1. Ecosystems and habitats

Nature Types in Norway classification system

Publisert Sist endret

Ever since the days of the 18th century Swedish botanist Carolus Linnaeus, biologists have had an orderly way to classify organisms into different species, families and kingdoms.  But there is no such universal agreed-upon system for classifying the enormous variation in ecosystems and habitats found in nature.

In 2005, the Norwegian Biodiversity Information Centre initiated a national project to address this need, and develop a classification system for the ecological variation found in Norway. Four years later, “Nature Types in Norway” was released. 

After NiN was published in 2009, NBIC received many comments and inputs. The idea is that NiN should be a dynamic system related to the increase in knowledge and user needs. In cooperation with most of the scientific institutions in Norway with expertise in this field, NBIC has revised the NiN system and presented a revised and upgraded version 2.0. Our Project leader was professor Rune Halvorsen at the Natural History Museum in Oslo.

Background

The challenge: Habitat types that stand out as clearly demarcated fragments of a mosaic landscape are not usually found in nature.

Nature changes from place to place and no two places have completely identical environmental conditions or exactly the same species composition.

Ecosystems or habitat types are therefore not concrete, well-defined entities that can be recognized in the same way as a wood anemone, a golden eagle or a polar bear can.

A habitat type is thus an abstraction, an ideal that sets the standard for what terms like “bilberry woodland”, “dune slack” and “hard-bottom coral garden” are supposed to mean. Consequently, there is no set answer for how the variation in these types should be interpreted.

The solution: “Nature types in Norway” (hereafter NiN) was designed to recognize that most of the variation in nature derives from a more or less gradual variation in species composition in response to gradual variations along ecological gradients.

The NiN type system covers the entire mainland of Norway, the Arctic islands and the marine areas that are under Norwegian sovereignty, and has been designed to meet the needs of as many users as possible and to reflect the patterns of variation in the environment.

The classification system

The heart of the NiN classification system can be described using three dimensions, explained in detail below. These are:

Scale - five nature type levels:

  • region
  • landscapes and seascapes
  • landscape element
  • ecological system
  • microhabitat

Generalisation - three levels of generalisation (or less) of nature types:

  • major type group
  • major type
  • descriptive system (based om the sources of variation)

Description systems - six sources of variation:

  • local ecoclines
  • condition or impact ecoclines
  • regional ecoclines
  • dominance (species or species groups)
  • objects related to site condition and history
  • landform variation

Theoretical underpinnings

NiN was designed with the fundamental understanding that most of the variation in nature is gradual (continuous).

This means that the species composition (which species are found together at a given place) changes gradually in concert with the gradual change in environmental conditions.

Many environmental factors vary together (the pH and the contents of calcium and nitrogen in the soil, for example) to form complex environmental gradients.

This variation results in a gradual change in the species composition along local complex environmental gradients.  

The complex environmental gradients are one of the most important underlying concepts for NiN.

More details on terminology and classification

Nature type levels

A cornerstone of the NiN system is that it consists of five parallel type classifications, one for each of five levels in the hierarchy of biodiversity. This recognizes that one of the most important forms of complexity in nature is diversity on various spatial scales.

These five levels; microhabitat, ecological system, landscape element, landscape and seascape, and region, are collectively referred to as nature type levels.

Major types

Variation within each and every one of the nature type levels, from finer to rougher categories, can be systematized in a hierarchy of levels that represent different grades of similarity or affinity, with broad, general units on higher levels divided into narrower, more specialized, units on lower levels.

NiN uses three levels that are basically identical for the classifications at each nature type level (see figure). The principal unit for each nature type level is called the major type.

A major type should be easy to recognize and must:

  • Have a characteristic appearance, such as a kelp forest seabed or an open avalanche system

  • Be linked by similar species composition, typically where the same life forms dominate the major type, such as trees in the “non-wetland terrestrial forest” major type.

  • Be distinguished as clearly as possible from other major types on the same nature type level.

The classification of a major type in the microhabitat, ecological system and landscape element nature type levels is also subject to a very specific criterion.  The same ecoclines be important throughout the major type, so that habitats belonging to the same major type can be further divided up using the same set of the most important ecoclines.

Major type group

NiN 1.0 has 68 major types on the ecological system level. The major type group hierarchical level provides a practical arrangement of these 68 major types in five rough, easily recognizable groups: marine system, tidal system, freshwater system, wetland system and non-wetland terrestrial system.

The descriptive system

Variation within the major types is described in a completely new way in NiN, by using a descriptive system as the third hierarchical level within the major types on each nature type level.

NiN divides ecological variation into six qualitatively different categories, sources of variation, which can be placed in two fundamentally different primary categories:

  • variation along ecoclines (mostly gradual variations in environmental factors and species composition; 3 categories)
  • other sources of ecological variation (3 categories)

NiN uses local ecoclines to divide the major types into basic types.

A full description of an area using the NiN system therefore consists of specifications of the major type and the basic type as well as a description of other properties within the area with respect to all sources of variation that are relevant on the nature type level and in the major type concerned.

Ecological system – the backbone of NiN typification

The ecological system is the lowest type level in NiN where the entire ecosystem, in other words the living part (the plants, animals, fungi and micro-organisms), the non-living part and the important processes are collectively typified.

This typification covers the entire Norwegian mainland and the maritime areas and Arctic islands under Norwegian sovereignty. The ecological system types express variation on relatively fine spatial scales where variation in species composition on the bottom (in water) and the ground (on land) first and foremost occurs.