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

by Frederic Edward Clements

Index

PLANT INDICATORS

THE RELATION OF PLANT COMMUNITIES TO PROCESS AND PRACTICE

By Frederic E. Clements

1

Concept and History

The practical aspect 3

The scientific aspect 3

Historical

Agricultural 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 Indicators

Cajander, 1909 14

Clements, 1910 14

Pearson. 1913-1914 15

Zon, 1915 16

Hole and Singh, 1916 16

Korstian, 1917 17

Grazing 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 Studies

Significance 26

The chresard 26

Gain, 1895 26

Kihlmann, 1890 27

Briggs and Shantz, 1912 27

The water requirement 28

Concept

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 Criteria

Bases and Methods of Determination

Fundamental relations 35

The 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 Basis

Kinds of response 43

Effect of habit 43

Individuality in response 44

Effect of extreme conditions 44

Phytometers 46

The 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 Basis

Scope 51

Sequence of indicators 52

Major successions as indicators 53

The Experimental Basis

Nature 53

Essentials 54

Indicator Criteria

Nature and kinds of criteria 55

Species and genera 65

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-Forms

Concept and history 64

Warming's system 64

Modifications of Warming's system 65

Indicator value 66

Ecads 67

Growth-Forms

Nature 68

Kinds 69

Indicator relations 69

Standard plants for growth correlations 70

Competition-forms 71

Communities as Indicators

Value 72

Kinds of communities 72

Community structures 73

Alternes 73

Layers 74

Aspects 75

Kinds of Indicators

Basis of distinction 76

Factor 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 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 Indicators

Nature and kinds 98

Paleic 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 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 Climax

Stipa-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 Prairie

Stipa-Koeleria Association

Extent 121

Factor relations 123

Sequence of dominants 123

Societies

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

Clans

Vernal clans 131

Estival clans 131

Serotinal clans 131

The Subclimax Prairie

Andropogon Associes

Nature 131

Range 132

Factor relations 133

Sequence 133

Grouping 134

Societies and Clans

The Mixed Prairie

Stipa-Borteloua Association

Nature 135

Effect of grazing and climatic cycles 135

Range 136

Grouping 137

Sequence of dominants 138

Societies of the Mixed Prairie

Prevernal societies 139

Vernal societies 139

Estival societies 139

Serotinal societies 139

The Short-Grass Plains

Bulbilis-Bouteloua Association

Nature 139

Range 140

Grouping of dominants 141

Factor relations 142

Sequence of dominants 142

Societies

Prevernal societies 143

Vernal societies 143

Estival societies 143

Serotinal societies 144

Clans

Prevernal clans 144

Vernal clans 144

Estival clans 144

Serotinal clans 144

The Desert Plains

Aristida-Bouteloua Association

Nature 144

Range 145

Rank of dominants 146

Grouping of dominants 146

Sequence of dominants 147

Societies

Vernal societies 148

Estival societies 148

Serotinal societies 149

Clans

The Bunch-Grass Prairie

Agropyrum-Stipa Association

Nature 149

Range 149

Factor relations and sequence 151

Societies

Prevernal societies 152

Vernal societies 152

Estival societies 152

Serotinal societies 152

Clans

Prevernal clans 152

Vernal clans 152

Estival clans 152

Serotinal clans 152

The Sagebrush Climax

Atriplex-Artemisia Formation

Nature 152

Unity of the formation 153

Range 154

Subclimax sagebrush 155

Associations 156

The Basin Sagebrush

Atriplex-Artemisia Association

Range 156

Rank and grouping 157

Correlations 158

Successional sequence 159

Societies

Grass communities appearing as societies 160

Vernal societies 160

Estival societies 160

Serotinal societies 160

The Coastal Sagebrush

Salvia-Artemisia Association

Range 160

The Desert Scrub Climax

Larrea-Prosopis Formation

Nature 162

Range 163

Unity of the formation 163

Structure of the formation 165

Summary of Dominants

Associations 166

Relation to other formations 167

The Eastern Desert Scrub

Larrea-Flourensia Association

Correlations and sequence 168

Societies

The Western Desert Scrub

Larrea-Franseria Association

Nature 170

Extent 171

Structure 172

Groupings 172

Factor relations 173

Successional relations 174

Root relations 176

Societies and Clans

The Chaparrel Climax

Quercus-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 Chaparral

Cercocarpus-Quercus Assoeiaiion

Nature and extent 183

Contacts 184

Groupings 185

Equivalence of dominants 186

Societies

Vernal societies 187

Estival societies 187

Serotinal societies 187

The Subclimax Chapparral

Rhus-Quercus Associes.

Nature 187

Extent and contacts 188

Groupings 189

Relations of the dominants 189

Societies

The Coastal Chapparal

Adenostoma-Ceanothus Association

Nature and extent 190

Groupings 191

Factor and seral relations 192

Societies

Prevernal societies 193

Vernal societies 193

Estival societies 193

The Woodland Climax

Pinus-Juniperus Formation

Nature 193

Range and extent 194

Unity of the formation 195

Structure of the formation 196

Contacts 197

The Pinon-Cedar Woodland

Pinus-Juniperus Association

Nature and extent 197

Societies

Shade societies 199

The Oak-Cedar Woodland

Quercus-Juniperus Aasociation

Nature and extent 200

Factor relations 201

Societies

Shade societies 202

The Pine-Oak Woodland

Pinus-Quercus Aaaociation

Nature and extent 202

The Montane Forest Climax

Pinus-Pseudotsuga Formation

Nature 205

Extent 205

Unity of the formation 205

Relationship and contacts 206

Associations 207

The Petran Montane Forest

Pinus-Pseudotsuga Aaaociation

Extent 207

Groupings 208

Factor relations 209

Seral relations 209

Societies and Clans

The Sierra Montane Forest

Pinus Association

Extent 211

Groupings 212

Factor and sersd relations 212

Societies

Shrubs 213

Herbs 214

The Coast Forest Climax

Thuja-Tsuga Formation

Nature 214

Extent 214

Unity 215

Relationship and contacts 215

Associations 216

The Cedar-Hemlock Forest

Thuja-Tsuga Association

Nature and extent 217

Groupings 217

Factor and seral relations 218

Societies

Shrubs 219

Herbs 219

The Larch-Pine Forest

Larix-Pinus Association

Nature and extent 219

Groupings 220

Factor and serai relations 220

Societies

The Subalpine Forest Climax

Picea-Abies Formation

Nature 222

Extent 222

Unity 222

Relationship and contacts 223

Associations 224

The Petran Subalpine Forest

Picea-Abies Association

Extent 224

Groupings 225

Factor and seral relations 225

====Societies====

The Sierran Subalpine Forest

Pinus-Tsuga Association

Extent 226

Groupings 227

Factor and serai relations 228

Societies

The Alpine Meadow Climax

Carex-Poa Formation

Nature 228

Extent 229

Unity 229

Relationship and contacts 230

Associations 231

The Petran Alpine Meadow

Carex-Poa Association

Extent 232

Dominants.

Groupings 232

Factor and seral relations 233

Societies

Vernal societies 234

Estival societies 234

The Sierran Alpine Meadow

Carex-Agrostis Association

Extent 234

Dominants

Groupings 235

Factor and seral relations 235

Societies

Agricultural Indicators

General relations 237

Land 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 Classification

Bases 245

Classification and use 245

Methods 246

Climatic 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 Indicators

Types of farming 255

Relation of types of farming to indicators 255

Edaphic indicators of types of farming 256

Crop 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 Cycles

Cycles of production 262

The excess-deficit balance 264

Anticipation of cycles 266

Grazing Indicators

Kinds of grazing 270

Grazing 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 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

Overgrazing

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 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 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 Indicators

Nature 336

Kinds of indicators 336

Forest Types

Bases 337

Comparison of views 342

Forest sites 343

Succession as a basis 344

Significance 345

Climatic 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 Indicators

Kinds 357

Prerequisites for planting and sowing 358

Use of climatic cycles 359

Reforestation indicators 369

Afforestation indicators 362

Bibliography 364

==Index 375==