Chapter IV: The Formation

METHODS OF INVESTIGATION AND RECORD

198. The need of exact methods 161
Quadrats
199. Uses 161
200. Possible objections 163
Kinds of Quadrats and Their Use
201. Size and kinds 164
202. Tapes and stakes 164
203. Locating quadrats 165
The List Quadrat
204. Description 165
205. Manner of use 166
206. Table of abundance 166
The Chart Quadrat
207. Description and use 167
208. The chart 168
209. Mapping 168
210. Factors and photographs 170
The Permanent Quadrat
211. Description and uses 170
212. Manner of use 172
The Denuded Quadrat
213. Description 173
214. Methods of denuding and recording 174
215. Physical factors 175
Aquatic Quadrats
216. Scope 175
Transects
217. The transect 176
The Line Transect
218. Description and method 176
219. The location and size 177
The Belt Transect
220. Details 178
The Permanent Transect
221. Advantages 179
222. Details 179
The Denuded Transect
223. 180
The Layer Transect
224. 180
Ecotone Charts
225. 181
The Migration Circle
226. Purpose 182
227. Location and method 182
228. The denuded circle 183
229. Photographs 183
Cartography
230. Value of cartographic methods 183
231. Standard scale 184
232. Color scheme 184
233. Formation and vegetation maps 185
234. Continental maps 187
Photography
235. 188
236. The camera and its accessories 188
237. The choice of a camera 190
238. The use of the camera 191
239. The sequence of details 192
240. The time of exposure 193
241. Developing 194
242. Finishing 195
Formation and Succession Herbaria
243. Concept and purpose 196
244. Details of collecting 197
245. Arrangement 197
246. Succession herbaria 198

DEVELOPMENT AND STRUCTURE

247. Vegetation an organism 199
248. Vegetation essentially dynamic 199
249. Functions and structures 199
Association
250. Concept 200
251. Causes 201
252. Aggregation 203
Kinds of Association
253. Categories 204
254. Stratum association 204
255. Ground association 205
256. Species guild association 206
257. Light association 206
258. Water-content association 208

THE DEVELOPMENT OF THE FORMATION

259. 210
Invasion
260. 210
Migration
261. 210
262. Mobility 211
263. Organs for dissemination 211
264. Contrivances for dissemination 212
265. Position of disseminules 214
266. Seed production 215
267. Agents of migration 216
268. The direction of migration 219
Ecesis
269. Concept 220
270. Germination of the seed 221
271. Adjustment to the habitat 223
Barriers
272. Concept 224
273. Physical barriers 225
274. Biological barriers 225
275. Influence of barriers 226
Endemism
276. Concept 227
277. Causes 228
278. Significance 228
Polyphylesis and Polygenesis
279. Concept 230
280. Proofs of polygenesis 231
281. Origin by polyphylesis 232
Kinds of Invasion
282. Continuous and intermittent invasion 234
283. Complete and partial invasion 235
284. Permanent and temporary invasion 235
Manner of Invasion
285. Entrance into the habitat 236
286. Influence of levels 238
Investigation of Invasion
287. 239
Succession
288. Concept 239
289. Kinds of succession 240
Primary Successions
290. 241
291. Succession through elevation 241
292. Succession through volcanic action 242
293. Weathering 243
294. Succession in residuary soils 243
295. Succession in colluvial soils 244
296. Succession in alluvial soils 245
297. Succession in aeolian soils 246
298. Succession in glacial soils 247
Secondary Successions
299. 247
300. Succession in eroded soils 247
301. Succession in flooded soils 248
302. Succession by subsidence 249
303. Succession in land slips 249
304. Succession in drained or dried soils 249
305. Succession by animal agency 250
306. Succession by human agency 250
307. Succession in burned areas 251
308. Succession in lumbered areas 252
309. Succession by cultivation 253
310. Succession by drainage 253
311. Succession by irrigation 253
312. Anomalous successions 254
313. Perfect and imperfect successions 254
314. Stabilization 255
Causes and Reactions
315. 256
316. Succession by preventing weathering 257
317. Succession by binding aeolian soils 258
318. Succession by reducing run-off and erosion 259
319. Succession by filling with silt and plant remains 260
320. Succession by enriching the soil 261
321. Succession by exhausting the soil 262
322. Succession by the accumulation of humus 263
323. Succession by modifying atmospheric factors 264
Laws of Succession
324. 264
Classification and Nomenclature
325. Basis 267
326. Nomenclature 267
327. Illustrations 270
Investigation of Succession
328. General rules 270
329. Method of alternating stages 271
330. The relict method 272

THE STRUCTURE OF THE FORMATION

331. 274
Zonation
332. Concept 274
Causes of Zonation
333. Growth 275
334. Reactions 276
335. Physical factors 276
336. Physiographic symmetry 278
Kinds of Zonation
337. 279
338. Radial zonation 280
339. Bilateral zonation 280
340. Vertical zonation 280
341. Vegetation zones 281
Alternation
342. Concept 283
343. Causes 284
344. Competition 285
345. Kinds of alternation 289
The Formation in Detail
346. The rank of the formation 292
347. The parts of a formation 295
348. Nomenclature of the divisions 299
349. The investigation of a particular formation 299
Classification and Relationship
350. Basis 300
351. Habitat classification 301
352. Nomenclature 302
353. Developmental classification 304
354. Regional classification 304
355. Mixed formations 304

EXPERIMENTAL VEGETATION

356. Scope and methods 306
Method of Natural Habitats
357. Natural experiments 307
Method of Artificial Habitats
358. Modification of habitat 307
359. Denuding 308
360. Modification of the formation by transfer 309
Method of Control Habitats
361. Competition cultures 310
362. Details of culture methods 311

GLOSSARY 314

BIBLIOGRAPHY 324

RESEARCH METHODS IN ECOLOGY