Botkin Environmental Science Earth as Living Planet 8th txtbk

G-10 Glossary
Inflection point The point where a graphed curve or an
equation representing that curve changes from convex to
concave, or from concave to convex.
Influent stream Type of stream that is everywhere above the
groundwater table and flows in direct response to precipitation.
Water from the channel moves down to the water table,
forming a recharge mound.
Input With respect to basic concepts of systems, refers to material
or energy that enters a system.
Inspirational justification for the conservation of nature An
argument for the conservation of nature on the grounds that
direct experience of nature is an aid to spiritual or mental
well-being.
In-stream use A type of water use that includes navigation,
generation of hydroelectric power, fish and wildlife habitat,
and recreation.
Intangible factor In economics, an intangible factor is one
you can’t touch directly, but you value it.
Integrated energy management Use of a range of energy
options that vary from region to region, including a mix of
technology and sources of energy.
Integrated pest management Control of agricultural pests
using several methods together, including biological and
chemical agents. A goal is to minimize the use of artificial
chemicals; another goal is to prevent or slow the buildup of
resistance by pests to chemical pesticides.
Integrated waste management (IWM) Set of management
alternatives including reuse, source reduction, recycling,
composting, landfill, and incineration.
Interference When, during succession, one species prevents
the entrance of later-successional species into an ecosystem.
For example, some grasses produce such dense mats that
seeds of trees cannot reach the soil to germinate. As long as
these grasses persist, the trees that characterize later stages
of succession cannot enter the ecosystem.
Island arc A curved group of volcanic islands associated with
a deep oceanic trench and subduction zone (convergent
plate boundary).
Isotope Atoms of an element that have the same atomic
number (the number of protons in the nucleus of the atom)
but vary in atomic mass number (the number of protons
plus neutrons in the nucleus of an atom).
Keystone species A species, such as the sea otter, that has a large
effect on its community or ecosystem so that its removal or
addition to the community leads to major changes in the
abundances of many or all other species.
Kinetic energy The energy of motion. For example, the
energy in a moving car that results from the mass of the car
traveling at a particular velocity.
Kwashiorkor Lack of sufficient protein in the diet, which
leads to a failure of neural development in infants and
therefore to learning disabilities.
Lag time The delay in time between the cause and appearance
of an effect in a system.
Land application Method of disposal of hazardous waste
that involves intentional application of waste material to
surface soil. Useful for certain biodegradable industrial
waste, such as oil and petroleum waste, and some organic
chemical waste.
Land ethic A set of ethical principles that affirm the right of
all resources, including plants, animals, and earth materials,
to continued existence and, at least in some locations, to
continued existence in a natural state.
Landscape perspective The concept that effective management
and conservation recognizes that ecosystems, populations,
and species are interconnected across large geographic areas.
Landslide Comprehensive term for earth materials moving
downslope.
Land-use planning A complex process involving development
of a land-use plan to include a statement of land-use
issues, goals, and objectives; a summary of data collection
and analysis; a land-classification map; and a report that
describes and indicates appropriate development in areas
of special environmental concern.
Late-successional species Species that occur only or primarily
in, or are dominant in, late stages in succession.
Law of the minimum (Liebig’s law of the minimum) The
concept that the growth or survival of a population is
directly related to the single life requirement that is in least
supply (rather than due to a combination of factors).
LD-50 A crude approximation of a chemical toxicity defined
as the dose at which 50% of the population dies on
exposure.
Leachate Noxious, mineralized liquid capable of transporting
bacterial pollutants. Produced when water infiltrates through
waste material and becomes contaminated and polluted.
Leaching Water infiltration from the surface, dissolving soil
materials as part of chemical weathering processes and
transporting the dissolved materials laterally or downward.
Lead A heavy metal that is an important constituent of
automobile batteries and other industrial products. Lead is
a toxic metal capable of causing environmental disruption
and health problems to people and other living organisms.
Liebig’s law of the minimum See Law of the minimum.
Life expectancy The estimated average number of years (or
other time period used as a measure) that an individual of
a specific age can expect to live.
Limiting factor The single requirement for growth available in
the least supply in comparison to the need of an organism.
Originally applied to crops but now often applied to any
species.
Linear process With respect to systems, refers to the addition
or subtraction of anything to a compartment in a system
where the amount will always be the same, no matter how
much you have added before and what else has changed
about the system and the environment. For example, if you
collect stones from a particular site and place them in a
basket and place one stone per hour, you will have placed
6 stones in 6 hours and 24 in 24 hours, and the change is
linear with time.
Lithosphere The outer layer of Earth, approximately 100 km
thick, of which the plates that contain the ocean basins and
the continents are composed.
Little Ice Age (LIA) A period of approximately 300 years
from the mid 1400 to 1700 where the Earth was a bit