- Control of plants, diseases, and animal pests by the use of natural
A collective term for the layer formed by the crowns of the taller trees
in a forest.The canopy is the highest layer of the forest--the intertwined
branches of mature trees that shade and protect lower forest layers
and provide a habitat for insects, birds and small mammals.
Dendrology - The identification and systematic classification of trees and shrubs.
Duff - Forest
litter and other organic debris in various stages of decomposition on
top of the mineral soil; typical of coniferous forests in cool climates,
where rate of decomposition is slow and where litter accumulation exceeds
Field layer - The field layer is the first layer of growth on the forest floor--a soft carpet of mosses, ferns, wildflowers, grasses and other low plants. It is a habitat for many insects, mammals, reptiles and amphibians.
- The litter layer is the floor of the forest, where decaying plant
matter and fungi undergo the transformation into soil. Bacteria, insects
and worms in the litter help break down the plant matter.
- A forest that has never been changed by management or harvesting.
is misapplied by many to describe any forest that appears to be old.
Individual trees in this type of forest are usually over 200 years old,
and there are large standing and fallen dead trees throughout the stand.
Sapling - A young tree of small diameter
- The art and science of producing and tending a forest; the theory
and practice of controlling forest establishment, composition, growth,
and quality of forests to achieve the objectives of management.
- The soil layer is the foundation of the forest, supporting and providing
moisture and nutrients to plant and tree roots. It consists of decomposed
plant matter and inorganic material, such as rocks, minerals and clay.
Virgin forest - A mature or overmature forest essentially uninfluenced by human activity.
- Loose material deposited by running water, typically streams. Usually
a mixture of clay, silt, sand, and gravel.
Artesian Spring - A flowing spring, where the water table is higher than the surrounding topography. Also called spring, hotspring, oasis.
Badlands - A region of barren land characterized by roughly eroded ridges, peaks, and mesas with sparse vegetation.
Butte - A tall, steeply-walled, isolated erosion resistant rock with very steep sides, generally higher than wide.
Canyon - A deep gully, caused by extensive persistent erosion relating to that typically of a river.
Desert - Receiving less than 10 inches of precipitation annually.
Dunes - Mounds of loose sand grains shaped up by the wind
Flash Flood - A sudden flood event through a valley, canyon or wash, following a short duration, high intensity rainfall.
Mesa - Broad, flat-topped hill surrounded by cliffs and capped with a resistant rock layer.
Mirage - A phenomenon that creates the optical illusion of water, often with inverted reflections, resulting from the distortion of light by air rising from the ground.
Playa - A very flat, dry lake bed of hard, mud-cracked clay.
Salt Lake or
Sink - A shallow body of salt water, where, in the cycle of water
flowing in and then evaporating, salty minerals are left behind, causing
the lake to become increasingly salty. Also see PAN
Semiarid - Receiving between 10 and 20 inches of precipitation annually
Sediment - Silt washed from the land and into the water. Soil, mineral Contains few decomposing plants; usually comprised of materials such as clay, sand, or silt. Soil, organic Contains large amount of decomposing plants.
Wetland - As defined by the U.S. Army Corps of Engineers: An area inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances does support, a prevalence of vegetation typically adapted for life in saturated soil conditions.
*Indicates definitions adapted from Project WILD or Project WILD Aquatic Education Activity Guide, 1992.