landscape conservation

An ecosystem conservation strategy that specifically identifies a suite of species, chosen because they use all the vital areas within an ecosystem; meeting the needs of these species will keep the ecosystem fully functional, thus meeting the needs of all species that live there. (Chapter 13)

LD₅₀ (lethal dose 50%)

The dose of a substance that would kill 50% of the test population. (Chapter 3)

leachate

Water that carries dissolved substances (often contaminated) that can percolate through soil. (Chapter 7)

LEED (Leadership in Energy and Environmental Design)

A certification program that awards a rating (standard, silver, gold, or platinum) to a building that includes environmentally sound design features. (Chapter 25)

less developed country

A country that has a lower standard of living than a developed country and has a weak economy; may have high poverty. (Chapter 4)

life expectancy

The number of years an individual is expected to live. (Chapter 4)

life-history strategies

Biological characteristics of a species (for example, life span, fecundity, maturity rate) that influence how quickly a population can potentially increase in number. (Chapter 9)

limiting factor

The critical resource whose supply determines the population size of a given species in a given ecosystem. (Chapter 8)

logical fallacies

Arguments that attempt to sway the reader without using reasonable evidence. (Chapter 3)

logistic growth

The kind of growth in which population size increases rapidly at first but then slows down as the population becomes larger; produces an S curve when plotted over time. (Chapter 9)

low-level radioactive waste (LLRW)

Material that has a low level of radiation for its volume. (Chapter 22)