The vegetation of Krakatoa was completely exterminated in 1883 by a thick coat of red-hot pumice.
Beneath the trees grew some kind of lush, wet, bushy vegetation with silver-lit leaves and stems here and there.
The rain had refreshed the vegetation and the trunks of the trees were dark against the bright green leaves.
The later period of the Mesozoic era saw the almost sudden advent of a fully developed angiospermous vegetation which rapidly occupied the earths surface, and which it is not easy to link on with any that preceded it.
The vegetation of the Palaeozoic era, till towards its close, was apparently remarkably homogeneous all over the world.
The primary regions of vegetation, already indicated, and their subordinate provinces may now be considered more in detail.
There has been in effect a successive shifting of zones of vegetation southwards from the pole.
We may draw with some certainty the conclusion that a general movement southward of vegetation had been brought about.
The types of vegetation (tropical forests, sclerophyllous forest, temperate forests, tundra, &c.) thus briefly outlined are groups of Schimpers climatic formations.
The vegetation is almost tropically luxuriant - palms, wild pineapples, and ferns growing profusely, and the valleys being filled with wild beans and patches of taro.
Kurz, Vegetation of the Andamans (1867); G.
Every great group or phylum of vascular plants, when it has become dominant in the vegetation of the world, has produced members with the tree habit arising by the formation of a thick woody trunk, in most cases by the activity of a cambium.
While the tropics preserve for us what remains of the preTertiary or, at the latest, Eocene vegetation of the earth, which formerly had a much wider extension, the flora of the North Temperate region is often described as the survival of the Miocene.
The Intermediate sub-region comprises the vegetation of the large area occupied by the steppes of the Old World, the prairies of the new and the forest region of both.
They are shrubby plants climbing over surrounding vegetation by means of tendrillike prolongations of the midrib of the leaf beyond the leaf-tip.
The study of the distribution of species dates back to the time of the early systematists, the study of vegetation to the time of the early botanical travellers.
The influence of man on plants and vegetation is also a biological factor, which is frequently ignored as such, and treated as if it were a thing apart.
Hence, in any cosmopolitan treatment of vegetation, it is necessary to consider the groups of plant communities from the standpoint of the climatic or geographical district in which they occur; and this indeed is consistently done by Schimper.
They endeavoured to define aspects of vegetation in which the forms exhibited an obvious adaptation to their climatic surroundings.
The boreal is cold, the austral warm, and the tropical affords conditions of heat and moisture to which the vegetation of the others would be intolerant.
In attempting to account for the distribution of existing vegetation we must take into account palaeontological evidence.
Putting aside the exotic vegetation of the north and east coast-line, the Australian bush gains its peculiar character from the prevalence of the so-called gum-trees (Eucalyptus) and the acacias, of which last there are 300 species, but the eucalypts above all are everywhere.
A most remarkable form of vegetation in the north-west is the gouty-stemmed tree (Adansonia Gregorii), one of the Malvaceae.
One thing is certain, that there is in Australia a flora that is a remnant of a vegetation once widely distributed.
Brilliantly colored spots and patches follow the action of acid fumes on the vegetation near towns and factories, and such particoloured leaves often present striking resemblance to autumn foliage.
When by the aid of man they surmount these, they often dominate with unexpected vigour the native vegetation amongst which they are colonists.
The water-courses and depressions of the shingly steppes afford pasturage sufficient for the guanaco, and in places support a thorny vegetation of low growth and starved appearance.
This has been done with success and in great detail by Grisebach, whose Vegetation der Erde from this point of view is still unsurpassed.
The evidence which has thus been briefly summarized, points unmistakably to the conclusion that existing vegetation originated in the northern hemisphere and under climatic conditions corresponding to what would now be termed sub-tropical.
He could still hear her stifled sobs as he cautiously moved down the slope, wedging his foot against rocks and small vegetation for purchase.
It is evident that it was originally a goddess who was supposed to be in control of Irkalla, corresponding to Ishtar in control of fertility and vegetation on earth.
The vegetation of each region has its distinctive character, modified here and there by elevation, irrigation from mountain streams, and by the saline character of the soil.
Except on Charles Island, where settlement has existed longest, little or no influence of the presence of man is evident in the group; still, the running wild of dogs and cats, and, as regards the vegetation, especially goats, must in a comparatively short period greatly modify the biological conditions of the islands.
High districts covered with oaks and chestnuts succeed to this almost tropical vegetation; a little higher up and we reach the elevated regions of the Pollino and the Sila, covered with firs and pines, and affording rich pastures even in the midst of summer, when heavy dews and light frosts succeed each other in July and August, and snow begins to appear at the end of September or early in October.
The question of universal names for vegetation units is bound lay with that of the universality or otherwise of particular O~ mations.
Such groups are interesting in that they are vegetation units whose physiognomy is, in a broad sense, related more to climatic than to edaphic conditions.
And it is a plausible conjecture that the vegetation of the globe had already in its main features been constituted at this period much as it exists at the present moment.
Lemstrbm believed atmospheric electricity to play an important part in the natural growth of vegetation, and he assigned a special role to the needles of fir and pine trees.
The valley below is filled with the richest vegetation, the undergrowth being largely composed of azaleas and rhododendrons.
Previous to its arrival Australia doubtless possessed considerable vegetation and a scanty fauna, chiefly invertebrate.
P. canadensis, the "cotton-wood" of the western prairies, and its varieties are perhaps the most useful trees of the genus, often forming almost the only arborescent vegetation on the great American plains.
From this point of view it is not sufficient, in attempting to map out the earths surface into regions of vegetation, to have regard alone to adaptations to physical conditions.
This, as will be explained, did not take place to anything like the same extent in North America, the vegetation of which still preserves a more Miocene facies.
Flora and Fauna.The flora of southern France and the Mediterranean is distinct from that of the rest of the country, which does not differ in vegetation from western Europe generally.
The contrast between this low zone and the upper zone of rich vegetation (above about Boo ft.) is curiously marked.
Finally, within any district of constant or fairly constant climatic conditions, it is possible to distinguish plant communities which are related chiefly to edaphic or soil conditions; and the vegetation units of these definite edaphic areas are the plant formations of some writers, and, in part, the edaphic formations of Schimper.
Naked crags, when they do appear, lift themselves from a sea of green, and a tropical vegetation, quite Malaysian in character, covers everything.
Practically the whole of the territory between the 145° meridian and the Great Dividing Range, as well as extensive tracts in the south and west, are a natural sheep pasture with climatic conditions and indigenous vegetation pre - eminently adapted for the growth of wool of the highest quality.
In the Old World the boreal zone is almost sharply cut off and afforded no means of escape for the Miocene vegetation when the climate became more severe.
The northern part of the Gran Chaco is partly wooded and swampy, and as the slope eastward is very gentle and the rivers much obstructed by sand bars, floating trees and vegetation, large areas are regularly flooded during rainy seasons.
In the extreme south, where an Arctic vegetation is found, the pastures are rich, and the forests, largely of the Antarctic beech (Fagus antarctica), are vigorous wherever the rainfall is heavy.
The territories of the Gran Chaco, however, are covered with a characteristic tropical vegetation, in which the palm predominates, but intermingled south of the Bermejo with heavy growths of algarrobo, quebracho-colorado, urunday (Astronium fraxinifolium), lapacho (Tecoma curialis) and palosanto (Guayacum officinalis), all esteemed for hardness and fineness of grain.
The problem, then, which plantdistribution presents is twofold: it has first to map out the earths surface into regions or areas of vegetation, and secondly to trace the causes which have brought them about and led to their restriction and to their mutual relations.
Above the level plain of absolutely smooth surface, devoid of houses or vegetation, the equipotential surfaces under normal conditions would be strictly horizontal, and if we could determine the potential at one metre above the ground we should have a definite measure of the potential gradient at the earth's surface.