Net primary productivity (NPP) and energy fixation for the world, circa 1950. (After Table 10.1 in Lieth, 1975; for comparison with later estimates) Energy Energy Energy Energy Ecosystem/ Vegetation unit Area NPP range Mean NPP Total NPP content content fixation fixation (10^12 m^2) (g/m^2/year) (g/m^2/year) (Pg/year) (kcal/g) (kJ/g) (MJ/m^2/year) (EJ/year) Forest 50.0 1290 64.5 1159.9 Forest, tropical rain 17.0 1000-3500 2000 34.0 4.1 17.2 34.3 583.6 Forest, raingreen 7.5 600-3500 1500 11.3 4.2 17.6 26.4 197.8 Forest, summergreen 7.0 400-2500 1000 7.0 4.6 19.3 19.3 134.8 Chaparral 1.5 250-1500 800 1.2 4.9 20.5 16.4 24.6 Forest, warm temperate mixed 5.0 600-2500 1000 5.0 4.7 19.7 19.7 98.4 Forest, Boreal 12.0 200-1500 500 6.0 4.8 20.1 10.0 120.6 Woodland 7.0 200-1000 600 4.2 4.6 19.3 11.6 80.9 Dwarf and open scrub 26.0 90 2.4 44.8 Tundra, arctic and alpine 8.0 100-400 140 1.1 4.5 18.8 2.6 21.1 Desert and semidesert scrub 18.0 10-250 70 1.3 4.5 18.8 1.3 23.7 Grassland 24.0 600 15.0 251.2 Savanna, tropical 15.0 200-2000 700 10.5 4.0 16.7 11.7 175.8 Grassland, temperate 9.0 100-1500 500 4.5 4.0 16.7 8.4 75.4 Extreme desert 24.0 1 - 0.5 Desert, extreme dry 8.5 0-10 3 - 4.5 18.8 0.1 0.5 Perpetual ice 15.5 0-1 0 - Cultivated and permanent crop 14.0 100-4000 650 9.1 4.1 17.2 11.2 156.2 Freshwater 4.0 1250 5.0 89.2 Wetland 2.0 800-4000 2000 4.0 4.2 17.6 35.2 70.3 Lake and stream 2.0 100-1500 500 1.0 4.5 18.8 9.4 18.8 TOTAL (for land masses) 149.0 669 100.2 1782.7 Footnotes NPP is given here in grams organic matter (dry weight). Ecosystem/ Vegetation subdivisions are named according to Ellenberg and Mueller-Dombois (1967) and Olson (1970). Areas are the result of the efforts of three consecutive groups of geobotany students at the University of North Carolina, Chapel Hill, USA (Lieth, 1975). NPP ranges were deduced from compilations of Lieth and co-workers (Lieth, 1975), with results very similar to those of Whittaker and Woodwell (1971). NPP mean values are original (Lieth, 1975): cf. Whittaker and Likens (1971), Whittaker (1970) and Odum (1971). Total NPP is the product of area and mean NPP, rounded to one decimal point. Energy content values are original (Lieth, 1975): cf. Jordan (1971) and Odum (1971). Values of 4.5 kcal/g were computed for reefs, estuaries and inshore waters; 4.9 kcal/g for open ocean and upwelling areas (Lieth, 1975). Values in kJ/g are by conversion. Annual energy fixation is calculated as (1) the product of mean NPP and mean energy content, and (2) the product of total NPP and mean energy content. References Ellenberg, H. and D. Mueller-Dombois (1967) Tentative physiognomic-ecological classification of plant formations of the Earth. Ber. Geobot. Inst. ETH Stiftg. Ruebel, Zuerich 37, 21-55. Jordan, C.F. (1971) Productivity of a tropical forest and its relation to a world pattern of energy storage. Journal of Ecology 59, 127-143. Lieth, H.F.H. (1975) Primary production of the major vegetation units of the world. In: Primary Productivity of the Biosphere (H. Lieth, and R.H. Whittaker, eds.). Ecological Studies 14. Springer-Verlag, New York and Berlin. pp. 203-215. Odum, E.P. (1971) Fundamentals of Ecology. 3rd edn. Saunders, Philadelphia. 574 pp. Olson, J.S. (1970) Geographic index of world ecosystems. In: D. Reichle, ed. Analysis of Temperate Forest Ecosystems. Ecological Studies 1, 297-304. Springer-Verlag, New York. Whittaker, R.H. (1970) Communities and Ecosystems. Macmillan, New York. 162 pp. Whittaker, R.H. and G.E. Likens (1971) World productivity estimate, Brussels Symp. 1969, published in Whittaker (1970) and Whittaker and Woodwell (1971). Whittaker, R.H. and G.E. Woodwell (1971) Measurement of net primary production of forests (French summ.) In: P. Duvigneaud, ed. Productivity of Forest Ecosystems: Proc. Brussels Symp. Ecology and Conservation 4, 159-175. UNESCO, Paris.