Dictionary of LA Flashcards
1
Q
A1 horizon
A
A soil layer that is a subhorizon of the A horizon, distinguishable by its darker color from the rest of the A horizon due to a higher content of organic matter.
2
Q
A2 horizon
A
A soil layer that is a subhorizon of the A horizon, distinguishable by its lighter color from the rest of the A horizon due to a lack of organic matter because of leaching or eluviation.
3
Q
A3 horizon
A
A soil layer that is a subhorizon of the A horizon, similar to the A2 horizon, but also transitional to the B horizon, with visually distinguishable changes from either.
4
Q
AAA
A
Abbreviation for the American Arbitration Association.
5
Q
AAN
A
Abbreviation for the American Association of Nurserymen (now known as the ANLA).
6
Q
AAN Standards
A
The American Standard for
Nursery Stock, as published by the American
Association of Nurserymen (AAN).
7
Q
AARS
A
Abbreviation for All-American Rose
Selections.
8
Q
AAS
A
Abbreviation for All-American Selection.
abacus A slab or division that forms the uppermost portion of the capital of a column, usually
wider than the column.
9
Q
abandonment
A
A word often used in contract
law to describe the failure of both parties to
abide by the terms of a contract.
10
Q
abate
A
Removal of material, usually in making a
design or producing a product from wood, metal,
stone, etc. In metal work, this may be descriptive
of the beating or pounding of a design into the
material.
11
Q
abat-vent
A
Angled members with some space
between them in an opening of an exterior wall
or fence used for access to light while blocking
wind and screening views. See also louver
12
Q
abaxial
A
In botanical terms, the side away from
the axis.
13
Q
ABC
A
- Abbreviation for aggregate base
course. - A reference to a type of soil profile.
- Abbreviation for Associated
Builders and Contractors
14
Q
ABC soil
A
A mature soil profile that contains
the three major soil horizons.
15
Q
aberrant
A
A descriptive term given to individual
plants or species different in some way from the
group they are associated with.
16
Q
abiotic
A
Not living
17
Q
abortive
A
In botanical terms, an imperfectly
developed portion of a plant
18
Q
Abram’s law
A
The strength of concrete is
directly influenced by the ratio of water to
cement.
19
Q
abrasion
A
The act of wearing away by friction.
20
Q
abrasive
A
A substance harder than the material
it is used against in rubbing or grinding to create friction and wear away the softer material. Examples of useful abrasives are diamonds, carbide
steel, metal shot, and sand (as with sandpaper).
21
Q
abrasive surface
A
A surface that is roughened for safety, such as the front tread of a stair.
22
Q
abrevoir
A
A space, gap, or joint between stones that is filled with cement or mortar.
23
Q
abscisic acid
A
A growth-inhibiting plant hormone, which also promotes leaf fall (abscission), the formation of potato tubers, and the change to dormancy in leaf buds.
24
Q
abscission
A
The natural separation of fruit, leaves, or flowers from a plant at a special area of tissue.
25
abscission layer
The layer of tissue in a plant
that facilitates the dropping of fruit, flowers, and
leaves that cease to function.
26
absolute pressure
In pumping references, the
| total pressure above absolute zero.
27
absorbed moisture
Water that has been
absorbed into the pore spaces of a solid such as
soil or wood.
28
absorber
1. That portion of a solar collector
that collects and absorbs radiant heat energy.
2. A material that collects and holds pollutants
such as oil from water runoff, usually within a
catch basin or an oil separator.
3. A device used
to arrest the shock of water hammer.
29
absorbing well or dry well or waste well
A well collecting surface waters, providing for the
water to be dispensed and absorbed into the
ground.
30
absorption
1. A process by which a gas and/or
liquid enters into a solid material. This occurs
through pores in a porous solid material. This
process is usually accompanied by a chemical
and/or physical change of the solid material.
2. The process by which radiant energy is converted to other forms of energy.
3. The increase
in weight of a solid material due to the process
described in (1.)
4. The increased weight of a
tile or brick when immersed into boiling water
or cold water for a determined period of time.
This weight change is usually expressed as a percentage of the weight of the dry weight.
5. A
process where one substance adheres to the surface of another
31
absorption bed
An excavation that is filled
with coarse aggregate and has a piping system for
distribution of septic tank effluent.
32
ABS plastic or ABS pipe
A plastic of acrylonitrile butadiene styrene often used to make pipe that is resistant to impact, heat, chemicals, and freeze-thaw. It is softer than PVC plastic and
usually black.
33
abut
1. To make contiguous or to make a contact point.
2. In real estate, two properties with
a common property line.
34
abutment
The part of a structure such as a
bridge or an arch that bears the weight of the
span and is usually made of masonry or concrete.
35
abuttals
Those boundaries of one piece of land
| that are in common with adjacent pieces of land.
36
abutting joint
A joint between two pieces of
wood, where the direction of the grain in one
piece of wood is at an angle (usually 90°) to the
grain in the other.
37
AC, ac, a-c, a.c.
1. Abbreviation for acre(s).
| 2. Abbreviation for alternating current
38
ACA
Abbreviation for ammoniacal copper
| arsenate. A thorn-like or spike-like protrusion.
39
acaulescent
In botanical terms, a plant or leaf
that is without a stem, or appears to be without a
stem.
40
ACC
Abbreviation for acid copper chromate.
41
accelerated erosion
The movement of
earthen particles in water runoff increased by
human activities influencing the land. Activities causing increased erosion include removal of
vegetation, loosening of soil, concentrating
areas of runoff, or interruption of natural
drainage patterns.
42
accelerator
A material or substance added to
concrete, grout, or mortar to increase its rate of
hardening, and/or decrease its setting time.
43
access
A way of vehicular, pedestrian, or other
| approach, entry, or exit.
44
access door
A door that provides access to
equipment for maintenance, inspection, or
repair.
45
access panel or access plate
A removable
panel or plate (usually secured with screws or
bolts) in a frame that is usually mounted in a
ceiling or wall and provides access to concealed
items or equipment. It permits inspection of an
otherwise inaccessible area. Wires and/or pipes
for irrigation systems or pumps are sometimes
concealed behind these panels in buildings.
They are also sometimes designed into park
restrooms and pavilions for infrequent access to
areas in ceilings or behind walls.
46
accessibility standards
Parameters and recommendations regarding accessibility of handicapped persons to walks, structures, etc. See
Americans with Disabilities Act and Uniform
Federal Accessibility Standards.
47
accessible
1. Easily accessed.
2. Reachable by
removal of a cover, panel, plate, or similar
obstruction.
3. Easily accessed by those disabled
in wheelchairs or walkers.
48
accessible means of egress
A path of travel,
usable by a person who has impaired mobility,
that leads to a public way.
49
accessory building
A building with a secondary use to that of the main building located
on the same plot. Refer to local jurisdictional
agencies for their definition.
50
accessory structure
A subordinate structure
detached from, but located near, a principal
building. Accessory structures usually include
garages, decks, fences, sheds, etc.
51
acclivity
A slope above; an upward slope.
52
accouplement
Placement of posts, columns,
| or pillars in sets of two (paired).
53
accrescent
A botanical term, something that
| increases in size with age.
54
ACD
Abbreviation for an automatic closing
| device.
55
ACE
Abbreviation for Agricultural Conservation Easement.
56
acerose
In botanical terms, a plant part shaped
| like a needle or having a needle-like tip.
57
acetone
A highly volatile solvent often used in
| lacquers, paint removers, thinners, etc.
58
acetylene
A colorless gas, that when mixed
with oxygen, burns at a temperature of about
3500°C; used in welding.
59
acetylene torch
A metal-cutting and welding
| instrument that operates on compressed acetylene (a colorless hydrocarbon) and oxygen.
60
achene
In botanical terms, a small, dry, onecelled, one-seeded, indehiscent fruit. In technical terms, it does not include those fruits with
specialized features such as a samara, caryopsis,
nut, or utricle.
61
achlamydeous
A flower without a perianth
| outside envelope, calyx, corolla
62
achromatic color
White light; a color that
| does not elicit hue
63
ACI
Abbreviation for American Concrete
| Institute.
64
acicular
In botanical terms, needle-shaped.
65
acid
1. In reference to soil, this indicates a pH
below 7.0 (neutral). 2. A chemical substance
capable of releasing excess protons (hydrogen
ions).
66
acid copper chromate (ACC)
A waterborne salt preservative for wood. Wood must be
pressure treated for this preservative to be effective. It is highly recommended by experts as it is
odorless, clean, does not leach, and its color can
be masked easily when dry by painting or applying a solid color stain. This stain is not only good
for preserving wood above grade, but can also be
used for preservation of wood to be placed
underground.
67
acid etched
A reference to a metallic surface,
glass, or concrete that has been treated in an
acid bath to provide a rough surface or to
remove a portion of its surface
68
acidic
1. Soil or water with a pH less than 7.0.Some only consider acidic to be 6.6 or less.
2. Igneous rocks containing more than 65%
silica.
69
acidity
The measure of a substance’s pH below
| neutral (7.0).
70
acid rain
Any rain that contains sulfur dioxide.
71
acid soil
Soil having an acid reaction. It is usually in reference to a soil having a pH value of
less than 6.6, but is technically applicable to any
value lower than 7.0, which is neutral. These
soils are common in areas of high rainfall. The
most common cure for highly acidic soils is the
addition of lime.
72
acisculis
An old term for a small mason’s pick,
| with a flat face and pointed peen.
73
ACM
Abbreviation for asbestos-containing
material. Any material with over 1% asbestos
content.
74
AC pipe
Asbestos-cement pipe that was commonly used for buried pipelines. It combines
strength with light weight and is immune to rust
and corrosion. It is no longer made because of
the health hazards associated with asbestos.
75
acquiescence
1. An act of concurrence by
adjoining property owners that resolves a
boundary dispute or establishes a common
boundary, where the definite or more accurate
position of same has not or cannot be defined by
survey. 2. The tacit consent of one owner, by
not making a formal objection, to what might
be an encroachment by an adjoining property
owner over a questionable boundary.
76
acre
English or U.S. measurement of area equal
to 4840 sq yd; 43,560 sq ft; 0.405 hectare;
4046.85 sq m.
77
acre-foot
1. A reference to a quantity of water
required to cover one acre to a depth of one foot.
acetylene
2. A quantity of any material equal to the
amount required to cover an acre one foot deep.
78
acrid
Sharply bitter, unpleasantly pungent, or
| harsh in smell or taste.
79
acropodium
1. A raised pedestal bearing a
statue.
2. The lowest member of a pedestal of a
statue.
80
acrylonitrile butadiene styrene (ABS)
A
plastic formulated into piping that is used primarily in landscape work for drainage systems,
storm sewers, irrigation systems, and underground electrical conduits. It is softer and much
more bendable than PVC.
81
ACS
Abbreviation for actual.
82
AC soil
An immature, incomplete soil profile
with only the A and C horizons present, and no
B horizon. These young soils commonly develop
from alluvium or on slopes.
83
actinomycetes
A group of soil microorganisms intermediate between fungi and bacteria.
They may be filamentous much like fungi, and
yet produce spores similar to bacteria. They are
microscopic in size and are usually the source of
the fresh, uniquely pleasant odor of newly tilled
soil. They are active in decomposition, especially of cellulose.
84
activated sludge
1. A recycled, dried product
of municipal sewage treatment plants. It has
higher concentrations of nutrients than composted sludge with a rating of approximately
6-3-0.5 for primary nutrients. It is usually sold in
a dry, granular form as a general-purpose fertilizer that does not burn, and is slow to release its
nutrients. The long-term effects of using sewage
sludge are still under investigation. Heavy metals such as cadmium may be present in the soil
where sewage sludge has been used, and they
may build up over time. There are possible negative effects depending on the content and origin of the sludge used. 2. Sewage within aerated
wastewater treatment basins and its associated
complex variety of living microorganisms. After
settling, a portion of this microbial sludge is
recycled to influent of the treatment system.
Microbes there continue to grow. The remaining
activated sludge is removed from the treatment
system and disposed of another way
85
active earth pressure
The horizontal pressure of retained earth in a horizontal direction.
86
active layer
The surface layer in climates
where permafrost exists. It is characterized by
freezing and thawing.
87
active open space
Land designated or reserved
for recreational facilities such as swimming pools,
ball fields, court games, picnic tables, exercise
courses, playgrounds, ice skating, etc.
88
active pressure
The force exerted by retained
| earth.
89
active recreation
Athletic activities, or those
activities of leisure requiring physical effort and
often requiring equipment. This type of activity
usually takes place at prescribed places, sites, or
fields. It includes such activities as swimming,
tennis, other court games, baseball, other field
sports, golf, playground activities, jogging, rowing, etc. See also passive recreation.
90
active sludge
A sludge that is rich in destructive bacteria; useful in breaking down fresh
sewage.
91
active solar energy system
A system that
collects solar energy and distributes that energy
by mechanical devices such as fans or pumps
that obtain their energy from a conventional
source (not from solar energy).
92
Act of God
An unexpected event not controllable by human influence.
93
actual
This word is often used in specifying
weight amounts of a specific nutrient in a fertilizer to be applied. This can be determined by
taking the percentage of the specific nutrient in
the fertilizer mix and multiplying it by the
weight of the fertilizer being used.
94
actual start of construction
The first placement of a permanent construction fixture on site.
95
aculeate
In botanical terms, prickly or beset
| with prickles.
96
acuminate
In botanical terms, sharply tapering
to a slender point. (Compare with retuse, cuspidate, aristate, emarginate, acute, mucronate,
obtuse.)
97
acute
In botanical terms, pointed, or ending in a
point less than a right angle. (Compare with
retuse, cuspidate, aristate, acuminate, emarginate,
mucronate, obtuse.)
98
acute angle
Any angle measuring less than 90°.
99
acute arch or lancet arch
A sharply pointed
arch whose centers are farther apart than the
width of the arch.
100
AD, ad
1. Abbreviation for air dried. 2. Abbreviation for access door. 3. Abbreviation for
area drain. 4. Abbreviation for as drawn. 5. A
designation of the surface grades of two sides of a
piece of lumber, especially plywood. 6. A Latin
prefix used in botanical terms meaning to or
toward.
101
ADA
Abbreviation for Americans with Disabilities Act.
102
adapt
To make suitable for a particular purpose,
| requirement, or condition, by means of modifications or changes.
103
adapter
1. A fitting or part that facilitates different types (copper, PVC, polyethylene, galvanized) or sizes of pipe to be connected together.
2. A device manufactured for the purpose of
connecting tubing or equipment (especially
electric) that is of different size, connection
type, or design.
104
adaptive use
The extensive alteration, restoration, and/or renovation of an existing structure
or building so that it will serve a new purpose.
105
ADD, add
1. Abbreviation for addendum.
| 2. Abbreviation for addition.
106
addendum
A change or revision to drawings,
specifications, or other information on a project
out for bid, which has an effect on bids. It occurs
before receipt of bids, and is usually stated in letter form that ethically should be delivered to all
bidders (in fairness) with the drawings or papers
indicating the change so as to allow understanding in comparison of bids. These changes become a part of construction documents for
contract purposes.
107
addition
1. Construction that increases the
height or floor area of an existing building or
adds such items as a porch or attached garage.
2. The increase to an existing contract amount.
The professional procedure for accommodating
such a change is a change order.
108
additive
A substance added to another substance to improve its characteristics such as
those used in paints, plasters, mortars, etc. See
also admixture.
109
additive alternate
An option on a bid for
more services or materials not in the base bid,
showing increased costs, if any, associated with
the option.
110
ADF
Abbreviation with reference to shipping
| lumber meaning after deducting freight.
111
ADH, adh
Abbreviation for adhesive.
112
adhesion
The physical attraction of unlike substances to one another. This is the force that
holds water molecules in soil-to-water interfaces
so that all water does not drain from soil after
saturation. This water is held in mesopores and
micropores, but there is not enough adhesion
force to hold water in the larger macropores.
113
adhesive
A substance that bonds to materials
| placed together, holding them in place.
114
Adj., adj
Abbreviation for adjustable.
115
adjoining grade elevation
The average elevation of the finish grade adjoining all exterior
walls of a building or structure calculated from
grade elevations taken at intervals (usually 10 ft
or 3 m) around the perimeter of the building.
116
adjustable hanger
An apparatus for holding
pipes or equipment hung from structures, which
has the ability to change the elevation of the
pipe or device held without detachment of the
apparatus from the structure.
117
adjustable wrench
A wrench with an adjustable portion of its jaw movable by a knurled
screw to facilitate grasping objects of varying sizes
(e.g., pipe wrench, crescent wrench).
118
adjusted sodium adsorption ratio
An
index of permeability problems with regard to
water quality
119
admixture
A material or chemical added to a
concrete mix to accelerate cure, retard curing,
repel water, or change its normal properties.
120
adobe
1. Clay used in making adobe brick.
| 2. Any unfired brick.
121
adobe brick
Clay and straw molded into
bricks, sun-dried and used in constructing structures. Adobe brick walls can be coated with lime
to improve weather resistance.
122
adpressed
In botanical terms, pressed against
| another part.
123
ADR
Abbreviation for alternative dispute resolution.
124
adsorption
Liquids, gases, or suspended matter
adhering to the surfaces of, or in the pores of, an
adsorbent material (without a chemical reaction
or bonding).
125
ADT
Abbreviation for average daily traffic.
126
advanced irrigation control system
A
smart controller that controls irrigation by monitoring the weather and/or the soil moisture. They
adjust station run time(s) and/or the frequency
when there are changes detected in the soil moisture and/or the weather. Some will monitor wind,
rain, and/or temperature. Another feature of
some of these controllers is that they can monitor
flow in pipes to determine if there is a break in the
line. The features of these controllers are not all
the same, but they include some method of automatically adjusting their schedules through the
seasons of the year in an attempt to keep the optimum amount of moisture in the soil. These controllers are quite helpful in preventing waste of
irrigation water, but their accuracy and usefulness
is only as good as their monitoring devices and
monitoring locations.
127
advanced wastewater treatment (AWT)
Treatment of wastewater more than the secondary treatment level.
128
advance ratio
o In furrow irrigation, a ratio of
the time for the water to reach the end of the
field to the total set time for irrigation.
129
advance time
1. The time required for a
selected stream of irrigation water to move from
the upper end of a field to the lower end. 2. The
time required for a selected surface irrigation
stream to move from one point in the field to
another.
130
adventitious
In botanical terms, developing in
| an unusual or irregular position, usually in reference to roots.
131
adventitious roots
Roots growing from the
stems of plants, usually sporadically. They may
be a natural component of the plant, such as
with Hedera helix (English ivy), which attaches
itself to walls, plants, cliffs, etc. with these small
rootlets. They are also sometimes developed in response to flooding. Flooding may cause these
roots to develop on stems when belowground
roots are in anaerobic soils.
132
adventive
A plant type that has been introduced to an area, but not naturalized, or a plant
that is only locally established.
133
adverse impact
negative environmental
| impact
134
advertisement for bids
A request made for
bids for public entities. There is usually a legal
requirement that this must be a public solicitation with notices easily available to the public (usually in newspapers) in the area of jurisdiction.
135
A/E
Abbreviation for architect-engineer
136
aerate
Mixing air into soil, water, or other substances as a natural process or designed effort.
137
aerated concrete
cellular concrete
138
aeration
1. Infiltration or mixing of air with a
substance.
2. In landscaping, it usually refers to
a portion of the micropores, mesopores, and
macropores in soil being filled with air. The surface soils (to about 3 ft deep) usually have sufficient aeration for plant growth.
3. In landscape
maintenance, it refers to loosening the soil to
add air by puncturing it with mechanical means.
Some gas-powered aeration machines remove a
small round core of soil. This practice not only
provides air to roots, but also allows for better
percolation of water to roots. This generally
improves plant growth.
4. In water treatment
and cleaning, providing higher oxygen concentrations for chemical and microbial treatment
processes.
139
aeration capacity
The volume fraction of airfilled pores in a particular soil at field capacity.
140
aerial cable
Any cable (especially electric) suspended overhead.
141
aerial photograph or aerophoto
A photograph taken directly above the earth’s surface.
142
aerial photomap
An aerial photograph or
aerial photomosaic map with information such
as place names, boundaries, and so on.
143
aerial photomosaic
A combination of aerial
photographs fit together, showing a portion of
the earth’s surface.
144
aerobic
Indicates the presence of oxygen and/or
organisms living or active in the presence of
oxygen.
145
aerophoto
aerial photograph.
146
aesthetic
1. The visual appearance or look of
an object, view, etc. 2. The theory of beauty or
sense of color.
147
aestival
Appearing or blooming in summer;
| pertaining to summer.
148
A-frame
A structural frame shaped like an
| upright capital letter A.
149
AG
1. Abbreviation for above grade. 2. Abbreviation for against the grain.
150
agaric
In botanical terms, a mushroom or having a form like one.
151
AGC
Abbreviation for Associated General
| Contractors.
152
agency
1. A relationship by which one party,
usually the agent, is empowered to enter into
binding transactions affecting the legal rights of
another party, usually called the principal. For
example, an agent may enter into a contract or
buy or sell property in another’s name or on
another’s behalf. 2. An administrative branch of
government (federal, state, or local).
153
agent
One who is empowered or authorized to
enter into binding legal transactions on behalf of
another, for a principal, or for an entity
154
Agg.
Abbreviation for aggregate.
155
agglomeration
Collecting tiny suspended particles into a mass of larger size.
156
AGGR
Abbreviation for aggregate.
157
aggradation
1. The addition of a material to
the ground surface to produce a uniform grade or
slope. 2. The filling of a stream channel with
sediment. This may occur because of low or slow
flows, and/or heavy sediment loads in the water
158
aggregate
1. In soils, a group of primary soil
particles that cohere to one another more
strongly than to other surrounding soil particles.
2. Any of several hard, inert materials such as
sand, gravel, or slag. 3. Inert materials (2) individually or a mixture of them placed for weightbearing stability of pavements, walls, footings,
etc. 4. A loose mixture of sand and crushed stone
used to mix with cement to create a concrete.
159
aggregate base course
A layer of aggregate
material placed beneath a pavement, structure,
etc., for bearing and stability
160
aggregate fruit
A fruit formed of two or more
| pistils, such as a raspberry
161
aggregate strength
The strength of an object
determined by adding together the breaking
strengths of the individual members of which
the object is made up (i.e., individual strand
members of a wire cable).
162
aggregation
In soils, groups of individual soil
particles, held together naturally and consisting
of particles of sand, silt, and clay separated from
each other by pores, cracks, or planes of weakness.
163
aggressive solids
Soils that may be corrosive
| to cast-iron and ductile-iron pipe.
164
agitating truck
A truck carrying a drum that
mixes hydromulch, concrete, etc., capable of
being mixed while moving.
165
agitation
The process of mixing mulches, seed,
liquids, and/or concrete. In mixing concrete, it
agitation must be agitated sufficient to prevent segregation, aggregation, or loss of plasticity
166
agitator
1. A mechanical device used to mix
various liquids and powders contained in a vessel. 2. A device for mixing and maintaining
plasticity while preventing segregation of the
components of concrete.
167
AGL
Abbreviation for above ground level.
168
agricultural district or agricultural preserves or agricultural security areas or
agricultural preservation districts or
agricultural areas or agricultural incentive areas or agricultural development
areas or agricultural protection areas
A
legally recognized geographic area designed to
preserve agriculture with a boundary formed by
one or more landowners (including government
landowners) and approved by at least one government agency. They are usually created for
fixed, renewable terms. Enrollment is voluntary;
landowners receive a variety of benefits including eligibility for reduced tax assessment, limits
to annexation and eminent domain, as well as
protection against excessive government regulation and private nuisance lawsuits.
169
agricultural protection zoning (APZ)
Any local land-use regulation protecting agricultural operations and/or their closely associated uses (e.g., limiting non-farmland uses,
prohibiting high-density land development,
requiring houses to be built on small lots,
restricting subdivision of land into parcels that
are too small to farm, etc.).
170
Agriculture Conservation Easement
A
legal agreement usually recorded at the county
(U.S.) restricting development on farmland.
Easement is restricted to farming and open space
use. (See also conservation easement.)
171
agronomic
The application of soil and plant
| science to crop production and soil management.
172
A horizon
The upper, darker soil layer (horizon) in a soil profile, comprised of materials that
include organic matter, and characterized by
high biotic activity. This is topsoil, which is the
best soil for sustaining plant growth without the
aid of fertilizers. It is ideal for growing plants
when comprised of approximately 45% mineral
material, 5% organic matter, 25% water, and
25% air. In some soil profiles, this topsoil layer
may be well developed and further divided into
subhorizons of A1, A2, A3, etc., or it may not be
present (deserts, above timberline, etc.). The
only layer that may be present above this layer is
the O horizon
173
AIA
Abbreviation for the American Institute of
| Architects.
174
AICP
Abbreviation for American Institute of
| Certified Planners.
175
air break
In a drainage system, a piping
arrangement in which a drain from an appliance, device, ground surface area, or fixture discharges into the open air and then into another
fixture, receptacle, or interceptor. This is used to
prevent back siphonage or backflow.
176
air compressor
A machine that compresses
air, creating higher pressures than the atmosphere and usually storing it in a tank for use.
This pressure may be used to inflate objects,
blow water out of pipes, operate pneumatic
tools, etc.
177
air-dried lumber
Wood cut to particular
dimensions and air-dried in stacks to remove
moisture. This drying produces a straighter product of true size, better at holding nails, and not
likely to shrink, split, or warp. Lumber is usually
marked as follows: S-GRN for green unseasoned
lumber with a moisture content of 20% or
higher; S-DRY for lumber with a moisture content of 19% or less; MC 15 for lumber that is
dried to 15% or less, etc.
178
air drill
pneumatic drill
179
air-entrained concrete
Concrete mixed with
air-entraining cement or agents to improve its
workability and resistance to frost. It incorporates minute air bubbles into the mix
180
air-entraining agent
Any substance or material added to concrete, mortar, grout, etc. that
produces air bubbles during the mixing process.
These agents make the mixture easier to work
and increase resistance to freezing.
181
air gap
In a drainage system, the vertical space
between the outlet of a drainpipe and the high
water elevation of the container into which it
flows.
182
air lance
A rod-shaped device that shoots compressed air for cleaning surfaces.
183
air layering
In gardening, a propagation
method of forcing a branch to root by making a
slanting cut or removing a ring of bark below a
node, dusting with rooting hormone, wrapping
the cut and node in moss, and enclosing in plastic tied tightly to the branch. Roots appear in
several months, then the branch can be cut free
with its roots and transplanted.
184
air-lift pump
A pump used for raising water
from a well that is comprised of a compressed air
delivery pipe surrounded by a larger pipe that
delivers water from below because of pressure
from the smaller pipe.
185
air purge valve
A device that removes
| trapped air from pressurized pipes
186
air release valve
A valve that releases air from
| a pipe or device under water pressure.
187
air vessel
An enclosed chamber with a volume
of air connected to a water system in which air is
compressed to varying degrees as water pressures
fluctuate. This assures a more uniform flow. It
also deters water hammer by air compression
when water shutoff occurs abruptly
188
AISC
Abbreviation for American Institute of
| Steel Construction.
189
AISI
Abbreviation for American Iron and Steel
| Institute.
190
AITC
Abbreviation for American Institute of
| Timber Construction.
191
AL
Abbreviation for aluminum.
192
alameda
A shaded walkway or promenade.
193
albedo
The reflective power of a material indicated by the percentage of incident radiation
reflected by a material. In landscape work, this is
usually important to consider with regard to
light and heat reflected and/or radiated from
large windows or light-colored surfaces on the
sunny side of walls or fences. It may cause damage to landscape plants (including lawns).
194
alburnum
The wood of a tree between its
| heartwood outer ring and the bark (sapwood).
195
ALCA
Abbreviation for Associated Landscape
| Contractors of America.
196
alder
A hardwood from alder trees having a
light color that darkens a bit toward brown as it
dries, and is comparatively lightweight
197
alfalfa valve
An outlet valve attached to the
top of a pipeline riser with an opening equal in
diameter to the inside diameter of the riser
pipe. Includes an adjustable cover to control
water flow.
198
algae
A group of microscopic autotrophic plants
that are unicellular or multicellular, do not
flower, lack true stems or roots, and grow in
water or humid conditions.
199
algae bloom
In water features, the rapid
| growth of algae instigated by an increase in temperature and the presence of nutrients.
200
algicide
A product used for controlling algae in
| water.
201
alidade
An instrument on a table useful for
determining the directions of distant points. It
was often used in mapmaking before the use of
GIS
202
alien
A reference sometimes made to a plant
that is native in one region but is then planted
in another region by human activity instead of
natural means.
203
alienation
Transfer of title by one person to
| another in real estate.
204
alignment
In highway and other linear ground
designs, this is a drawing plan depicting horizontal direction as distinguished from a profile
drawing that depicts the vertical components.
205
alkaline
1. Composed of a base. 2. Soil or
| water with a pH higher than 7.0 (neutral).
206
alkaline soils
1. Soils having a pH greater
than 7.0 (neutral). These soils are common in
areas of light annual rainfall. 2. Soils having an
exchangeable sodium percentage greater than
15%. 3. Soils having a sufficient exchangeable
sodium (alkali) to interfere with plant growth
and cause dispersion or swelling of clay materials
within the soil.
207
alkalinity
The amount of a substance’s pH
above neutral (7.0). In water, it is a measure of
the capacity of water to neutralize acids. It
accomplishes this through one or more bases in
the water. Those bases can be one or more of
carbonates, bicarbonates, hydroxides, borates,
silicates, or phosphates.
208
alkali soils
Soils with an excess of sodium often
having a pH of over 8.5 and not suitable for the
growth of most plants. The common remedy
used to prepare alkali soils for planting is to
apply gypsum and leach the soil heavily with
water
209
All-American Rose Selections
A nonprofit
association of rose growers and introducers dedicated to introducing new rose types and promoting existing exceptional rose types. Since 1938,
the AARS seal of approval has annually been
awarded to outstanding new rose varieties.
210
All-American Selection (AAS)
) Plants recommended (and awarded) annually by an organization as tested, new, previously unsold
varieties of flowers and vegetables, giving recognition to those considered outstanding. They
have growing facilities in the United States,
Mexico, New Zealand, and Canada. Categories
include field-grown flowers, vegetables, and bedding plants. The first varieties were chosen in
1932. The candidates are grown and tested at
trial gardens located at seed companies, universities, and botanical gardens. There are two
types of medals awarded. The gold medal signifies exceptional merit and is seldom awarded.
The normal award is given to plants with outstanding characteristics. Because these plants
are judged by a panel of experts, credibility is
also awarded to the winners.
211
allée
A wide walk, drive, etc., with trees or tall
shrubs on either side. This is a French term used
for referencing a walk of gravel, sand, or turf,
bordered by palisades, hedges or trees usually
with branches trained to meet and interweave
overhead, shading the surface below (allee couallée of trees
alidade Allen wrench
verte). The French sometimes used them in geometrically designed gardens or parks. (Compare
to avenue.)
212
allelopathy
A condition in which a plant produces antibiotic chemicals that repress its
growth or the growth of other plants.
213
Allen wrench
A hexagonal bent bar used to
tighten and loosen screws or bolts that have a
hexagonal indentation for insertion.
214
all-heart lumber
Lumber that is completely
| heartwood with no sapwood.
215
alliaceous
A plant onion-like in odor or other
| aspects.
216
allochthonous
Substances (usually organic
carbon) produced outside of and flowing into a
wetland from the surrounding environment.
217
allopatric
1. A botanical term to describe
plants occupying different geographical regions.
2. In botanical terms, occupying well-separated
habitats in the same region. (Compare with
sympatric.)
218
allotment garden
A privately or publicly
owned garden divided into sections and assigned
to individuals for their use.
219
allowable depletion or allowable soil
| depletion
1. The portion of plant-available
water that is given for plant use prior to irrigation based on plant and management considerations. 2. The amount of water depleted from the soil between irrigation cycles, including
that which is lost to drainage and percolation.
3. That part of soil moisture stored in the plant
root zone managed for use by plants. This is usually expressed as an equivalent depth of water in
inches per acre, or inches. 4. Allowable soil
depletion or allowable soil water depletion
before wilting point occurs.
220
allowable load
The maximum weight safely
budgeted for a structural member spanning
between two points.
221
allowable stress factor (Kas)
The percentage of evapotranspiration in the landscape that
can still produce an acceptable plant quality. In
some cases, applications as low as 40% of evapotranspiration have allowed a marginal but acceptable plant quality. This is a management
decision, and the effects of these adjustments
must be closely monitored
222
alloy
A combination of two or more metals, or
of a nonmetallic substance with metal, usually
for some improved quality
223
alluvial fan
Sediment deposited by a stream in
a fan shape (when viewed from the air), usually
at the bottom of a slope. This is a common land
feature in dry regions at the base of slopes where
streams slow, allowing their sediment to settle
and deposit
224
alluvium
1. Any material deposited out of
water that has been carried from another place.
2. The soils of floodplains and alluvial fans comprised mostly of detrital material.
225
alpine
1. Growing on slopes above timberline.
2. A term loosely used in reference to rock garden plants. 3. A plant native to alpine or boreal
forest regions. They are often referenced and
used in ornamental plantings.
226
ALS
Abbreviation for American Lumber Standards.
227
ALT, alt.
1. Abbreviation for alternate. 2. Abbreviation for altitude.
228
alternate
In botanical terms, any plant parts
(leaves, buds, branches, etc.) arranged singly at
the stem nodes (not on opposite sides). They
alternate which side of the branch they emerge
from.
229
alternate bid
An optional bid to the base bid
that deducts or adds services or materials and
usually increases or decreases the base bid
accordingly.
230
alternate host
Either of two plants that a fungus or insect finds necessary to sustain its life.
Some insects or diseases must alternate from one
plant type to another in their life cycle. These
diseases and insects can be eliminated if a large
enough area does not have one of the necessary
host plants. For example, the wooly apple aphid,
which depends on both elms and apple trees;
some rust diseases that are dependent on barberry and wheat; or rust diseases dependent on
juniper and white pine.
231
alternating current
Electrical current regularly alternating its direction of flow (at a fixed
rate) in opposite directions. Power companies
use this current to facilitate transmission over
long distances
232
alternative dispute resolution
The resolution of a dispute without litigation.
233
ALTN
Abbreviation for alteration.
234
alum.
Abbreviation for aluminum.
235
aluminum
1. A silver-white, malleable, metallic element with good thermal and electrical
conductivity, resistance to oxidation, and high
reflectivity when polished. 2. A metal pres-ent in
most soils, but more prevalent in acid soils. It
becomes more soluble, more available, and more
likely to cause toxicity to plants as soil acidity
increases. In strongly acidic soils (5.5 pH or
below), this is often a detriment to plant growth
and can be toxic to them.
236
aluminum brass
Brass with some aluminum
| added to increase its corrosion resistance.
237
aluminum bronze
A copper-aluminum alloy
| having good corrosion resistance.
238
aluminum plate
Flat aluminum sheet material.
239
aluminum-silicon bronze
A copper alloy
with aluminum and silicon added to increase
strength and hardness.
240
aluminum sulfate
An inorganic fertilizer that
is acidic and lowers pH. Aluminum can be toxic
to plants if overused.
241
ALY
Abbreviation for alloy.
242
ambient pressure
See working pressure.
243
ambient sound
The noise level in a space that
contains only the noise out of one’s control such
as rushing water, or street traffic, or motors, etc.
It is any combination of sounds from external
sources close by or far away
244
amendment
soil amendment
245
amenity
Aesthetic characteristics or other features of land development that increase its desirability or its marketability. Amenities may
include such things as a unified building design,
recreational facilities, security systems, views,
landscaping, attractive site design, adjacent
open space or water bodies.
246
ament
In botanical terms, an indeterminate
spike-like (spicate) arrangement of flowers on a
stem (inflorescence) having scaly bracts and
unisexual flowers with no petals (apetalous).
247
amentiferous
Descriptive of a plant bearing
| aments.
248
American Arbitration Association
A nonprofit association founded in 1926 to study benefits and techniques of arbitration; offers neutral
arbitrators
249
American Association of Nurserymen
A
trade organization that has now changed its
name to the American Nursery and Landscape
Association
250
American Institute of Architects (AIA)
A professional organization of architects.
251
American National Standards Institute
| ANSI
Previously known as the American
Standards Association. This is an organization
of nearly 400 trade associations, technical societies, professional groups, and consumer organizations that establishes standards for materials
and devices.
252
American Nursery and Landscape Association
A trade organization providing education, research, and public relations for its
members who grow and sell plants or install
landscapes. Their web site is www.anla.org (previously known as AAN, American Association
of Nurserymen).
253
American Society for Testing and Materials (ASTM)
An organization that performs
tests and establishes standard specifications for
materials; their standards are usually referred to
as ASTM.
254
American Society of Consulting Arborists
An organization with members dedicated to the
protection of the environment by promoting
tree and plant life for safety, functionality, and
beauty
255
American Society of Landscape Architects (ASLA)
A national (U.S.) professional organization of landscape architects
promoting the analysis, design, management,
and stewardship of the natural and built environments through education, advocacy, communication, and fellowship. Their web site is
www.asla.org.
256
Americans with Disabilities Act (ADA)
A federal law requiring public facilities to be
accessible for those with physical disabilities.
(See also Uniform Federal Accessibility Standards.)
257
ammeter
An instrument that measures electric
| current in amperes.
258
ammoniacal copper arsenate (ACA)
A
waterborne salt preservative for wood. Wood
must be pressure treated for this preservative to
be effective. It is highly recommended by
experts as it is odorless, clean, does not leach,
and its color can be masked easily when dry by
painting or applying a solid color stain. Besides
being good for preserving wood in weather
aboveground, this stain can be used for wood
placed in water and underground.
259
ammonia nitrogen
A reduced type of nitrogen made as a by-product of organic matter
decomposing and synthesizing.
260
ammoniated superphosphate
A compound chemical fertilizer containing 2 to 4%
nitrogen, and 14 to 49% available phosphoric
acid (phosphorus).
261
ammonification
Bacterial decomposition
| from organic nitrogen to ammonia.
262
ammonium nitrate
A nitrogen fertilizer with
15% nitrogen (15-0-0). Also known as nitrate of
ammonia. It has 32.5 to 34% immediately availammonium nitrate
15
able nitrogen. It must have ventilation or it can
catch fire or explode. It cakes easily in storage.
263
ammonium sulfate
A nitrogen fertilizer with
| 21% nitrogen (21-0-0). See sulfate of ammonia
264
amp.
Abbreviation for ampere.
265
ampacity
A word combining ampere and
capacity that expresses the current-carrying
capacity of electrical conductors in amperes.
266
amperage
Electric current expressed in amperes.
267
ampere, amp
The standard unit for measuring
electrical current that is based on the number of
electrons flowing past a given point per second.
One volt acting across a resistance of one ohm
provides a current flow of one ampere. Many
devices and components of wiring systems are
rated for the amount of amperes they can safely
carry.
268
amphibious
Plants able to live in water or on
| land.
269
amphitheater, amphitheatre
An outdoor
theater, usually semicircular or elliptical, with a
stage or area for performances surrounded by
seats that rise above the area allowing participants a view of the action, speaker, or displays.
270
amplexicaul
A botanical term referring to
some kinds of leaves clasping a stem at their
base.
271
ampliate
e A botanical term meaning enlarged
| or dilated.
272
an-
Greek prefix in botanical terms meaning
| not, from, or without.
273
anaerobic
1. Any environment low in oxygen
or free of it. 2. Living or existing without air.
3. In landscape work, this usually refers to soils
that are waterlogged or need aeration to support
most plants. Root rot is a common problem in
anaerobic soils. See also backfill.
274
analysis
Separation, examination, investigation, and determination of constituent parts,
including detailed aspects of a situation, condition, or phenomenon.
275
anastomosing vein
The veins in a leaf forming a complex network. See also dichotomous
vein, simple vein.
276
anchor
Something that holds a member or element securely in place.
277
anchor bolt
Usually an L-shaped bolt set in
concrete or masonry with its threaded end
exposed and pointing upward for fastening
materials, structures, or equipment.
278
anchoring cement
Grout placed in sleeves to
| anchor pipes or tubing in place within them.
279
anchor roots
The roots of plants that give stability to the plant so that it can stand upright
and withstand wind.
280
androecium
A botanical term referring to all
| of the stamens of a flower, considered collectively.
281
anemometer
A device for measuring wind
speed. These instruments and the information
they produce assist in determining water needs
of plant material. They usually consist of cuplike devices held on arms arranged radially
around a point where they spin in the wind,
allowing recording of speed through a wire.
282
anemophilous
A botanical term describing
| pollination by wind. (Compare with entomophilous, ornithophilous.)
283
angiosperm
The name of the division in the
plant classification system indicating inclusion
of all flowering plants with seeds that develop in
an ovary. They are the most prolific vascular
plants on earth. This division is made up of two
classes: monocotyledons and dicotyledons. See
also taxon.
284
angle dozer
A bulldozer with its blade angled
| to push the earth to one side.
285
angle iron
An L-shaped iron or steel piece.
286
angle of repose
The maximum slope at which
a material can be piled or inclined without sliding or falling. This term is often used in reference to clay materials, piled soil, gravel, or wet
concrete.
287
angle valve
A valve for adjusting, turning on,
or turning off a flow. This type of valve is configured with its water outlet oriented 90° from its
water inlet. It delivers water on a 90° angle from
the direction of water entering it.
288
angular aggregate
Aggregate with more sharp
edges than rounded edges. It is often produced
by crushing.
289
anhydrate
A mineral calcium sulfate useful in
Portland cement manufacturing to allow for
controlling its set time.
290
anion
A negatively charged ion that is attracted
toward the anode during electrolysis. The most
common anions in soils and waters are bicarbonate, sulfate, carbonate, nitrate, and chloride
ions.
291
ANLA
Abbreviation for the American Nursery
| and Landscape Association
292
annexation
The legally binding or recognized
inclusion of land into an existing community,
city, township, etc., that results in a change in its
boundary. Annexation generally refers to the new
inclusion of properties just outside a city, town,
municipality, etc., but it may also involve the
transfer of land from one municipality to another.
293
annual
1. A plant with a life cycle of one year
or less. These plants flower, set seed, and die
within one growing season. A winter annual germinates in the fall and fruits the following spring
or summer. 2. Yearly or over a 12-month period.
294
annual rings
A woody (dicotyledenous) plant’s
annual circular growth marks of the xylem visible when branches or trunks are cut horizontally
(to their longitudinal axis). This is a portion of
wood formed in one year of a woody plant’s
growth. The rings are concentric and become
wider and lighter colored with good moisture and
sun, and darker and thinner otherwise.
295
annular nail
A nail with tapered rings along its
shank, difficult to be removed from a material in
which it is pounded. Also called a ring nail
296
annulus
In plant identification, this means a
little ring, and refers to the specialized, thickwalled cells encircling the sporangium of most
ferns.
297
anod.
Abbreviation for anodized.
298
anodize
A hard, noncorrosive, electrolytic,
| oxide film on the surface of a metal.
299
anodized
A metal that has been submitted to
electrolytic forces in forming a coat of protective
or decorative film.
300
anoxic
The absence of oxygen (both free oxygen and chemically bound oxygen).
301
ANSI
Abbreviation for American National
| Standards Institute.
302
anther
The part of the stamen of a flower that
produces pollen and consists of two pollen sacs
with a connecting layer.
