Table 1 Variables that were used to characterize core breeding territory habitat sites (20 m × 20 m) and unused sites of male Chinese Grouse, at Lianhuashan, Gansu, China, 2009–2012

Slope aspect

Slope aspect in °

Slope gradient

Slope gradient in °

Distance to edge

Length between forest and gaps/clearance in m

Distance to water

Length between forest and creek/water hole

Tall deciduous trees

Number of deciduous trees (≥ 5 m) per ha

Small deciduous trees

Number of deciduous trees and bushes (height: ≥ 0.5 m, < 5 m) per ha

Tall coniferous trees

Number of coniferous trees (≥ 5 m) per ha

Small coniferous trees

Number of coniferous trees (height: ≥ 0.5 m, < 5 m) per ha

Tall willow trees

Number of willow trees (≥ 5 m) per ha

Small willow trees

Number of willow trees (height: ≥ 0.5 m, < 5 m) per ha

Willow cover

Area covered by willow trees ≥ 0.5 m, estimated in 10% steps

Rowan trees

Number of rowan trees (≥ 0.5 m) per ha

Canopy cover

Area covered by crowns, estimated in 10% steps

Shrub cover

Area covered by shrub layer (≥ 0.5 m, < 5 m) in 10% steps

Grass cover

Area covered by grass, estimated in 10% steps

Herbaceous cover

Area covered by herbaceous, estimated in 10% steps

Fern cover

Area covered by fern, estimated in 10% steps

Moss cover

Area covered by moss, estimated in 10% steps

Stand structure

Stand structure in four categories

 1 = one layered

 2 = two layered

 3 = three layered

 4 = multi-layered

Stem structure

Stem distribution in four categories

 1 = crowed, defined as canopy closure (≥ 0.8)

 2 = normal, defied as canopy closure (≥ 0.3, < 0.8)

 3 = spare, defined as canopy closure (≥ 0.1, < 0.3)

 4 = grouped, defined as canopy closure (≥ 0, < 0.1)