Biological diversity or biodiversity:

The variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems. (CBD, Article 2)

The CBD and the international environmental community distinguish three levels of biological diversity: habitat diversity (between and within ecosystems and habitats), species diversity (between species within a specific habitat or ecosystem) and genetic diversity (genetic variation within individual species).

Landscape:

Landscape is defined by the European Landscape Convention as "an area, as perceived by people, whose character is the result of the action and interaction of natural and/or human factors." This definition reflects the idea that landscapes evolve through time and underlines that a landscape forms a whole, and whose natural and cultural components are taken together.

The term "landscape diversity" is not explicitly defined in the convention, but using the Preamble of the European Landscape Convention as guidance, we can determine that for the purposes of that convention landscape diversity encompasses the multitude of landscapes in urban areas and in the countryside, in degraded areas as well as in areas of high quality, in areas recognised as being of outstanding beauty as well as everyday areas.

Habitat:

Habitat is defined by the CBD as the place or type of site where an organism or population naturally occurs.

The EU Habitats Directive defines the term "natural habitat" as terrestrial or aquatic areas distinguished by geographic, abiotic and biotic features, whether entirely natural or semi-natural, and the term "habitat of species" as an environment defined by specific abiotic and biotic factors, in which the species lives at any stage of its biological cycle.

Semi-natural habitats are habitats that have been modified or created by human activities, but still hold species that occur naturally in the area, and in which natural processes are the most significant force in their development.

Degraded habitats are habitats altered by various impacts: pollution, human overuse of resources, invasive species, etc. The substantial loss of habitats and their increasing degradation is today a major issue.

Species:

Endemic species are species native and unique to a defined place or region.

Endangered species are species in danger of extinction throughout all or significant proportion of their range.

Threatened species:
The IUCN Red List categories define threatened species as species facing an extremely high risk of extinction in the wild in the immediate (critically endangered), near (endangered) or medium-term (vulnerable) future.

Invasive alien species (IAS) are non-native species introduced deliberately or unintentionally outside their natural habitats, where they become established, proliferate and spread in ways that cause damage to their receiving environment.

Conservation:

Conservation demands maintenance of the conditions necessary for continued resource existence, and the reference point should be the status quo of the given living resource. This term is also understood as requiring that natural resources be exploited without exceeding the limits that guarantee the renewal and the sustainability of the resources.

The EU Habitats Directive defines conservation as a series of measures required to maintain or restore the natural habitats and the populations of species of wild fauna and flora at a favourable conservation status. In this definition the concept of conservation includes also the concept of restoration.

Sustainable use:

According to the Convention on Biological Diversity, sustainable use means the use of components of biological diversity in a way and at a rate that does not lead to the long-term decline of biological diversity, thereby maintaining its potential to meet the needs and aspirations of present and future generations.

Sustainable use provides incentives for conservation and restoration because of the social, cultural and economic benefits that people derive from that use. Sustainable use cannot be achieved without effective conservation measures.

Restoration:

Restoration is an activity complementary to conservation and sustainable use. It is defined as "the return of an ecosystem or habitat to its original community structure, natural complement of species, and natural functions" (World Resource Institute).

Restoration requires firstly the identification of habitats and ecosystems that have been degraded, followed by the design and implementation of measures to bring those back to a favourable conservation status.

Ecological networks:

Since its first appearance on the nature conservation scene in the early 1980s, the concept of ecological networks has gained increasing awareness. The concept is straight forward:
the fragmentation of habitats can be counteracted by creating buffer zones to protect the surviving natural areas and connecting these core areas via stepping stones and corridors, which allow species to colonise new areas and to move freely in search of food or a mate.

Several ecological networks exist on a regional level such as the Pan-Euroepan Ecological Nework, the Emerald Network, the Natura 2000 Network, the European Green Belt, the Carpathian Network of Protected Areas, and the Alpine Network of Protected Areas.

Protected Area:

A protected area is defined by the Convention on Biological Diversity as a geographically defined area which is designated or regulated and managed to achieve specific conservation objectives.

IUCN defines a protected area as: "an area of land and/or sea especially dedicated to the protection and maintenance of biological diversity, and of natural and associated cultural resources, and managed through legal or other effective means." IUCN categorises protected areas by management objective and has identified six distinct categories of protected areas: strict nature reserve/wilderness area; national park; natural monument; habitat/species management area; protected landscape/seascape; and managed resource protected area.