In
natural science, subaerial (literally "under the air"), has been used since 1833,
[Subaerial](_blank)
in the Merriam-Webster dictionary. notably in
geology
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ea ...
and
botany
Botany, also called plant science (or plant sciences), plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "bot ...
, to describe features and events occurring or formed on or near the
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surf ...
's land surface.
They are thus exposed to Earth's atmosphere. This may be contrasted with ''
subaqueous'' events or features located below a water surface, ''
submarine'' events or features located below a sea surface, ''
subterranean'' events or features located below ground, or ''
subglacial'' events or features located below
glacial ice such as
ice sheet
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at ...
s.
Geology
For example, a
subaerial eruption of a
volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates ...
is one that ejects material in the open but "under the air" (under the atmosphere). Subaerial
weathering
Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs '' in situ'' (on site, with little or no movemen ...
is weathering by rain, frost, rivers etc.
The term "subaerial" may exclude processes occurring in caves.
The term is often used in
sedimentology
Sedimentology encompasses the study of modern sediments such as sand, silt, and clay, and the processes that result in their formation (erosion and weathering), transport, deposition and diagenesis. Sedimentologists apply their understanding of mo ...
.
Botany
Leaves are subaerial organs of plants.
[Macgregor Skene]
Biology of Flowering Plants
page 2. ed. Discovery Publishing House, New Delhi, reprinted in 2006. .
Some plants may have subaerial roots,
either totally (
epiphytic
An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...
plants such as some
orchids
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant.
Along with the Asteraceae, they are one of the two largest families of flowering ...
) or more commonly only partly so. The
oil palm tree can grow roots into accumulations of decaying leaves on the soil surface; these roots are said to be subaerial.
Epiphyte plants growing above ground that do not feed from their tree support (for example through their
haustorium
In botany and mycology, a haustorium (plural haustoria) is a rootlike structure that grows into or around another structure to absorb water or nutrients. For example, in mistletoe or members of the broomrape family, the structure penetrates th ...
or feeding part having dug into the tree, such as
Mistletoe
Mistletoe is the common name for obligate hemiparasitic plants in the order Santalales. They are attached to their host tree or shrub by a structure called the haustorium, through which they extract water and nutrients from the host plant ...
)
[Macgregor Skene]
''op. cit.''
p. 229. have subaerial roots (for example some
Ficus
''Ficus'' ( or ) is a genus of about 850 species of woody trees, shrubs, vines, epiphytes and hemiepiphytes in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending int ...
species).
[Macgregor Skene]
''op. cit.''
p. 71.
Subaerial stems are the stems that do not rise up but grow just above the ground. As a type of asexual
propagation, these subaerial
stolon
In biology, stolons (from Latin '' stolō'', genitive ''stolōnis'' – "branch"), also known as runners, are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external ...
s, also called ''runners'', often develop roots and leaves from their nodes.
["Subaerial Stem Modifications" on ''tutorvista.com''.]
Some pond plants have subaerial leaves as well as submerged leaves (
water plantain,
flowering rush).
[Macgregor Skene, ''op. cit.'', p. 294.]
See also
*
Specialized root types
*
Velamen – epidermis of subaerial roots in some orchids and other epiphytic plants
References
{{reflist
Geology terminology
Botanical nomenclature