Biodiversity

“ Use of Terms
⁠For the purposes of this Convention: "Biological diversity" means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems. "Biological resources' includes genetic resources, organisms or parts thereof, populations, or any other biotic component of ecosystems with actual or potential use or value for humanity. ”

“ The landscapes that we see around us today are the visible manifestations of human ecosystems: the concepts of 'wild landscapes' or 'natural landscapes' that imply some sort of landscape that has evolved without the aid of people is nonsense.
For the greater part of our history, people have lived in ecological balance with the environment. We lived as viable people exploiting the ecosystems of which we were part in a sustainable manner. Thus our ecosystems remained healthy and were able to continue to supply the resources that we required from them. ”

“ 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. ”

“ Similarly, after tracing upwards from the Amphibia the widening extent and complexity which the environment, as practically considered, assumes—after observing further how increasing heterogeneity in the flora and fauna of the globe, itself progressively complicates the environment of each species of organism—it might finally be shown that the same general truth is displayed in the history of mankind, who, in the course of their progress, have been adding to their physical environment a social {106}environment that has been growing ever more involved. ”

“ Moreover, the relationship of an animal species with its ecosystem is dynamic. The species is not just a passive occupant of an ecosystem: it influences the ecosystem and changes it for its own survival. ”

“ Even the recent ice ages did not result in a diminution of species.
The Biosphere of our earth is Eco Island on a global scale, made up of an almost infinite number of sub-systems: as a natural ecosystem, the Biosphere is a Viable Ecosystem.
3.9 REAL ECOLOGY: HUMAN SOCIETY
The Natural Ecosystem defines the natural environment; that is, the described environment without human society. But in reality, as we have already made clear, human society has to be added to the ecological equation. ”

“ A key question for this paper is when novel growth forms, such as C4 grasses, assembled into ecosystems that began to alter their environment by burning on a regular basis. Phylogenies are based on origination and diversification and it is not clear how diversification processes relate to increased ecological extent or importance of an evolutionary innovation. Sometimes the evolution of a new growth form may produce a novel biotic habitat which may then initiate novel radiations of species dependent on that habitat. ”

“ Some species must have been more adapted to northern climates, others to the soils of western or eastern regions and so on. These qualities must have decided the general lines of the distribution, and the species must have been segregated according to their respective climatic qualities, and their adaptability to soil and weather. A struggle for life and a natural selection must have accompanied and guided the distribution, but there is no reason to assume that the various forms were changed by this process, and that we see them now endowed with other qualities than they had at the outset. ”

“ The attempt to substitute these laws for those of variation and natural selection has failed in cases where we can apply a definite test, as in that of the origin of spines on trees and shrubs; while the extreme diversity of vegetable structure and form among the plants of the same country and of the same natural order, of itself affords a proof of the preponderating influence of variation and natural selection in keeping the many diverse forms in harmony with the highly complex and ever-changing environment. ”

“ In fact the whole work of the introduction and diffusion of valuable food-animals in territory not naturally included in the habitat of the species is based on our knowledge that the habitat of a species is often determined by physical barriers rather than by exclusive fitness of environment. Within the natural habitat the environment is fit for the species' existence, outside of it the environment may be fit. ”

“ For, as species spread themselves gradually over the globe, they are exposed from time to time to variations in climate, and to changes in the quantity and quality of their food; they meet with new plants and animals which 575 assist or retard their development, by supplying them with nutriment, or destroying their foes. The nature, also, of each locality, is in itself fluctuating; so that, even if the relation of other animals and plants were invariable, the habits and organization of species would be modified by the influence of local revolutions. ”

“ Equally important are the vital life processes carried out by nature, including stabilization of climate, protection of watersheds and soil, preservation of nurseries and breeding grounds, and so on. Conserving these processes cannot be divorced from conserving the individual species within natural ecosystems. Managing species and ecosystems together is clearly the most rational way to approach the problem. ”

“ And then, what is to be said for the multitude of species to be found in the same localities, the same forests, the same jungles, the same lakes, the same streamlets, where there is literally no room for any difference in the environments at all? ”

“ Species evolution into more diverse forms is like a fast breeder nuclear reactor: the more species there are in an ecosystem, the more interaction there will be both within and between species, resulting in the evolution of yet more species that in turn feed the process. ”

“ From time to time, at long intervals, extensive changes of physical geography and climate, produced by crust elevations, partly enforce by change of temperature, and partly permit by opening of gateways, extensive migrations and dispersals of species, by which mingling and struggle for life and final readjustment takes place, and extreme diversity is prevented. Such mingling of different faunas and floras on the same ground, and the severe struggle for life that thus ensues, and the survival of the fittest in many directions, are, as already shown, among the most powerful factors of evolution. ”

“ Even the forests of the temperate zones, in all favourable situations, exhibit a considerable variety of trees of distinct genera and families, and it is only when we approach the outskirts of forest vegetation, where either drought or winds or the severity of the winter is adverse to the existence of most trees, that we find extensive tracts monopolised by one or two species. ”

“ Because of humankind's growing dominance of the Biosphere, all ecosystems are now ultimately human ecosystems. Ecological problems arise when an ecosystem is seen, in ignorance, as something separate from humankind. ”

“ But these are, after all, exceptional, and characterise those regions only where the climate is little favourable to forest vegetation. In the tropical and all the warm temperate parts of the earth, where there is a sufficient supply of moisture, the forests present the same variety of species as does the turf of our old pastures; and in the equatorial virgin forests there is so great a variety of forms, and they are so thoroughly intermingled, that the traveller often finds it difficult to discover a second specimen of any particular species which he has noticed. ”

“ This spectrum of interconnected vegetation types provides essential habitat for wildlife, ranging from large, charismatic animals to less visible and less familiar forms of life, such as fungi and insects. ”

“ But on the special-creation theory we can see no reason why the 400 species should all have been deposited in America. And, as already observed, we must remember that this correlation between a geographically restricted habitat and the zoological or botanical affinities of its inhabitants, is repeated over and over and over again in the [213] faunas and floras of the world, so that merely to enumerate the instances would require a separate chapter. ”

“ Why the members of a given species which have apparently unlimited power to travel should be confined to a certain and frequently a narrowly circumscribed area has excited the curiosity of man for many centuries.
A point is gained in reference to the distribution of animal species when it is remembered that animals are either directly or indirectly dependent on plants for food, and it follows that if plants, as we have seen, are so largely controlled in their distribution by climate, the secret of the distribution of animals is to be sought in the same direction. ”

“ But the degree of adaptation of species to the climates under which they live is often overrated. We may infer this from our frequent inability to predict whether or not an imported plant will endure our climate, and from the number of plants and animals brought from warmer countries which here enjoy good health. We have reason to believe that species in a state of nature are limited in their ranges by the competition of other organic beings quite as much as, or more than, by adaptation to particular climates. ”

“ But land and water plants, were they not sensitive to all the influences which combined make their environments, and had they not reacted to these influences, would never have attained the diversity which they now possess. The dependence of all living things upon water, and their power of reacting to all the influences of their environment to which they are sensitive, are the most striking phenomena displayed by animals and plants. ”

“ Again, along with all these changes have come not less important changes in the distribution of species. Vegetation has been greatly modified by changes of climate and of altitude; while every union of lands before separated has led to extensive migrations of animals into new countries, disturbing the balance that before existed among its forms of life, leading to the extermination of some species and the increase of others. ”

“ Although these animals are now practically extinct from so many areas, their former presence is proved by the hard- wooded and spinous trees and shrubs which have almost alone survived. And thus natural selection has acted on the original flora and fauna in which this obscurely understood evolutionary response to environmental conditions played such a vast and primary part. Natural selection is not the act of creation, but the effect of competition ”

“ When we reflect on the vast diversity of the plants and animals which have been cultivated, and which have varied during all ages under the most different climates and treatment, I think we are driven to conclude that this greater variability is simply due to our domestic productions having been raised under conditions of life not so uniform as, and somewhat different from, those to which the parent-species have been exposed under nature. ”

“ When we reflect how easily different species, in a great lapse of ages, may be each overtaken by gales and hurricanes, and, abandoning themselves to the tempest, be scattered at random through various regions of the earth's surface, where the temperature of the atmosphere, the vegetation, and the animal productions, might be suited to their wants, we shall be prepared to find some species capriciously distributed, and 645 to be sometimes unable to determine the native countries of each. ”

“ How many other species have changed their nature, that is to say, become perfected or degraded, through great changes in the distribution of land and ocean, through the cultivation or neglect of the country which they inhabit, through the long-continued effects of climatic changes, so that they are no longer the same animals that they once were? ”

“ Forests which now seem entirely unrelated will be seen to possess the most intimate developmental connection, and the fuller insight into the life history gained in this way will have a direct bearing upon methods of conservation, etc. It will further show that the forester must know other vegetations as well, since grassland and thicket formations have an intimate influence upon the course of the succession, as well as upon the advance of a forest frontier. ”

“ Not only do native plants live under natural conditions, but they are protected from picking, from grazing of domestic livestock, and from the competition of exotic species, and from other activities of mankind that would disrupt their normal habitat or disturb their native way of life. ”

“ To accomplish the dissemination of animal and vegetable life, to an extent commensurate with the capacity of the globe, separate regions were supplied with distinct stocks of plants and animals. But the case of man required no such arrangement to secure a large occupancy of the earth with his species. Endued with a constitution capable of accommodating itself to extreme diversities of climate, and with intelligence to invent methods of protection against atmospheric influences ”

“ And as we walk through those noiseless forests, where the machinery of species-making is ever in silent motion, we become aware that we are treading one of Nature’s great workshops for the manufacture of species and genera. ”

“ Of course the establishment of this heterogeneity is furthered by natural selection, which, where a protective covering is needed, gives an advantage to those individuals in which it has become strongest. But that this divergence of structure commences as a direct adaptation, is clearly shown by other facts than the foregoing. There is the fact that many of the plants which in our gardens develop bark with considerable rapidity, do not develop it with the same rapidity in a greenhouse. ”