark and other foliage. These epiphytes are generally found in regions that experience moderate to high precipitation throughout the year. By blanketing the host, these epiphytes can inadvertently inhibit the sun's UV rays from triggering the host's photosynthetic machinery, essentially starving the host. As a result, targets of epiphite colonization have developed methods of getting rid of these nuisances. Some trees shed their bark, thus casting off all unwelcome guests. Many plants have specialized leaves that will route standing water off of the leaf, ultimately denying mosses the moist substrate they require to colonize. These are referred to as "drip tip" leaves.

Orchids

The most exquisite epiphytes are also revered by many as the most beautiful flowers in existence. The orchid features elaborate petal arrangements of stunning vibrancy. While they are present on every continent except Antarctica, the most spectacular species exist in the tropics. They range in size from a half of an inch to twenty-five feet.

Ferns

Ferns are an ultra-diverse class of flowerless epiphyte. Of the approximately 825 varieties of ferns that reside in the forests of Costa Rica, one of the most remarkable is the appropriately-named resurrection fern. During periods of low precipitation this fern withers, turns brown, and shuts down its photosynthetic processes. When a base-level of moisture returns to the soil, the plant is resurrected and maintains its normal functioning. Another interesting fern to look out for is the tree fern, an upright variety with formidable-looking thorny bristles.

Bromeliads

If the flora of the world were commended for their adaptability, bromeliads would surely win the award for creativity. These epiphytes have evolved tightly wrapped leaves that act as small reservoirs, collecting water, leaf detritus, and insects. From the resulting stew, bromeliads ingest the nutrients necessary for life. less ↑