Plant community

“ Each association, if the plants composing it be examined, will be found to consist of an assemblage of species, large and small, brought together by their superior fitness for the particular conditions which prevail. There are mostly in each association one or more dominant species—such as the trees of an Oak wood, or the Heather of a moor—which by their abundance or vigorous growth control the association. The shelter which they give may protect some of the members of the community: the shade which they cast may keep out other plants which otherwise would invade the ground. ”

“ The plant ecologist is aware of the effect of the struggle for space, food, and light upon the nature of a plant formation, but the sociologist has failed to recognize that the same processes of competition and accommodation are at work determining the size and ecological organization of the human community. ”

“ Plant Communities.—The study of plant communities (Formationslehre or synecology) has made much progress in recent years. Even here, however, general agreement has not been reached; and the questions involved in relating the facts of the distribution of plant communities to the factors of the habitat are very imperfectly understood. Plant communities may be classified as follows:—
A plant association is a community of definite floristic composition: it may be characterized by a single dominant species ”

“ Is it any wonder if horticulture in its best sense—that is, the culture of the garden as a whole—is not what it should be? No gardener can get prizes for well-kept beds, for effects of harmonious colouring, for arrangement of shrubberies, for the grouping of herbaceous plants. He is tempted for the sake of a single specimen to sacrifice the beauty of a whole plant, or the clusters of an entire fruit-tree. That it is most important for nurserymen to be able to compare new species, [74] or new varieties of old species, is of course undeniable. ”

“ Plants must live together. They associate; they become adapted or accustomed to each other. Some can live in shade; they thrive in the forest, where sun-loving plants perish. Others prefer the sun, and thereby live together. There are plant societies.
Fig. 252. Weak, narrow-leaved grasses grow in the cat-tail forest.
Every distinct or separate area has its own plant society. There is one association for the hard-tramped dooryard,—knot-weed and broad-leaved plantain with interspersed grass and dandelions; one for the fence-row,—briars and choke-cherries and hiding weeds ”

“ Once more, we have already from Farleton Fell observed that plants do not grow higgledy-piggledy over the country, but are arranged in more or less definite societies depending on similarity of climate, soil, and other external conditions. Studied from this point of view, the flora resolves itself into a series of communities, each requiring a certain set of conditions for its continued welfare. ”

“ Not the least interesting feature of these plant societies is that we must view them as associations of plants, often of widely differing origin due to the vicissitudes of plant distribution, but all taking their part in the society to which they belong and often, as individuals, losing their life that the society may live. Upon such a conception a wood or prairie, or river bank, or salt marsh or alpine garden upon a mountain summit are, with many other plant societies, places of intense conflict. ”

“ No phenomena give better expression of the climate and the soil of a region than plant communities. When monographs of several of the fruits of temperate North America shall have been completed, with statements of likes and dislikes of the fruits and their varieties as to climate and soil, material should be available to establish plant communities from which can be drawn valuable generalizations.
All, howsoever interested in pomology, are dependent upon descriptions of fruits. ”

“ Now the sunflower we have just thought of is probably growing in a garden well looked after by a gardener, who sees that it gets all the light and water and just the kind of soil it needs. It is therefore protected and cared for to a certain extent, but who looks after the wild plants which manage to grow everywhere? These have not only their own lives to live, but by their own efforts must overcome difficulties which are not even felt by the cultivated ones. ”

“ Yes; you will no doubt be astonished to hear that the plain “seedsman” at the town end, who sells you your roots and bulbs and seedlings, keeps in his pay a staff of plant-hunters—men of botanical skill, who traverse the whole globe in search of new plants and flowers, that may gratify the heart and gladden the eyes of the lovers of floral beauty. ”

“ Our market gardeners understand all this: they do not rest when they have drained the land and regulated the manure, nor do they place their shrubs as close as possible upon the ground. They arrange, judiciously, to give each plant its share of sunlight and of air, and even open out the centres of their trees and bushes to the sun: they cherish health, and, constantly observing nature's laws, they look for multiplied and healthy fruit. ”

“ What our cotton fields of the South, the wheat and corn fields of the Middle West, the jute in India, and the coconut palm and sugar cane in the tropics have done to dictate the economic destiny of those regions is common knowledge. Hundreds of less important plants throughout the world contribute their quota to the huge debt that man owes to the plant world. Probably no other feature of plant life offers such attractions as the study of man’s uses of plants, which is known as Economic Botany, and for which our Government maintains a large staff of experts. ”

“ I was helped in my decision, so far as the Jonathans and Rome Beauties were concerned, by the discovery that more than half of the old orchard was composed of these varieties.
There is little question as to the wisdom of planting trees of kinds known to have done well in your neighborhood. They are just as likely to do well by you as by your neighbor. If the fruit be to your liking, you can safely plant, for it is no longer an experiment; some one else has broken that ground for you. ”

“ To them we are indebted for our tulip-trees, our magnolias, our maples, our robinias, our western platanus, and a host of other noble trees, that already share the forest, and contest with our native species, the right to our soil.
At no period of the world has the number of plant-hunters been so great as at present. Will you believe it, hundreds of men are engaged in this noble and useful calling? ”

“ The farmer steps in and selects those plants which give promise of being most useful or most beautiful and then decreases or eliminates the struggle for these selected plants, by destroying the plants which are least desirable, by fertilizing and tilling the soil, by conserving moisture, and by improving the physical conditions of the land, thereby making it more comfortable for the plants which he has chosen. The selected or "improved" plant, by reason of being more comfortable and better nourished, tends to vary in one or more directions from the wild and unimproved types. ”

“ And yet cultivation is on an entirely different scale, a mere pot of earth taking the place of barrowsful under out-of-door culture. In the garden I simply place a plant at the requisite depth and in the proper exposure and soil; in the greenhouse a finer discrimination is called for. ”

“ The taste of the horticultural public being thus decidedly for the Rose, a demand will exist for all the information respecting soil, planting, cultivating, etc., and this information we shall endeavor to supply in a simple and concise manner, avoiding, as far as possible, all technicalities, and adapting it to the use of the cultivator of a single plant in the crowded border of a city garden, or to the more extended culture of a commercial establishment. ”

“ It is, however, not clear why the simple transference into garden soil should result in such a thorough and persistent revolution in the plant organism. No one will seriously maintain that in the open country the development of plants is ruled by other laws than in the garden bed. ”

“ We have endeavoured in this chapter to give some faint notion of the hundreds and thousands of ingenious contrivances utilized by plants in order to ensure the dispersal and future prosperity of their children.
268 Every species is always trying to colonize new ground, to seek fresh fields and new pastures. Plants are not content to keep to the old habitats, but every species tries to scatter its pioneers over all the neighbouring country, so that, as often happens, if it is exterminated or suppressed in one locality, new generations luxuriate elsewhere. ”

“ Mixed cultures are distinguished as layered cultures, when 311the species are of very different height. Thus, rosettes have been grown with stemmed plants, tall slender forms with low branching ones, erect plants with twining and climbing plants, etc. Further evidence as to the nature of competition has been sought by means of ecad cultures, and factor cultures. In the former, plants of different response to water and light are grown together under the same conditions, in order to evaluate the part played by the nature of the plant. ”

“ Though our country’s vegetation has lost in scientific interest, it has gained vastly in both economic and æsthetic value by the introduction of useful and ornamental plants from all the Temperate regions of the world; and besides, a large number of species have followed in man’s footsteps, and, taking advantage of the disturbance of the native flora caused by his operations, endeavour with more or less success to establish a footing in the country. ”

“ But as much of this favourable region is utilized by the human race for the production of plants used for food or for industry, it often happens, as in our own country, that the natural plant communities are to a great extent destroyed, and can be studied only on{25} land left undisturbed because unsuitable for cultivation—on heaths and moors, in swamps and lakes, on sea-sands, chalk downs, and so on ”

“ Before we trespass on the domains of arboriculture, horticulture, or agriculture, under which heads the cultivation of useful or ornamental plants divides itself, some consideration is required of those plants which, quasi-wild, are usually included in accounts of the vegetation under the head of aliens, denizens, colonists, and so forth. ”

“ The very great modifications which cultivated plants are constantly undergoing under our eyes, and the numerous varieties and races which spring up among them, certainly countenance the doctrine, that every domesticated vegetable, however dependent upon human care for growth and propagation in its present form, may have been really derived, by a long Succession of changes, from some wild plant not now perhaps much resembling it. ”

“ Therefore, where the proper conditions cannot be given, it will be far wiser to devote your space to plants more suited to house culture.
Aspidistra, araucaria, Pandanus and the rubber plant are exceptions; two of them being remarkable for their hardihood under neglect and ignorance. While many of the foliage plants will live under almost any conditions, it must be remembered, however, that the better care they receive the more beautiful they will be. ”

“ With this idea well fixed in your mind, you will easily see that when you know the country from which a plant has come, a knowledge of the physical geography of that country will be helpful in knowing how to make the plant happy and prosperous.
We must also make the plant comfortable in the soil. There is great difference in what plants require to make them comfortable. Some, like thistles or mullein or ragweed, will thrive on almost any soil and are no more exacting as to food than a goat or a mule; but other plants are as notional as children reared in the lap of luxury. ”

“ Each species of plant must, of course, solve for itself the problem, during the course of its development, whether its energies will be best employed by hoarding nutriment for its own future use in bulbs and tubers, or by producing richly-endowed seeds which will give its offspring a better chance of rooting themselves comfortably, and so surviving in safety amid the ceaseless competition of rival species. ”

“ In this way the Bureau of Plant Industry is steadily gaining control over the powers of nature through redirection of the vital energy of the plants along more useful lines directed toward ends of human welfare. The control is collective no less than individual: Native plants vary, and the fitter survive; Darwin noted the increasing variation of plants under domestication, and thereby detected a natural law of increasing plasticity of types; and now under the law variability is accelerated and the fitter forms are selected and multiplied, so that the efficiency of crops is increased. ”

“ It should never be forgotten that the species of plants making up the dominant plant societies in different parts of the world are dictated by quite other conditions than those that result in the dominance of the society itself. ”

“ The number of nursery collections of hardy plants being now more numerous than they were a few years ago, getting the plants is not so difficult as it once was. The sources of supply are these nurseries; seed houses, who have lists of hardy plant seeds—many kinds may be easily raised from seed; botanic gardens, in which many plants are grown that hitherto have not found a place in our gardens, and were not fitted for any mode of culture except that herein suggested; orchards and cottage gardens in pleasant country places may supply desirable things from time to time ”