Aeroplankton
Encyclopedia
Aeroplankton is the term used to describe the tiny lifeforms which float and drift in the air, carried by the current
of the wind
; it is the atmospheric analogue
to oceanic plankton
.
Most of the living things that make up aeroplankton are very small to microscopic
in size, and many can be difficult to identify because of their tiny size. Scientists can collect them for study in traps and sweep nets from airplanes
, kites or balloons.
The aeroplankton comprises numerous microbes
, including virus
es, about 1000 different species of bacteria
, around 40,000 varieties of fungi
, and hundreds of species of protist
s, algae
, moss
es and liverworts
that live some part of their life cycle as aeroplankton, often as spore
s, pollen
, and wind-scattered seed
s.
A large number of small animals, mainly arthropod
s (such as insect
s and spider
s), are also carried upwards into the atmosphere by air currents and may be found floating several thousand feet up.
Aphid
s, for example, are frequently found at high altitudes.
Many species of spiders deliberately use the wind to propel themselves around an area. The spider will find a vantage point (such as a branch, fence or surface) and, pointing its abdomen
upward, eject fine threads of silk
from the spinnerets. At some point, the friction of the air upon the silk thread(s) is great enough to get the spider lifted into the air and carried off by the breeze. This is called ballooning. Ballooning spiders
(see Linyphiidae
) are capable of drifting many miles away from where they started. The flexibility of their silk draglines can aid the aerodynamics of their flight, causing the spiders to drift an unpredictable and sometimes long distance http://news.bbc.co.uk/1/hi/sci/tech/5174012.stm.
Air current
Air currents may be caused by differences in temperature, pressure, or impurity concentration. Temperature differences can cause air currents because warmer air is less dense than cooler air, causing the warmer air to appear "lighter." Thus, if the warm air is under the cool air, air currents will...
of the wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
; it is the atmospheric analogue
Analogy (biology)
An analogy is a trait or an organ that appears similar in two unrelated organisms. The cladistic term for the same phenomenon is homoplasy, from Greek for same form. Biological anologies are often the result of convergent evolution....
to oceanic plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
.
Most of the living things that make up aeroplankton are very small to microscopic
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
in size, and many can be difficult to identify because of their tiny size. Scientists can collect them for study in traps and sweep nets from airplanes
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...
, kites or balloons.
The aeroplankton comprises numerous microbes
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
, including virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es, about 1000 different species of bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, around 40,000 varieties of fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
, and hundreds of species of protist
Protist
Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy...
s, algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
es and liverworts
Marchantiophyta
The Marchantiophyta are a division of bryophyte plants commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information....
that live some part of their life cycle as aeroplankton, often as spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s, pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
, and wind-scattered seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s.
A large number of small animals, mainly arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s (such as insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s), are also carried upwards into the atmosphere by air currents and may be found floating several thousand feet up.
Aphid
Aphid
Aphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies or whiteflies, are small sap sucking insects, and members of the superfamily Aphidoidea. Aphids are among the most destructive insect pests on cultivated plants in temperate regions...
s, for example, are frequently found at high altitudes.
Many species of spiders deliberately use the wind to propel themselves around an area. The spider will find a vantage point (such as a branch, fence or surface) and, pointing its abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
upward, eject fine threads of silk
Spider silk
Spider silk is a protein fiber spun by spiders. Spiders use their silk to make webs or other structures, which function as nets to catch other animals, or as nests or cocoons for protection for their offspring...
from the spinnerets. At some point, the friction of the air upon the silk thread(s) is great enough to get the spider lifted into the air and carried off by the breeze. This is called ballooning. Ballooning spiders
Ballooning (spider)
Ballooning is a term used for the mechanical kiting that many spiders, especially small species, as well as certain mites and some caterpillars use to disperse through the air. Many small spiders use gossamer or especially fine silk to lift themselves off a surface or use the silk as an anchor in...
(see Linyphiidae
Linyphiidae
Linyphiidae is a family of spiders, including more than 4,300 described species in 578 genera worldwide. This makes Linyphiidae the second largest family of spiders after the Salticidae. New species are still being discovered throughout the world, and the family is poorly known...
) are capable of drifting many miles away from where they started. The flexibility of their silk draglines can aid the aerodynamics of their flight, causing the spiders to drift an unpredictable and sometimes long distance http://news.bbc.co.uk/1/hi/sci/tech/5174012.stm.