GLOSSARY OF ECOLOGY TERMS
I to M

Our glossary contains most of the scientific terms you'll encounter while using this site:

A-D | E-H | I-M | N-S | T-Z

I | J | K | L | M

I

Indicator species, n: Species that serve as early warnings that a community or an ecosystem is being degraded. Fish and amphibians make particularly excellent indicator species. Large predators (those generally at the apex of the food pyramid) are also good indicators in many habitats.

Integrated pest management (IPM), n: Combined use of biological, chemical, and cultivation methods in proper sequence and timing to keep the size of a pest population below the size that causes economically unacceptable loss of a crop or livestock animal.

Interspecific competition, n: Members of two or more species trying to use the same limited resources in an ecosystem.

Intraspecific competition, n: Two or individual organisms of a single species trying to use the same limited resources in an ecosystem.

K

Keystone species, n: Species that play roles affecting many other organisms in an ecosystem.

Kwashiorkor, n: Type of malnutrition that occurs in infants and very young children when they are weaned from mother's milk to a starchy diet low in protein.

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L

Land-use planning, n: Process for deciding the best present and future use of each parcel of land in an area.

Late successional plant species, n: Mostly trees that can tolerate shade and that form a relatively stable complex forest community.

Laterite: n. Product of rock decomposition with high iron and aluminum hydroxide content. Generally bright red to deep orange in color. 2. Land, usually in the tropics, baked by the sun after deforestation removes the protective and restorative forest layer above the soil. Abiotic hardpack ground, red in color. Normal soil microbiotic community, as well as macrobiotic flora and fauna, are absent. Prone to extensive erosion due to lack of plant cover. Lateritized hillsides have contributed to several devastating and deadly landslides in tropical countries.

Laterization, n: The process of turning formerly healthy soils into laterite. What becomes of tropical forest lands when deforested and left exposed to the elements. The ground becomes extremely hard and cannot be penetrated by germinating forest seeds, so recolonization is slow or absent.

Lichen, n: A symbiotic relationship between a fungus and a moss. The moss does most of the work, producing sugars for the lichen's collective metabolic pathways. Lichen are generally low-growing, vary in color from bright orange or yellow to gray or black, and are often found growing on rocks and tree bark. An easy mnemonic to assist recall of the nature of a lichen's symbiosis is: "A fungus took a likin' to a moss, and now they live together."

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M

Marasmus, n: Nutritional-deficiency disease caused by a diet that does not have enough calories and protein to maintain good health.

Mass extinction, n: A catastrophic, widespread -- often global -- event in which major groups of species are wiped out over a relatively short period when compared to normal ( background ) extinction rates. There have been five major mass extinctions, of natural causes (in at least one case due to an asteroid impacting the earth), in the earth's history. We are now entering a sixth great mass extinction, this time of unnatural causes... human activities.

Median lethal dose (LD50), n: Amount of a toxic material per unit body weight of test animals that kills half the test population in a certain time.

Monocropping, v: The act of planting and maintaining a monoculture .

Monoculture, n: Cultivation of a single crop, usually on a large area of land. This unnatural agricultural system generally requires the use of large quantities of artificial fertilizers, herbicides, pesticides, nematocides, and other pest control efforts. Even with these chemical aids, monocultures are prone to disease outbreaks and pest infestations, largely due to the genetic homogeneity of such systems.

Mutualism, n: One category of symbiosis in which both participating species generally benefit.

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