What Is Ecology? (1961)

all right we've got a real antique here let's stop this at $5 $5 for a genuine antique do I hear $5 there's a lady with $5 do I hear six I hear six do I hear seven $7 here who say eight I hear $8 who say 10 10 over here who say $1 $1 is the bid I want to 11 11 it is who say 12 a farm family is selling out their land is no longer productive the farm has failed because its owners did not understand the proper relationship of plants and animals to their land such knowledge relates to a science ecology a river has Ed its banks millions of dollars worth of crops equipment and Liv stock have been lost here too practical man those who manage the lands probably did not know or care enough about the consequences of their actions these consequences also relate to ecology in Oklahoma there is a dust storm another likely example of neglect or ignorance in the principles of ecology what is ecology it is the science which deals with the interrelationships between all living plants and animals and their environment in this film we shall study some of these relationships and show how they can assist us in maintaining the productivity of our land to begin with each living organism is surrounded by its environment the living environment and the non-living or physical environment like the rocks and soil around these Bears let us look at a typical living organism a young tree some aspects of its physical environment are the soil in which it lives the light and heat to which it is exposed and the amount of water available to it in contrast the living environment consists of all the plants and animals that live around the given organism and interact with it organisms May interact with their living environment in a variety of ways for example between two members of the same species there may be sexual contact among several members there may be cooperation as among these ants among large populations there may be social organization in which the actions of a number of individuals are beneficial to all or there may be a collection or aggregation of many individuals in which the members achieve the level of social Toleration between members of different species other sorts of relationships may exist for example one species feeding on another one such relationship is predation as evidenced when a bird prays upon a caterpillar another relationship is parasitism such as a caterpillar Infested by a wasp during the laral stage this young wasp Pupa has been feeding on the body tissues of the caterpillar still another relationship is mutualism for example termites eat wood which they cannot digest certain flagellates that live in the intestines of termites can digest the wood these flagellates can live only in the termite intestine thus the two species assist one another and are mutually dependent upon each other some ants and aphids demonstrate still another relationship called commensalism these ants tend the aphids as Farmers tend cows in turn the ants obtain drops of a sugary secretion from the aphids the ants seemingly derive benefit and the aphids apparently do not suffer harm from an ecologist point of view all the plants and animals within a specified area constitute a community ecologists frequently study the organisms of a community in terms of the flow of energy and matter from organism to organism within the community in every community in water or on land the original source of energy is the sun sunlight strikes the leaves of green plants the primary food producers for the entire Community by the process of photosynthesis they produce food substances that nourish the plants themselves and also supply energy for the many plant eaters or herbivores such as the caterpillar or the rabbit plant eaters in turn provide energy for meat eaters the carnivores after death their bodies Supply food for scavengers and the microscopic decomposers which in turn return energy to the physical environment dead plants too decompose providing food for other scavengers and decomposers substances from their bodies eventually are returned to the soil as these substances are absorbed by the food producers they enter a new cycle such a cycle operates not only in a forest but in every living community on Earth so in every Community there is continuous change certain changes are periodic in a forest Community as day changes toight the chirping of birds gives way to the sounds of crickets and frogs some animals sleep other animals such as these bats in the cave emerge and become active in the absence of sunlight photosynthesis ceases at dawn the process is renewed another type of change that takes place over a period of many years or centuries is called E iCal succession here is an example occurring in a sand dune area in any Barren area a few Pioneer plants will in time take hold they eventually create conditions unfavorable for themselves but favorable for other plants and animals this new community in turn creates favorable conditions for still others and so on until finally a self-perpetuating stage is reached in which conditions are relatively stable this is called a climax community the ecologist is also interested in the distribution of plants and animals throughout the world what forms of life are found where and which are found in association with others a large association with a specific type of climate soil and life is known as a biome each biome consists of many communities but each has one thing in common a general type of climax vegetation and its related animal forms the principle biomes are the high Arctic biome the coniferous forest the temperate deciduous forest the lands the desert the tropical rainforest and the marine biome here is an example of an ecological study in the temperate forest biome related to conservation this is a model of a drainage area in the southeastern United States where ecologists were investigating on a large scale the effects of abuse in lumbering farming grazing and soil management in the drainage Valley of one tributary they cut away the forest in another Valley they left the forest of a second tributary untouched in the cut over area they soon observed that during a heavy rain the forest soil was washed away and that the volume of runoff water reached flood proportions in the control area the soil remained Inta tact and the water remained clear and the flow normal in the valley of a third tributary they farmed heavily according to the traditional practices again the soil was washed away and flooding occurred in the valley of a fourth tributary extensive grazing was permitted and the same undesirable results observed after a rainfall the eroded soil was collected and measured at each tributary such comparisons are of theoretical value to ecologists and of practical value to people who must use the soil applying such knowledge to the management and conservation of our soil animals and plants is the practical aspect of ecology through the study of ecology we learn to understand the interrelationships of living organisms in their environment