# Plant Indicators: the Relation of Plant Communities to Process and Practice

Index
​PLANT INDICATORS
THE RELATION OF PLANT COMMUNITIES TO PROCESS AND PRACTICE
By Frederic E. Clements
1

## Concept and HistoryConcept and History

       The practical aspect 3
       The scientific aspect 3

### HistoricalHistorical
#### Agricultural IndicatorsAgricultural Indicators

       Hilgard, 1860 5
       Chamberlin, 1877 5
       Merriam, 1898 6
       Hilgard, 1906 8
       Clements, 1910 9
       Shantz, 1911 10
       Kearney, Briggs, Shantz, McLane, and Piemeisel, 1914 11
       Shantz and Piemeisel, 1917 12
       Shantz and Aldous, 1917 13
       Weaver, 1919 13

#### Forest IndicatorsForest Indicators

       Cajander, 1909 14
       Clements, 1910 14
       Pearson. 1913-1914 15
       Zon, 1915 16
       Hole and Singh, 1916 16
       Korstian, 1917 17

#### Grazing IndicatorsGrazing Indicators

       Smith, 1899 19
       Bentley. 1902 20
       Griffiths, 1901, 1904, 1907, 1910, 1915.... 21
       Sampson, 1908, 1909, 1913, 1914 22
       Jardine, 1908, 1909, 1910, 1913 23
       Wooton, 1915, 1916 23
       Jardine and Hurtt. 1917 24
       Jardine and Anderson, 1919 24
       Sarvis, 1919 25

#### Chresard and Water Requirement StudiesChresard and Water Requirement Studies

       Significance 26
       The chresard 26
       Gain, 1895 26
       Kihlmann, 1890 27
       Briggs and Shantz, 1912 27
       The water requirement 28

### ConceptConcept

       General 28
       Animals as indicators 29
       Plant and community 29
       Sequences 30
       Direct and indirect sequences 31
       Direction of indication 32
       Scope 32
       Materials 33
       Basing studies 34

## Bases and CriteriaBases and Criteria
### Bases and Methods of DeterminationBases and Methods of Determination

       Fundamental relations 35

#### The Physical BasisThe Physical Basis

       Direct and indirect factors 36
       Controlling and limiting factors 36
       Climatic and edaphic factors 37
       Climates and habitats 38
       Variation of climate and habitat 39
       Inversion of factors 40
       Measurement of habitats 42

#### The Physiological BasisThe Physiological Basis

       Kinds of response 43
       Effect of habit 43
       Individuality in response 44
       Effect of extreme conditions 44
       Phytometers 46

#### The Associational BasisThe Associational Basis

       Nature of association 47
       Dominants 47
       Equivalence of dominants 48
       Absence of dominants 49
       Subdominants 50
       Secondary species 51
       Plant and animal association 51

#### The Successional BasisThe Successional Basis

       Scope 51
       Sequence of indicators 52
       Major successions as indicators 53

#### The Experimental BasisThe Experimental Basis

       Nature 53
       Essentials 54

### Indicator CriteriaIndicator Criteria

       Nature and kinds of criteria 55
       Species and genera 65

#### Life-Forms.Life-Forms.

       History 57
       Pound and Clements, 1898-1900 57
       Raunkiaer, 1905 58
       Warming. 1908 69
       Drude. 1913 60
       Comparison of the systems 62
       Vegetation-forms 62
       Indicator significance of vegetation-forms 63

#### Habitat-FormsHabitat-Forms

       Concept and history 64
       Warming's system 64
       Modifications of Warming's system 65
       Indicator value 66
       Ecads 67 ​

#### Growth-FormsGrowth-Forms

       Nature 68
       Kinds 69
       Indicator relations 69
       Standard plants for growth correlations 70
       Competition-forms 71

#### Communities as IndicatorsCommunities as Indicators

       Value 72
       Kinds of communities 72
       Community structures 73
       Alternes 73
       Layers 74
       Aspects 75

## Kinds of IndicatorsKinds of Indicators

       Basis of distinction 76

#### Factor IndicatorsFactor Indicators

       Basis and kinds 76
       Quantitative sequences 77
       Climatic and edaphic indicators 77
       Water indicators 78
       Light indicators 79
       Temperature indicators 81
       Indicators of solutes 83
       Saline indicators 83
       Lime indicators 84
       Aeration indicators 85
       Indicators of factor-complexes 88
       Soil indicators 88
       Slope-exposure indicators 88
       Altitude indicators 89
       Organism indicators 90

#### Process IndicatorsProcess Indicators

       Nature 91
       Kinds 91
       Fire indicators 92
       Lumbering indicators 93
       Cultivation indicators 93
       Grazing indicators 94
       Indicators of irrigation and drainage 95
       Construction indicators 96
       Physiographic indicators 97
       Climatic indicators 97

#### Practice IndicatorsPractice Indicators

       Nature and kinds 98

#### Paleic IndicatorsPaleic Indicators

       Paleo-ecology 99
       Nature of paleic indicators 100
       Kinds 101
       Paleic indicators of climates and cycles 103
       Paleic indicators of succession 103
       Plant indicators of animals 104
       Animal indicators of plants 104

## Climax Formations Of Western North AmericaClimax Formations Of Western North America

       Nature 105
       Tests of a climax 105
       Structure and development 106
       Societies 107
       Names of climax communities 109
       Seral communities 109
       Indicator significance of climax formations 111
       Significance of succession 111
       Indicator value of disturbed areas 112
       Summary of the climax formations 113

### The Grassland ClimaxThe Grassland Climax
#### Stipa-Bouteloua FormationStipa-Bouteloua Formation

       General relations 114
       Unity of the grassland 116
       Correlation with climate 116
       Use of weather records 116
       Relationship of associations 118
       Floristic relations 119
       Ecological relations 120
       Subdominants 120
       Developmental relations 121

### The True PrairieThe True Prairie
#### Stipa-Koeleria AssociationStipa-Koeleria Association

       Extent 121
       Factor relations 123
       Sequence of dominants 123

#### SocietiesSocieties

       Nature 125
       Control of dominants 125
       Relation to consociation 126
       Origin 126
       Mixed societies 127
       Aspects 127
       Zones and alternes 128
       Studies of prairie societies 129

#### ClansClans

       Vernal clans 131
       Estival clans 131
       Serotinal clans 131

### The Subclimax PrairieThe Subclimax Prairie
#### Andropogon AssociesAndropogon Associes

       Nature 131
       Range 132
       Factor relations 133
       Sequence 133
       Grouping 134

#### Societies and ClansSocieties and Clans
### The Mixed PrairieThe Mixed Prairie
#### Stipa-Borteloua AssociationStipa-Borteloua Association

       Nature 135
       Effect of grazing and climatic cycles 135
       Range 136
       Grouping 137
       Sequence of dominants 138

#### Societies of the Mixed PrairieSocieties of the Mixed Prairie

       Prevernal societies 139
       Vernal societies 139
       Estival societies 139
       Serotinal societies 139 ​

### The Short-Grass PlainsThe Short-Grass Plains
#### Bulbilis-Bouteloua AssociationBulbilis-Bouteloua Association

       Nature 139
       Range 140
       Grouping of dominants 141
       Factor relations 142
       Sequence of dominants 142

#### SocietiesSocieties

       Prevernal societies 143
       Vernal societies 143
       Estival societies 143
       Serotinal societies 144

#### ClansClans

       Prevernal clans 144
       Vernal clans 144
       Estival clans 144
       Serotinal clans 144

### The Desert PlainsThe Desert Plains
#### Aristida-Bouteloua AssociationAristida-Bouteloua Association

       Nature 144
       Range 145
       Rank of dominants 146
       Grouping of dominants 146
       Sequence of dominants 147

#### SocietiesSocieties

       Vernal societies 148
       Estival societies 148
       Serotinal societies 149

#### ClansClans
### The Bunch-Grass PrairieThe Bunch-Grass Prairie
#### Agropyrum-Stipa AssociationAgropyrum-Stipa Association

       Nature 149
       Range 149
       Factor relations and sequence 151

#### SocietiesSocieties

       Prevernal societies 152
       Vernal societies 152
       Estival societies 152
       Serotinal societies 152

#### ClansClans

       Prevernal clans 152
       Vernal clans 152
       Estival clans 152
       Serotinal clans 152

### The Sagebrush ClimaxThe Sagebrush Climax
#### Atriplex-Artemisia FormationAtriplex-Artemisia Formation

       Nature 152
       Unity of the formation 153
       Range 154
       Subclimax sagebrush 155
       Associations 156

### The Basin SagebrushThe Basin Sagebrush
#### Atriplex-Artemisia AssociationAtriplex-Artemisia Association

       Range 156
       Rank and grouping 157
       Correlations 158
       Successional sequence 159

#### SocietiesSocieties

       Grass communities appearing as societies 160
       Vernal societies 160
       Estival societies 160
       Serotinal societies 160

### The Coastal SagebrushThe Coastal Sagebrush
#### Salvia-Artemisia AssociationSalvia-Artemisia Association

       Range 160

### The Desert Scrub ClimaxThe Desert Scrub Climax
#### Larrea-Prosopis FormationLarrea-Prosopis Formation

       Nature 162
       Range 163
       Unity of the formation 163
       Structure of the formation 165

#### Summary of DominantsSummary of Dominants

       Associations 166
       Relation to other formations 167

### The Eastern Desert ScrubThe Eastern Desert Scrub
#### Larrea-Flourensia AssociationLarrea-Flourensia Association

       Correlations and sequence 168

#### SocietiesSocieties
### The Western Desert ScrubThe Western Desert Scrub
#### Larrea-Franseria AssociationLarrea-Franseria Association

       Nature 170
       Extent 171
       Structure 172
       Groupings 172
       Factor relations 173
       Successional relations 174
       Root relations 176

#### Societies and ClansSocieties and Clans
### The Chaparrel ClimaxThe Chaparrel Climax
#### Quercus-Ceanothus FormationQuercus-Ceanothus Formation

       Nature 177
       Unity of the chaparral formation 178
       Climatic relations 178
       Origin and succession 179
       Range and extent 180
       Structure of the formation 181
       Grouping of dominants 181
       Associations 183

### The Petran ChaparralThe Petran Chaparral
#### Cercocarpus-Quercus AssoeiaiionCercocarpus-Quercus Assoeiaiion

       Nature and extent 183
       Contacts 184
       Groupings 185
       Equivalence of dominants 186 ​

#### SocietiesSocieties

       Vernal societies 187
       Estival societies 187
       Serotinal societies 187

### The Subclimax ChapparralThe Subclimax Chapparral
#### Rhus-Quercus Associes.Rhus-Quercus Associes.

       Nature 187
       Extent and contacts 188
       Groupings 189
       Relations of the dominants 189

#### SocietiesSocieties
### The Coastal ChapparalThe Coastal Chapparal
#### Adenostoma-Ceanothus AssociationAdenostoma-Ceanothus Association

       Nature and extent 190
       Groupings 191
       Factor and seral relations 192

#### SocietiesSocieties

       Prevernal societies 193
       Vernal societies 193
       Estival societies 193

### The Woodland ClimaxThe Woodland Climax
#### Pinus-Juniperus FormationPinus-Juniperus Formation

       Nature 193
       Range and extent 194
       Unity of the formation 195
       Structure of the formation 196
       Contacts 197

### The Pinon-Cedar WoodlandThe Pinon-Cedar Woodland
#### Pinus-Juniperus AssociationPinus-Juniperus Association

       Nature and extent 197

#### SocietiesSocieties

       Shade societies 199

### The Oak-Cedar WoodlandThe Oak-Cedar Woodland
#### Quercus-Juniperus AasociationQuercus-Juniperus Aasociation

       Nature and extent 200
       Factor relations 201

#### SocietiesSocieties

       Shade societies 202

### The Pine-Oak WoodlandThe Pine-Oak Woodland
#### Pinus-Quercus AaaociationPinus-Quercus Aaaociation

       Nature and extent 202

### The Montane Forest ClimaxThe Montane Forest Climax
#### Pinus-Pseudotsuga FormationPinus-Pseudotsuga Formation

       Nature 205
       Extent 205
       Unity of the formation 205
       Relationship and contacts 206
       Associations 207

### The Petran Montane ForestThe Petran Montane Forest
#### Pinus-Pseudotsuga AaaociationPinus-Pseudotsuga Aaaociation

       Extent 207
       Groupings 208
       Factor relations 209
       Seral relations 209

#### Societies and ClansSocieties and Clans
### The Sierra Montane ForestThe Sierra Montane Forest
#### Pinus AssociationPinus Association

       Extent 211
       Groupings 212
       Factor and sersd relations 212

#### SocietiesSocieties

       Shrubs 213
       Herbs 214

### The Coast Forest ClimaxThe Coast Forest Climax
#### Thuja-Tsuga FormationThuja-Tsuga Formation

       Nature 214
       Extent 214
       Unity 215
       Relationship and contacts 215
       Associations 216

### The Cedar-Hemlock ForestThe Cedar-Hemlock Forest
#### Thuja-Tsuga AssociationThuja-Tsuga Association

       Nature and extent 217
       Groupings 217
       Factor and seral relations 218

#### SocietiesSocieties

       Shrubs 219
       Herbs 219

### The Larch-Pine ForestThe Larch-Pine Forest
#### Larix-Pinus AssociationLarix-Pinus Association

       Nature and extent 219
       Groupings 220
       Factor and serai relations 220

#### SocietiesSocieties
### The Subalpine Forest ClimaxThe Subalpine Forest Climax
#### Picea-Abies FormationPicea-Abies Formation

       Nature 222
       Extent 222
       Unity 222
       Relationship and contacts 223
       Associations 224

### The Petran Subalpine ForestThe Petran Subalpine Forest
#### Picea-Abies AssociationPicea-Abies Association

       Extent 224
       Groupings 225
       Factor and seral relations 225
====Societies==== ​

### The Sierran Subalpine ForestThe Sierran Subalpine Forest
#### Pinus-Tsuga AssociationPinus-Tsuga Association

       Extent 226
       Groupings 227
       Factor and serai relations 228

#### SocietiesSocieties
### The Alpine Meadow ClimaxThe Alpine Meadow Climax
#### Carex-Poa FormationCarex-Poa Formation

       Nature 228
       Extent 229
       Unity 229
       Relationship and contacts 230
       Associations 231

### The Petran Alpine MeadowThe Petran Alpine Meadow
#### Carex-Poa AssociationCarex-Poa Association

       Extent 232
       Dominants.
       Groupings 232
       Factor and seral relations 233

#### SocietiesSocieties

       Vernal societies 234
       Estival societies 234

### The Sierran Alpine MeadowThe Sierran Alpine Meadow
#### Carex-Agrostis AssociationCarex-Agrostis Association

       Extent 234

#### DominantsDominants

       Groupings 235
       Factor and seral relations 235

#### SocietiesSocieties
## Agricultural IndicatorsAgricultural Indicators

       General relations 237

### Land ClassificationLand Classification

       Nature 237
       Relation to practices 238
       Proposed bases of classification 238
       The indicator method of land classification 240
       Use of climax indicators 240
       Soil indicators 241
       Shantz's results 242

### A System of Land ClassificationA System of Land Classification

       Bases 245
       Classification and use 245
       Methods 246

### Climatic CyclesClimatic Cycles

       Nature 247
       The 11-year cycle 247
       Evidences 248
       Periods of drought 250
       Recurrence of drought periods 251
       Significance of the sun-spot cycle 252
       Prediction of drought periods 253
       Utilization of cycles 254

### Farming IndicatorsFarming Indicators

       Types of farming 255
       Relation of types of farming to indicators 255
       Edaphic indicators of types of farming 256

### Crop IndicatorsCrop Indicators

       Nature and kinds 257
       Climatic indicators of the types of crops 258
       Climatic indicators of kinds of crops 259
       Climatic indicators of varieties 259
       Life zones and crop zones 260
       Edaphic indicators of crops and methods 261
       Indicators of native or ruderal forage crops 262

### Agricultural Practice and Climatic CyclesAgricultural Practice and Climatic Cycles

       Cycles of production 262
       The excess-deficit balance 264
       Anticipation of cycles 266

## Grazing IndicatorsGrazing Indicators

       Kinds of grazing 270

### Grazing TypesGrazing Types

       Kinds of grazing indicators 271
       Significance of climax types 272
       Formations as indicators 273
       Associations as indicators 273
       Consociations as indicators 274
       Local grazing types 275
       Savannah as an indicator 276
       Kinds of savannah 278
       Savannah in relation to fire and grazing 279
       Significance of seral types 279
       Prisere communities as indicators 280
       Subsere communities as indicators 282
       Fire indicators and grazing 283

### Carrying CapacityCarrying Capacity

       Nature and significance 284
       Determining factors 284
       Relation to communities and dominants 285
       Nutrition content 286
       Relation to climatic cycles 292
       Relation to rodents 293
       Relation to herd and management. 293
       Measurement of carrying capacity 294
       Present and potential carrying capacity 295 ​

### OvergrazingOvergrazing

       Nature 295
       Causes 297
       Indicators of Overgrazing 297
       Societies as indicators 298
       Halfshrubs as indicators 299
       Cacti as indicators 300
       Shrubs as indicators 300
       Annuals as indicators 301
       Prairie and plains indicators 302
       Desert plains indicators 302
       Bunch-grass prairie indicators 303
       Great Basin indicators 304
       Overgrazing in the past 304
       Succession and cycles 307
       Relation of tall-grasses and short-grasses 308
       Overgrazing cycles 309

### Range ImprovementRange Improvement

       History 310
       Prerequistes 311
       Essential factors 312
       Proper stocking 312
       Rotation grazing 314
       Rodent eradication 316
       Eradication of poisonous plants 317
       Eradication of weeds and cacti 319
       Eradication of brush 320
       Manipulation of the range 321
       Plant introduction on the range 322
       Prerequisites for seeding and planting 324
       New investigations 326
       Forage development 327
       Water development 328
       Herd management 329

### Essentials of a Grazing PolicyEssentials of a Grazing Policy

       A proper land system 330
       Essentials 330
       The Kent grazing bill 331
       Classification and range surveys 334
       Production cycles 334
       Ranch management surveys 335

## Forest IndicatorsForest Indicators

       Nature 336
       Kinds of indicators 336

#### Forest TypesForest Types

       Bases 337
       Comparison of views 342
       Forest sites 343
       Succession as a basis 344
       Significance 345

#### Climatic and Edaphic IndicatorsClimatic and Edaphic Indicators

       Climatic indicators 345
       Edaphic indicators 348
       Water-content indicators 348
       Light indicators 349
       Site indicators 349
       Growth as an indicator 360
       Burn indicators 353
       Grazing indicators 355
       Cycle indicators 367

### Planting IndicatorsPlanting Indicators

       Kinds 357
       Prerequisites for planting and sowing 358
       Use of climatic cycles 359
       Reforestation indicators 369
       Afforestation indicators 362

## Bibliography 364Bibliography 364

==Index 375==