Roots and root systems Functions(for soil ecosystem): Structural stability Production of pores (when dead Soil Density Root Thickness(mm) 0.75 Courtesy Mac Kirby CSIRo Land and Water 10 mm
Roots and root systems Functions (for soil & ecosystem): • Structural stability • Production of pores (when dead) Courtesy Mac Kirby CSIRO Land and Water
Roots and root systems Functions(for soil ecosystem): Structural stability Production of pores(when dead) Source of c and other nutrients for soil organisms Source of organic matter
Roots and root systems Functions (for soil & ecosystem): • Structural stability • Production of pores (when dead) • Source of C and other nutrients for soil organisms • Source of organic matter
Distribution of organic material Hardwood forest Tallgrass prairie kg/ha Aboveground(地上部) 136000 8000 Belowground(地下部) Roots 57000 136000 Soil organisms 6300 Litter layer(枯枝落叶层)48000 Soil organic matter 173000 400000 Belowground Total 278000 542300 Stevenson and cole 1999
Distribution of organic material Stevenson and Cole 1999 Aboveground(地上部) Belowground(地下部) Roots Soil organisms Litter layer(枯枝落叶层) Soil organic matter Belowground Total Hardwood forest 136 000 57 000 48 000 173 000 278 000 Tallgrass prairie 8000 136 000 6300 400 000 542 300 kg/ha
Global annual root turnover in different ecosystems Annual root turnover ( of maximum root mass) Trees: total root system 0 Trees: fine roots 56 Grasslands Shrublands 34 Wetlands 55 Gilt and Jackson 2003
Global annual root turnover in different ecosystems Gill and Jackson 2003 Annual root turnover (% of maximum root mass) 10 56 53 34 55 Trees: total root system Trees: fine roots Grasslands Shrublands Wetlands
Roots and root systems Functions(for soil ecosystem): Structural stability Production of pores(when dead) Source of C and other nutrients for soil organisms Source of organic matter Influence depth of water-table Potential for removal of toxic materials (bioremediation)
Roots and root systems Functions (for soil & ecosystem): • Structural stability • Production of pores (when dead) • Source of C and other nutrients for soil organisms • Source of organic matter • Influence depth of water-table • Potential for removal of toxic materials (bioremediation)