Soil Ecology in Northern Forests: A Belowground View of a Changing World

Half-title......Page 3
Title......Page 5
Copyright......Page 6
Dedication......Page 7
Contents......Page 9
Preface......Page 13
1.1 History of forest soil studies......Page 15
1.2 Soil formation......Page 17
Soil-forming processes......Page 21
1.3 Trees and soil environment......Page 22
2.1.1 Texture......Page 24
2.1.2 Soil structure......Page 27
Soil air......Page 29
2.1.3 Water......Page 31
2.2.1 Acidity and alkalinity......Page 34
2.2.2 Cation exchange capacity and nutrient availability......Page 36
2.2.3 Salinity......Page 38
2.3.1 Litter......Page 39
2.3.2 Humus inherited and humified organic substances......Page 41
2.3.3 Organo-mineral complexes......Page 42
2.4 Soil fertility......Page 44
3 Forest soil development and classification......Page 46
3.1.1 Soil formation processes......Page 47
3.2 Soil profile......Page 51
3.2.1 Soil horizons......Page 52
3.2.2 Soil depth......Page 54
3.2.3 Time......Page 55
3.3.1 History and principles of soil classification......Page 56
3.3.2 USDA classification......Page 57
3.3.3 FAO classification......Page 61
3.4 Examples of typical temperate and boreal forest soils......Page 64
3.4.1 Leptosols......Page 66
3.4.3 Cambisols......Page 67
3.4.4 Podzols......Page 68
3.4.5 Gleysols......Page 69
3.4.6 Histosols......Page 70
4.1 Mycorrhizas......Page 71
4.1.1 Emanating hyphae and rhizomorphs......Page 74
4.1.2 Identification of mycorrhizas......Page 76
4.1.3 Determination of the extraradical and extramatrical mycelium......Page 78
4.2 Community structure......Page 80
4.2.2 Relating ectomycorrhizal community structure to ecosystem function......Page 90
5.1.1 Water-binding forces in soils......Page 92
5.1.2 Water potential......Page 93
5.1.3 Soil moisture heterogeneity......Page 94
5.2 Water acquisition by roots and mycorrhizas......Page 96
5.3 Hydraulic redistribution......Page 100
5.4 Waterlogging......Page 104
5.5 Drought......Page 107
6 Forest carbon cycle......Page 108
6.1 The global carbon cycle......Page 109
6.2 Formation of organic matter......Page 110
6.3 Belowground carbon cycles......Page 112
6.3.1 Belowground biomass pool and fluxes......Page 113
6.3.2 Consumption: soil fauna......Page 122
6.3.3 Final stages of organic matter breakdown......Page 123
6.4 Soil humus......Page 126
6.4.1 Mor and mull humus......Page 127
6.4.2 Chemical composition of humus......Page 129
6.4.3 Peat formation......Page 130
7 Nutrient cycling......Page 132
7.1 Nutrient supply and uptake......Page 133
7.2.1 N cycling......Page 138
7.2.2 Importance of CN ratios......Page 142
7.2.3 Climate change and the N cycle......Page 144
7.3 Phosphorus......Page 147
7.4 Potassium, calcium and magnesium......Page 151
7.5 Forest nutrient cycle and climate change......Page 152
8.1 Atmospheric CO2 enrichment technology......Page 157
8.2 Increased forest production......Page 160
8.3 Soil C dynamics......Page 162
8.4 Soil CO2 efflux......Page 173
8.5 High CO2 and soil N cycle......Page 174
8.6 Diversity of soil biota......Page 176
9.1 Emission, transport and deposition of pollutants......Page 179
9.2 Inputs of acidity......Page 182
9.2.1 Soil acidification nutrient loss, Al release, Al in soil solutions......Page 183
9.2.2 Soil solution speciation of Al......Page 188
9.3 Heavy metals in forest soils......Page 189
9.4 Loss of base cations......Page 192
9.5 Aluminium accumulation and toxicity......Page 197
9.5.2 Base cations......Page 200
9.6 Heavy metal effects on trees......Page 201
9.7.1 Effects of soil acidity on roots, rooting depth and root growth......Page 202
9.7.2 Chronology of soil acidification......Page 207
9.7.3 Soil acidity and mycorrhizas......Page 209
9.7.4 Recovery from acidification......Page 212
10.1 Nitrogen cycle......Page 213
10.2 Tree growth and biomass allocation......Page 217
10.3 Changes in ground vegetation......Page 223
10.4 Changes in ectomycorrhizal community structure and function......Page 225
10.5 Increased susceptibility to pathogens and insects......Page 227
10.6 Export of NO3 with seepage water......Page 228
11 Soil functioning and climate change......Page 231
11.1 Effects of climate change......Page 232
11.1.1 Increasing temperature......Page 234
11.1.2 Changing rainfall......Page 238
11.1.3 Nitrogen deposition......Page 241
11.2 Feedback effects of forests......Page 244
11.2.1 Contribution of northern forests to the global C cycle......Page 245
11.2.2 Forest expansion and the water cycle......Page 247
11.3 Environmental benefits and ecosystem services of forest soils......Page 250
11.3.1 Carbon sequestration......Page 251
11.3.2 Water cycle......Page 253
11.3.3 Biodiversity......Page 254
References......Page 256
Index......Page 271