Table 3.

Estimated annual prey kill by the global spider community (expressed as fresh weight g year⁻¹) assessed with method II

Biome type	Number of assessments	Prey kill (g m−2 year−1)	Area in m2	Prey kill of entire area (g year−1)
		(X)	(Y)	(X) × (Y)
Tropical forestsa	1	16	17.5 × 1012	280 × 1012
Temperate and boreal forestsb	3	2–10	24.1 × 1012	48–240 × 1012
Unmanaged grasslands and savannasc	7	2–10	13.7 × 1012	27–137 × 1012
Permanent pastures and mown meadows/Mediterranean shrublandsd	2	1–4	31.7 × 1012	32–127 × 1012
Annual croplande	4	0.1–1	13.5 × 1012	1–14 × 1012
Others (urban areas, deserts, arctic tundra, etc.)f	1	0.2	33.3 × 1012	7 × 1012
Global total (without ice-covered area)			133.8 × 1012	395–805 × 1012

^aRobinson and Robinson (1974)

^bKirchner (1964); combined data Reichle and Crossley (1967)/Moulder and Reichle (1972); Schaefer (1990)

^cBristowe (1958); Kajak et al. (1971); Van Hook (1971); Nyffeler and Benz (1978, 1989); Ysnel (1993); Malt (1996)

^dKajak et al. (1971); Nyffeler (1982)

^eLuczak (1975); Nyffeler and Benz (1979); Nyffeler and Benz (1988a,b); Jmhasly and Nentwig (1995)

^fNyffeler (1976)