Ecology

“ There can be little question in regard to the essential identity of physiology and ecology. This is evident when it is clearly seen that the present difference between the two fields is superficial. Ecology has been largely the descriptive study of vegetation; physiology has concerned itself with function; but, when carefully analyzed, both are seen to rest upon the same foundation. In each, the development is incomplete: ecology has so far been merely superficial, physiology too highly specialized. ”

“ Apart from botany, the physical side of ecology is largely a question of soil physics, and of physiography. On the other hand, vegetation is coming more and more to be regarded as a fundamental factor in zoogeography and in sociology. Furthermore, with respect to the latter, it will be pointed out below that the principles of association which have been determined for plants, viz., invasion, succession, zonation, and alternation, apply with almost equal force to man. ”

“ Ecology is the science of the intricate web of relationships between living organisms and their living and nonliving surroundings. These interdependent living and nonliving parts make up ecosystems. Forests, lakes, and estuaries are examples. ”

“ The organism is thus considered as an agent which, transforming and utilizing substance and energy, produces a varied number of physiological conditions and forms of activity, which in turn furnish the basis for the constant process of response between the organism and its environment.
Aggregate Ecology.—The study of aggregate ecology is the investigation of the ecological development, relations, and responses of animals based upon hereditary or taxonomic units, as in a family community, or in genera, families, orders, etc. ”

“ For this reason, and for others arising out of an almost complete dearth of methods of investigation, ecology is still almost entirely a floristic study in practice, although there is a universal recognition of the much greater value of the viewpoint which rests upon the relation between the formation and its habitat. ”

“ This home economy of plants, or how they meet the environment and each other, is called Plant Ecology, a phase of botany now much studied, for it tells us more directly than most other plant research what the actual response to various factors of the environment may be. Just as plant distribution is the reflection of many, usually widely operating forces, so ecology narrows down to individual plants or groups of them the impact of the immediately surrounding conditions upon vegetation. ”

“ It is precisely the relation that exists between cause and effect, and its fundamental importance lies in the fact that all questions concerning the plant lead back to it ultimately. Other relations are important, but no other is paramount, or able to serve as the basis of ecology. Ecology sums up this relation of cause and effect in a single word, and it may be that this advantage will finally cause its general acceptance as the proper name for this great field. ”

“ With such an understanding of the general rules of the game we may turn to the application or art of ecology, to indicate its relation to general problems. With a grounding in the general principles of organic response to the total environment, one is able to see that the disturbances due to man are a problem in the adjustment of the highest type of animal, as a member of an animal association, to its complete environment. The “control of nature” for which men strive is the process of making the environments and associations to order. ”

“ The ecology of living animals must furnish us with whatever firm basis we have for the interpretation of the conditions of life in the past, upon which the paleontologist, stratigrapher, or paleogeographer must depend, at least in part, for his interpretations. ”

“ There has been a growing appreciation of the fact that the superficial methods of descriptive ecology made it impossible to build upon such a foundation, and they, indeed, were making actual progress in the field of ecology more and more difficult. Ecologists have now begun to see clearly that precise methods are as indispensable in the habitat as they are to the study of the structure and modification of the plant. ”

“ Ecology and Physiology.—Whilst our knowledge of the nature and effect of habitat is still in a very rudimentary condition, much progress has been made in recent years in the study of plant communities, but even here the questions involved in relating the facts of the distribution of plant communities to the factors of the habitat are very imperfectly understood. ”

“ Finally, it must be constantly kept in mind that ecology is still in a very plastic condition, and in consequence, methods, fundamental principles, and matters of nomenclature and terminology must be approached without prejudice in order that the best possible development of this field may be attained. ”

“ This definition is not sufficiently comprehensive to include all the elements that logically fall within the range of human ecology. In the absence of any precedent let us tentatively define human ecology as a study of the spatial and temporal [32] relations of human beings as affected by the selective, 64distributive, and accommodative forces of the environment. ”

“ The quotations from Brooks, on a preceding page, show even more explicitly the intimate relation which exists between biology and ecology. At first glance they may seem to prove almost too much—that biology and ecology are synonymous. They show at least that ecology is concerned with fundamental biological problems—the responses of organisms to their complete environments. ”

“ They exhibit both development and structure, and are subject to the laws of invasion, succession, zonation, and alternation, though these are not altogether similar to those known for plants, a fact readily explained by the motility of animals. Considered from the above point of view, zoogeography is a virgin field, and it promises great things to the student who approaches it with the proper training.
24. Sociology. In its fundamental aspects, sociology is the ecology of a particular species of animal, and has in consequence, a similar close connection with plant ecology. ”

“ The youngest branch of Botany is Ecology or the study of vegetation in relation to habitat—particularly soil in its widest sense. This department deals with the recognition and distribution of the different types of plant community in relation to topography and the factors—chemical, physical and biologic—which determine this distribution. Ecology has the great merit of taking its followers into the field, where they are confronted with a wide range of problems not hitherto regarded as strictly within the province of the botanist. ”

“ Ecology should have a great part to play in helping to break down the frontiers which have too long tended to separate Botany from the other sciences, and the maintenance of which is not in the true interests of the subject.
↑ Darwin and Modern Science. ”

“ The cutting down and washing of the [Pg 28] lands, the draining and filling of depressions, the flooding of the lands, the destruction (or succession) of plant and animal associations (including crop rotation) , are processes brought about or practiced by other organisms or animal agencies. An ecological standpoint gives us a consistent, comprehensive orientation of all these natural and “artificial” activities and processes, and shows the unity in all organic responses to the environment. Man’s influence in the main consists of hastening or retarding “natural processes.” ”

“ The following list will probably aid one but little in gaining this general conception, but once the student has it he will find the list of much assistance. Undoubtedly a relatively new and fertile field for investigation would be to study the interrelations of plants and their pollinators as an ecological community, the association being taken as a unit rather than the individual species of plants or animals.
Bouvier, E. L.
1905. ”

“ A student of general zoölogy should be grounded not only in physiological and developmental processes, but also in the relations of the organisms to their complete environment. The ecologist requires also the grounding in physiological, developmental, and ecological processes of adjustment, but as well he must understand the processes by which the vegetation and the physical environment have been and are being developed and their method of mutual interrelations and adjustment. It is difficult for some students to develop the ecological phases in the field. ”

“ Of this, fitness of environment is quite as essential a component as the fitness which arises in the process of organic evolution; and in fundamental characteristics the actual environment is the fittest possible abode of life.” Such is the thesis which this work seeks to establish through discussions of the physical and chemical characteristics of life and cosmogony, and through critical study of the properties of matter in their biological relations. ”

“ Since animals are free for the most part, and hence not confined so strictly to one spot as plants, their dependence upon the 16habitat is not so evident. The relation is further obscured by the fact that no physical factor has the direct effect upon them which water or light exerts upon the plant. Vegetation, indeed, as the source of food and protection, plays a more obvious, if not a more important part. ”

“ Methods. All field experiments in evolution are based upon a change of habitat. The latter is accomplished by the modification of the habitat itself, or by the transfer of the species to one or more different habitats, or to different areas of the same habitat. ”

“ So far as known to the writer, human activities in general have never been fully and comprehensively oriented from the ecological standpoint, even by the humanitarians themselves, although some important preliminary steps have been taken. ”

“ This is also an argument for the ecological organization of a vast number of natural history surveys, because the associational grouping of observations and responses gives the most intimate knowledge of the life of animals in the network of their environmental relations. ”

“ To understand rightly the daily accumulating stores of organic reliquiæ, requires more than a slight knowledge of existing nature,—more even than an acquaintance with animal and vegetable forms. The philosophy of their existence must be considered—the variations of their structure, with respiration in air or in water—life in fresh or salt water—in trees or on the ground—carnivorous or herbivorous food—their geographical distribution dependence—on climate and atmospheric conditions. ”

“ Perhaps the most subtle of human influences are to be seen in the distribution of plant and animal life upon the globe. Some of man’s doings in this domain are indeed plain enough, such as the extirpation of wild animals, the diminution or destruction of some forms of vegetation, the introduction of plants and animals useful to himself, and especially the enormous predominance given by him to the cereals and to the spread of sheep and cattle. ”

“ The species which, by natural selection and adaptation have fitted themselves to the environment are, as a rule, the trees which will do best in that locality. That is a principle I think which ought to be thoroughly well fixed in mind. ”

“ Go to a swale, swamp, roadside, forest, weedy field, or other place, and ask the pupil to note: (1) that the flora of the place is unlike that of places with different physical features; (2) that these particular plants grow together [365] because they can all survive under similar conditions; (3) what these conditions are,—whether sun, shade, dry soil, wet soil, sand, clay, rock; (4) what particular plant is most abundant or gives character to the society.
Fig. 255. Two plant societies,—the close-bitten sward and the rushy pond.
Study one society thoroughly. ”

“ What is said of the dissemination of fish, shells, and reptiles may be consistently said of vegetation.
The earth is filled with the seed of every plant and tree and shrub that ever sprang into life in any place, clime or time. Dig to whatever depth [76] you will, the substance you throw out, whether earth or stone, when exposed to the air, will produce some growth of vegetation. Frequently something entirely new and different from the surrounding vegetation. ”

“ Like the Vegetable Kingdom, animals are limited to certain areas by the conditions of climate and soil, the environment of an animal determining its development and survival. There are various systems of classification of animals. ”

“ We shall study more closely in this paper one of these communities of life conditions—the plant world of the water—and inquire into the connection existing between its most marked peculiarities and the conditions of life afforded by the water. If we walk along the shore of a large pond sheltering a rich growth of plants, or of a bush-lined stream, the vegetable inhabitants will be divided, at first sight, into three groups—the shore plants on the banks; the floating leaves and flowers of the surface plants ”

“ If in closing these observations, intended to show the progressive development of animal life out of the life of the lower kingdoms of nature, we look to the changes which animal life operates upon them, facts present themselves worthy of the most serious consideration. We have seen how the vegetative life is nourished by inorganic life, and how vegetation in its turn operates changes in many ways upon the surface of the earth, and even on the atmosphere. ”

“ Give these plants the least bit of fair play as regards environment—a sheltered glen, or the shores of a loch or firth, where there is sufficient moisture, plenty of sun, and good soil enriched by the water running down from the wonderful bird cliffs inhabited by hundreds of thousands if not millions of birds, or by the droppings of reindeer, musk-oxen, and other animals, and a veritable paradise of verdure is produced. ”