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