LIST OF ILLUSTRATIONS 



Xlll 



95- 

 96. 



97- 



99. 

 100. 



lOI. 



102. 

 103- 



104. 



105- 

 106. 

 107. 

 108. 

 109. 

 110. 



III. 

 1 12. 



113- 

 114. 



115- 



116. 



117. 



118. 



119. 



120. 

 121. 



122. 

 123. 



124. 

 125. 



126. 



127. 



128. 



129. 

 130. 



131- 



132. 



Mixed deciduous forest in northeastern United States — in summer 339 

 Open scrubby Birch ' forest ' in Finmark, northern Norway . . 344 



Boreal coniferous forest surrounding lake-side bog in sheltered valley 



in Troms, northern Norway ....... 347 



Outside the taiga in northern Ungava, Canada .... 347 



' Lake-forest ' of southeastern Canada, in summer . . 349 



The same area of ' lake-forest ' but under winter conditions, with 



snow covering the ground . . . . . . .350 



Warm-temperate rain forest in southeastern United States . . 352 



Bald-cypress swamp in southeastern United States . . . 353 



Rocky area with patches of mixed scrub of ' maquis ' type in the 



Mediterranean island of Corsica . . . . . -356 



Sierran chaparral climax, Santa Barbara, California . . . 356 



Sclerophyllous forest in Australia, dominated by lofty Guni-trees . 357 

 The North American Prairie : mid- and short-grass communities . 362 

 Salt desert and salt-marsh of a warm-temperate region . . 367 



Pine ' Krummholz ' at timber-line in the Rocky Mountains . . 377 



Tundra on Southampton Island, Hudson Bay .... 384 

 Marshy tundra near the south shore of Hudson Strait, dominated by 



Cotton-grasses, Sedges, and Grasses ..... 385 



Dry tundra on raised area overlooking Hudson Bay . . .386 



Mesophytic Sedge-grass tundra on the north coast of Alaska near 



Point Barrow, overlooking the Arctic Ocean .... 388 

 Extensive area of damp ' hillock tundra ' on the coast of Spitsbergen 388 

 Discontinuous tundra-like tract of mixed Grasses, Northern Wood-rush, 



forbs, and Polar Willow, in inland valley, West Spitsbergen, grazed 



by a pair of wild Reindeer ....... 389 



Tangled Willow scrub in the low-arctic belt of the Northwest 



Territories, Canada. ........ 391 



Patchy scrub of Glaucous Willow and Scrub Birch, up to nearly 



2 metres high, in southwestern Greenland . . . .391 



Dense low-arctic heath dominated by Arctic Blueberry in northern- 

 most Quebec .......... 393 



' Snow-patch ' darkened by Arctic Bell-heather, southern Baffin 



Island ........... 394 



Mixed middle-arctic heath with many light-coloured and other 



Lichens ........... 394 



' Polygons ' in northernmost Spitsbergen ..... 396 



Fell-field on calcareous soil in exposed situation, northernmost 



Labrador .......... 397 



Lichen barrens in the uplands of central Baffin Island, looking south 398 

 Monotonous tract of prairie-like fell-field in the vicinity of the 



Magnetic North Pole, Prince of VVales Island, Canadian Arctic 



Archipelago .......... 39^ 



Shingly beach bound by swarded Lyme-grass .... 400 



Looking down on a salt-marsh dominated by Pacific Silverweed and 



Creeping Alkali-grass ........ 4°° 



Luxuriant ' patchwork quilt ' of mixed and many-coloured Lichens 



and Mosses developed near top of bird-cliff . . . .401 



Looking down on a luxuriant mossy mat on the manured periphery 



of a wildfowl nesting-ground in Spitsbergen .... 402 

 Purple Saxifrage barrens on exposed ridge overlooking the sea in 



northernmost Baffin Island ....... 403 



' Late-snow ' patch in the highlands of central Baffin Island . 404 



Looking down on the Herb-like Willow zone of the late-snow area 



shown in Fig. 129 . . . . • • • • • 4^4 



Luxuriant lakeside marsh dominated by Water Sedge and Tall 



Cotton-grass .......... 4°^ 



Fine bed of Scheuchzer's Cotton-grass beside tarn in northern 



Spitsbergen .......-.• 4^7 



