Habitat
Zoologists frequently delimit their communities by reference to plants or environmental factors. The most universal classification of habits is that of Elton & Miller (1954):
(i) Terrestrial system Formations:   
Formations:
  • Open-ground type — if any dominant plants, these not more than 15 cm (6 in) high.
  • Field type—dominant life form coincides with field layer, usually not more than 2 m in height.
  • Scrub type—dominant life form does not exceed a shrub layer, height generally not over 7.6 m (25 ft).
  • Woodland type —trees dominant life form.
Vertical layers:
Subsoil and rock.
  • Topsoil.
  • Ground zone, including low-growing vegetation, less than 15 cm (6 in).
  • Low canopy —up to about 7.6 m (25 ft).
  • High canopy.
  • Air above vegetation.
(ii) Aquatic system.
Formation types: these are shown in table below.
 
 
A:
Very small
B
Small
C
Medium
D
Large
E
Very large
1
Still
Tree hole
Small pond 20 m2
Pond 0.5 ha
Large pool 50 ha
Lake or sea
2
Slow
Trickle
Gutter
Ditch
Field dyke
Canal
River bank
Water
 
 
 
 
3 Medium
Trickle
Lowland brook
Lowland river
Lowland large river
River estuary
4
Fast
Spring
Upland weir
Small torrent stream
Large torrent stream
 
 
 
 
5
Vertical
Water drip
Pipe outlet
Small weir
Water-fall
Large weir
Medium water-fall
Large water-fall
 
 
Vertical layer:
  • Bottom, light, dark zones, water mass, light and dark zones - free : water not among vegetation
  • Submerged vegetation.
  • Water surface — upper and under surface of film of floating leaves.
  • Emergent vegetation — reed swamp and similar vegetation, the bases of which are in the water. Air above vegetation.
(iii) Aquatic
Terrestrial transition system - defined further by body type with which it occurs and by vegetational systems corresponding to the terrestrial system.
(iv) Subterranean system
Caves and underground waters.
(v)  Domestic system.
(vi) General system
  • Dying and dead wood.
  • Macro-fungi.
  • Dung.
  • Carrion.
  • Animal artefacts — nests, etc.
  • Human artefacts — fence posts, straw stacks, etc.
Further division of the habitat into communities may be made on the type of plant but in soil and freshwater studies, divisions have been based on the fauna itself; these techniques have been used in few other situations, but their use could undoubtedly be extended.