Planet Scout Glossary

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ABDOMEN:

The rear body segment of an arthropod such as a wasp.

ARROYO:

A normally dry streambed, usually found in a desert, which occasionally carries heavy, brief, stream flow, which drains toward the basin center.

BAJADA:

A large number of contguous alluvial fans, which eventually coalesce with one another.

BIODIVERSITY:

A large number of different living beings in one location.

BOLSON:

A basin center or sink, found in an arroyo, which collects runoff from brief desert storms; the last place where water evaporates from, leaving behind minerals carried in suspension.

BOSQUE:

A Spanish word that means "forest" in general; in this context it specifically refers to a stand of mesquite trees in the Sonoran Desert.

CAM-IDILING:

Under conditions of extreme stress, the stomates of a succulent will remain closed day and night, and within the plant, a low level of gas exchange will continue, with some recycling of oxygen and carbon dioxide occurring.

CAMOUFLAGE:

Concealment by disguise or protective coloring.

CANOPY:

The top layer of a forest, made up of the branches and leaves of the tallest trees.

CARAPACE:

The top shell of a turtle or crustacean.

CARNIVORE:

An animal (or plant such as the venus fly trap!) that eats meat.

CHAPARRAL:

Desert grassland.

CHUBASCO:

A late summer or early fall storm occurring in North American deserts which is occasionally severe.

COHORT:

A group of similarly aged cacti of about the same size growing near each other in a desert.

CRASSULACEAN ACID METABOLISM (CAM):

Plants open stomates at night when it is cooler and then store received Carbon Dioxide (CO2) as an organic acid. During the day the stomates remain closed while photosynthesis occurs within the plant using the stored CO2.

DESERT (characteristics of North American Deserts):

-low and often irregular patterns of precipitation
-prolonged high temperatures
-extreme temperature fluctuations
-low humidity
-high percentage of possible sunlight received (90%)
-soil high in minerals and low in humus
-extreme erosion of the ground surface by wind and water.

DESERTIFICATION (also called XERIFICATION):

The process of becoming a desert; especially if caused by human misuse of an ecosystem. The effects are as follows:
1. reduction of surface streamflow
2. declining watertable
3. salinization of topsoil and water
4. severe soil erosion
5. desolation of native vegetation
According to studies reported by A. M. Rea in At the Desertıs Green Edge, roughly 10% of the U.S. landmass is currently in a state of severe desertification. Another 20% is threatened by desertification.

DESSICATION:

Dryness resulting from the removal of water

DIAPAUSE:

A holding or resting state marked by a temporary stoppage of growth, reduced metabolism, and often an enhanced resistance to such climatic conditions as drought, heat or cold; a timing mechanism used by some arthropods to cope with desert extremes.

DORSAL:

The back side of an animal, the opposite of the ventral side.

DROUGHT-ESCAPERS:

Plants which never meet the desert head-on, except as seeds; oasis-perennials or annuals which appear only during rainy seasons; not true xerophytes.

DUST DEVILS:

Rotating air currents occasionally as much as several hundred feet in height and carrying dust, sand, and debris; an uprising whirling column.

ECHOLOCATION:

A method used by bats to locate prey while flying at night; the bat emits ultrasonic sounds from the voice box and listens for the echoes that bounce off objects in the environment. A bat can determine size, shape, direction of travel, and texture of prey with echolocation. It can even detect something as narrow as a human hair.

EPHEMERALS:

Annual plants which spend most of their lives in seed form, waiting for water. When rain comes, they may appear within 3 days after germination, and blossom and seed within a very few weeks; often produce showy arrays.

EPIPHYTE:

A plant, such as a tropical orchid or a staghorn fern, that grows on another plant such as a tree, upon which it depends for mechanical support but not for nutrients. Also called aerophyte or air plant.

ESTIVATION:

Summer dormancy, similar to hibernation ­ often adopted by small mammals in response to such factors as cold, heat, drought, or food shortage.

EVAPOTRANSPIRATION:

Total loss of water from the soil both by evaporation from the soil surface and by transpiration from the plants growing in that soil.

EXOSKELETON:

A hard outer structure, such as the shell of an insect or crustacean, that provides protection or support for an organism.

EXOTIC RIVERS:

Moving bodies of water which pass through a desert carrying water that is largely derived from sources outside the desert.

EXTINCT:

No longer existing or living anywhere on the planet. Dinosaurs are extinct.

EXTIRPATION:

Local extinction, no longer living in a certain place, but still found elsewhere.

FOOD CHAIN:

A succession of organisms in an ecological community that constitutes a continuation of food energy from one organism to another as each consumes a lower member and in turn is preyed upon by a higher member. (the coyote eats the mouse, the mouse eats the grain...)

FOOD WEB:

A complex of interrelated food chains in an ecological community.

GLOCHIDS:

Very tiny hairs that some cacti (such as the Beavertail Cactus) have in place of spines. Avoid getting these on your skin, as they can be very irritating and difficult to remove.

GULAR FLUTTER:

The rapid fluttering of the skin on the ventral surface of the throat; a more efficient mode of evaporative cooling used by some small birds.

HALOPHYTE:

A plant capable of growing in salty soil; often found growing in playas, where buildup of minerals may be extreme, prohibiting other plants from growing there.

HERBIVORES:

Plant eaters.

HOMEOTHERM:

An animal (such as a human) with a relatively uniform body temperature maintained nearly independent of the environmental temperature.

HYDROPHYTE:

A plant requiring an abundance of water, which grow in water or in soil too waterlogged for most other plants.

INTERDEPENDENCE:

Mutually dependent, the idea that organisms need each other to survive in a stable ecosystem.

MARSUPIAL:

Any of various nonplacental mammals of the order Marsupialia, including kangaroos, opossums, bandicoots, and wombats, found principally in Australia and the Americas, the females carry their babies in a ventral pouch.

MESOPHYTE:

A plant growing under medium conditions of moisture.

METAMORPHOSIS:

A change in the form and often habits of an animal during normal development after the embryonic stage. Metamorphosis includes, in insects, the transformation of a maggot into an adult fly and a caterpillar into a butterfly and, in amphibians, the changing of a tadpole into a frog.

MICROHABITAT:

Small pieces of a habitat, where climatic conditions vary enough to affect animals and plants that live there; an area under a cottonwood tree vs. an unshaded patch of sand nearby.

MIGRATION:

To change location periodically, especially by moving seasonally from one region to another, as when geese migrate from north to south (in the northern hemisphere) during the winter.

MIRAGE:

The promise of water where none exists; a visual illusion.

NOCTURNAL:

To be active during the night, and resting during the day.

OPERCULUM:

A lid or flap covering an aperture, such as the gill cover in some fishes or the horny shell cover in snails or other mollusks.

PARASITE:

An organism that grows, feeds, and is sheltered on or in a different organism while contributing nothing to the survival of its host.

PARENCHYMA:

The water storage tissue of a cactus.

PLAYA:

A dry lake characterized by a buildup of minerals which remain after water has evaporated.

PHOTOPHORE:

A light-producing organ found especially in marine fishes that emits light from specialized structures or derives light from symbiotic luminescent bacteria.

POIKILOTHERM:

An animal (reptile) which displays a variable body temperature usually just slightly higher than the temperature of their environment.

PREDATOR:

An organism that lives by preying on other organisms.

PREHENSILE:

Adapted for seizing, grasping, or holding, especially by wrapping around an object: a monkey's prehensile tail.

PROBOSCIS:

1. A long flexible snout or trunk, as of an elephant.
2. The slender, tubular feeding and sucking organ of certain invertebrates, such as insects, worms, and mollusks.

RELATIVE HUMIDITY:

The amount of water vapor contained in the air at any one time compared to the amount it is capable of containing.

SCAVENGER:

An animal, such as a bird or insect, that feeds on dead or decaying matter.

SITTING SPOT:

A ventral region of thin skin on an amphibian through which the animal is actually able to absorb water from the ground.

SUCCULENT

A plant which stores a considerable amount of water in its leaves or body, characterized by a waxy cuticle and plump leaves or stems (all cacti, plus agaves and euphorbias), generally very slow growth rate.

SYMBIOSIS:

A close, prolonged association between two or more different organisms of different species that may, but does not necessarily, benefit each member.

TINAJA:

Deep holes worn in rock in a streambed, especially at the base of a sudden drop in the wash.

TURGID:

A word used to describe the leaves of a plant which is getting enough water in its system; swollen or distended; the opposite of shriveled and limp.

URTICATING HAIRS:

Defensive hairs of a tarantula with backward-pointing barbs that are irritating and hard to remove from the skin because of the barbs; a tarantula will brush these hairs into the face of an attacker.

UNDERSTORY:

An underlying layer of vegetation, especially the plants that grow beneath a forest's canopy.

VENTRAL:

The front side of an animal; the opposite of dorsal. Your belly button is on the ventral side of your body. The tag in your shirt is on the dorsal side.

VERNAL:

Of, relating to, or occurring in the spring.

VIRGA:

Rain that evaporates before reaching the earth.

XEROPHYTE

A plant adapted for life and growth with a limited water supply.