The total genetic diversity and its distribution within and among a set of populations. It is shaped by many factors, including life history, population size, geographical or environmental barriers, gene flow, selection and population crashes or bottlenecks.

A decrease in the gene pool of the population due to an event that drastically reduces the size of that population, such as an environmental disaster, the hunting of a species to the point of extinction, or habitat destruction that results in the deaths of organisms. Due to the event, many alleles, or gene variants, that were present in the original population are lost and the remaining population has a very low level of genetic diversity.

A group composed of a collection of organisms in which the most recent common ancestor of all the included organisms is not included, usually because the common ancestor lacks the characteristics of the group. Polyphyletic taxa are considered unnatural, and usually are reclassified once they are discovered to be polyphyletic.

The simultaneous cultivation or growth of two or more compatible agricultural products (intercropping, some crops and livestock, agroforestry, agriculture and aquaculture).

Refers the organisation of small-, medium-, and large-scale democratic units that each may exercise considerable independence to make and enforce rules within a circumscribed scope of authority for a specified geographical area. Some units may be general-purpose governments whereas others may be highly specialized.

An organizational structure where multiple independent actors mutually order their relationships with one another under a general system of rules.

Pollution is the introduction of contaminants into the natural environment that cause adverse change.

The commonly accepted practice that those who produce pollution should bear the costs of managing it to prevent damage to human health or the environment. A polluter pays principle aims at preventing anybody from reaping the benefits at the expense of (or even considerable harm to) other members of the society.

The degree to which either seed or fruit production, or both, of a plant becomes reduced in the total absence of animal pollinators.

Decrease in abundance or diversity, or both, of pollinators.