d

ecological dictionary

D

Dairy farmer

A producer of milk products.

Decomposers

Living organisms in the ecosystem that break down and consume organic material and the remains of dead organisms.

DDT

Dichloro-diphenyl-trichloroethane. A colorless, odorless chemical (insecticide) used to combat detrimental insects. The compound can be very hazardous to environmental and human health, due to its persistence and potential toxicity. DDT is still in use to combat malaria.

Defoliation

Natural falling of trees’ leaves.

Deforestation

To cut down or destroy a forest.

Degradation

The gradual decomposition or wearing down of a chemical compound or substance.

Deposit

A place that contains natural, non-renewable resources such as minerals.

DNA

A nucleic acid in the form of a long chain of chemical units called nucleotides. Each nucleotide has one of 4 different bases (adenine, thymine, guanine or cytosine) attached to it. The information encoded in genes is determined by the order of the different nucleotides along the chain. DNA usually exists as two complementary chains that bind together and are twisted into a spring-like structure called a double helix.

Drought

A long period of dry weather. The causes and effects of droughts are especially important issues for sub-Saharan Africa. Droughts can be caused by both human and natural factors.

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