Do Ferns Give Off Oxygen?

Ecology and History

• The evolution of ferns marked a turning point in our planet's ecological history. Fossil evidence indicates that ferns and their botanical cousins were the first plants to colonize land in large numbers more than 300 million years ago. Their evolution included the development of true root structures to anchor them to the ground, vascular tissues to transport water and nutrients to plant structures and true leaves. Along with mosses and algae, ferns produced much of the atmospheric oxygen needed to support more complex life forms, including dinosaurs, modern animals and humans. Also, the carbon-based fossil fuels we use today are the ancient remains of plants like ferns.

Photosynthesis

• Ferns are considered autotrophs. Unlike animals and humans, they can produce their own energy using naturally occurring factors in the environment. Photosynthesis involves absorbing carbon dioxide from the air and reacting it with energy from sunlight in the presence of water. This takes places in specialized plant cells, called chloroplasts. This metabolic process creates sugars the plant needs for ongoing growth and oxygen as a waste product. Carbon dioxide and oxygen are exchanged with the atmosphere through specialized pores in leaf structures, called stomata.

Types of Ferns

• Nearly three-quarters of all ferns live in tropical environments. The rest occur in temperate regions across the globe. They range in size from less than 1 inch to massive tree forms that grow almost 75 feet tall. Hardy varieties are usually lower-growing ground covers that spread over time via creeping roots and windborne spores. Epiphytic forms are common in the tropics. These grow nestled in tree branches, high in rainforest canopies.

Requirements

• Although ferns need sunlight to carry out photosynthesis, many prefer growing in partial to full shade, receiving mostly indirect sunlight. Some will tolerate full sun if they have lots of water. Most benefit from growing in fertile, loamy soils with high amounts of organic matter, although some species tolerate swampy soils. In general, soils that retain moisture consistently without becoming too boggy are the most suitable for growing ferns. Many ferns can also be grown as potted house plants. Tropical varieties can be kept indoors during cold periods then moved outside during the warmer months.